1 Academic Unit of Anaesthesia, University of Leeds, Leeds General Infirmary, Leeds LS1 3EX, UK. 2 Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK
*Corresponding author. E-mail: s.howell@leeds.ac.uk
![]() |
Abstract |
---|
Br J Anaesth 2004; 92: 57083
Keywords: arterial pressure; complications, hypertension; risk, perioperative
![]() |
The importance of hypertension |
---|
|
![]() |
Historical background |
---|
The introduction of antihypertensive drugs led to concerns that patients on such drugs might be at increased risk of perioperative cardiac lability. In 1966, Dingle recommended that patients presenting for anaesthesia and surgery should, if possible, undergo autonomic testing before their operation. This would give some indication of their risk of cardiac lability and whether or not their antihypertensive therapy should be continued.14 These recommendations were overtaken by the work of Prys-Roberts and colleagues, who published a series of studies on the interaction between hypertension and anaesthesia. The first of these studies examined a small group of 34 patients undergoing anaesthesia and elective surgery.62 Fifteen of the patients were classified as normotensive, although by current standards all of their control patients would now be considered hypertensive. The remainder of the patients were classified as treated or untreated hypertensives. By current standards, these patients would probably be considered to have severe hypertension as several were reported as having systolic arterial pressures of 220230 mm Hg. The patients underwent intensive haemodynamic monitoring. The authors reported that the untreated hypertensive patients had a greater decrease in arterial pressure at induction of anaesthesia and that they were more prone to intraoperative myocardial ischaemia. There were no adverse events reported in either the control or hypertensive groups.
On the basis of these findings the authors recommended that, where possible, hypertensive patients should have anaesthesia and surgery deferred to allow their hypertension to be treated. This recommendation led to a major change in anaesthetic practice, and to the modern perception that where possible untreated hypertensives should not be subjected to elective anaesthesia and surgery without first treating their arterial pressure. However, these recommendations should be applied with some caution. The perception of what constitutes hypertension has changed considerably since these studies were undertaken. Arterial pressures that in the early 1970s would have been considered acceptable are today consistent with levels of hypertension where treatment is obligatory. As already stated, all of the control patients in the study by Prys-Roberts and colleagues would now be considered to be hypertensive. The recommendations of Prys-Roberts and colleagues therefore need to be reconsidered in the light of the modern views of hypertension and its management.
![]() |
The classification of hypertension |
---|
|
|
![]() |
Defining the questions |
---|
1. Is having a diagnosis of hypertension of itself associated with increased perioperative risk, regardless of the arterial pressure at the time of admission to hospital for surgery?
2. Is elevated arterial pressure at the time of admission for surgery associated with increased perioperative cardiac risk?
3. What is the importance, if any, of poorly controlled hypertension in the perioperative setting? Is there any interaction between elevated admission arterial pressure and being diagnosed with hypertensive disease previously such that this increases perioperative risk?
4. Does the treatment of elevated admission arterial pressure before surgery reduce perioperative cardiac risk?
For the purposes of this review the term hypertensive patient refers to anyone who has been labelled a hypertensive: that is, someone for whom interventions to lower persistently raised arterial pressure would be appropriate, or someone who is already on treatment for hypertension. Raised arterial pressure will be described as such.
The core of this review will be an examination of the available observational studies that address the first three questions and a discussion of the issues surrounding the interpretation of these studies. Related issues including arterial pressure measurement, white coat hypertension, the use of ambulatory arterial pressure monitoring, and perioperative arterial pressure lability will also be discussed. Recommendations will be offered for the perioperative management of hypertensive patients, although these are based only on observational data. It should be stated at the outset that the authors know of no randomized controlled trial that addresses the final question. The practice of deferring elective surgery to allow poorly controlled arterial pressure to be treated is solely based on the perception that such elevated pressure is associated with increased perioperative risk, and therefore reducing the arterial pressure must be a good thing to do. There is no level one evidence to support this approach.76
![]() |
Hypertensive disease and anaesthesia |
---|
All searches were limited to articles in English. The abstracts of the papers identified were scanned on-line to identify relevant papers. The reference lists of those papers that were identified for inclusion in the meta-analysis were also scanned to identify further relevant studies.
The papers identified from these searches were read in full. Those that included data concerning the association between hypertensive disease and perioperative cardiovascular complications were identified. Reports were included if they examined outcomes considered to be major cardiovascular complications occurring up to 30 days after anaesthesia and surgery. Major cardiovascular complications were considered to be cardiovascular death, myocardial infarction, new or more severe angina, heart failure, life-threatening arrhythmias, and cerebrovascular accident. Several studies examined minor complications such as perioperative bradycardia and tachycardia, and perioperative hypotension and hypertension, and more serious complications. Where it was impossible to separate information on major complications from data on all complications, both major and minor, the study was excluded. Studies that reported the association between hypertension and perioperative myocardial ischaemia detected on Holter monitoring but did not contain data on the association between hypertension and clinically evident events were excluded.
For a study to be included, it had to be possible to derive from the report the crude odds ratio for the association between hypertension and perioperative cardiovascular complications, together with the variance of that odds ratio. The ideal would have been to include the adjusted odds ratios in which allowance had been made for the effect of other confounding variables. In most instances, this was not available.
A number of relevant studies were not primarily designed to examine hypertension or other perioperative cardiovascular risk factors, but were studies of diagnostic tests for preoperative cardiovascular assessment or (in one case) of the value of actively warming the patient during surgery. We have included those studies where the report of the study included relevant data on the association between hypertension and perioperative cardiovascular complications.
A number of studies examining stroke after carotid endarterectomy have been excluded, as it is argued that these studies examined a particular complication in an exceptional population, and the findings from such studies may not generalize to patients undergoing other types of surgery.
The main focus of this meta-analysis was the association between hypertensive disease and perioperative complications, rather than any association between admission arterial pressure and such complications. Consequently, studies that defined hypertension solely in terms of the level of admission arterial pressure were excluded. Studies were included where the definition of hypertension was not given in the report. For example, in the Multi-Center Study of General Anesthesia, the anaesthetist was asked to indicate if the patient was hypertensive or not, but the definition of hypertension used is not given.20
A total of 4691 citations were identified from the MEDLINE database. From these, 128 potentially relevant studies were identified from 126 reports. (The full list of 126 citations can be viewed in the version of this review published on the British Journal of Anaesthesia website at http://bja.oupjournals.org/.) For these 128 studies, the full reports were obtained and read in detail. Ninety-eight studies described in 97 reports were excluded from further analysis.
In 80 studies, including the two studies described in a single paper, an effect estimate for the association between hypertension and cardiac complications was not given and could not be derived from the publication. Three studies were excluded because they appeared to include patients who had been examined in another study already included in the meta-analysis. In each case, only one of the pair of papers concerned was included in the meta-analysis.39 41 58 In six of the excluded studies, hypertension was defined in terms of the arterial pressure alone with no reference to hypertensive disease. In two studies, hypertension was defined as either an elevated admission arterial pressure or a history of treatment with antihypertensive medications and no indication was given of which patients fell into each category. In three of the excluded studies, no distinction was made between major cardiovascular complications such as perioperative myocardial infarction and minor complications such as intraoperative bradycardia. One study was excluded because preoperative coronary artery by-pass grafting and perioperative cardiac complications were grouped together as one outcome. Separate information was not given on the association between hypertension and perioperative complications. One study included data on 676 operations in 617 patients. No information was given on which patients underwent more than one procedure. It was felt that using data from this study could lead to an underestimate of the variance of the odds ratio for hypertension and the study was excluded from the meta-analysis. (The full list of excluded studies can be viewed in the electronic version of this paper.)
Initially, it was planned to restrict this review and meta-analysis to patients undergoing general anaesthesia. It rapidly became clear that this was not practical. In those papers containing useful data that also gave information on the type of anaesthesia used a significant proportion of patients received regional or local anaesthesia.3 5 26 53 64 67 69 75 78 81 Many papers, that did not indicate the type of anaesthesia used, included patients some of whom were likely to have been managed with local regional anaesthesia, for example those undergoing carotid endarterectomy or lower limb revascularization.
Thirty studies were included in the final meta-analysis (Table 2).36 16 18 21 22 26 30 33 34 3941 43 44 53 54 58 64 67 69 70 72 75 77 78 81 These studies were published between 1978 and 2001 and include 12 995 patients. The analysis included two separate studies by Rao and colleagues, both described in the same paper.64 One was a retrospective study of 364 patients anaesthetized between June 1973 and June 1976, and the other a prospective study of 733 patients anaesthetized between July 1977 and June 1982.
|
|
![]() |
Pre-existing hypertension and target organ damage |
---|
Similar considerations apply in the perioperative setting. Many reviews have highlighted the associations between the sequelae of hypertension, such as heart failure and ischaemic heart disease, and perioperative complications.9 15 The meta-analysis of observational studies described above suggested an association between a diagnosis of hypertension and increased perioperative cardiac risk. However, the odds ratio was small and the conclusion must be treated with some circumspection in the light of heterogeneity of the studies examined. This is not to dismiss the role of clinically evident target organ damage in increasing perioperative risk. A recent study by Lee and colleagues identified ischaemic heart disease, heart failure, and renal failure as risk factors for perioperative cardiac complications.42 In assessing perioperative risk of major cardiovascular complications, pre-existing hypertension per se may be of limited importance, but this does not grant the anaesthetist a licence to ignore the target organ damage caused by hypertension. Such damage may carry significant risk and its importance should be assessed using guidelines such as those referenced above.9 15
![]() |
Admission arterial pressure and perioperative cardiac risk |
---|
None of the studies described above examined admission arterial pressure as a continuous variable. All have taken a specific cut-off for arterial pressure. The only studies of which the authors are aware that have examined arterial pressure as a continuous variable are those by Howell and colleagues.33 34 The first was a retrospective case controlled study which examined patients who died of a cardiac cause within 30 days of anaesthesia and elective surgery and a matched controlled population who underwent the same operations but who did not die.34 There were no significant differences between admission systolic and diastolic pressures between the cases and the controls (Fig. 4). The second was a similar study of emergency surgery; again there were no significant differences between the arterial pressures of the cases and the controls, although in this case there was a tendency for the survivors to have higher admission arterial pressure than those patients who died.33 While both of these studies suggest that there is no association between admission arterial pressure and perioperative cardiac risk, they are both limited by the fact that most of the patients studied had Stage 1 or Stage 2 hypertension. Few patients with Stage 3 hypertension were studied.
|
The evidence from medical studies suggests that patients with Stage 3 hypertension are at significantly increased risk of target organ damage, whether or not this is clinically evident. For example, Stamler and colleagues, and Liao and colleagues demonstrated a steadily increasing incidence of ECG abnormalities in this population.45 73 There is certainly evidence to support a steadily increasing incidence of postoperative myocardial ischaemia with increasing admission systolic arterial pressure.31 Many patients with admission arterial pressures consistent with Stage 3 hypertension will have isolated systolic hypertension. There is evidence from the Framingham population of significantly increased cardiovascular risk in this population. Recent analyses suggest that systolic pressure and pulse pressure are more reliable indicators of cardiovascular risk than diastolic pressure.25 On the basis of these data, we suggest that it is appropriate to defer anaesthesia and surgery where possible in patients with admission arterial pressures consistent with Stage 3 hypertension, especially if there is evidence of target organ damage. However, it must be borne in mind that this recommendation is made on the basis of evidence of risk in medical patients rather than data on perioperative risk. Studies of perioperative risk in patients with Stage 3 hypertension are required.
![]() |
Isolated systolic hypertension |
---|
While the studies of hypertension undertaken by Prys-Roberts and colleagues used the then standard definition of hypertension of a diastolic arterial pressure of greater than 95 mm Hg, it is clear from their publications that many of their patients had severe systolic hypertension.5962 Most later studies that have included an examination of the association between admission arterial pressure and perioperative complications have focused on older patients: for example, in the study by Cooperman and colleagues the average age of the patients was 61 yr; in the study by Eerola and colleagues, 69 of the 111 patients studied were over 60 yr old; and in the study of myocardial re-infarction by Steen and colleagues, 361 of the 466 patients studied were aged 60 yr or over.13 17 75 It is likely that the majority of poorly controlled hypertensives in these studies had isolated systolic hypertension.
A recent study by Aronson and colleagues examined the association between isolated systolic hypertension and cardiovascular complications in patients undergoing cardiac surgery and these data are worth rehearsing here. This was a prospective study of over 2000 patients in 24 centres undergoing elective cardiac surgery. Patients were classified as having normal preoperative arterial pressure, isolated systolic hypertension (systolic arterial pressure greater than 140 mm Hg), diastolic hypertension (diastolic arterial pressure greater than 90 mm Hg) or a combination of these. After adjusting for other risk factors, isolated systolic hypertension was associated with a small but statistically significant increase in the likelihood of perioperative morbidity (odds ratio 1.3, 95% confidence interval 1.11.6).2 The mean systolic arterial pressure of the patients with isolated systolic hypertension is not given, although as the average age of the patients was 65 yr, it is tempting to speculate that it was considerably greater than 140 mm Hg.
It is clear that many of the patients who present for surgery and have arterial pressures consistent with Stage 3 hypertension will be elderly patients with isolated systolic hypertension. There are few if any studies that explicitly examine the impact of isolated systolic hypertension on outcome from non-cardiac surgery and, as with Stage 3 hypertension, work in this area is required. However, the findings of the study by Aronson and colleagues and the work of Franklin and colleagues on the Framingham population do little to reassure the anaesthetist.
![]() |
White coat hypertension |
---|
The various guidelines on the management of hypertension all indicate that the arterial pressure should be measured on a number of occasions over a period of weeks before the diagnosis of hypertension is confirmed. It is rare for the anaesthetist to have this luxury and often a decision has to be made on perioperative management on the basis of two or three readings taken over a period of hours.
Both doctors and nurses may produce an initial elevation in arterial pressure when they visit a patient, but the effect is greater for doctors than for nurses. This is impressively illustrated by data from Mancia and colleagues. They studied 30 subjects who underwent a 24-h intra-arterial recording after 57 days in hospital. During the intra-arterial recording period the arterial pressure was additionally measured at different times using a sphygmomanometer by a male doctor and a female nurse, half of the subjects being randomized to see the doctor first, and the other half the nurse. When the doctor took the first reading, the arterial pressure rose by an average of 22/14 mm Hg. The rises when the first arterial pressure was taken by a nurse were only half as great. The arterial pressure usually returned to near baseline after 10 min when the reading was taken by a nurse, but this was not the case when the pressure was taken by a doctor (Fig. 5).47 It is clear from their data that, in many surgical patients, the admission arterial pressure will not equate to the patients usual arterial pressure. If a member of the medical staff finds the patients arterial pressure to be elevated, this should be confirmed by a nurse with appropriate training.
|
![]() |
Cardiovascular lability |
---|
The clinical impact of wide variations in arterial pressure is difficult to quantify, not least because most anaesthetists would not be prepared to leave large changes in arterial pressure untreated for more than a short period of time. Charleson and colleagues reported that, within a high-risk group of hypertensive patients and diabetic patients undergoing elective non-cardiac surgery, those with more than 1 h of a decrease in mean arterial pressure of greater than/equal to 20 mm Hg and those with less than 1 h of a decrease in arterial pressure of greater than/equal to 20 mm Hg and more than 15 min of an increase in arterial pressure of greater than/equal to 20 mm Hg were at greatest risk of complications.8 In so far as we can tell, the use of vasoactive drugs was allowed in the perioperative period. One has to ask if, in the patients who had wide excursions of arterial pressure, a decision was made not to treat these changes in arterial pressure or if the changes in arterial pressure were refractory to treatment because of ongoing perioperative cardiovascular complications. The association between intraoperative myocardial ischaemia and haemodynamic changes is certainly not clear-cut. In a study of 100 patients who either had, or were at risk for, coronary artery disease, intraoperative ischaemic episodes were preceded by acute increases in arterial pressure in only 15% of episodes and by acute decreases in only 8% of episodes.48 A recent paper by Reich and colleagues has described an association between intraoperative hypertension and tachycardia and adverse outcome in protracted surgery.66 It was by no means clear, however, that this was a causal association.
![]() |
Perioperative management of patients with hypertension or raised arterial pressure |
---|
With regard to the management of surgical patients with elevated admission arterial pressure, there are few substantive guidelines over which patients should be cancelled to allow treatment before surgery or the duration of such treatment before proceeding with surgery. The American Heart Association/American College of Cardiology (ACC/AHA) guidelines comment that hypertension (Stages 1 and 2) is not an independent risk factor for perioperative cardiovascular complications.15 However, they suggest that Stage 3 hypertension (SAP 180 mm Hg and/or DAP
110 mm Hg) should be controlled before surgery.15 To quote the guidelines:
In many instances establishment of an effective treatment regimen can be achieved over several days to weeks of preoperative outpatient management. If surgery is more urgent, rapid acting agents can be administered to allow effective control in a matter of minutes or hours. Beta-blockers appear to be particularly attractive agents. Continuation of preoperative antihypertensive treatment through the perioperative period is critical.
The observational data presented in this review support the recommendations for Stages 1 and 2 hypertension. The AHA/ACC recommendations for Stage 3 hypertension are not supported by substantial data relating exclusively to patients with arterial pressures greater than 180/110 mm Hg. The best perioperative management of these patients remains unclear. The options available to the anaesthetist are: to ignore the elevated arterial pressure and to continue with anaesthesia and surgery; to institute acute treatment to control the arterial pressure; or to defer surgery for a period of weeks to allow the arterial pressure to be controlled.
High arterial pressures are associated with high levels of after load and cardiac work. This may predispose to myocardial ischaemia and infarction, especially in the presence of coronary artery disease and left ventricular hypertrophy, and therefore simply ignoring markedly elevated arterial pressure may not be appropriate. However, there is evidence that very rapid control of arterial pressure with drugs such as sublingual nifedipine is associated with increased morbidity and mortality.79 Taken together, these concerns pose the dilemma that markedly raised arterial pressures and wide excursions of arterial pressure should be avoided in the perioperative period, but that dramatic acute reductions in arterial pressure may also be fraught with risk.
Observational data lend weight to these concerns. The work of Charleson and colleagues suggests that excursions in mean arterial pressure of greater than 20% in patients with hypertension and or diabetes are associated with perioperative complications.8 The work of Gould and colleagues indicates that marked perioperative reductions in arterial pressure may be associated with reduced splanchnic blood flow even in the well filled patient.28 The best course of action for the anaesthetist would seem to be to defer surgery to allow the arterial pressure to be treated. However, there are no trial data to suggest that this strategy reduces perioperative risk and this advice takes no account of the many issues and problems associated with cancelling an operation within 24 h of surgery. Also, if surgery is deferred to allow the arterial pressure to be treated, it is unclear for how long treatment should be given before the patient returns to have his or her operation.
Weksler and colleagues reported recently the results of a clinical trial in which patients were brought to a waiting room in the operating theatre suite, sedated with midazolam, and had their diastolic pressures measured whilst awaiting surgery.82 989 patients whose diastolic arterial pressure was between 110 and 130 mm Hg immediately before surgery were entered into the trial. 589 patients were randomized to receive nifedipine 10 mg administered intranasally, while 400 patients were randomized to have their surgery postponed. Those patients in whom surgery was deferred remained in hospital until the diastolic arterial pressure was below 110 mm Hg for at least 3 consecutive days. The frequency of perioperative hypotension and hypertension was similar in the two groups, as was the incidence of tachyarrhythmias and bradyarrhythmias. There were no neurological or cardiovascular complications in either group. This study has a number of weaknesses. It was not blinded, it ran over a 9-yr period, during which many other aspects of patient management could have changed, and systolic hypertension was not studied. However, it offers no support for deferring anaesthesia and surgery to allow the arterial pressure to be treated.
We suggest that, if the patient is considered fit for surgery in other respects, their operation should not be deferred simply on account of an elevated admission arterial pressure. If the arterial pressure is consistently elevated to levels of 180 mm Hg systolic or greater or 110 mm Hg diastolic or greater, surgery may proceed, but care should be taken to ensure perioperative cardiovascular stability. Invasive arterial pressure monitoring is indicated for major procedures, and the arterial pressure should be actively managed to prevent excursions of the mean arterial pressure of greater than 20% from baseline. Monitoring should continue into the postoperative period until it is clear that the patient is cardiovascularly stable. It may be appropriate to manage the patient in a high dependency area in the immediate postoperative period. In those patients in whom there is no contraindication, perioperative beta-adrenergic block may be of value. These drugs are known to reduce perioperative myocardial ischaemia and cardiovascular complications in high-risk patients.49 57 They carry the additional merit of not producing marked arterial pressure reductions in normotensive subjects. It should be pointed out that Boersma and colleagues have produced observational data that support the widespread use of perioperative beta-adrenergic blockade, but that the available data from randomized controlled trials only provide clear support for their use in high-risk patients with demonstrable new wall motion abnormalities on dobutamine stress echocardiography.6 32 Clinical trial data to support the use of perioperative beta-adrenergic block in other patients with cardiac disease are awaited. There may be a place for other sympatholytic therapies such as alpha-2 agonists or thoracic epidural block. The pharmacology and use of the alpha-2 agonists has been reviewed by Khan and colleagues.37 A meta-analysis by Rogers and colleagues suggested that neuroaxial block does offer protection from perioperative myocardial injury.68 The validity of this finding has been challenged and the current position remains unclear.1 Although Weksler and colleagues reported no problems with intranasal nifedipine administered to 589 patients immediately before surgery, we are unable to recommend its use because of the concerns expressed by Varon and colleagues.79 82
In making clinical judgements about perioperative management, white coat hypertension is an ever-present problem. If the preoperative arterial pressure is giving cause for concern, several further readings should be obtained by someone who is competent to do so. It seems indefensible to defer planned surgery on the basis of a single arterial pressure reading. In view of the vigorous alerting reaction that can be produced by a visit from a doctor, readings obtained by an experienced nurse may be invaluable. If at all possible, the patients family doctor should be contacted and enquiry made about arterial pressure readings obtained in the family practitioners office. It must be a source of irritation for the patient and family doctor for surgery to be deferred and the patient be sent back for treatment of their arterial pressure when the they have been on carefully monitored treatment for months or years and the arterial pressure is known to be well controlled.
![]() |
Addendum |
---|
As in previous publications from the JNC, there are no recommendations or guidelines for the perioperative care of the hypertensive patient.10
![]() |
Longer version of this paper |
---|
![]() |
References |
---|
2 Aronson S, Boisvert D, Lapp W. Isolated systolic hypertension is associated with adverse outcomes from coronary artery bypass grafting surgery. Anesth Analg 2002; 94: 107984
3 Ashton CM, Petersen NJ, Wray NP, et al. The incidence of perioperative myocardial infarction in men undergoing noncardiac surgery. Ann Intern Med 1993; 118: 50410
4 Badner NH, Knill RL, Brown JE, Novick TV, Gelb AW. Myocardial infarction after noncardiac surgery. Anesthesiology 1998; 88: 5728[ISI][Medline]
5 Baron JF, Mundler O, Bertrand M, et al. Dipyridamole-thallium scintigraphy and gated radionuclide angiography to assess cardiac risk before abdominal aortic surgery. N Engl J Med 1994; 330: 6639
6 Boersma E, Poldermans D, Bax JJ, et al. Predictors of cardiac events after major vascular surgery: role of clinical characteristics, dobutamine echocardiography, and beta-blocker therapy. JAMA 2001; 285: 186573
7 Charlson ME, MacKenzie CR, Gold JP, et al. The preoperative and intraoperative hemodynamic predictors of postoperative myocardial infarction or ischemia in patients undergoing noncardiac surgery. Ann Surg 1989; 210: 63748[ISI][Medline]
8 Charlson ME, MacKenzie CR, Gold JP, Ales KL, Topkins M, Shires GT. Intraoperative blood pressure. What patterns identify patients at risk for postoperative complications? Ann Surg 1990; 212: 56780[ISI][Medline]
9 Chassot PG, Delabays A, Spahn DR. Preoperative evaluation of patients with, or at risk of, coronary artery disease undergoing non-cardiac surgery. Br J Anaesth 2002; 89: 74759
10 Chobanian AV, Bakris GL, Black HR, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA 2003; 289: 256072
11 Chung F, Mezei G, Tong D. Pre-existing medical conditions as predictors of adverse events in day-case surgery. Br J Anaesth 1999; 83: 26270
12 Committee of World Health Organisation-International Society of Hypertension. 1999 World Health Organization-International Society of Hypertension (WHO-ISH). Guidelines for the Management of Hypertension. J Hypertens 1999; 17: 15183[CrossRef][ISI][Medline]
13 Cooperman M, Pflug B, Martin EW, jr, Evans WE. Cardiovascular risk factors in patients with peripheral vascular disease. Surgery 1978; 84: 5059[ISI][Medline]
14 Dingle HR. Antihypertensive drugs and anaesthesia. Anaesthesia 1966; 21: 15172[ISI][Medline]
15 Eagle KA, Berger PB, Calkins H, et al. ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). 2002. American College of Cardiology Web site. Available at http./www.acc.org/clinical/guidelines/perio/driIndex.htm
16 Eagle KA, Coley CM, Newell JB, et al. Combining clinical and thallium data optimizes preoperative assessment of cardiac risk before major vascular surgery. Ann Intern Med 1989; 110: 85966[ISI][Medline]
17 Eerola M, Eerola R, Kaukinen S, Kaukinen L. Risk factors in surgical patients with verified preoperative myocardial infarction. Acta Anesthesiol Scand 1980; 24: 21923[ISI][Medline]
18 Eichelberger JP, Schwarz KQ, Black ER, Green RM, Ouriel K. Predictive value of dobutamine echocardiography just before noncardiac vascular surgery. Am J Cardiol 1993; 72: 6027[ISI][Medline]
19 Forrest JB, Rehder K, Cahalan MK, Goldsmith CH. Multicenter study of general anesthesia. III. Predictors of severe perioperative adverse outcomes. Anesthesiology 1992; 76: 315[ISI][Medline]
20 Forrest JB, Rehder K, Goldsmith CH, et al. Multicenter study of general anesthesia. I. Design and patient demography. Anesthesiology 1990; 72: 25261[ISI][Medline]
21 Foster ED, Davis KB, Carpenter JA, Abele S, Fray D. Risk of noncardiac operation in patients with defined coronary disease: the Coronary Artery Surgery Study (CASS) registry experience. Ann Thorac Surg 1986; 41: 4250[Abstract]
22 Frank SM, Fleisher LA, Breslow MJ, et al. Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events. A randomized clinical trial. JAMA 1997; 277: 112734[Abstract]
23 Franklin SS, Gustin W 4th, Wong ND, et al. Hemodynamic patterns of age-related changes in blood pressure. The Framingham Heart Study. Circulation 1997; 96: 30815
24 Franklin SS, Jacobs MJ, Wong ND, LItalien GJ, Lapuerta P. Predominance of isolated systolic hypertension among middle-aged and elderly US hypertensives: analysis based on National Health and Nutrition Examination Survey (NHANES) III. Hypertension 2001; 37: 86974
25 Franklin SS, Khan SA, Wong ND, Larson MG, Levy D. Is pulse pressure useful in predicting risk for coronary heart disease? The Framingham heart study. Circulation 1999; 100: 35460
26 Gillespie DL, LaMorte WW, Josephs LG, Schneider T, Floch NR, Menzoian JO. Characteristics of patients at risk for perioperative myocardial infarction after infrainguinal bypass surgery: an exploratory study. Ann Vasc Surg 1995; 9: 15562[ISI][Medline]
27 Goldman L, Caldera DL. Risks of general anesthesia and elective operation in the hypertensive patient. Anesthesiology 1979; 50: 28592[ISI][Medline]
28 Gould TH, Grace K, Thorne G, Thomas M. Effect of thoracic epidural anaesthesia on colonic blood flow. Br J Anaesth 2002; 89: 44651
29 Group for Collaborative Research: Systolic Hypertension in the Elderly Program. Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension. Final results of the Systolic Hypertension in the Elderly Program (SHEP). JAMA 1991; 265: 325564[Abstract]
30 Heiba SI, Jacobson AF, Shattuc S, Ferreira MJ, Sharma PN, Cerqueira MD. The additive values of left ventricular function and extent of myocardium at risk to dipyridamole perfusion imaging for optimal risk stratification prior to vascular surgery. Nuclear Med Commun 1999; 20: 88794[ISI][Medline]
31 Howell SJ, Hemming AE, Allman KG, Glover L, Sear JW, Foex P. Predictors of postoperative myocardial ischaemia. The role of intercurrent arterial hypertension and other cardiovascular risk factors. Anaesthesia 1997; 52: 10711[ISI][Medline]
32 Howell SJ, Sear JW, Foex P. Peri-operative beta-blockade: a useful treatment that should be greeted with cautious enthusiasm. Br J Anaesth 2001; 86: 1614
33 Howell SJ, Sear JW, Sear YM, Yeates D, Goldacre M, Foex P. Risk factors for cardiovascular death within 30 days after anaesthesia and urgent or emergency surgery: a nested case-control study. Br J Anaesth 1999; 82: 67984
34 Howell SJ, Sear YM, Yeates D, Goldacre M, Sear JW, Foex P. Risk factors for cardiovascular death after elective surgery under general anaesthesia. Br J Anaesth 1998; 80: 149[CrossRef][ISI][Medline]
35 Joint National Committee on prevention detection, evaluation, and treatment of high blood pressure. The sixth report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med 1997; 157: 241346[Abstract]
36 Kaplan NM. Clinical Hypertension, 8th edn. Philadelphia: Lippincott Williams and Wilkins, 2002; 3536, 9296
37 Khan ZP, Ferguson CN, Jones RM. Alpha-2 and imidazoline receptor agonists. Their pharmacology and therapeutic role. Anaesthesia 1999; 54: 14665[CrossRef][ISI][Medline]
38 Khattar RS, Senior R, Lahiri A. Cardiovascular outcome in white-coat versus sustained mild hypertension: a 10-year follow-up study. Circulation 1998; 98: 18927
39 Kontos MC, Brath LK, Akosah KO, Mohanty PK. Cardiac complications in noncardiac surgery: relative value of resting two-dimensional echocardiography and dipyridamole thallium imaging. Am Heart J 1996; 132: 55966[ISI][Medline]
40 Koutelou MG, Asimacopoulos PJ, Mahmarian JJ, Kimball KT, Verani MS. Preoperative risk stratification by adenosine thallium 201 single-photon emission computed tomography in patients undergoing vascular surgery. J Nuclear Cardiol 1995; 2: 38994[ISI]
41 Larsen SF, Olesen KH, Jacobsen E, et al. Prediction of cardiac risk in non-cardiac surgery. Eur Heart J 1987; 8: 17985[Abstract]
42 Lee TH, Marcantonio ER, Mangione CM, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999; 100: 10439
43 Lette J, Waters D, Bernier H, et al. Preoperative and long-term cardiac risk assessment. Predictive value of 23 clinical descriptors, 7 multivariate scoring systems, and quantitative dipyridamole imaging in 360 patients. Ann Surg 1992; 216: 192204[ISI][Medline]
44 Lette J, Waters D, Lassonde J, et al. Postoperative myocardial infarction and cardiac death. Predictive value of dipyridamole-thallium imaging and five clinical scoring systems based on multifactorial analysis. Ann Surg 1990; 211: 8490[ISI][Medline]
45 Liao YL, Liu KA, Dyer A, et al. Major and minor electro cardiographic abnormalities and risk of death from coronary heart disease, cardiovascular diseases and all causes in men and women. J Am Coll Cardiol 1988; 12: 1494500[ISI][Medline]
46 Longnecker DE. Alpine anesthesia: can pretreatment with clonidine decrease the peaks and valleys? Anesthesiology 1987; 67: 12[ISI][Medline]
47 Mancia G, Parati G, Pomidossi G, Grassi G, Casadei R, Zanchetti A. Alerting reaction and rise in blood pressure during measurement by physician and nurse. Hypertension 1987; 9: 20915[Abstract]
48 Mangano DT, Hollenberg M, Fegert G, et al. Perioperative myocardial ischemia in patients undergoing noncardiac surgeryI: Incidence and severity during the 4 day perioperative period. The Study of Perioperative Ischemia (SPI) Research Group. J Am Coll Cardiol 1991; 17: 84350[ISI][Medline]
49 Mangano DT, Layug EL, Wallace A, Tateo I. Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group. N Engl J Med 1996; 335: 171320
50 OBrien E, Coats A, Owens P, et al. Use and interpretation of ambulatory blood pressure monitoring: recommendations of the British hypertension society. BMJ 2000; 320: 112834
51 OBrien E, Staessen JA. Critical appraisal of the JNC VI, WHO/ISH and BHS guidelines for essential hypertension. Expert Opin Pharmacother 2000; 1: 67582[Medline]
52 OConnell D, Glasziou P, Hill S, Sarunac J, Lowe J, Henry H. Results of clinical trials and systematic reviews: to whom do they apply? In: Stevens A, Abrams K, Brazier J, Fitzpatrick R, Lilford R, eds. The Advanced Handbook of Methods in Evidence Based Healthcare. London: Sage Publications, 2001; 5672
53 Ombrellaro MP, Dieter RA, 3rd, Freeman M, Stevens SL, Goldman MH. Role of dipyridamole myocardial scintigraphy in carotid artery surgery. J Am Coll Surg 1995; 181: 4518[ISI][Medline]
54 Pasternack PF, Grossi EA, Baumann FG, et al. Silent myocardial ischemia monitoring predicts late as well as perioperative cardiac events in patients undergoing vascular surgery. J Vasc Surg 1992; 16: 1719[CrossRef][ISI][Medline]
55 Perloff D, Sokolow M. Ambulatory blood pressure: mortality and morbidity. J Hyperten Suppl 1991; 9: S313
56 Pickering TG, Coats A, Mallion JM, Mancia G, Verdecchia P. Blood pressure monitoring. Task force V: white-coat hyper tension. Blood Press Monit 1999; 4: 33341[Medline]
57 Poldermans D, Boersma E, Bax JJ, et al. The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group. N Engl J Med 1999; 341: 178994
58 Poldermans D, Fioretti PM, Boersma E, et al. Dobutamine-atropine stress echocardiography in elderly patients unable to perform an exercise test. Hemodynamic characteristics, safety, and prognostic value. Arch Intern Med 1994; 154: 26816[ISI][Medline]
59 Prys-Roberts C, Foex P, Biro GP, Roberts JG. Studies of anaesthesia in relation to hypertension. V. Adrenergic beta-receptor blockade. Br J Anaesth 1973; 45: 67181[ISI][Medline]
60 Prys-Roberts C, Foex P, Greene LT, Waterhouse TD. Studies of anaesthesia in relation to hypertension. IV. The effects of artificial ventilation on the circulation and pulmonary gas exchanges. Br J Anaesth 1972; 44: 33549[ISI][Medline]
61 Prys-Roberts C, Greene LT, Meloche R, Foex P. Studies of anaesthesia in relation to hypertension. II. Haemodynamic consequences of induction and endotracheal intubation. Br J Anaesth 1971; 43: 53147[ISI][Medline]
62 Prys-Roberts C, Meloche R, Foex P. Studies of anaesthesia in relation to hypertension. I. Cardiovascular responses of treated and untreated patients. Br J Anaesth 1971; 43: 12237[ISI][Medline]
63 Ramsay LE, Williams B, Johnston GD, et al. British Hypertension Society guidelines for hypertension management 1999: summary. BMJ 1999; 319: 6305
64 Rao TL, Jacobs KH, El Etr AA. Reinfarction following anesthesia in patients with myocardial infarction. Anesthesiology 1983; 59: 499505[ISI][Medline]
65 Redon J, Campos C, Narciso ML, Rodicio JL, Pascual JM, Ruilope LM. Prognostic value of ambulatory blood pressure monitoring in refractory hypertension: a prospective study. Hypertension 1998; 31: 7128
66 Reich DL, Bennett-Guerrero E, Bodian CA, Hossain S, Winfree W, Krol M. Intraoperative tachycardia and hyper tension are independently associated with adverse outcome in noncardiac surgery of long duration. Anesth Analg 2002; 95: 2737
67 Riles TS, Kopelman I, Imparato AM. Myocardial infarction following carotid endarterectomy: a review of 683 operations. Surgery 1979; 85: 24952[ISI][Medline]
68 Rodgers A, Walker N, Schug S, et al. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ 2000; 321: 1493
69 Shah KB, Kleinman BS, Rao TL, Jacobs HK, Mestan K, Schaafsma M. Angina and other risk factors in patients with cardiac diseases undergoing noncardiac operations. Anesth Analg 1990; 70: 2407[Abstract]
70 Sicari R, Picano E, Lusa AM, et al. The value of dipyridamole echocardiography in risk stratification before vascular surgery. A multicenter study. The EPIC (Echo Persantine International Study) GroupSubproject: risk stratification before major vascular surgery. Eur Heart J 1995; 16: 8427[Abstract]
71 Sprague HB. The heart in surgery. An analysis of the results of surgery on cardiac patients during the past ten years at the Massachusetts General Hospital. Surg Gynecol Obstet 1929; 49: 548
72 Sprung J, Abdelmalak B, Gottlieb A, et al. Analysis of risk factors for myocardial infarction and cardiac mortality after major vascular surgery. Anesthesiology 2000; 93: 12940[ISI][Medline]
73 Stamler J, Dyer AR, Shekelle RB, Neaton J, Stamler R. Relationship of baseline major risk factors to coronary and all-cause mortality, and to longevity: findings from long-term follow-up of Chicago cohorts. Cardiology 1993; 82: 191222[ISI][Medline]
74 Stamler J, Stamler R, Neaton JD. Blood pressure, systolic and diastolic, and cardiovascular risks. US population data. Arch Intern Med 1993; 153: 598615[Abstract]
75 Steen PA, Tinker JH, Tarhan S. Myocardial reinfarction after anesthesia and surgery. JAMA 1978; 239: 256670[Abstract]
76 Stevens A, Abrams K. Consensus, reviews and meta-analysis. In: Stevens A, Abrams K, Brazier J, Fitzpatrick R, Lilford R, eds. Methods in Evidence Based Healthcare. London: Sage, 2001; 3679
77 Stratmann HG, Younis LT, Wittry MD, Amato M, Mark AL, Miller DD. Dipyridamole technetium 99m sestamibi myocardial tomography for preoperative cardiac risk stratification before major or minor nonvascular surgery. Am Heart J 1996; 132: 53641[ISI][Medline]
78 Varma MK, Puri GD, Chari P, Verma JS, Kohli KK. Perioperative myocardial infarction in coronary artery disease patients and at-risk for coronary artery disease patients undergoing non-cardiac surgery. Natl Med J India 1996; 9: 2147[ISI][Medline]
79 Varon J, Marik PE. The diagnosis and management of hypertensive crises. Chest 2000; 118: 21427
80 Verdecchia P, Schillaci G, Borgioni C, Ciucci A, Porcellati C. White-coat hypertension. Lancet 1996; 348: 14445[Medline]
81 vonKnorring J. Postoperative myocardial infarction: a pros pective study in a risk group of surgical patients. Surgery 1981; 90: 5560[ISI][Medline]
82 Weksler N, Klein M, Szendro G, et al. The dilemma of immediate preoperative hypertension: to treat and operate, or to postpone surgery? J Clin Anesth 2003; 15: 17983[CrossRef][ISI][Medline]