1 Third Department of Internal Medicine, Division of Nephrology, 2 Third Department of Internal Medicine, Division of Cardiology and 3 Division of Clinical Engineering, Ohashi Hospital, Toho University School of Medicine, Tokyo, Japan
![]() |
Abstract |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Methods. A total of 103 consecutive haemodialysis patients (123 lesions) underwent procedurally and clinically successful percutaneous revascularization. Patients were treated with three different strategies: (i) balloon angioplasty in 55 patients (69 lesions); (ii) coronary stenting with balloon angioplasty in 23 patients (25 lesions); and (iii) coronary stenting with rotational atherectomy in 25 patients (29 lesions) who had severely calcified stenotic coronaries.
Results. The rates of in-hospital mortality were similar in the three groups. The 1-year incidence of overall events and major adverse cardiac events (MACE) were significantly higher in the balloon group than in the stent with/without rotational atherectomy groups (75% vs 36 and 28%, P<0.01; 71% vs 32 and 28%, P<0.01). Use of coronary stenting (relative risk=0.006, P<0.001) and the presence of calcified coronary lesion (relative risk=68.2, P<0.001) were independent predictors of the 1-year MACE-free survival after percutaneous revascularization. The 3-year MACE-free survival rate was significantly lower in the balloon group than in the stent with/without rotational atherectomy groups (11% vs 33 and 47%, P<0.005 and P<0.001).
Conclusions. This study shows that coronary stenting reduces the incidence of MACE in haemodialysis patients with/without calcified coronary lesions. Moreover, coronary stenting reduces the restenosis rate of both complex and restenotic lesions, and rotational atherectomy prior to coronary stenting reduces the restenosis rate of the severely calcified coronary lesions. These results suggest that coronary stenting with/without rotational atherectomy has led to an improved long-term outcome in the haemodialysis patients with coronary artery disease.
Keywords: balloon angioplasty; cardiac event; haemodialysis; rotational atherectomy; stent
![]() |
Introduction |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Recently, it has been reported that coronary stenting reduces restenosis rates [9], and that rotational atherectomy followed by stenting is a useful interventional treatment for revascularization of severely calcified stenotic coronary lesions [10]. Coronary lesions in haemodialysis patients are often moderately or severely calcified due to a calciumphosphate balance disorder [11,12]. Although percutaneous revascularization using coronary stenting might be expected to reduce coronary restenosis in haemodialysis, there have been few reports evaluating the effect of coronary stenting in such patients [13,14].
Until 1992, all haemodialysis patients were treated with balloon angioplasty in our institution. In 1993, coronary stenting became available, and the decision to stent was based on vessel size, lesion morphology, and the absence of clinical contraindications. Starting in 1997, we used the rotational atherectomy in patients with severely calcified coronary lesions. Here, we performed a retrospective study comparing balloon angioplasty with coronary stenting in haemodialysis patients with coronary artery disease. We also evaluated the clinical and angiographic predictors of the cumulative incidence of major adverse cardiac events (MACE), including cardiac death, non-fatal acute myocardial infarction, coronary artery bypass surgery, and repeated percutaneous revascularization in these patients.
![]() |
Subjects and methods |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Percutaneous coronary revascularization
Selection of device or strategy was mostly dependent on the morphologic characteristics of the target lesion and a history of target lesion restenosis. Balloon angioplasty was performed using standard techniques. All patients received aspirin (162 mg daily) starting 3 days before the procedure. Heparin (100 IU/kg) was administered just before the procedure. Stent implantation also was performed using standard techniques. Rotational atherectomy was performed with the Rotablator system (Boston Scientific, Natick, MA, USA) and the decision to perform adjunctive balloon angioplasty was left to the operator. Treatment with ticlopidine (200 mg daily) was started immediately after the stent placement and was continued for at least 4 weeks. All patients received long-term aspirin (81162 mg daily) in the follow-up period.
Lesion morphology was classified according to the AHA/ACC Classification Task Force. Lesion treatment was considered to be successful when there was a greater than 20% gain in luminal diameter. Reference and minimal luminal diameter, and lesion length were determined by use of a quantitative coronary angiographic measurement system.
Angiography and clinical follow-up
During the study period, we routinely attempted to obtain a follow-up coronary angiography 612 months after the initial procedure to evaluate the presence of restenosis, regardless of symptomatic status. Angiography was performed earlier if clinically indicated. Non-invasive examinations, including myocardial scintigraphy, echocardiography, and exercise electrocardiography, were performed at regular intervals after the initial follow-up angiography because diabetic and haemodialysis patients commonly do not have typical symptoms of myocardial ischaemia. Patients who died without repeat coronary angiography within 12 months were excluded from angiographic data analysis. Restenosis was defined angiographically as a luminal narrowing of 50% at a previously dilated site. Following hospital discharge, patients were either seen at our hospital or contacted by telephone for follow-up. Follow-up was successful in all patients. The primary end-point of the study was incidence of the MACE and non-cardiac death during the 40 months after successful percutaneous revascularization before December 2000.
Statistical analysis
Statistical analysis was performed with a commercially available software program (StatView 5.0, SAS Institute, Cary, NC, USA). Data are expressed as the mean value±SD. The 2 test or Fisher's exact test for categorical variables and Student's t-test for continuous variables were used to evaluate differences between measured values. P values <0.05 were considered statistically significant. Univariate logistic analysis was used to select the clinical and angiographic predictors of MACE after percutaneous revascularization. Independent predictors of the MACE were determined by using a multivariate stepwise logistic regression model. The relative risk ratios and 95% confidence intervals are presented in tabular form for the final multivariate model. The MACE-free survival rates and the overall survival rates in the three groups were determined by the KaplanMeier method.
![]() |
Results |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
|
Angiographic and procedural characteristics
The angiographic characteristics of the study groups are shown in Table 3. Although the incidence of multivessel disease and the target vessels for percutaneous revascularization did not differ among the three groups, the incidence of calcified lesions, especially severely calcified lesions was significantly higher in the stent with rotational atherectomy group than in the balloon group. Compared with the balloon group, the stent with rotational atherectomy group was more likely to have revascularization performed on AHA/ACC type C lesions. The pre-procedure quantitative coronary angiographic analysis showed that the lesion length was significantly longer in the stent with rotational atherectomy group than in the balloon group. The minimal luminal diameter obtained as a result of the revascularization was significantly larger in the stent groups than in the balloon group.
|
Long-term results of percutaneous coronary intervention
The 1-year clinical and angiographic outcomes of the three groups are shown in Table 4. The in-hospital mortality rates and the duration of in-hospital stay were similar in the three groups. Six patients (11%) in the balloon group, one patient (5%) in the stent with balloon group, and four patients (16%) in the stent with rotational atherectomy group died within 1 year after discharge. None of the deceased patients had undergone their first follow-up angiography before death. During the 1-year follow-up, there were higher incidences of overall events and MACE in the balloon group than in the coronary stent groups. However, the incidences of cardiac death and non-cardiac death were not significantly different among the three groups. The incidence of target lesion restenosis was significantly higher in the balloon group than in the stent groups.
|
As shown in Table 5, the incidence of MACE within 1 year after percutaneous revascularization was predicted independently by two variables. Coronary stenting was the variable that was most closely associated with a decreased risk of MACE, and the presence of moderate to severely calcified coronary lesions was the variable that was most closely associated with an increased risk of MACE after percutaneous revascularization based on stepwise logistic regression analysis.
|
![]() |
Discussion |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Haemodialysis patients have a high cardiac morbidity and mortality, mainly due to coronary artery disease [16,17]. As a result, haemodialysis patients frequently require percutaneous revascularization. However, the long-term results after balloon angioplasty have been disappointing in these patients, mainly because of accelerated restenosis. A restenosis rate of 4781% after successful balloon angioplasty has been reported in haemodialysis patients, which is significantly higher than for the general population [28]. The incidence of MACE depends on the rate of restenosis. The high rate of target lesion restenosis decreased the MACE-free survival rates after balloon angioplasty.
The increase in the minimal luminal diameter as a result of percutaneous revascularization was greater in patients treated with coronary stenting than in patients treated with balloon angioplasty [9,10]. The minimal luminal diameter after balloon angioplasty has generally been found to be smaller in haemodialysis patients than in the general population, because of coronary artery calcification [11]. However, coronary stenting decreased the prevalence of MACE and target lesion restenosis in haemodialysis patients in this study. The repeat coronary revascularization rate at 1-year after coronary stenting has been reported to be between 33% and 37% in haemodialysis patients [13,14]. In our study, the incidence of MACE 1-year after revascularization was 28% in the coronary stent with balloon group. The lower rate of MACE is probably due to a decreased incidence of severely calcified lesions in our population.
Until 1997, there were no effective percutaneous revascularization devices for treating complex coronary lesions with severe calcification. In this study, haemodialysis patients who had severely calcified and complex stenotic coronary lesions underwent plaque debulking by rotational atherectomy prior to coronary stenting. Although they were high-risk patients, the incidence of MACE was significantly lower than in those patients treated by balloon angioplasty. These results suggest that the larger minimal luminal diameter created by coronary stenting for less calcified lesions, or rotational atherectomy use prior to stenting for severely calcified lesions, tends to prevent early restenosis because of decreased elastic recoil and/or coronary remodeling in those patients. Rotational atherectomy may favour homogeneous dilatation, production of a circular intima-lumen interface in calcified coronary lesions, an increase in luminal size, and a decrease in plaque-plus-media area [10].
Coronary artery calcification occurs more frequently in young adults with end-stage renal disease than in either normal subjects of the same age and gender or older adults with normal renal function [19]. The duration of treatment with dialysis was substantially longer in the patients with coronary artery calcification than in those without calcification [20]. The mechanism responsible for vascular calcification in patients with chronic renal failure remains uncertain, and the relationship between arterial-wall calcification and the atherosclerotic or restenotic process is not fully understood [21]. Patients with calcification had higher serum phosphorus concentrations and a higher serum calciumphosphorus ion product. Furthermore, their daily intake of calcium-containing phosphate-binding agents was nearly twice as great as in patients without calcification. Therefore, long-term exposure to the abnormalities in minimal metabolism that characterize chronic renal failure and the treatment of these abnormalities appear to contribute to the development of coronary artery calcification in patients with end-stage renal disease [20].
Our study has several potential limitations. First, this study was retrospective and the number of patients was small. Therefore, the quality of the data does not allow us to draw conclusions with the same confidence as would be derived from a large-scale prospective trial. Second, the cost of the coronary stenting and rotational atherectomy was not calculated. Consequently, it is difficult to determine whether there is a cost-effective MACE-free survival advantage for performing coronary stenting with/without rotational atherectomy in haemodialysis patients.
This study shows that coronary stenting reduces the incidence of MACE in haemodialysis patients with/without calcified coronary lesions. Moreover, coronary stenting reduces the restenosis rate of both complex and restenotic lesions, and rotational atherectomy prior to coronary stenting reduces the restenosis rate of the severely calcified coronary lesions. These results suggest that coronary stenting with/without rotational atherectomy has led to an improved long-term outcome in the haemodialysis patients with coronary artery disease.
![]() |
Acknowledgments |
---|
![]() |
Notes |
---|
![]() |
References |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|