Servicio de Cardiología
Complejo Hospitalario de Jaén
Pza del Zodiaco No.8, 5B
23009 Jaén
Spain
Tel: +34 637 463857
Fax: +34 953 270692
E-mail address: maapalomares{at}secardiologia.es
Servicio de Neumología
Hospital Universitario La Paz
Madrid
Spain
Servicio de Neumología
Hospital Universitario La Paz
Madrid
Spain
We read with great interest the article by Rutten et al.1 who report a significant association between the presence of chronic obstructive pulmonary disease and unrecognized heart failure in elderly patients. Approximately, 50% of heart failure patients in their study had isolated diastolic heart failure.
The authors suggested that the association between the two disorders may be attributable to the increased prevalence rates of atherosclerosis found in chronic obstructive pulmonary disease patients and the impressive smoking status of these patients. However, there is one other possible explanation for the high prevalence of heart failure in the chronic obstructive pulmonary disease in elderly patients. Some patients may have obstructive sleep apnoea (OSA). The possible presence of sleep-related disordered breathing was not ruled out in this study and it has been demonstrated that OSA can originate diastolic dysfunction independent of other factors.2 Indeed, the treatment of OSA among patients with congestive heart failure and left ventricular (LV) systolic dysfunction leads to improvement in cardiac function,3 suggesting that OSA may also have an adverse effect on LV systolic function.
The prevalence of OSA is not greater in chronic obstructive pulmonary disease patients than in the general population, but this association, the so-called overlap syndrome, is not rare, as chronic obstructive pulmonary disease and OSA are both frequently occurring diseases.4,5 In fact, OSA has a two- to three-fold higher prevalence in subjects older than 65 years when compared with those in middle age.6 Overlap patients are at a higher risk of developing respiratory insufficiency than are pure OSA patients. These facts could have contributed to overestimate the real prevalence of heart failure in pure chronic obstructive pulmonary disease patients.
References
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