Diastolic dysfunction as predominant form of CHF confirmed

Context

Evidence is emerging suggesting that a large proportion of people suffering from congestive heart failure (CHF) actually have diastolic dysfunction rather than systolic. This is contrary to the previous beliefs that systolic heart failure was the only kind. It is now known that diastolic heart failure may be the more common form of heart failure in older adults, especially in women.

Significant findings

The authors found that the overall prevalence of heart failure in the cohort was 8.8%. This was associated with increased age, particularly among women, in whom the rate increased from 6.6% in those aged 65 to 69 years, to 14% in those aged 85 years and older. Multivariate analysis showed that subjects with CHF were more likely to be older (odds ratio [OR] 1.2 for 5-year difference), men (OR 1.1), and more often had a history of myocardial infarction (OR 7.3), atrial fibrillation (OR3.0), diabetes mellitus (OR 2.1), renal dysfunction (OR 2.0 for creatine =1.5 mg/dl), and chronic pulmonary disease (OR 1.8; women only). In addition, physical examination revealed that among those with heart failure, 55% had normal left ventricular systolic function and 80% had either normal or only mildly reduced systolic function. Isolated diastolic function appeared to be more common among women than men (67% versus 42%; P<0.01).

Comments

The authors pointed out that while numerous studies have elucidated the pathophysiology, prognosis and therapy for CHF with reduced systolic left ventricular function, there is a notable dearth of similar data in patients with CHF and normal systolic function. For instance, most clinical heart failure treatment trials have focused on patients with ejection fractions of less than 45%. However, the current data suggest that such criteria may include only 21% of elderly patients with heart failure living in the community. The authors conclude that more data is needed in order to set up management guidelines for this dominant subset.

Methods

The authors assessed 4842 independent, community-dwelling people aged over 65 years who were taking part in the Cardiovascular Health Study - a National Heart, Lung and Blood Institute-sponsored cohort study of cardiovascular disease in the elderly. The patients had echocardiograms, full examinations, and were asked to complete questionnaires about their medical history, family history, personal habits, physical activity, and socioeconomic status.