Why and when do patients with heart failure and normal left ventricular ejection fraction die? Analysis of >600 deaths in a community long-term study

Background

The aim of the study was to examine the causes of the death of patients with heart failure (HF) and evaluate the differences in this respect between patients with and without depression of left ventricular ejection fraction (LVEF).

Method

All patients hospitalized with HF between 1995 and 2002 in the cardiology service of a tertiary hospital were assessed. LVEF was evaluated by echocardiography during hospitalization and was considered normal when it was ≥50%. After a mean follow-up time of 3.7 ± 2.8 years, 615 cases had terminated in death.

Results

The most common cause was refractory HF, both in the whole group (39%) and in both the subgroups defined with respect to LVEF (normal and depressed). There was no statistically significant difference between the normal and depressed subgroups as regard the distribution of deaths, although the depressed group showed a somewhat greater incidence of sudden death (21% as against 16% in the normal group) and a somewhat smaller incidence of death due to refractory HF (37% as against 47%). However, in the depressed LVEF group, the cumulative risk of death due to acute myocardial infarction in the first 1.5 years first increased rapidly and then more slowly, whereas the reverse pattern was held in the normal left ventricular systolic function group, in which it was the cumulative risks of death from noncardiovascular or vascular noncardiac causes that initially increased more rapidly than later.

Conclusions

The spectrum of causes of death among patients with HF who have been hospitalized is independent of LVEF in the long term. In the short term, there are differences between patients with normal LVEF and depressed LVEF as regard the dynamics of the risks of death from acute myocardial infarction, noncardiac vascular causes, and noncardiovascular causes. These results may help orient the short-term and long-term management of HF, especially for patients with normal LVEF, for whom there is still no well-established consensus strategy.