Approximately 50% of patients with heart failure have a left ventricular ejection
fraction of at least 45%, but no therapies have been shown to improve the outcome
of these patients. Therefore, we studied the effects of irbesartan in patients with
this syndrome.
We enrolled 4128 patients who were at least 60 years of age and had New York Heart
Association class II, III, or IV heart failure and an ejection fraction of at least
45% and randomly assigned them to receive 300 mg of irbesartan or placebo per day.
The primary composite outcome was death from any cause or hospitalization for a cardiovascular
cause (heart failure, myocardial infarction, unstable angina, arrhythmia, or stroke).
Secondary outcomes included death from heart failure or hospitalization for heart
failure, death from any cause and from cardiovascular causes, and quality of life.
During a mean follow-up of 49.5 months, the primary outcome occurred in 742 patients
in the irbesartan group and 763 in the placebo group. Primary event rates in the irbesartan
and placebo groups were 100.4 and 105.4 per 1000 patient-years, respectively (hazard
ratio, 0.95; 95% confidence interval [CI], 0.86 to 1.05; P=0.35). Overall rates of
death were 52.6 and 52.3 per 1000 patient-years, respectively (hazard ratio, 1.00;
95% CI, 0.88 to 1.14; P=0.98). Rates of hospitalization for cardiovascular causes
that contributed to the primary outcome were 70.6 and 74.3 per 1000 patient-years,
respectively (hazard ratio, 0.95; 95% CI, 0.85 to 1.08; P=0.44). There were no significant
differences in the other prespecified outcomes.
Irbesartan did not improve the outcomes of patients with heart failure and a preserved
left ventricular ejection fraction. (ClinicalTrials.gov number, NCT00095238.)
2008 Massachusetts Medical Society