Marked improvement in left ventricular ejection fraction during long-term beta-blockade in patients with chronic heart failure: clinical correlates and prognostic significance.

BACKGROUND: Some patients with heart failure (HF) may have a marked improvement
in left ventricular ejection fraction (LVEF) after long-term beta-blockade. We
compared the clinical characteristics and the prognosis of these patients with
those of other patients.
METHODS: One hundred seventy-one patients with chronic HF were assessed before
and after 9 to 12 months of maintenance therapy with metoprolol or carvedilol.
RESULTS: Thirty-eight patients (22%) showed an increase in their LVEF >or=15
units (from 20% +/- 8% to 43% +/- 10%). Compared with the other patients (LVEF
change from 21% +/- 7% to 26% +/- 9%, P <.0001 for differences between groups),
these patients also had a greater decline in the left ventricular end-diastolic
volume (from 175 +/- 74 mL/m(2) to 113 +/- 36 mL/m(2)) and in the right atrial,
mean pulmonary artery, and pulmonary wedge pressures, with a greater increase in
the cardiac index, stroke volume index, stroke work index, and maximal functional
capacity. Their long-term prognosis was excellent, with a 2-year cumulative
survival rate of 95%, versus 81% for the other patients, and a
hospitalization-free survival rate of 73%, versus 50% for the other patients (all
P <.05). By means of multivariate analysis, only the nonischemic cause of HF and
the mean arterial pressure at baseline were independently associated with an
increase of >or=0.15 in LVEF.
CONCLUSIONS: Patients who show a marked improvement in their LVEF after long-term
beta-blockade have an excellent prognosis and have a high prevalence of
nonischemic HF and a higher blood pressure at baseline.