Heart Failure with Preserved Ejection Fraction: Two New Studies

Outcome data are presented for heart failure patients with or without preserved EF.

Clinicians and researchers are focusing increasingly on the distinction between reduced ejection fraction (EF) and preserved EF in patients with heart failure (corresponding roughly to the distinction between patients with systolic and diastolic heart failure).

Mayo Clinic investigators examined the records of 4596 patients who were hospitalized from 1987 to 2001 with decompensated heart failure and echocardiographic assessment of EF. EF was reduced (<50%) in 53% of patients and preserved ( 50%) in 47%. The proportion of heart failure patients with preserved EF increased steadily from 1987 through 2001. Patients with preserved EF were older, more likely to be female or obese, more likely to have atrial fibrillation or hypertension, and less likely to have coronary disease or substantial valvular disease than were patients with reduced EF. Five-year mortality was only slightly higher among patients with reduced EF than among those with preserved EF (68% vs. 65%). During the 15-year study, survival rates gradually improved in the reduced-EF group but not in the preserved-EF group.

Canadian researchers studied 2802 patients admitted to 103 Ontario hospitals from 1999 to 2001 with diagnoses of heart failure and imaging assessment of EF. EF was reduced (<40%) in 56% of patients and preserved (>50%) in 31%. Findings from presenting histories and physical examinations were similar in the two groups. One-year mortality was slightly higher in the reduced-EF group than in the preserved-EF group (26% vs. 22%, P=0.07).

Ejection fraction is preserved in a substantial proportion of patients who are hospitalized with heart failure; this observation indicates the importance of diastolic dysfunction. Determining which interventions clearly reduce mortality in heart failure patients with preserved EF is essential.

Reference:

Owan TE et al. Trends in prevalence and outcome of heart failure with preserved ejection fraction. N Engl J Med 2006 Jul 20; 355:251-9.