A retrospective cohort study found that patients with heart failure and improved or recovered ejection fraction (HFrecEF) had lower mortality rates and less frequent hospitalizations compared with patients with heart failure and reduced ejection fraction or preserved ejection fraction.

The results suggested to the researchers that patients with HFrecEF might be clinically different from other heart failure patients.

Lead researcher Andreas P. Kalogeropoulos, MD, MPH, of the Emory University School of Medicine in Atlanta, and colleagues published their results online July 6 in JAMA Cardiology.

“Heart failure with recovered ejection fraction should be treated as a distinct entity for clinical and research purposes,” they wrote.

For this analysis, the researchers evaluated 2,166 adult outpatients with heart failure who received care by cardiologists at Emory Healthcare between Jan. 1, 2012, and April 30, 2012. They reviewed medical records for symptoms, signs and treatment of heart failure as well as other characteristics.

They defined HFrecEF as current left ventricular ejection fraction (LVEF) of greater than 40 percent but previously documented LVEF of 40 percent or less. They classified as reduced ejection fraction as current LVEF of 40 percent or lower regardless of previous LVEF assessments and preserved ejection fraction as current and all previous LVEF assessments of greater than 40 percent.

Of the patients, 16.2 percent had HFrecEF, 21.5 percent had heart failure with preserved ejection fraction and 62.3 percent had heart failure with reduced ejection fraction.

At baseline, patients with HFrecEF tended to be younger; less likely to have coronary artery disease, diabetes and kidney disease; more likely to receive an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker regimen; less likely to receive loop diuretics, aspirin or digoxin; and less likely to receive an implantable cardioverter-defibrillator or cardiac resynchronization therapy.

After a median follow-up period of three years, the age- and sex-adjusted mortality rates were 4.8 percent in patients with HFrecEF, 13.2 percent in patients with heart failure with preserved ejection fraction and 16.3 percent in patients with heart failure with reduced ejection fraction.

Patients in the HFrecEF group also had fewer all-cause, cardiovascular and heart failure-related hospitalizations than the other two groups. They were also less likely to experience the composite end points of death or cardiovascular hospitalization and death or heart failure hospitalization that are commonly used in clinical trials.

The researchers mentioned the study had a few limitations, including that they classified heart failure based on available echocardiographic data and could have misclassified some patients. They also said the study may be subject to referral bias toward more advanced heart failure, which was heart failure with reduced ejection fraction.

In addition, they may have underestimated hospitalization rates because they did not include hospitalizations outside of Emory Healthcare. Further, the study only took place at one center, so the findings may not be generalizable to other settings.