Heart failure patients with mid-range ejection fraction: clinical features and prognosis

Aim. To analyze clinical and echocardiographic characteristics and prognosis in patients with heart failure mid-range ejection fraction.

Methods. The study included 76 patients with stable heart failure I–IV functional class, with a mean age of 66.1±10.4 years. All patients were divided into 3 subgroups based on the left ventricular ejection fraction: the first group — heart failure patients with reduced ejection fraction (below 40%), 21.1%; the second group — patients with mid-range ejection fraction (from 40 to 49%), 23.7%; the third group — patients with preserved ejection fraction (>50%), 55.3%. The clinical characteristics of all groups were compared. The quality of life was assessed by the Minnesota Satisfaction Questionnaire (MSQ), the clinical condition was determined by using the clinical condition assessment scale (Russian “Shocks”). The prognosis was studied according to the onset of cardiovascular events one year after enrollment in the study. The endpoints were cardiovascular mortality, myocardial infarction (MI), stroke, hospitalization for acutely decompensated heart failure, thrombotic complications. Statistical analysis was performed by using IBM SPSS Statistics 20 software. Normal distribution of the data was determined by the Shapiro–Wilk test, nominal indicators were compared between groups by using chi-square tests, normally distributed quantitative indicators — by ANOVA. The Kruskal–Wallis test was performed to comparing data with non-normal distribution.

Results. Analysis showed that the most of clinical characteristics (etiological structure, age, gender, quality of life, results on the clinical condition assessment scale for patients with chronic heart failure and a 6-minute walk test, distribution by functional classes of heart failure) in patients with mid-range ejection fraction (HFmrEF) were similar to those in patients with reduced ejection fraction (HFrEF). At the same time, they significantly differed from the characteristics of patients with preserved ejection fraction (HFpEF). Echocardiographic data from patients with mid-range ejection fraction ranks in the middle compared to patients with reduced and preserved ejection fraction. In heart failure patients with mid-range ejection fraction, the incidence of adverse outcomes during the 1st year also was intermediate between heart failure patients with preserved ejection fraction and patients with reduced ejection fraction: for all cardiovascular events in the absence of significant differences (17.6; 10.8 and 18.8%, respectively), myocardial infarction (5,9; 0 and 6.2%), thrombotic complications (5.9; 5.4 and 6.2%). Heart failure patients with mid-range ejection fraction in comparison to patients with preserved ejection fraction and reduced ejection fraction had significantly lower cardiovascular mortality (0; 2.7 and 12.5%, p >0.05) and the number of hospitalization for acutely decompensated heart failure (0; 2,7 and 6.2%).

Conclusion. Clinical characteristics of heart failure patients with mid-range and heart failure patients with reduced ejection fraction are similar but significantly different from those in the group of patients with preserved ejection fraction; echocardiographic data in heart failure patients with mid-range ejection fraction is intermediate between those in patients with reduced ejection fraction and patients with preserved ejection fraction; the prognosis for all cardiovascular events did not differ significantly in the groups depending on the left ventricular ejection fraction.