Spectrum of epidemiological and clinical findings in patients with heart failure with preserved ejection fraction stratified by study design: a systematic review

Background Heart failure with preserved ejection fraction (HFpEF) represents a major global and economic burden, but its epidemiological, clinical, and outcome data have varied according to study design. Methods and results We conducted a systematic review of published HFpEF clinical trials and observational studies (community-based studies and registries) from August 1998 to July 2013 using PubMed and EMBASE databases. Two independent investigators manually screened and extracted relevant data. We included 62 articles (19 describing clinical trials, 12 describing community-based observational studies, and 31 describing registries). The ejection fraction (EF) cut-off values ranged widely for HFpEF from >40% to >55%. However, differences in EF cut-offs were not clearly associated with incidence and prevalence data across studies. Of all patients with heart failure in community studies, 33-84% had HFpEF, which tended to be higher than reported in registries. The HFpEF patients in included studies were primarily older, white (>70%) patients with hypertension (50-90%) and coronary artery disease (up to 60%). All-cause mortality and all-cause hospitalizations ranged from 13% to 23% (26-50 months follow-up) and 55% to 67% (37-50 months follow-up), respectively, in clinical trials; cardiovascular causes accounted for 70% of both outcomes. All-cause mortality tended to be higher in registries than in clinical trials and community-based observational studies up to 5 years into follow-up. Conclusions Important differences in EF thresholds, epidemiological indices, clinical profiles, treatment patterns, and outcomes exist across contemporary HFpEF clinical trials, observational studies, and registries. Precision in definition and inclusion of more uniform populations may facilitate improved profiling of HFpEF patients.