Abstract
BACKGROUND: Heart failure and left ventricular ejection fraction in the normal range (HFnEF) (left ventricular ejection fraction [LVEF] of ≥55% for men and ≥60% for women) is understudied. OBJECTIVES: The authors aimed to characterize patients with HFnEF compared with those with preserved (≥50%) yet below the normal LVEF. METHODS: In an Asian HF registry, clinical characteristics, echocardiographic features, and outcomes were compared across: 1) HFnEF; 2) heart failure with preserved left ventricular ejection fraction (HFpEF) (LVEF of ≥50%) and below normal LVEF; and 3) community-based controls without HF. Cluster analysis of echocardiographic parameters was performed and validated in an external cohort. RESULTS: Among 1,765 patients with HFpEF (age 68 ± 12 years; 50% women), 1,313 (74.4%) had HFnEF. Compared with patients with HFpEF and below normal LVEF, patients with HFnEF had less coronary artery disease (33.7% vs 27.9%), greater LV wall thickness, and higher stroke volume, but similar 2-year age-adjusted all-cause mortality (HR: 0.8; 95% CI: 0.6-1.2). Five echocardiographic clusters with similar 2-year mortality were identified: 1) normal LV (normal structure despite increased filling pressure; least comorbidities) in 25%; 2) restrictive (smallest stroke volume; predominantly elderly women) in 26%; 3) hypertrophic (most concentric hypertrophy; more men) in 25%; 4) high output (greatest stroke volume; predominantly obese younger men) in 10%; and 5) atrial dominant (most left atrial myopathy; mainly elderly women with multiple comorbidities) in 10%. Similar patterns were found in the validation cohort. CONCLUSIONS: The majority of patients with HFpEF had normal LVEF, which consists of patients with different patterns of cardiac features and clinical characteristics. Results may carry implications for targeted treatment approaches in HFpEF.