New echocardiographic predictors of clinical outcome in patients presenting with heart failure and a preserved left ventricular ejection fraction: a subanalysis of the Ka (Karolinska) Ren (Rennes) Study

Objectives To identify electrocardiographic and echocardiographic predictors of mortality and hospitalizations for heart failure (HF) in the KaRen study. Background KaRen is a prospective, observational study of the long-term outcomes of patients presenting with heart failure and a preserved ejection fraction (HFpEF). Method We identified 538 patients who presented with acute cardiac decompensation, a >100pg/mL serum b-type natriuretic peptide (BNP) or >300pg/mLN-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and a left ventricular ejection fraction (LVEF) >45%. After 4-8 weeks of standard treatment, 413 patients (mean age=76 +/- 9 years, 55.9% women) returned for analyses of their clinical status, laboratory screen, and detailed electrocardiographic and Doppler echocardiographic recordings. They were followed for a mean of 28 months thereafter. The primary study endpoint was time to death from all causes or first hospitalization for heart failure. Results Mean LVEF was 62.4 +/- 6.9% and median NT-proBNP 1410 pmol/L. PR interval >200ms was present in 11.2% of patients and 14.9% had a >120ms QRS duration, with left bundle branch block in only 6.3%. Over a mean follow-up of 28 months, 177 patients (42.9%) reached a primary study endpoint, including 61 deaths and 116 hospitalizations for heart failure. After adjustment for age, gender, New York Heart Association class, atrial fibrillation history, creatinine, sodium, BNP, ejection fraction, and right ventricular fractional shortening, only E/e remained as a predictor, with a hazard ratio=1.49 and P = 0.0012. Conclusion The incidence of hospitalizations for HF and deaths in KaRen was high and E/e' predicted adverse clinical outcomes. These observations should help in the risk stratification and therapy of HFpEF.