Prognostic estimation of advanced heart failure with low left ventricular ejection fraction and wide QRS interval

Abstract

Background: Cardiac resynchronization therapy (CRT) has been known to improve the outcome of advanced heart failure (HF) but is still underutilized in clinical practice. We investigated the prognosis of patients with advanced HF who were suitable for CRT but were treated with conventional strategy. And we developed a risk model to predict mortality to improve the facilitation of CRT. Method and Results: Patients with symptomatic HF with LVEF ≤35% and QRS interval >120ms were consecutively enrolled at Severance Cardiovascular Hospital. After those patients who had received device therapy were excluded, 239 patients (160 males, mean 67 ± 11 years) were eventually recruited.During a follow-up of 308 ± 236 days, 56 (23%) patients died. Prior stroke, heart rate >90bpm, and serum Na ≤135mEq/L and serum creatinine ≥1.5mg/dL were identified as independent factors using Cox proportional hazards regression. Based on the risk model, assigned points to each of the risk factors proportional to the regression coefficient, patients were stratified into three risk groups: low- (0), intermediate- (1~5), and high-risk (>5 points). The 2-year mortality rates of each risk group were 5, 31, and 64 percent, respectively. The C statistic of the risk model was 0.78. The model was validated in a cohort from a different institution: C statistic 0.80. Conclusion: The mortality of patients with advanced HF who were managed conventionally was effectively stratified using a risk model. It might be useful for clinicians to be more proactive about adopting CRT to improve patients’ prognosis.