Abstract
AIMS: Left ventricular ejection fraction (LVEF) is considered an indicator of cardiac resynchronization therapy (CRT). Longitudinal studies on the predictive value of LVEF are scarce. We aimed to comprehensively evaluate the prognostic role of LVEF in the outcomes of Chinese patients with CRT. METHODS AND RESULTS: Three hundred ninety-two patients were divided into three tertiles of LVEF: ≤25%, 25-30%, and 30-35%, and four groups by LVEF changes: <0% (negative response); ≥0% and ≤5% (non-response); >5% and ≤15% (response); and >15% (super-response). One hundred six patients were super-responders. During a median follow-up of 3.6 years, 141 reached the composite endpoint. Odds ratios (ORs) for super-response depicted a reversed U-shaped relationship for baseline LVEF with a peak at 25-30%. Independent predictors of super-response were smaller left atrial diameter [odds ratio 0.897, 95% confidence interval (CI) 0.844-0.955, P = 0.001], smaller left ventricular end-diastolic diameter (OR 0.937, 95% CI 0.889-0.989, P = 0.018), and higher estimated glomerular filtration rate (OR 1.018, 95% CI 1.001-1.035, P = 0.042) in Tertile 1; atrial fibrillation (OR 0.278, 95% CI 0.086-0.901, P = 0.033), left bundle branch block (OR 4.096, 95% CI 1.046-16.037, P = 0.043), and left ventricular end-diastolic diameter (OR 0.929, 95% CI 0.876-0.986, P = 0.016) in Tertile 2; while female sex (OR 2.778, 95% CI 1.082-7.132, P = 0.034) and higher systolic blood pressure (OR 1.045, 95% CI 1.013-1.079, P = 0.006) in Tertile 3. An inverse association with the composite endpoint was found in Tertile 1 vs. Tertile 2 (hazard ratio 1.934, 95% CI 1.248-2.996, P = 0.003). The prognostic effects of CRT response in Tertile 3 and Tertile 1 varied significantly (P for trend = 0.017 and <0.001). Among three tertiles in super-responders, event-free survival was similar (P for trend = 0.143). CONCLUSIONS: Left ventricular ejection fraction of 25-30% is associated with a better prognosis of super-response. Predictors of super-response are different for LVEF tertiles. CRT responses would have better prognostic performance than LVEF tertiles at baseline, which should be considered when clinicians screening eligible patients for CRT.