Prognostic Value of QRS Duration in Patients with Dilated Cardiomyopathy According to Left Ventricular Ejection Fraction.

BACKGROUND

The prognostic significance of QRS duration (QRSd) in patients with dilated cardiomyopathy (DCM) and a left ventricular ejection fraction (LVEF) between 30% and 50% is unclear, resulting in questions regarding eligibility for cardiac resynchronisation therapy. This study aimed to explore the prognostic role of QRSd in patients with DCM and a LVEF 30-50% or LVEF < 30.

METHODS

Patients hospitalised at Fuwai hospital with DCM who had a LVEF ≤ 50% were prospectively included. The primary outcomes were a composite of death, heart transplantation, and rehospitalisation for worsening heart failure.

RESULTS

Among the 633 patients included, 302 (47.7%) had a LVEF of 30-50%. The multivariable hazard ratio (HR) for QRSd ≥ 120 ms was 1.65 (95% confidence interval [CI] 1.29-2.11, p < 0.001) for overall DCM patients, 2.8 (95% CI 1.82-4.30, p < 0.001) for patients with LVEF 30-50%, and 1.41 (95% CI 1.02-1.94, p = 0.036) for patients with LVEF < 30%. QRSd ≥ 120 ms tended to be more strongly associated with outcome in patients with LVEF 30-50% than in those with LVEF < 30% despite the non-significant interaction (p = 0.067). DCM patients with QRSd ≥ 120 ms and LVEF 30-50% did not experience a significantly better outcome than those with LVEF < 30% and QRSd < 120 ms after propensity-score matching (HR 0.91, 95% CI 0.61-1.36, p = 0.645).

CONCLUSIONS

QRSd independently predicts prognosis in DCM patients irrespective of LVEF and identifies a group of high-risk patients who may benefit from device implantation despite the absence of severely reduced LVEF.