Programmed Ventricular Stimulation for Risk Stratification in Nonischemic Cardiomyopathy With Preserved or Mildly Reduced LVEF.

Background

A substantial proportion of sudden cardiac deaths occur in patients with nonischemic cardiomyopathy (NICM) and left ventricular ejection fraction (LVEF) ≥40% who do not meet current criteria for implantable cardioverter-defibrillator (ICD) implantation.

Objectives

This study sought to evaluate programmed ventricular stimulation (PVS) for arrhythmic risk stratification in patients with NICM, cardiac magnetic resonance-confirmed myocardial scar, and LVEF ≥40%.

Methods

Consecutive patients with NICM, LVEF ≥40%, late gadolinium enhancement on cardiac magnetic resonance, and frequent premature ventricular complexes (PVCs; >5%) or nonsustained ventricular tachycardia who underwent PVS at a tertiary center (2014-2025) were included. The primary outcome was a major arrhythmic event (MAE): sustained ventricular tachycardia/fibrillation, appropriate ICD therapy, or sudden cardiac death.

Results

Among 182 patients (median aged 62 years; 33% women), PVS was positive in 45 (25%). Over a median 3.5-year follow-up, MAE occurred in 13 of 45 PVS-positive (29%) vs 2 of 137 PVS-negative patients (1.5%; P < 0.001), yielding a negative predictive value of 98.5%. Additional MAE predictors included multifocal PVCs/nonsustained ventricular tachycardia (HR: 6.6; 95% CI: 1.8-24.4), family history of sudden cardiac death (HR: 16.7; 95% CI: 4.5-62.3), QRS ≥100 milliseconds (HR: 5.2; 95% CI: 1.4-19.2), and LVEF ≤50% (HR: 4.4; 95% CI: 1.4-13.4; all P < 0.05). A noninvasive risk score incorporating these 4 variables yielded an optimism-corrected C-statistic of 0.892 (95% CI: 0.805-0.957).

Conclusions

PVS represents a useful tool for risk stratification of arrhythmic events in patients with NICM, myocardial scar and preserved or mildly reduced LVEF, identifying those who may benefit from primary prevention ICD implant.