Long-Term Nonprogression Is a Form of Response to Cardiac Resynchronization Therapy.

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in selected heart failure patients. A distinct subpopulation (so-called "nonprogressors") of patients shows neither amelioration nor worsening of echocardiographic parameters after CRT implantation.

OBJECTIVES

The authors sought to investigate the long-term outcomes and prognosis of a distinct subpopulation of heart failure patients termed "nonprogressors," after CRT implantation.

METHODS

Retrospective single-center cohort analysis of 391 patients after CRT implantation. Based on echocardiography, patients were categorized into "super-responders" (Δ left ventricular ejection fraction [LVEF] >15% compared to baseline), "responders" (ΔLVEF >5% compared to baseline), "nonprogressors" (ΔLVEF ±5% compared to baseline), and "progressors" (ΔLVEF <-5% compared to baseline). The primary composite outcome was all-cause death, implantation of a ventricular assist device, or heart transplantation. Statistics included univariable and multivariable Cox proportional hazard regression analysis and Kaplan-Meier survival curves to explore outcome data.

RESULTS

Three hundred ninety-one patients (23% female, mean age 65 years, mean baseline LVEF 27%) were included. Postimplantation echocardiograms were performed after a mean of 37 months after CRT implantation. A total of 134 patients (34%) were nonprogressors. After a mean follow-up of another 57 months, progressors were significantly more likely to reach the composite endpoint of death, ventricular assist device implantation, or heart transplantation compared to nonprogressors (adjusted HR: 2.26 [95% CI: 1.35-3.78]; P = 0.002). Patients with positive echocardiographic response and super-response fared significantly better compared to nonprogressors.

CONCLUSIONS

Nonprogressors form a relevant, to date poorly characterized group of CRT patients, whose long-term survival is significantly better compared to progressors or negative responders.