Predictors and Outcomes of Cardiac Resynchronization Therapy Extended to the Second Generator

5 years ago

Predictors and Outcomes of Cardiac Resynchronization Therapy Extended to the Second Generator

A proportion of patients who receive cardiac resynchronization therapy (CRT) with defibrillator (CRT-D) live to receive a second generator. Controversy exists on whether an implantable cardioverter-defibrillator (ICD) should be offered to patients who have normalized or near normalized left ventricular ejection fraction (LVEF) at the time of generator replacement (GR).

Objective

To evaluate incidence of appropriate ICD therapy after CRT-D GR.

Methods

This series involved 1,026 consecutive patients who underwent CRT-D implant between January 2002 and December 2012. Echocardiography was assessed before the initial device implant and before GR. ICDs were monitored at our device clinic in person or remotely, or both.

Results

Of the cohort, 227 patients (22.1%) underwent CRT-D GR at our institution. Approximately 48% of patients who received new CRT-D generators were no longer meeting the guidelines indication for ICD use at GR. These patients received subsequent appropriate ICD therapies at a significantly lower rate than those with LVEF <35% (12% vs 35%, P<.001). Of these patients, 47 (20.7%) had LVEF improve to ≥50% at GR. ICD therapy for ventricular arrhythmia in the ischemic group was 18.2%, while no patient in the nonischemic group received ICD therapy from the second generator after GR.

Conclusion

Improvement in LVEF after CRT-D is associated with significantly reduced incidence of appropriate ICD therapy. Ventricular arrhythmia is less likely to develop with normalized LVEF in nonischemic cardiomyopathy.

Publisher URL: www.sciencedirect.com/science

DOI: S1547527117310810