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NORMALIZATION OF LEFT VENTRICULAR EJECTION FRACTION FOLLOWING CARDIAC RESYNCHRONIZATION THERAPY IS ASSOCIATED WITH A REDUCTION IN APPROPRIATE ICD THERAPY
A290 JACC March 17, 2015 Volume 65, Issue 10S
Arrhythmias and Clinical EP Normalization of Left Ventricular Ejection Fraction Following Cardiac Resynchronization Therapy Is Associated with a Reduction in Appropriate ICD Therapy Oral Contributions Room 1B Sunday, March 15, 2015, 9:17 a.m.-9:28 a.m. Session Title: Highlighted Original Research: Arrhythmias/Clinical EP and the Year In Review Abstract Category: 6. Arrhythmias and Clinical EP: Devices Presentation Number: 900-14 Authors: Ammar M. Killu, Avishay Grupper, Anya Mazo, Tracy Webster, Kelly Brooke, Paul Friedman, David Hodge, Samuel Asirvatham, Michael Glikson, Yong-Mei Cha, Mayo Clinic, Rochester, MN, USA, Sheba Medical Center, Tel Aviv, Israel
Background: Cardiac resynchronization therapy (CRT) improves survival, yet the effect of normalized left ventricular ejection fraction (EF) on ICD therapy burden is unknown. We hypothesized that normalized EF reduces ventricular tachycardia/fibrillation (VT/VF) and, therefore minimizes appropriate ICD therapy.
Methods: We assessed 556 patients who received CRT-D for primary prevention between 2002-2012 at Mayo Clinic, Rochester and Sheba Medical Center, Israel. Patients were categorized as super-responders (SR, post CRT-D EF ≥50%) and non-super-responders (nonSR, post CRT-D EF <50%). The event rate of appropriate ICD therapy for VT/VF (antitachycardia pacing & shock therapy) was collected; electrograms were reviewed and adjudicated. The event rate was analyzed using Kaplan-Meier estimate and compared between groups.
Results: Of 556 patients, 54 (9.7%) were SR. At baseline, SR were more likely to be female (39 vs 20%, P<.001) and have non-ischemic etiology (69 vs 42%, P<.001) compared to non-SR. Baseline EF was 25.0 vs 23.7% (P=.23) which improved by 32 vs 5% (P<.05) in the SR and non-SR groups following CRT-D, respectively. SR had greater improvement in NYHA class (-0.84 vs -0.52) and LV end-systolic dimension (-19.9 vs -3.3mm) than non-SR (P<.05 for all). Compared to non-SR, SR were less likely to receive appropriate ICD therapy (5 vs 26% at 5 years [P=.005]).
Conclusion: Normalization of EF after CRT reduces VT/VF events that require ICD therapy, although arrhythmic events continue to occur.
Arrhythmias and Clinical EP Normalization of Left Ventricular Ejection Fraction Following Cardiac Resynchronization Therapy Is Associated with a Reduction in Appropriate ICD Therapy Oral Contributions Room 1B Sunday, March 15, 2015, 9:17 a.m.-9:28 a.m. Session Title: Highlighted Original Research: Arrhythmias/Clinical EP and the Year In Review Abstract Category: 6. Arrhythmias and Clinical EP: Devices Presentation Number: 900-14 Authors: Ammar M. Killu, Avishay Grupper, Anya Mazo, Tracy Webster, Kelly Brooke, Paul Friedman, David Hodge, Samuel Asirvatham, Michael Glikson, Yong-Mei Cha, Mayo Clinic, Rochester, MN, USA, Sheba Medical Center, Tel Aviv, Israel
Background: Cardiac resynchronization therapy (CRT) improves survival, yet the effect of normalized left ventricular ejection fraction (EF) on ICD therapy burden is unknown. We hypothesized that normalized EF reduces ventricular tachycardia/fibrillation (VT/VF) and, therefore minimizes appropriate ICD therapy.
Methods: We assessed 556 patients who received CRT-D for primary prevention between 2002-2012 at Mayo Clinic, Rochester and Sheba Medical Center, Israel. Patients were categorized as super-responders (SR, post CRT-D EF ≥50%) and non-super-responders (nonSR, post CRT-D EF <50%). The event rate of appropriate ICD therapy for VT/VF (antitachycardia pacing & shock therapy) was collected; electrograms were reviewed and adjudicated. The event rate was analyzed using Kaplan-Meier estimate and compared between groups.
Results: Of 556 patients, 54 (9.7%) were SR. At baseline, SR were more likely to be female (39 vs 20%, P<.001) and have non-ischemic etiology (69 vs 42%, P<.001) compared to non-SR. Baseline EF was 25.0 vs 23.7% (P=.23) which improved by 32 vs 5% (P<.05) in the SR and non-SR groups following CRT-D, respectively. SR had greater improvement in NYHA class (-0.84 vs -0.52) and LV end-systolic dimension (-19.9 vs -3.3mm) than non-SR (P<.05 for all). Compared to non-SR, SR were less likely to receive appropriate ICD therapy (5 vs 26% at 5 years [P=.005]).
Conclusion: Normalization of EF after CRT reduces VT/VF events that require ICD therapy, although arrhythmic events continue to occur.