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His-Bundle Pacing: A Novel Treatment for Left Bundle Branch Block Cardiomyopathy
The 23rd Annual Scientific Meeting HFSA effective method of rhythm control and resulted in fewer strokes than medical management alone. Outcomes Outcome
Primary Outcome AF at 1 year (%) Secondary Outcome Stroke at 1 year (%) Stroke at 2 year or more (%) All cause mortality at 1 year (%) All cause mortality at 2 year or more (%) Hospitalizations at 1 year
Ablation n=85
Medical Therapy n=95
Relative Risk (95% CI)
P Value
16(20.2)
63(70.7)
0.29(0.18, 0.45)
<0.001
2(2.3) 5(5.8) 3(3.5)
9(9.5) 25(26.3) 2(2.1)
0.37(0.10, 1.33) 0.22(0.09, 0.56) 1.68(0.29, 9.79)
0.11 <0.001 0.56
5(5.8)
9(9.5)
0.62(0.22, 1.78)
0.37
51
52
1.10(0.85, 1.41)
0.48
226 His-Bundle Pacing: A Novel Treatment for Left Bundle Branch Block Cardiomyopathy Rajeev Singh, Subodh Devabhaktuni, Fatima Ezzeddine, Joel W. Simon, Kavita Khaira, Gopi Dandamudi; Indiana University School of Medicine, Indianapolis, IN Background: LBBB Cardiomyopathy is a reversible cardiomyopathy resulting from chronic left ventricular dysynchrony from left bundle branch block (LBBB). His-bundle pacing (HBP), as opposed to pure mechanical correction, alters the underlying substrate for dysynchrony, providing a physiologic instead of mechanical treatment of LBBB. Objective: To assess the feasibility of HBP for cardiac resynchronization therapy (CRT) in LBBB Cardiomyopathy patients Methods: Retrospective chart review was conducted on patients who underwent cardiac resynchronization therapy at Indiana University Health and Ezkenazi Hospital between August 1, 2015 to August 30, 2017. A subset of patients who met the pre-defined syndrome criteria of LBBB cardiomyopathy: 1) History of pre-existing LBBB of at least 6 months or greater 2) LVEF of > 50% at the time of diagnosis of LBBB 3) Progressive decrease in LVEF to 40% with development of NYHA functional class II to IV symptoms 4) No other identifiable cause of cardiomyopathy who underwent HBP were
Figure 1. Echocardiographic Parameters and QRS duration of Patients Undergoing HBP-CRT.
S85
identified. Clinical, echocardiographic, and electrophysiologic variables were extracted at baseline and follow-up. Comparison of the means at baseline and follow up was performed using 2-tailed t testing. A p value <0.05 was considered significant. Results: From August 2015 to August 2017, 73 patients underwent CRT. 9 patients (12%) met criteria for LBBB Cardiomyopathy with 7 of those patients (78%) successfully undergoing HBP-CRT. Average time from device implantation to last follow-up was 14.5 months. Mean LVEF improved from 25 § 6% to 50 § 4% (p<0.0001). Mean left ventricular end systolic dimension (LVESD) decreased from 48 § 5 mm to 37 § 2 mm (p=0.0008) and mean left ventricular end diastolic dimension (LVEDD) decreased from 55 § 5 mm to 48 § 6 mm (p=0.04). Mean QRS duration decreased from 152 § 13 ms to 115 § 19 ms (p=0.001). New York Heart Association (NYHA) classification improved from an average of 2.7 § 0.5 to 2 § 0 (p=0.002). There were no device infections, procedural complications, heart failure hospitalizations, or deaths in patients who underwent HBP-CRT. Conclusions: Improvement of left ventricular function with HBP indicates that LBBB-induced cardiomyopathy is reversible and can be treated with physiological pacing. His-bundle pacing is a viable technique for pursuing cardiac resynchronization therapy in patients with LBBB Cardiomyopathy.
227 The Effect of Frailty on Mortality and Defibrillator Implantation in Older Recipients of Cardiac Resynchronization Therapy Roy Sriwattanakomen, Shahzad Ahmad, Don Mathew, Meghana Amit, Amit Hemadri, Daniel E. Forman, Samir F. Saba; University of Pittsburgh Medical Center, Pittsburgh, PA Background: Cardiac resynchronization therapy guidelines do not distinguish between defibrillators (CRT-D) and pacemakers (CRT-P). Drivers of CRT device choice remain uncertain but may be influenced by comorbidities and frailty, particularly in older recipients. Purpose: We sought to evaluate the effect of frailty, measured as deficit accumulation, on mortality and CRT device choice in older (age75 yrs) heart failure patients. Methods: In 502 consecutive older CRT recipients with EF35% implanted between 2002 and 2014 (age 81§4 yrs; 71% men; 19% CRT-P), we retrospectively collected 36 dichotomous variables each reflecting the presence or absence of a deficit and summed these to create a frailty score which has been previously validated in the primary care setting as a predictor of mortality. We divided the score into quartiles of fit, mild, moderate, and severe frailty and tested its association with survival from time of device implant (Cox regression) and type of CRT device implanted (chisquare). Results: Over a median follow up of 4.7 yrs, 414 (82%) patients died. Frailty quartile predicted mortality in unadjusted analysis (Figure) and similarly after adjustment for device type, ejection fraction, and age at time of device implant. The 1-, 3-, and 7-year cumulative survival between fit and severely frail recipients were 98% vs. 71% (p=0.02), 86% vs. 51% (p<0.001), and 53% vs. 16% (p<0.001) respectively. While 89% of fit patients received CRT-D, 85% of mildly, 79% of moderately, and 70% of severely frail patients received the device (chi-square=16.1, p=0.001). Despite the decreased frequency of CRT-D in frailer patients, there was no difference in survival by device type (unadjusted hazard ratio=0.81 (95% CI: 0.63-1.05); adjusted hazard ratio=0.88 (0.68-1.15)). Conclusion: A frailty score predicts mortality in older CRT recipients and tracks physician tendency towards CRT-P implantation among the frail relative to the fit. Yet, even among the severely frail, CRT-D remained the norm in our sample despite its lack of known benefit on survival compared to CRT-P. As a result, type of device implanted did not predict survival, indicating that physician intuition may be limited regarding frailty assessment and patient outcome. Use of a frailty score may assist in CRT device choice by helping physicians identify patient frailty extent and providing individualized risk assessment.
Primary Outcome AF at 1 year (%) Secondary Outcome Stroke at 1 year (%) Stroke at 2 year or more (%) All cause mortality at 1 year (%) All cause mortality at 2 year or more (%) Hospitalizations at 1 year
Ablation n=85
Medical Therapy n=95
Relative Risk (95% CI)
P Value
16(20.2)
63(70.7)
0.29(0.18, 0.45)
<0.001
2(2.3) 5(5.8) 3(3.5)
9(9.5) 25(26.3) 2(2.1)
0.37(0.10, 1.33) 0.22(0.09, 0.56) 1.68(0.29, 9.79)
0.11 <0.001 0.56
5(5.8)
9(9.5)
0.62(0.22, 1.78)
0.37
51
52
1.10(0.85, 1.41)
0.48
226 His-Bundle Pacing: A Novel Treatment for Left Bundle Branch Block Cardiomyopathy Rajeev Singh, Subodh Devabhaktuni, Fatima Ezzeddine, Joel W. Simon, Kavita Khaira, Gopi Dandamudi; Indiana University School of Medicine, Indianapolis, IN Background: LBBB Cardiomyopathy is a reversible cardiomyopathy resulting from chronic left ventricular dysynchrony from left bundle branch block (LBBB). His-bundle pacing (HBP), as opposed to pure mechanical correction, alters the underlying substrate for dysynchrony, providing a physiologic instead of mechanical treatment of LBBB. Objective: To assess the feasibility of HBP for cardiac resynchronization therapy (CRT) in LBBB Cardiomyopathy patients Methods: Retrospective chart review was conducted on patients who underwent cardiac resynchronization therapy at Indiana University Health and Ezkenazi Hospital between August 1, 2015 to August 30, 2017. A subset of patients who met the pre-defined syndrome criteria of LBBB cardiomyopathy: 1) History of pre-existing LBBB of at least 6 months or greater 2) LVEF of > 50% at the time of diagnosis of LBBB 3) Progressive decrease in LVEF to 40% with development of NYHA functional class II to IV symptoms 4) No other identifiable cause of cardiomyopathy who underwent HBP were
Figure 1. Echocardiographic Parameters and QRS duration of Patients Undergoing HBP-CRT.
S85
identified. Clinical, echocardiographic, and electrophysiologic variables were extracted at baseline and follow-up. Comparison of the means at baseline and follow up was performed using 2-tailed t testing. A p value <0.05 was considered significant. Results: From August 2015 to August 2017, 73 patients underwent CRT. 9 patients (12%) met criteria for LBBB Cardiomyopathy with 7 of those patients (78%) successfully undergoing HBP-CRT. Average time from device implantation to last follow-up was 14.5 months. Mean LVEF improved from 25 § 6% to 50 § 4% (p<0.0001). Mean left ventricular end systolic dimension (LVESD) decreased from 48 § 5 mm to 37 § 2 mm (p=0.0008) and mean left ventricular end diastolic dimension (LVEDD) decreased from 55 § 5 mm to 48 § 6 mm (p=0.04). Mean QRS duration decreased from 152 § 13 ms to 115 § 19 ms (p=0.001). New York Heart Association (NYHA) classification improved from an average of 2.7 § 0.5 to 2 § 0 (p=0.002). There were no device infections, procedural complications, heart failure hospitalizations, or deaths in patients who underwent HBP-CRT. Conclusions: Improvement of left ventricular function with HBP indicates that LBBB-induced cardiomyopathy is reversible and can be treated with physiological pacing. His-bundle pacing is a viable technique for pursuing cardiac resynchronization therapy in patients with LBBB Cardiomyopathy.
227 The Effect of Frailty on Mortality and Defibrillator Implantation in Older Recipients of Cardiac Resynchronization Therapy Roy Sriwattanakomen, Shahzad Ahmad, Don Mathew, Meghana Amit, Amit Hemadri, Daniel E. Forman, Samir F. Saba; University of Pittsburgh Medical Center, Pittsburgh, PA Background: Cardiac resynchronization therapy guidelines do not distinguish between defibrillators (CRT-D) and pacemakers (CRT-P). Drivers of CRT device choice remain uncertain but may be influenced by comorbidities and frailty, particularly in older recipients. Purpose: We sought to evaluate the effect of frailty, measured as deficit accumulation, on mortality and CRT device choice in older (age75 yrs) heart failure patients. Methods: In 502 consecutive older CRT recipients with EF35% implanted between 2002 and 2014 (age 81§4 yrs; 71% men; 19% CRT-P), we retrospectively collected 36 dichotomous variables each reflecting the presence or absence of a deficit and summed these to create a frailty score which has been previously validated in the primary care setting as a predictor of mortality. We divided the score into quartiles of fit, mild, moderate, and severe frailty and tested its association with survival from time of device implant (Cox regression) and type of CRT device implanted (chisquare). Results: Over a median follow up of 4.7 yrs, 414 (82%) patients died. Frailty quartile predicted mortality in unadjusted analysis (Figure) and similarly after adjustment for device type, ejection fraction, and age at time of device implant. The 1-, 3-, and 7-year cumulative survival between fit and severely frail recipients were 98% vs. 71% (p=0.02), 86% vs. 51% (p<0.001), and 53% vs. 16% (p<0.001) respectively. While 89% of fit patients received CRT-D, 85% of mildly, 79% of moderately, and 70% of severely frail patients received the device (chi-square=16.1, p=0.001). Despite the decreased frequency of CRT-D in frailer patients, there was no difference in survival by device type (unadjusted hazard ratio=0.81 (95% CI: 0.63-1.05); adjusted hazard ratio=0.88 (0.68-1.15)). Conclusion: A frailty score predicts mortality in older CRT recipients and tracks physician tendency towards CRT-P implantation among the frail relative to the fit. Yet, even among the severely frail, CRT-D remained the norm in our sample despite its lack of known benefit on survival compared to CRT-P. As a result, type of device implanted did not predict survival, indicating that physician intuition may be limited regarding frailty assessment and patient outcome. Use of a frailty score may assist in CRT device choice by helping physicians identify patient frailty extent and providing individualized risk assessment.