An Update on Device Therapy

1. An Update on Device Therapy Lai Chow Kok, MD, FACC

2. Introduction Pacemaker ICD CRT (Biventricular devices) New technologies

3. Long term effects of RV apical pacing Increased myocardial perfusion defect Structural changes Mechanical dyssynchrony Development of heart failure Atrial fibrillation

5. 177 pts randomized with followup of 1 year177 pts randomized with followup of 1 year

6. Patients with isolated congenital complete atrioventricular block (ICAVB) represent a unique patient group in which to investigate the effects of long-term RV pacing. They usually are younger, are without SHD, and are available for long-term follow-up. Although recent studies have reported pacing-induced ventricular remodeling and poor outcomes in patients with ICAVB, risk factors associated with the detrimental effect of pacing continue to be poorly defined.8,9Immune-mediated cardiomyopathy has been recognized in patients with a positive rheumatoid factor test result12?16 and in infants born to mothers with antinuclear antibodies (ANAs).12,17?20 Thus, we hypothesized that the presence of ANA in adult congenital ICAVB patients may be associated with worse outcomes after pacemaker implantation.In this observational study, we assessed the effect of prolonged RV pacing on the development of HF, ventricular function, and actuarial survival in ICAVB patients with (Ab+) and without (Ab?) ANA and compared these findings with those from an age- and sex-matched Minnesota population.17,18 Predictors for pacing-induced outcomes were also determined. 419 pts screened. 315 excluded. 103 pts. ANA positive in 18, 85 negative These results suggest that in young patients without structural heart disease, pacing from the RV position does not appear to have a detrimental effect on heart size or performance. Patients with isolated congenital complete atrioventricular block (ICAVB) represent a unique patient group in which to investigate the effects of long-term RV pacing. They usually are younger, are without SHD, and are available for long-term follow-up. Although recent studies have reported pacing-induced ventricular remodeling and poor outcomes in patients with ICAVB, risk factors associated with the detrimental effect of pacing continue to be poorly defined.8,9Immune-mediated cardiomyopathy has been recognized in patients with a positive rheumatoid factor test result12?16 and in infants born to mothers with antinuclear antibodies (ANAs).12,17?20 Thus, we hypothesized that the presence of ANA in adult congenital ICAVB patients may be associated with worse outcomes after pacemaker implantation.In this observational study, we assessed the effect of prolonged RV pacing on the development of HF, ventricular function, and actuarial survival in ICAVB patients with (Ab+) and without (Ab?) ANA and compared these findings with those from an age- and sex-matched Minnesota population.17,18 Predictors for pacing-induced outcomes were also determined. 419 pts screened. 315 excluded. 103 pts. ANA positive in 18, 85 negative These results suggest that in young patients without structural heart disease, pacing from the RV position does not appear to have a detrimental effect on heart size or performance.

9. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated superiority of shock-only, single-lead implantable cardioverter-defibrillator (ICD) therapy over placebo for reducing all-cause mortality in a primary prevention population with New York Heart Association (NYHA) class II or III ischemic or nonischemic heart failure (HF) and a left ventricular ejection fraction 35%.1,2 Amiodarone had no effect on total mortality compared with placebo. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated that implantable cardioverter-defibrillator therapy reduces all-cause mortality in patients with New York Heart Association class II/III heart failure and a left ventricular ejection fraction 35% on optimal medical therapy. A total of 2521 subjects were randomized to placebo, amiodarone, or shock-only, single-lead implantable cardioverter-defibrillator therapy. Over a median follow-up of 45.5 months, 6 SCD-HeFT was unique among primary prevention trials of ICD therapy for including a placebo-controlled antiarrhythmic drug therapy arm. At the time of trial design, 2 studies had suggested conflicting results relative to the potential benefit of amiodarone as a primary prevention strategy to reduce sudden cardiac death in HF patients, the Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure (CHF-STAT)23 and Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA).24 SCD-HeFT clearly resolved this question when amiodarone was shown to have no benefit on reducing all-cause mortality. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated superiority of shock-only, single-lead implantable cardioverter-defibrillator (ICD) therapy over placebo for reducing all-cause mortality in a primary prevention population with New York Heart Association (NYHA) class II or III ischemic or nonischemic heart failure (HF) and a left ventricular ejection fraction 35%.1,2 Amiodarone had no effect on total mortality compared with placebo. The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated that implantable cardioverter-defibrillator therapy reduces all-cause mortality in patients with New York Heart Association class II/III heart failure and a left ventricular ejection fraction 35% on optimal medical therapy. A total of 2521 subjects were randomized to placebo, amiodarone, or shock-only, single-lead implantable cardioverter-defibrillator therapy. Over a median follow-up of 45.5 months, 6 SCD-HeFT was unique among primary prevention trials of ICD therapy for including a placebo-controlled antiarrhythmic drug therapy arm. At the time of trial design, 2 studies had suggested conflicting results relative to the potential benefit of amiodarone as a primary prevention strategy to reduce sudden cardiac death in HF patients, the Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure (CHF-STAT)23 and Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (GESICA).24 SCD-HeFT clearly resolved this question when amiodarone was shown to have no benefit on reducing all-cause mortality.

11. COMPANIONPrimary endpoint: Death, any hosp., iv Rx > 4 hrs The primary endpoint of the study was time to death or hospitalization. Hospitalization was defined as all cause except for elective admission for CRT/CRT-D implantation and also include treatment for decompensated CHF with vasoactive drugs for a period > 4 hours in urgent care setting. As shown here, CRT/ CRT-D showed significant reduction in primary endpoint compared to OPT after 1 year followup.The primary endpoint of the study was time to death or hospitalization. Hospitalization was defined as all cause except for elective admission for CRT/CRT-D implantation and also include treatment for decompensated CHF with vasoactive drugs for a period > 4 hours in urgent care setting. As shown here, CRT/ CRT-D showed significant reduction in primary endpoint compared to OPT after 1 year followup.

12. COMPANIONSecondary endpoint: All-Cause Mortality

13. MADIT-CRTPrimary endpoint: Survival from CHF

17. One of the limitations of CRT is the rate of nonresponder; about 1/3 pts total of 115 consecutive patients undergoing CRT for standard clinical indications at a single center were followed prospectively. Retrospectively analysisOne of the limitations of CRT is the rate of nonresponder; about 1/3 pts total of 115 consecutive patients undergoing CRT for standard clinical indications at a single center were followed prospectively. Retrospectively analysis

21. Detection of paroxysmal atrial fibrillation (AF) can be difficult. Asymptomatic episodes are recognized to occur, even in patients who also have symptomatic AF. Intermittent ambulatory monitoring has significant limitations. The XPECT study assessed the ability of a leadless implantable cardiac monitor (ICM) with a dedicated AF detection algorithm to detect AF during continuous long-term monitoring. The device is implanted subcutaneously and has longevity of up to 3 years. In 247 patients with a high risk of AF, 46-hour ECG recordings were compared with AF detection capabilities of the ICM. The ICM algorithm identified AF episodes exceeding 2 minutes in duration with a high degree of sensitivity. False-positive AF detections caused by frequent atrial extrasystoles or oversensing of myopotentials were observed in some patients. The ICM may be a useful tool for AF detection and quantification of AF. Further studies are warranted to assess potential clinical utility.Detection of paroxysmal atrial fibrillation (AF) can be difficult. Asymptomatic episodes are recognized to occur, even in patients who also have symptomatic AF. Intermittent ambulatory monitoring has significant limitations. The XPECT study assessed the ability of a leadless implantable cardiac monitor (ICM) with a dedicated AF detection algorithm to detect AF during continuous long-term monitoring. The device is implanted subcutaneously and has longevity of up to 3 years. In 247 patients with a high risk of AF, 46-hour ECG recordings were compared with AF detection capabilities of the ICM. The ICM algorithm identified AF episodes exceeding 2 minutes in duration with a high degree of sensitivity. False-positive AF detections caused by frequent atrial extrasystoles or oversensing of myopotentials were observed in some patients. The ICM may be a useful tool for AF detection and quantification of AF. Further studies are warranted to assess potential clinical utility.