The Choice of ICD Therapy with Secondary Prevention: Single-chamber ICD or Dual-chamber ICD?

1. The Choice of ICD Therapy with Secondary Prevention:Single-chamber ICD or Dual-chamber ICD? Xing-Peng Liu, MD. Heart Center, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China

2. Q 1/4: Does DC-ICD really reduce inappropriate shocks? JACC 2004; 44: 2362

3. Study design • 60 patients who had a standard indication for ICD implantation for the second prevention were included • 29 had single-chamber and 31 had dual-chamber settings • Primary endpoint: the deliverance of inappropriate therapy for atrial arrhythmias • Secondary endpoint: appropriate and inappropriate arrhythmia classification JACC 2004; 44: 2362

4. Results • During a mean F/U of 12 months, 653 tachyarrhythmia episodes with stored EGM occurred in 39 patients • All ventricular tachyarrhythmias were appropriately detected in both groups. The sensitivity for ventricular tachyarrhythmias in both groups was 100% • Inappropriate detection was observed in 109 atrial tachyarrhythmia episodes (18 patients) • The number of misclassified episodes was NOT significantly different between the two groups (51 in the SC-ICD group vs. 58 in the DC-ICD group) JACC 2004; 44: 2362

6. JACC 2004; 44: 2362

8. Study design and results • 92 ICD patients ( SC-ICD: 45 pts DC-ICD: 47 pts) • Indication for ICD placement: VT/VF, aborted SCD and syncope • F/U:7.5 months • In the DC-ICD group, 38 (75%) of 51 episodes of inappropriate therapies were related to atrial sensing problems JCE 2001; 12: 134-42

9. Conclusions • DC-ICD and SC-ICD are equally safe and secure during implantation and follow-up • Both are equally effective for therapy of life-threatening ventricular tachyarrhythmias • DC-ICD did NOT offer benefits in avoiding inadequate detections and inappropriate therapies of supraventricular tachyarrhythmias

10. Different Voices…

11. Inappropriate detection rate Circulation 2006; 113: 2876

12. The rate of inappropriate SHOCKS was similar between the 2 groups! Circulation 2006; 113: 2876

13. 1544 ICD patients, NO significant differences were observed in the incidence of inappropriate shocks when comparing SC-ICD, DC-ICD and bi-V ICDs JACC 2011; 57: 556-62

14. Minimizing inappropriate shocks: SC-ICD can do more! • Cutoff rates and detection zones • Detection time/beats • SVT discriminators • Minimizing oversensing • Greater use of antitachycardia pacing (ATP) • …….

15. Arrhythmia detection in SC- and DC-ICDs: the more leads, the better? • Evidence for DC-ICDs as first line approach for prevention of inappropriate shocks is NOT compelling at present • DC-ICDs are preferred only when bradycardia support is required

16. Q 2/4: Is backup pacing helpful in ICD patients without an indication for antibradycardia pacing

17. DAVID trial: study design • Multi-center, randomized, single-blind, parallel 2-group design • Enrolled ICD indicated patients • no indication for antibradycardia pacing • LVEF 40% • No persistent or frequent, uncontrolled AF • Median: 8.4 months(Range: 0-23.6 months) JAMA, 2002, 288: 3115

18. Flow of Patients Evaluated in the DAVID Trial

19. DAVID trial: results JAMA, 2002, 288: 3115

20. DAVID trial: Main Endpoints JAMA, 2002, 288: 3115

21. Q 3/4: Does DC-ICD increase the complications significantly? Theoretically,… SC-ICDs hava less complications Dc-ICDs have a higher incidence of device-related complications --Implant duration /risk --Electrode dislodgement --More infections ……

22. DC-ICD increase complication and mortality! • National Cardiovascular Data Registry (NCDR) JACC 2011; 58: 1007-13

23. Selection of Study Participants From the NCDR ICD Registry

24. Single- versus dual-chamber ICD Implantation Complication Rates

25. NCDR registry: conclusions • Dual-chamber ICD implantation is common, and nearly 60% of these devices are used in patients without a pacing indication • Despite their unclear clinical benefit, dual-chamber ICDs are associated with increased odds of complications and in-hospital mortality after implantation compared with single-chamber devices

26. Q 4/4: How about the budget considerations of DC- or SC-ICDs? Cost of the ICDs in Beijing

27. We must take into account the replacement issue… • REPLACE registry, 2009 • PM and ICD generator repalcements that include planned lead additions or revisions are associated with: -- A low total infection rate(1.1%) -- A modest peri-operative major complication rate (2.4%) -- A 6m significant major complication rate (15.3%) • SC-ICD: more longevity and less replacement

28. Why SC-ICD is a better choice for second prevention? Because… • DC-ICD… --No significant improvement in reducing inappropriate shocks --Backup pacing is not helpful for the majority of patients --More device-related complications --Expensive, short longevity and more replacement • SC-ICD… --The performance of reducing inappropriate shocks is good too, --without loss of sensitivity for VT detection -- Better safety profile, and MORE…

29. THANK YOU

30. Rebuttal

31. DC-ICD or SC-ICD: Is this a question? • M, 27 y/o, HCM with sudden cardiac arrest • No bradycardia on Holter monitoring • Symptomatic Paroxysmal AF for 4 yrs • Echo: IVS=23 mm, LVPW=11mm, LVEF=67%, LA=41mm If you want to implant a DC-ICD, you must know these… -- DC-ICD related complication rate: 4% per year! (HCM guideline 2011 ) -- More replacement in the future! -- Implant another atrial lead? or CURE the AF by PV isolation? …….