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

Q 1/4: Does DC-ICD really reduce inappropriate shocks?

JACC 2004; 44: 2362

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

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

JACC 2004; 44: 2362

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

SC-ICD DC-ICD total P value

inappropriate shocks patients

6(13%) 10(21%) 16(17%) NS

inappropriatelyShocks episodes

22 (31%) 51 (69%) 73(10%) NS

JCE 2001; 12: 134-42

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

Different Voices…

Inappropriate detection rate

Circulation 2006; 113: 2876

The rate of inappropriate SHOCKS was similar between the 2 groups!

Circulation 2006; 113: 2876

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

• Cutoff rates and detection zones

• Detection time/beats

• SVT discriminators

• Minimizing oversensing

• Greater use of antitachycardia pacing (ATP)

• …….

Minimizing inappropriate shocks: SC-ICD can do more!

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

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

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

Flow of Patients Evaluated in the DAVID Trial

DAVID trial: results

VVI-40 DDDR-70 HR (p-value, adj.)

CHF Hospitalization or Death

16.1% 26.7% 1.61(p = 0.03)

CHF Hospitalization

13.3% 22.6% 1.54(p=0.07)

Death 6.5% 10.1%1.61

(p=0.15)

JAMA, 2002, 288: 3115

DAVID trial: Main Endpoints

JAMA, 2002, 288: 3115

Theoretically,…

SC-ICDs hava less complications

Dc-ICDs have a higher incidence of device-related complications

--Implant duration /risk

--Electrode dislodgement

--More infections

……

Q 3/4: Does DC-ICD increase the complications significantly?

DC-ICD increase complication and mortality!

• National Cardiovascular Data Registry (NCDR)

JACC 2011; 58: 1007-13

Selection of Study Participants From the NCDR ICD Registry

Single- versus dual-chamber ICD Implantation Complication Rates

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

Q 4/4: How about the budget considerations of DC- or SC-ICDs?

Cost of the ICDs in Beijingmanufacturer type Price(RMB)

Medtronic Marquis VR7230Cx 89950

Marquis DR7274 144375

InsyncIII 7285(CRT-D) 153708

Boston Scientific Vitality 2 VR T175 103845

Vitality 2 DR T165 160177

Biotronik Lumax 300VR-T 115500

Lumax 300DR-T 172410

Lumax 300HF-T 197263

St. Jude Medical ICD-V-196 92935

ICD-V-239 132468

ICD-V-350 152124

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

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…

THANK YOU

Rebuttal

• 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

DC-ICD or SC-ICD: Is this a question?

-- 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?

…….

If you want to implant a DC-ICD, you must know these…