[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
Original Contribution
May 15, 2013

Association of Single- vs Dual-Chamber ICDs With Mortality, Readmissions, and Complications Among Patients Receiving an ICD for Primary Prevention

Author Affiliations

Author Affiliations: Department of Medicine, Denver Health Medical Center, Denver (Dr Peterson), Department of Medicine (Drs Peterson, Varosy, and Magid) and Department of Health Systems, Management, and Policy (Dr Magid), University of Colorado Denver Anschutz Medical Campus, Aurora; Institute for Health Research, Kaiser Permanente Colorado (Drs Peterson, Varosy, Magid, and Masoudi), and Department of Medicine, Eastern Colorado VA Health Care System (Dr Varosy), Denver; Department of Medicine, VA Palo Alto Health Care System, Palo Alto, California (Dr Heidenreich); Department of Medicine, Yale University, New Haven, Connecticut (Dr Curtis and Mr Wang); Department of Medicine, University of California, San Francisco (Drs Dewland and Go); Division of Research, Kaiser Permanente Northern California, Oakland, and Department of Medicine, Stanford University, Palo Alto (Dr Go); Department of Epidemiology, Marshfield Clinic and Marshfield Clinic Research Foundation, Marshfield, Wisconsin (Dr Greenlee); and Department of Health Care Policy at Harvard Medical School and Department of Biostatistics at the Harvard School of Public Health, Boston, Massachusetts (Dr. Normand).

JAMA. 2013;309(19):2025-2034. doi:10.1001/jama.2013.4982

Importance Randomized trials of implantable cardioverter-defibrillators (ICDs) for primary prevention predominantly used single-chamber devices. In clinical practice, patients often receive dual-chamber ICDs, even without clear indications for pacing. The outcomes of dual- vs single-chamber devices are uncertain.

Objective To compare outcomes of single- and dual-chamber ICDs for primary prevention of sudden cardiac death.

Design, Setting, and Participants Retrospective cohort study of admissions in the National Cardiovascular Data Registry's (NCDR) ICD registry from 2006-2009 that could be linked to Centers for Medicare & Medicaid Services fee-for-service Medicare claims data. Patients were included if they received an ICD for primary prevention and did not have a documented indication for pacing.

Main Outcomes and Measures Adjusted risks of 1-year mortality, all-cause readmission, heart failure readmission, and device-related complications within 90 days were estimated with propensity-score matching based on patient, clinician, and hospital factors.

Results Among 32 034 patients, 12 246 (38%) received a single-chamber device and 19 788 (62%) received a dual-chamber device. In a propensity-matched cohort, rates of complications were lower for single-chamber devices (3.51% vs 4.72%; P < .001; risk difference, −1.20 [95% CI, −1.72 to −0.69]), but device type was not significantly associated with 1-year mortality (unadjusted rate, 9.85% vs 9.77%; hazard ratio [HR], 0.99 [95% CI, 0.91 to 1.07]; P = .79), 1-year all-cause hospitalization (unadjusted rate, 43.86% vs 44.83%; HR, 1.00 [95% CI, 0.97-1.04]; P = .82), or hospitalization for heart failure (unadjusted rate, 14.73% vs 15.38%; HR, 1.05 [95% CI, 0.99-1.12]; P = .19).

Conclusions and Relevance Among patients receiving an ICD for primary prevention without indications for pacing, the use of a dual-chamber device compared with a single-chamber device was associated with a higher risk of device-related complications and similar 1-year mortality and hospitalization outcomes. Reasons for preferentially using dual-chamber ICDs in this setting remains unclear.