@article {516306,
	title = {Association of single- vs dual-chamber ICDs with mortality, readmissions, and complications among patients receiving an ICD for primary prevention},
	journal = {JAMA},
	volume = {309},
	number = {19},
	year = {2013},
	month = {2013 May 15},
	pages = {2025-34},
	abstract = {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{\textquoteright}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.},
	keywords = {Aged, Cohort Studies, Death, Sudden, Cardiac, Decision Making, Defibrillators, Implantable, Equipment Design, Female, Heart Failure, Humans, Male, Mortality, Patient Readmission, Primary Prevention, Registries, Retrospective Studies, Risk, United States},
	issn = {1538-3598},
	doi = {10.1001/jama.2013.4982},
	author = {Peterson, Pamela N and Varosy, Paul D and Heidenreich, Paul A and Wang, Yongfei and Dewland, Thomas A and Curtis, Jeptha P and Go, Alan S and Greenlee, Robert T and Magid, David J and Normand, Sharon-Lise T. and Masoudi, Frederick A}
}
