title: Usefulness of Atrial Fibrillation as a Marker for Adverse Cardiovascular Outcomes in Both Primary and Secondary Prevention in Patients With Implantable Cardioverter-Defibrillators.
abstract: Whether the risk factors for cardiovascular (CV) outcomes are different in primary versus secondary prevention implantable cardioverter-defibrillator (ICD) patients is unclear. We sought to identify predictors of CV outcomes in ICD recipients for primary (G1) versus secondary prevention (G2). Consecutive patients who had ICD implanted during August 2005 to December 2009 were included. The primary outcome was a composite of appropriate shock, acute coronary syndrome, ischemic stroke, coronary revascularization, heart failure exacerbation, CV hospitalization, or all-cause death. We used Cox proportional hazards model and a stepwise selection method to fit the most parsimonious model to predict the primary outcome in all patients and separately for G1 and G2 patients. We followed 223 (184 G1 and 39 G2, mean age 61 years) patients through December 31, 2012; 141 (63.2%) developed the primary outcome. In all patients, atrial fibrillation (AF; hazard ratio 6.72, 95% CI 4.20 to 10.75; p <0.001), use of antiarrhythmic drug (1.55, 1.02 to 2.36; p = 0.04), and lower estimated glomerular filtration rate (0.99, 0.98 to 0.997; p = 0.01) were associated with increased risk of the primary outcome; the attributable risks were 21.6%, 16.0%, and 15.9%, respectively. In G1, AF, hypertension, and lower estimated glomerular filtration rate were associated with increased risk, whereas in G2, AF, use of antiarrhythmic drug, and nonischemic cardiomyopathy were associated with increased risk. In conclusion, although risk factors are different for primary and secondary prevention patients, AF is a strong and consistent risk factor for adverse outcomes in both populations.
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Electronic address: Chang905@umn.edu.
authors.forename: Ian C Y
authors.initials: IC
authors.lastname: Chang
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Yusuf M
authors.initials: YM
authors.lastname: Agamawi
authors.affiliation: Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Erin
authors.initials: E
authors.lastname: Austin
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Wayne O
authors.initials: WO
authors.lastname: Adkisson
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Henri
authors.initials: H
authors.lastname: Roukoz
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Lisa N
authors.initials: LN
authors.lastname: von Wald
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Scott
authors.initials: S
authors.lastname: Sakaguchi
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: David G
authors.initials: DG
authors.lastname: Benditt
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Electronic address: chenx484@umn.edu.
authors.forename: Lin Y
authors.initials: LY
authors.lastname: Chen
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications / Q000401:mortality / Q000628:therapy*; D002423:Cause of Death / Q000639:trends; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D011322:Primary Prevention / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D055502:Secondary Prevention / Q000379:methods*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors