Skip to main content Accessibility help

Inequitable distribution of implantable cardioverter defibrillators in Ontario

  • Jacob A. Udell (a1), David N. Juurlink (a2), Alexander Kopp (a3), Douglas S. Lee (a4), Jack V. Tu (a2) and Muhammad M. Mamdani (a5)...


Objectives: Implantable cardioverter defibrillator (ICD) therapy reduces the risk of sudden death in patients with ischemic cardiomyopathy, but their novelty and cost may represent barriers to utilization. The objective of this study was to examine the influence of age, gender, place of residence, and socioeconomic status on rates of ICD implantation for the primary prevention of death.

Methods: We conducted a population-based retrospective cohort study involving the entire province of Ontario, Canada. Patients were eligible if they had survived following hospitalization for heart failure from 1 January 1993, to 31 March 2004, and previously sustained an acute coronary syndrome within 5 years. Patients with an existing ICD or a documented history of cardiac arrest were excluded, as were patients who died in the hospital. Primary outcome was ICD implantation.

Results: We identified 48,426 patients hospitalized for heart failure who survived to hospital discharge. Of these, 440 received an ICD, with a gradual 30-fold increase in implantation rates over the study period (.12–3.9 percent). ICD recipients were more likely to be men (odds ratio [OR] = 4.14; 95 percent confidence interval [CI], 3.24–5.30), younger than 75 years of age (OR = 3.19; 95 percent CI, 2.57–3.96), reside in a metropolitan area (OR = 1.42; 95 percent CI, 1.04–1.9), and live in a higher socioeconomic neighborhood (OR = 1.32; 95 percent CI, 1.08–1.61).

Conclusions: Among patients with heart failure and a previous myocardial infarction, ICD use is increasing in Ontario. However, the application of this technology is characterized by major sociodemographic inequities. The causes and consequences of the pronounced age and gender discrepancies, in particular, warrant further investigation.



Hide All
Al-Khatib SM, Anstrom KJ, Eisenstein EL, et al. 2005 Clinical and economic implications of the multicenter automatic defibrillator implantation trial-II. Ann Intern Med. 142: 593600.
Anand SS, Xie CC, Mehta S, et al. 2005 Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) Investigators. Differences in the management and prognosis of women and men who suffer from acute coronary syndromes. J Am Coll Cardiol. 46: 18451851.
Austin PC, Daly PA, Tu JV. 2002 A multicenter study of the coding accuracy of hospital discharge administrative data for patients admitted to cardiac care units in Ontario. Am Heart J. 144: 290296.
Ayanian JZ, Epstein AM. 1991 Differences in the use of procedures between women and men hospitalized for coronary heart disease. N Engl J Med. 325: 221225.
Bardy GH, Lee KL, Mark DB, et al. 2005 Sudden Cardiac Death in Heart Failure (SCD-HeFT) Investigators. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med. 352: 225237.
Bearden D, Allman R, McDonald R, et al. 1994 Age, race, and gender variation in the utilization of coronary artery bypass surgery and angioplasty in SHEP. SHEP 7. Cooperative Research Group. Systolic hypertension in the elderly program. J Am Geriatr Soc. 42: 11431149.
Bigger JT, Fleiss JL, Kleiger R, Miller JP, Rolnitzky LM; the Multicenter Post-Infarction Research Group. 1984 The relationships among ventricular arrhythmias, left ventricular dysfunction, and mortality in the 2 years after myocardial infarction. Circulation. 69: 250258.
Buxton AE, Lee KL, Fisher JD, et al. 1999 A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med. 341: 18821890. [Erratum, N Engl J Med. 2000;342:1300].
Cardiac Care Network of Ontario. 2005. Advisory panel regarding prophylactic ICDs and resynchronization therapy for management of patients with left ventricular dysfunction and heart failure. Final report and recommendation. February, 2004. Available at Accessed March 13
Centers for Medicare and Medicaid Services. 2005. National coverage analysis: Decision memo for implantable defibrillators (CAG-00157R3). Available at: Accessed March 13
Connolly SJ, Gent M, Roberts RS, et al. 2000 Canadian Implantable Defibrillator Study (CIDS): A randomized trial of the implantable cardioverter defibrillator against amiodarone. Circulation. 101: 12971302.
Ezekowitz JA, Armstrong PW, McAllaster FA. 2003 Implantable cardioverter defibrillators in primary and secondary prevention: A systematic review of randomized, controlled trials. Ann Intern Med. 138: 445452.
Fisher JD. 2005 Who needs a defibrillator? The beat goes on. J Am Coll Cardiol. 46: 17271728.
Gardner MJ, Leather R, Teo K. 2000 Prevention of sudden cardiac death from ventricular arrhythmia: Epidemiology. Can J Cardiol. 26 (Suppl C): 10C12C.
Ghali WA, Faris PD, Galbraith PD, et al. 2002 Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) Investigators. Sex differences in access to coronary revascularization after cardiac catheterization: Importance of detailed clinical data. Ann Intern Med. 136: 723732.
Giacomini MK. 1996 Gender and ethnic differences in hospital-based procedure utilization in California. Arch Intern Med. 156: 12171224.
Gillis AM. 2004 Prophylactic implantable cardioverter-defibrillators after myocardial infarction–not for everyone. N Engl J Med. 351: 25402542.
Glazier RH, Creatore MI, Agha MM, Steele LS. 2003 Inner City Toronto Time Trends Working Group. Socio-economic misclassification in Ontario's Health Care Registry. Can J Public Health. 94: 140143.
Gregoratos G, Abrams J, Epstein AE, et al. 2002 ACC/AHA/NASPE 2002 guideline update for implantation of cardiac pacemakers and antiarrhythmia devices: Summary article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines). J Am Coll Cardiol. 40: 17031719.
Groeneveld PW, Heidenreich PA, Garber AM. 2003 Racial disparity in cardiac procedures and mortality among long-term survivors of cardiac arrest. Circulation. 108: 286291.
Groeneveld PW, Heidenreich PA, Garber AM. 2005 Trends in implantable cardioverter-defibrillator racial disparity: The importance of geography. J Am Coll Cardiol. 45: 7278.
Hellermann JP, Jacobsen SJ, Reeder SJ, et al. 2003 Heart failure after myocardial infarction: Prevalence of preserved left ventricular systolic function in the community. Am Heart J. 145: 742748.
Hohnloser SH, Kuck KH, Dorian P, et al. 2004 The DINAMIT Investigators. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial infarction. N Engl J Med. 351: 24812488.
Hunt SA. 2005 ACC/AHA 2005 guideline update for the diagnosis and management of chronic heart failure in the adult: Summary article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2001 Guidelines for the Evaluation and Management of Heart Failure). J Am Coll Cardiol. 46: 11161143.
Jauhar S, Slotwiner DJ. 2004 The economics of ICDs. N Engl J Med. 351: 25422544.
Josephson ME, Wellens HJ. 2004 Implantable defibrillators and sudden cardiac death. Circulation. 109: 26852691.
McAlister FA, Tu JV, Newman A, et al. 2005 How many patients with heart failure are eligible for cardiac resynchronization? Insights from two prospective cohorts. Eur Heart J. 27: 323329.
McClellan MB, Tunis SR. 352 Medicare coverage of ICDs. N Engl J Med. 3: 222224.
Medical Advisory Secretariat, Ontario Ministry of Health and Long-Term Care . 2005. Implantable cardioverter defibrillator–prophylactic use. Health technology scientific literature review. June 2003. Available at: Accessed March 13
Moss AJ, Hall WJ, Cannom DS, et al. 1996 Multicenter Automatic Defibrillator Implantation Trial Investigators. Improved survival with an implanted defibrillator in patients with coronary disease at high risk for ventricular arrhythmia. N Engl J Med. 335: 19331940.
Moss AJ, Zareba W, Hall WJ, et al. 2002 Multicenter Automatic Defibrillator Implantation Trial II Investigators. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med. 346: 877883.
Myerburg RJ, Kessler KM, Castellanos A. 1992 Sudden cardiac death. Structure, function, and time-dependence of risk. Circulation. 85 (Suppl): I2I10.
Ng E, Wilkins R, Perras A. 1993 How far is it to the nearest hospital? Calculating distances using the Statistics Canada postal code conversion file. Health Rep. 5: 179188.
Ovsyshcher IE, Furman S. 2003 Determinants of geographic variations in pacemakers and implantable cardioverter defibrillator implantation rates. Pacing Clin Electrophysiol. 26: 474478.
Parkes J, Chase DL, Grace A, Cunningham D, Roderick PJ. 2005 Inequity of use of implantable cardioverter defibrillators in England: Retrospective analysis. BMJ. 330: 454455.
Pauker SG, Estes NAM, Salem DN. 2005 Preventing sudden cardiac death: Can we afford the benefit? Ann Intern Med. 142: 664666.
Sanders GD, Hlatky MA, Owens DK. 2005 Cost-effectiveness of implantable cardioverter-defibrillators. N Engl J Med. 353: 14711480.
Sheldon R, O'Brien BJ, Blackhouse G, et al. 2001 Canadian Implantable Defibrillator Study (CIDS) Investigators. Effect of clinical risk stratification of cost-effectiveness of the implantable cardioverter-defibrillator: The Canadian Implantable Defibrillator Study. Circulation. 104: 16221626.
Siebels J, Kuck KH. 1994; Implantable cardioverter defibrillator compared with antiarrhythmic drug treatment in cardiac arrest survivors (the Cardiac Arrest Study Hamburg) Am Heart J. 127: 11391144.
Solomon SD, Zelenkifske S, McMurray JJV, et al. 2005 Valsartan in Acute Myocardial Infarction Trial (VALIANT) Investigators. Sudden death in patients with myocardial infarction and left ventricular dysfunction, heart failure, or both. N Engl J Med. 352: 25812588.
1997 The Antiarrhythmic versus Implantable Defibrillators (AVID) Investigators. A comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. N Engl J Med. 337: 15761583.
2005. The Technology Assessment Unit of the McGill University Health Centre. Use of the implantable cardiac defibrillator (ICD) at the McGill University Health Centre (MUHC). A technology assessment. September 2003. Available at: Accessed March 13
Tu JV, Donovan LR, Austin PC, et al. 2005. Quality of cardiac care in Ontario. Phase I. Report 2. Toronto: Institute for Clinical Evaluative Sciences;
Tu JV, Donovan LR, Lee DS, et al. 2004. Quality of cardiac care in Ontario. Phase I. Report 1. Toronto: Institute for Clinical Evaluative Sciences;
Voigt A, Ezzeddine R, Barrington W, et al. 2004 Utilization of implantable cardioverter-defibrillators in survivors of cardiac arrest in the United States from 1996 to 2001. J Am Coll Cardiol. 44: 855858.
Wilbur DJ, Zareba W, Hall WJ, et al. 2004 Time dependence of mortality and defibrillator benefit after myocardial infarction. Circulation. 109: 10821084.
Zipes DP, Wellens HJ. 1998 Sudden cardiac death. Circulation. 98: 23342351.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed