Elsevier

American Heart Journal

Volume 157, Issue 2, February 2009, Pages 391-397.e1
American Heart Journal

Clinical Investigations
Electrophysiology
Competing risk analysis of cause-specific mortality in patients with an implantable cardioverter-defibrillator: The EVADEF cohort study

https://doi.org/10.1016/j.ahj.2008.09.023Get rights and content

Background

Although implantable cardioverter-defibrillator (ICD) therapy has been evaluated in randomized controlled trials, enrolling highly selected patients, mortality events in ICD patients have received little attention in routine medical care. We sought to assess the 24-month total and cause-specific mortality rates and their predictors in “real life” patients with an ICD.

Methods

The Évaluation Médico-Économique du Défibrillateur Automatique Implantable study was a French multicenter, prospective, observational cohort study of ICD patients with a 2-year follow-up. Cause-specific mortality rates and predictors at implantation of sudden cardiac death (SCD) or progressive heart failure (HF) death were assessed using competing risk methodology.

Results

From June 2001 to June 2003, 2,296 unselected patients were implanted and followed until June 2005. During a mean follow-up of 20.5 ± 6.7 months, 274 deaths occurred: 29 (10.6%) were SCD and 146 (53.3%) were HF deaths, corresponding to 24-month cause-specific mortality rates of 1.4% (95% confidence interval 0.9%-1.9%) and 6.9% (95% confidence interval 5.8%-8.0%), respectively. Among the characteristics at implantation, ejection fraction (EF) <30% and history of atrial fibrillation were independently associated with SCD; age, high New York Heart Association class, systemic hypertension, prior atrial fibrillation, QRS duration, EF <30%, and lack of β-blocker therapy were independently associated with HF death.

Conclusions

In this large cohort of “daily” patients, the 2-year incidence of SCD (1.4%) was comparable with the event rate observed in randomized controlled trials; HF remained the predominant mode of death. An EF <30% at implantation appears to be the most important predictor of ICD-unresponsive SCD.

Section snippets

Study design

The Évaluation Médico-Économique du Défibrillateur Automatique Implantable (EVADEF) study was a multicenter prospective cohort study of ICD patients conducted in 22 centers in France (Appendix A). This study was designed to evaluate the medical benefit of ICD in France, with a specific focus on cause-of-death analysis. The project was set up under the auspices of the French Society of Cardiology, initiated by its working group on arrhythmias, solicited and funded by the French Ministry of

Results

A total of 2,396 patients who underwent ICD implantation in the 22 participating French centers were included. Among those, 100 patients were lost to follow-up or withdrew their consent. The remaining 2,296 patients contributed to the 2-year follow-up for 3,916 patient-years and were included in our analysis. This population represented up to 70% of the overall ICD implantation activity in France between June 2001 and June 2003.

Discussions

The EVADEF cohort study represents one of the most important “real-life” ICD patient evaluations reported to date. In this setting, we have demonstrated that the results from randomized controlled trials, on which our guidelines are based, may be effectively applied to routine standard medical care. Sudden cardiac death was diagnosed in only 1.4% of patients after a 2-year follow-up, with an increase in incidence of HF mortality, which represented most cardiovascular deaths. Moreover, whereas

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    This study was supported by a special grant from the French Ministry of Health (Paris, France) (Soutien aux Innovations Diagnostiques et Thérapeutiques Coûteuses).

    Presented in part at the Annual Congresses of the American Heart Association (Chicago, IL, November 11-14, 2006) and the European Society of Cardiology (Barcelona, Spain, September 2-5, 2006; Vienna, Austria, September 1-5, 2007).

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    The investigators of the Évaluation Médico-Économique du Défibrillateur Automatique Implantable (EVADEF) Study are listed in Appendix A.

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