Risk Stratification for Primary Implantation of a Cardioverter-Defibrillator in Patients With Ischemic Left Ventricular Dysfunction

Abstract

Our data suggest a U-shaped pattern for ICD efficacy in the low-EF population, with pronounced benefit in intermediate-risk patients and attenuated efficacy in lower- and higher-risk subsets.

Evaluation of the Impact of a Chronic Total Coronary Occlusion on Ventricular Arrhythmias and Long‐Term Mortality in Patients With Ischemic Cardiomyopathy and an Implantable Cardioverter‐Defibrillator (the eCTOpy‐in‐ICD Study)

“…It could be postulated that an ICD does decrease mortality from VAs, but that CTO patients have a higher mortality because of the presence of other comorbidities, such as diabetes mellitus. In addition, when looking at the MADITII risk score (which was developed in a primary prevention population post myocardial infarction) in our population,15 a trend towards less CTO patients with risk score 0 and more CTO patients with risk scores of 1 and 2 can be appreciated. In the MADITII population,15 these risk score groups were at lower risk for mortality.…”

“…At baseline, we calculated an adjusted MADITII (Multicenter Automatic Defibrillator Implantation Trial II) risk score for all patients. The previously published MADITII risk score15 entails presence of New York Heart Association functional class >II, atrial fibrillation at baseline, a QRS duration of >120 ms, age >70 years, and blood urea nitrogen >26 mg/dL. Presence of any of these variables was scored as 1, and per patient a total risk score was calculated (with a maximum score of 5).…”

Primary prevention with the ICD in clinical practice: not as straightforward as the guidelines suggest?

“…14,15 Even in the MADIT II study, Goldenberg et al reported that the one-third of the study population who possessed no other risk factors than an LVEF <30% had no mortality benefit from the ICD. 16 Conversely, these authors demonstrated that patients with one or two additional risk factors (age >70 years, NYHA functional class >II, blood urea nitrogen (BUN) >9.3 mmol/l and <17.8 mmol/l, atrial fibrillation and QRS duration >120 ms) who comprised more than half of the study population had the greatest benefit from ICD therapy with a two-year mortality of 15% compared with 28% in the control population.…”

“…In MADIT II patients, when three or more of the mentioned risk factors were present, survival was not superior in the ICD group compared with the conventional group. 16 Especially severe chronic kidney disease delineates a very high-risk population in whom any possible benefit of the ICD is attenuated by the high overall mortality: with BUN >25 mmol/l or creatinine >250 µmol/l, two-year mortality was approximately 50% in both the ICD and conventional therapy group (hazard ratio 1.00, CI 0.5 to 2.2). 16 In a retrospective study of 35 patients with chronic kidney disease, out of 229 who had an ICD implanted for primary prevention, Cuculich et al registered a one-year survival of 61.8% in patients with a serum creatinine of >177 µmol/l or on chronic dialysis, compared with 96.3% in controls.…”

“…16 Especially severe chronic kidney disease delineates a very high-risk population in whom any possible benefit of the ICD is attenuated by the high overall mortality: with BUN >25 mmol/l or creatinine >250 µmol/l, two-year mortality was approximately 50% in both the ICD and conventional therapy group (hazard ratio 1.00, CI 0.5 to 2.2). 16 In a retrospective study of 35 patients with chronic kidney disease, out of 229 who had an ICD implanted for primary prevention, Cuculich et al registered a one-year survival of 61.8% in patients with a serum creatinine of >177 µmol/l or on chronic dialysis, compared with 96.3% in controls. 17 This lack of benefit in the more diseased population was also apparent in the SCDHeFT trial: whereas in NYHA class II patients there was a 46% reduction in risk of death, patients in NYHA class III had no advantage with an ICD compared with placebo.…”