ICD therapy reduces risk of sudden, all-cause death

Compared with conventional care, primary prevention with implantable cardioverter-defibrillator, or ICD, therapy lowered the incidence of sudden and all-cause death for patients with ischemic and nonischemic cardiomyopathy, according to data published in Annals of Internal Medicine.

“For primary prevention, the main indications for an ICD are related to the prevention of threatening ventricular tachycardia or ventricular fibrillation,” Michalina Kołodziejczak, MD, from the Systematic Investigation and Research on Interventions and Outcomes MEDICINE Research Network, Dr. Antoni Jurasz Memorial University Hospital and Nicolaus Copernicus University in Poland, and colleagues wrote. “In this setting, controversy recently was sparked by the findings of a clinical study questioning the benefits of ICDs and emphasizing the medical improvements in heart failure management.”

To investigate this uncertainty, researchers compared ICD therapy with conventional care for the primary prevention of death from various causes in adults with ischemic or nonischemic cardiomyopathy. For their systematic review and meta-analysis, the investigators searched several clinical databases over a 40-year period for randomized controlled trials that reported mortality outcomes in the primary prevention setting comparing ICD therapy with conventional care. They included four trials involving 1,781 patients with nonischemic cardiomyopathy, six involving 4,414 patients with ischemic cardiomyopathy and one involving 2,521 patients with both types of cardiomyopathy. Patients were followed for a mean of 3.2 years.

The results showed that overall, the rate of all-cause mortality decreased from 28.26% with conventional care to 21.37% with ICD therapy (HR = 0.81; 95% CI, 0.7-0.94; P = .043). The reductions were similar for both nonischemic (HR = 0.81; 95% CI, 0.72-0.91) and ischemic disease (HR = 0.92; 95% CI, 0.63-1.06).

The incidence of sudden death dropped from 12.15% with conventional care to 4.39% with ICD therapy (HR = 0.41; 95% CI, 0.3-0.56), with similar declines observed in patients with ischemic (HR = 0.39; 95% CI, 0.23-0.68) and nonischemic (HR = 0.44; 95% CI, 0.17-1.12) disease. The treatments did not result in significant differences in noncardiac and any cardiac deaths.

“Primary prevention ICD placement compared with conventional care produces a statistically significant reduction in all-cause mortality, driven by reduced rates of sudden arrhythmic death,” Kołodziejczak and colleagues wrote. “The findings of the present review, in line with current guidelines, support the value of the ICD strategy in the primary prevention setting in patients with ischemic or nonischemic cardiomyopathy.” – by Savannah Demko

Disclosure: Kołodziejczak reports no relevant financial disclosures. Please see the full study for a complete list of all other authors’ relevant financial disclosures.