February 10, 2015 – The DCRI’s Paul Hess, MD, and colleagues conducted a meta-analysis of five earlier studies to determine the efficacy of ICDs in older patients.
A recent meta-analysis of five major clinical trials indicates that older patients can still benefit from implantable cardiac devices (ICDs), although the benefit diminishes with age.
The study suggests age alone should not prevent clinicians from considering ICDs for older patients who are at risk of sudden cardiac death. Instead, doctors should take into consideration a number of factors before deciding for or against an ICD, including patient preference, periprocedural risk, and comorbidity burden.
The study, conducted by the DCRI’s Paul Hess, MD (pictured); Sana Al-Khatib, MD, MHS; Rex Edwards, BA; Kerry Lee, PhD; Daniel Mark, MD, MPH; Gillian Sanders, PhD; and colleagues from other institutions, was published this week in the online edition of the journal Circulation: Cardiovascular Quality and Outcomes.
Earlier research has established the efficiency of ICDs in preventing sudden cardiac death. As a consequence, ICD use has grown considerably in recent years, particularly among older patients. More than 40 percent of ICDs are implanted in patients over 70 years of age; more than 10 percent of recipients are older than 80. However, as older patients have been underrepresented in previous clinical trials, the efficacy of ICDs in this population is uncertain.
In this study, Hess and his colleagues pooled data from five previous trials: the Multicenter Automatic Defibrillator Implantation Trial I (MADIT-I), the Multicenter UnSustained Tachycardia Trial (MUSTT), the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II), the Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation Trial (DEFINITE), and the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT).
The final study population included 3,530 patients from all five clinical trials. The median age of the overall sample was 62; 390 patients out of the total sample were 75 years or older. Older patients were more likely to have symptoms of advanced heart failure, and were more likely to have several comorbidities, including atrial fibrillation, hypertension, peripheral vascular disease, and pulmonary disease. They were also more likely to have been revascularized either surgically or percutaneously.
The researchers found that the survival benefit observed in earlier studies persisted across a range of ages, although it diminishes with continuing age. The study also found no evidence that age increases the likelihood of rehospitalization after ICD implantation. This finding, researchers noted, was biologically plausible and consistent with the current understanding of sudden cardiac death. However, they noted that there were relatively few patients older than 75 included in their analyses. Additional studies of older patients with ICDs are still needed, they concluded.