ICDs may be underused among older patients after heart attack
Implantation may be overlooked during transitions of care, but an ICD was associated with lower 2-year mortality rates.
Fewer than 1 in 10 eligible older patients with low ejection fraction following a myocardial infarction (MI) received an implantable cardioverter-defibrillator (ICD) within 1 year, a study found.
Because ICD implantation is not recommended within 40 days of an MI, the decision to implant one can be overlooked during the transition of post-MI care from inpatient to outpatient care, the study authors noted. They examined ICD implantation rates and associated mortality among more than 10,000 Medicare beneficiaries with a mean age of 78 years and with an ejection fraction of 35% or less after an MI treated at 441 U.S. hospitals between 2007 and 2010. Results appeared in the June 23/30 Journal of the American Medical Association.
The cumulative 1-year ICD implantation rate among the 785 studied patients was 8.1% (95% CI, 7.6% to 8.7%). Relative to patients who did not receive an ICD within 1 year, patients with ICD implantation were more likely to have:
- prior coronary artery bypass graft procedures (31% vs. 20%; adjusted hazard ratio [HR], 1.49; 95% CI, 1.26 to 1.78),
- higher peak troponin levels (median, 85 vs. 51 times the upper limit of normal; adjusted HR, 1.02 per 10-fold increase; 95% CI, 1.01 to 1.03),
- in-hospital cardiogenic shock (13% vs. 8%; adjusted HR, 1.57; 95% CI, 1.25 to 1.97), and
- cardiology follow-up within 2 weeks after discharge (30% vs. 20%; adjusted HR, 1.64; 95% CI, 1.37 to 1.95).
Implantation of ICD was associated with lower 2-year mortality (15.3 events per 100 patient-years [128 deaths in 838 patient-years] vs. 26.4 events per 100 patient-years [3,033 deaths in 11,479 patient-years]; adjusted HR, 0.64; 95% CI, 0.53 to 0.78), the study also found. The authors noted that the “post-MI care transition is a point of vulnerability amenable to potential quality improvement interventions” and called for more research on interventions that “encourage close outpatient follow-up, improve communication and implementation of longitudinal care plans, and educate patients.”
An editorialist called it “concerning” that so few potentially ICD-eligible elderly patients are undergoing implantation, considering the significantly improved survival rates associated with the device. “Even though the use of ICDs for primary prevention may not seem to make as much sense for an 80-year-old patient as it does for a patient in his or her 50s or 60s, an older patient at risk for sudden cardiac death should have the same opportunity to choose potentially lifesaving therapy,” the editorial stated.