Fewer than 10 percent of older adults received an implantable cardioverter-defibrillator (ICD) following an MI, according to an analysis of Medicare beneficiaries who had low ejection fraction.
Although the patients were at an increased risk of sudden cardiac death, only 8.1 percent were implanted with the device within a year of their MI event.
After two years, patients who received an ICD had a lower mortality rate (15.3 events per 100 patient-years) compared with patients who did not receive an ICD (26.4 events per 100 patient-years).
Sean D. Pokorney, MD, MBA, of the Duke University Medical Center in Durham, N.C., and colleagues published their findings online in JAMA on June 23.
“It’s not that we think the numbers should be 100 percent,” Pokorney told Cardiovascular Business. “We’re certainly not saying that everybody who has a weak heart needs to get an ICD after they have a heart attack. But we do think that 8 percent is far too low. The concern is that there’s this gap in care.”
Pokorney noted that guidelines recommend patients not get an ICD until at least 40 days after their MI event. When patients wait for the device, they typically receive aspirin, dual antiplatelet therapy, beta blockers, ACE inhibitors, statins or other medical therapy.
During that 40-day time period, patients are transitioning from the inpatient hospital setting to an outpatient setting and seeing various providers, which may contribute to a lack of communication about the need for an ICD.
The researchers examined 10,381 patients with MI and ejection fraction of 35 percent or lower who participated in ACTION Registry-GWTG (Acute Coronary Treatment and Intervention Outcomes Network-Registry Get With The Guidelines), a quality improvement program.
The patients were admitted to 484 hospitals in the U.S. between Jan. 2, 2007 and Sept. 30, 2010 and were eligible for ICD implantation. The median age was 78, and 75 percent of patients underwent in-hospital revascularization. The patients were older than in previous studies, according to Pokorney.
For the 8.1 percent of patients who received an ICD within a year, the median time from hospital admission to ICD implantation was 137 days.
Pokorney said there was significant variation among the hospitals. Patients in hospitals in the 90th percentile of ICD implantation were 2.4 times more likely to receive an ICD compared with patients in the 10th percentile.
If patients had a follow-up visit with a cardiologist within two weeks of hospital discharge, they were more likely to have an ICD implanted, which Pokorney said was associated with better outcomes.
The researchers examined claims data and could not determine the reasons for the low ICD rates. However, they performed numerous subgroup analyses. For instance, they excluded all patients who had a history of cancer, stroke or end-stage renal disease because those patients were at the highest risk of death for reasons other than sudden cardiac death. Still, the implantation rate was only 9.7 percent in the remaining patients.
They also found that the rates of ICD implantation were similar when comparing patients with the most severe and least severe MIs and when comparing patients who were older than 80 and younger than 80. The relationship between ICD implantation and improved mortality was consistent in males, females, patients younger than 80 and patients older than 80.
Pokorney said patients might have opted not to get an ICD because of comorbidities or after speaking with their providers about quality of life issues related to the device.
“Patients need to be actively engaged in their care,” he said. “They need to make sure that they are getting early follow-up with their providers and that they’re helping to facilitate the communication of what happened in the hospital.”
To determine why patients did not receive an ICD, the researchers are currently assessing patients in the registry who were in the Duke system because they have access to their medical records. They do not have access to records from other hospitals and health systems.