Marie Thibault

An article published in the Journal of the American Medical Association on June 23 points to a low rate of ICD implantation in elderly patients who have suffered a heart attack, although ICD use is linked to lower death rates.

According to the study, “Implantable Cardioverter-Defibrillator Use Among Medicare Patients with Low Ejection Fraction After Acute Myocardial Infarction,” 8.1% of eligible heart attack survivors over age 65 with a low ejection fraction (EF) were implanted with an ICD within a year following their heart attack. This implantation rate looks especially low with the finding that patients implanted within one year had a lower risk of two-year mortality (15.3 events per 100 patient years) versus patients who did not receive an ICD (26.4 events per 100 patient years.)

“Defibrillators are life-saving therapies that have a lot of evidence supporting their use,” said Tracy Wang, MD, associate professor of cardiology at the Duke University School of Medicine and senior author of the study, in a Duke Medicine press release. “But not every older patient wants one. There is a trade-off between the risks and benefits of the device. But current data suggests that we are grossly underutilizing this therapy.”

The study included more than 10,000 post-myocardial infarction patients over age 65 with an EF less than or equal to 35% who were potentially eligible to receive an ICD for primary prevention. This group had a median age of 78 years, 46% were female, and 44% were 80 years old or older. A similar mortality benefit from ICD implantation was seen in patients across genders and age.

Kenneth Stein, MD, FACC senior vice president and chief medical officer at Boston Scientific, wrote in an e-mail to MD+DI, “These are sobering results and they should serve as a call to action. The study makes it clear that even now, more than a decade since the publication of the trials proving that ICDs save lives in this population, large numbers of patients are not getting access to this therapy and that lives are needlessly being lost.”

Boston Scientific provided a grant to help fund this study. Funding also came from a grant from the Agency for Healthcare Research and Quality. Boston Scientific also funded the major Multicenter Automatic Defibrillator Implantation Trial (MADIT) trials that served to increase medicine’s understanding of ICD therapy. “We will continue to support education on the appropriate indications for ICD implantation until all patients who could benefit from the therapy can get access to it,” Stein wrote.

While 8.1% of these patients were implanted with an ICD within one year, there was significant disparity in implant rates between hospitals. The top-implanting hospitals had a 11.5% rate of 1-year ICD implantation while the lowest-implanting centers had a 4.8% rate. Patient who were younger, male, presented with a ST segment elevation MI, had large infarcts, showed evidence of cardiogenic shock during hospitalization, and undertook early cardiology follow-up within two weeks of hospital discharge were more likely to receive an ICD within one year.

The study authors emphasized the importance that cardiology follow-up and medical care following a heart attack had on likelihood of receiving an ICD, especially since current standard of care recommends patients wait 40 days after a heart attack to receive an ICD. “The inpatient to outpatient transition of care is important for ICD consideration after MI, since there is an obligate 40-day waiting period between the inpatient MI and when the patient is eligible for the therapy,” according to the study.

Sean Pokorney, MD, MBA, study author at Duke University Medical Center’s Division of Cardiology, wrote in an email to MD+DI, “We need to ensure that all patients with a low ejection fraction and weak heart squeeze after a myocardial infarction have close outpatient cardiology follow-up with their primary providers, as increased patient contact with the health care system was associated with a higher likelihood of ICD implantation in our study.”

Pokorney notes that more work is needed to understand how elderly patients consider the risks and benefits of ICDs, and how to best predict which patients would benefit most from the therapy.

“We do not believe that 100% of patients with weak hearts at the time of their myocardial infarction should be getting ICDs, but we believe that 8% is too low,” Pokorney wrote.

Marie Thibault is the associate editor at MD+DI. Reach her at [email protected] and on Twitter @medtechmarie. 

[Image courtesy of PAKORN/FREEDIGITALPHOTOS.NET]