ICDs, or implantable cardioverter defibrillators, are battery-powered devices implanted beneath the skin and can detect irregular heart rhythms and restore a normal heartbeat by giving an electric shock.
Study author Brett D. Atwater, M.D., director of electrophysiology and electrophysiology research at Inova Heart and Vascular Institute in Fairfax, Virginia, said, "Cardiac rehabilitation programs offer patients a safe environment to increase physical activity after implantable cardioverter defibrillators (ICD) implantation. Evidence has also shown cardiac rehab lessens the risk of additional hospitalization and death, but cardiac rehabilitation programs are underutilized, especially among women, the elderly, people from diverse racial and ethnic groups and those living in rural areas." This study aimed to see if physical activity outside of a conventional cardiac rehabilitation program could provide similar results.
The Centers for Medicare and Medicaid Services (CMS) Virtual Research Data Center was used to examine health and physical activity data for over 42,000 Medicare beneficiaries who had ICDs implanted between January 1, 2014, and December 31, 2016. The patients were on average 75 years old, with 72% being male and 90% white. Sensors in the ICDs detected physical activity by measuring the participant's movements and heart rate.
During the study period, only 3% of patients who received ICDs engaged in a cardiac rehabilitation program. Those who received cardiac rehabilitation increased their physical activity by roughly 10 minutes per day during their sessions, compared to a one-minute decline in those who did not receive cardiac rehabilitation. When compared to individuals who did not participate in cardiac rehabilitation, those who did were 24 percent less likely to die in the one to three years following ICD implantation. In this study, every 10 minutes of increased daily physical activity was linked to a 1.1 percent lower risk of mortality from any cause among all participants.
The study results support the idea that the benefits of increased physical activity achieved in cardiac rehabilitation programs can be replicated at home, thus allowing patients with ICDs to improve their outcomes.