Physical activity after ICD implantation beneficial, in or out of cardiac rehabilitation
Patients with HF and CAD who increased their daily levels of physical activity after receiving an implantable cardioverter defibrillator had better 1-year survival vs. those who did not, researchers reported.
The association between physical activity and better outcomes after ICD implantation was consistent regardless of whether the patient was in a cardiac rehabilitation program or exercising at home, according to data published in Circulation: Cardiovascular Quality and Outcomes.
“Our study examined whether physical activity outside of a formal cardiac rehabilitation program could yield similar benefits, and we found it did,” Brett D. Atwater, MD, director of electrophysiology and electrophysiology research at Inova Heart and Vascular Institute in Fairfax, Virginia, said in a press release. “This suggests that additional options like home-based cardiac rehabilitation might help more patients realize the health benefits of increased physical activity.”
For this retrospective observational study, researchers included 41,731 Medicare beneficiaries (mean age, 75 years; 72% men) who underwent ICD implantation, of whom 3.2% participated in cardiac rehabilitation. Daily ICD measurements of physical activity and Medicare claims data were used to determine whether elevated physical activity was associated with lower odds or HF hospitalization or death.
Changes in physical activity
Overall, participants in cardiac rehabilitation attended a median of 24 sessions, during which time daily physical activity increased by a mean of 9.7 minutes per day. Physical activity decreased by a mean of 1 minute per day among nonparticipants (P compared with participants < .001).
“In this study, any physical activity counted toward daily totals, as long as the patient was moving and the heart rate increased at the same time,” Atwater said in the release. “Prior work shows that simple activities of daily living such as walking around the house or doing the dishes, count toward these totals and can improve health compared to sitting still.”
Benefits of physical activity after ICD implantation
Elevated ICD-detected physical activity was associated with improved 1-year survival among patients with HF and CAD, with a 1.1% reduced risk for death for every 10 minutes of additional daily exercise (HR = 0.989; 95% CI, 0.979-0.996; P < .001). Findings were similar for 1-year HF hospitalization risk (HR = 0.99; 95% CI, 0.986-0.995; P < .001).
To ascertain whether participation in cardiac rehabilitation altered the effects of physical activity on outcomes, researchers performed two additional analyses.
After propensity matching cardiac rehabilitation participants with nonparticipants by demographics, comorbidities and baseline physical activity, participants experienced lower 1- to 3-year mortality (HR = 0.76; 95% CI, 0.69-0.85; P = .03).
The second analysis included change in physical activity during cardiac rehabilitation or the same time frame after ICD implant. Researchers observed no differences in mortality between those who were enrolled in a cardiac rehabilitation program and those who were not (HR = 1; 95% CI, 0.82-1.21; P = .87).
“Cardiac rehabilitation programs offer patients a safe environment to increase physical activity after 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,” Atwater said in the release. “The causes of underutilization are a combination of providers failing to prescribe and patients being unwilling to participate because of the time requirements for participation, the travel to and from the rehab facility and out of pocket costs associated with that.”