# Disparity of Predictors for Participation in Phase 2 Cardiac Rehabilitation Between Younger and Older Patients With Cardiovascular Diseases

## TL;DR

Older patients with heart disease are less likely to join cardiac rehab, and different factors predict participation in younger versus older groups.

## Contribution

Identifies distinct predictors of cardiac rehabilitation participation in younger and older patients with cardiovascular diseases.

## Key findings

- Residential address and left ventricular ejection fraction (LVEF) are common predictors across age groups.
- Grip strength uniquely predicts OCR participation in older patients.
- Disease type (HF vs. IHD) is a key predictor only in younger patients.

## Abstract

Background: Outpatient cardiac rehabilitation (OCR) is vital to improve the prognosis in patients with cardiovascular diseases (CVD). Despite its benefits, participation rates remain low, particularly among older adults. Previous studies have reported several demographic and clinical predictors for OCR participation, but differences between younger and older patients remain unclear. This study aimed to clarify disparities in predictors for OCR participation between younger and older patients with CVD.

Methods: This retrospective cohort study was conducted at a single Japanese regional core hospital from January 2019 to December 2023. Patients admitted for heart failure (HF) or ischemic heart disease (IHD) and referred to inpatient cardiac rehabilitation were included. Patients were categorized as younger (<75 years) or older (≥75 years) and further divided based on OCR participation (attended ≥1 session). Demographic, clinical, and physical function data, including the Short Physical Performance Battery and the Japanese version of the Cardiovascular Health Study criteria, were collected. Classification and regression tree (CART) analysis was used to identify predictors of OCR participation in each age group.

Results: A total of 1800 patients were analyzed (829 younger, 971 older). OCR participation rates were 21.5% in younger and 8.9% in older patients (OR 0.35, 95% CI 0.27-0.47, p<0.01). In younger patients, CART analysis identified residential address as the primary predictor, followed by left ventricular ejection fraction (LVEF) and disease type. Participation was highest (55%) in those living locally, with LVEF <47%, and admitted for IHD. In older patients, grip strength was the primary predictor, followed by residential address and LVEF. Participation was highest (58%) in those with grip strength ≥18 kg, living locally, and LVEF <26%. While LVEF and residence address were common predictors in both groups, grip strength was a unique predictor for older adults, and disease type (HF vs. IHD) was relevant only in younger patients.

Conclusions: This study revealed disparities in predictors for OCR participation between younger and older patients with CVD. Although residence address and LVEF influenced participation across both groups, grip strength and type of CVD emerged as factors in older and younger, respectively. Individual strategies are necessary to enhance participation rate in OCR and long-term patient outcomes.