Intrinsic capacity outperforms frailty in cardiac rehab outcomes

The observational study evaluated 551 older adults aged 65 and older who were hospitalized for exercise-based cardiac rehabilitation in Italy. Researchers assessed participants before rehabilitation using a Comprehensive Geriatric Assessment. They calculated two four-domain intrinsic capacity scores—covering cognition, psychological status, locomotion, and vitality measured via handgrip strength or nutrition—alongside a deficit-accumulation frailty index. The team measured functional outcomes using the six-minute walking test before and after the rehabilitation program.

All geriatric measures were significantly associated with post-rehabilitation walking performance. However, intrinsic capacity operationalized with handgrip strength showed the strongest association and explanatory power for walking ratios (β = 0.571, R²adj = 0.362), outperforming the nutrition-based metric (β = 0.498, R²adj = 0.347). The frailty index showed a smaller, negative association (β = -0.281, R²adj = 0.235). Adjusted mixed-effects models confirmed these patterns for total walking distance.