Relationship Between Fitness and Morbidy and Mortality in Patients After Revascularization

Introduction

Multidisciplinary cardiac rehabilitation has proven beneficial in decreasing cardiac morbidity and mortality. The purpose of this study is to evaluate the correlation between the degree of change in fitness and hospitalizations or mortality of participants in a rehabilitation program after myocardial infarction (MI) or coronary revascularization (surgical or percutaneous)

Methods

We examined 5,337 patients with coronary artery disease (84% male and 16% female, age 62±11) undergoing cardiac rehabilitation at Sheba Medical Center between the years 2010 and 2016. Fitness level was estimated by aerobic capacity during exercise stress test (estimated METs) before beginning the program, and after six months of training. The primary end point was all-cause hospital admissions and mortality.

Results

High baseline fitness level (corrected for age and gender) was found to be a protective factor, 7.2% of patients with high fitness level met the primary end point compared to 10.1% of the patient with lower fitness level at baseline (p<0.001). In both groups, absence of improvement after six months of rehabilitation was associated with higher risk of hospitalization and death (32.4% vs. 8.4% and 24.7% vs 4.4% respectfully, log rank p<0.001).

In multi-variant analysis adjusted for past cardiac history, comorbidities and baseline functional capacity, lack of functional improvement, defined as the bottom tertile of METs gained, was the strongest independent predictor or the primary end point (HR 3.71; CI 2.85-4.83; P<0.001)

Conclusions

The objective improvement of fitness level is a strong prognostic factor in patients with coronary artery disease. Patients who improve their baseline fitness, in both the low baseline fitness and the high baseline fitness groups, show a significant decrease in their risk for hospitalization or death. This suggests that providing opportunities to improve their fitness is highly beneficiary while those who do not show improvement may require closer follow-up by treating physicians