Predictors of Changes in Peak Oxygen Uptake After Outpatient Cardiac Rehabilitation: Importance of Cardiac Rehabilitation Attendance

Abstract

Objective: To determine whether the number of cardiac rehabilitation (CR) sessions attended and selected clinical characteristics were predictive of patients who exhibited improvement in peak oxygen uptake (VO₂peak) after CR.

Patients and methods: Using the Rochester Epidemiology Project records-linkage system, we identified all consecutive patients aged 18 years or older from Olmsted County, Minnesota, who underwent cardiopulmonary exercise testing before and after CR from 1999 to 2017. Regression models were created to assess the clinical predictors of VO₂peak improvement (>0% baseline) after CR.

Results: The analysis included 671 patients, of which 524 (78%) patients exhibited VO₂peak improvement after CR. The significant univariate predictors of VO₂peak improvement included younger age (odds ratio [OR], 0.98; 95% CI, 0.96-0.99), lower pre-CR VO₂peak (OR, 0.96; 95% CI, 0.94-0.99), and no history of peripheral artery disease (OR, 0.50; 95% CI, 0.31-0.81) (all, P<.005). The significant independent predictors of VO₂peak improvement from the multivariable analysis included the number of CR sessions (OR, 1.04; 95% CI, 1.02-1.05), younger age (OR, 0.96; 95% CI, 0.94-0.98), lower pre-CR VO₂peak (OR, 0.92; 95% CI, 0.89-0.95), and no history of peripheral artery disease (OR, 0.47; 95% CI, 0.28-0.78) (all, P<.005).

Conclusion: These findings highlight the importance of patient participation in CR sessions and individual clinical characteristics in influencing VO₂peak improvement after CR in patients with cardiovascular disease.

Keywords: BMI, body mass index; CPET, cardiopulmonary exercise test; CR, cardiac rehabilitation; CVD, cardiovascular disease; PAD, peripheral artery disease; VO2peak, peak oxygen uptake.