Training intensity and improvements in exercise capacity in elderly patients undergoing European cardiac rehabilitation – the EU-CaRE multicenter cohort study

Abstract

Objectives Guidelines for exercise intensity prescription in Cardiac Rehabilitation (CR) are inconsistent and have recently been discussed controversially. We aimed (1) to compare training intensities between European CR centres and (2) to assess associations between training intensity and improvement in peak oxygen consumption (V˙O2) in elderly CR patients. Methods Peak V˙O2, heart rate and work rate (WR) at the first and second ventilatory thresholds were measured at start of CR. Training heart rate was measured during three sessions spread over the CR. Multivariate models were used to compare training characteristics between centres and to assess the effect of training intensity on change in peak V˙O2. Results Training intensity was measured in 1011 out of 1633 EU-CaRE patients in 7 of 8 centers and the first and secondary ventilatory threshold were identified in 1166 and 817 patients, respectively. The first and second ventilatory threshold were found at 44% (SD 16%) and 78% (SD 9%) of peak WR and 78% (SD 9%) and 89% (SD 5%) of peak heart rate, respectively. Training intensity and session duration varied significantly between centres but change in peak V˙O2 over CR did not. Training above the first individual threshold (β 0.62, 95% confidence interval [0.25–1.02]) and increase in training volume per hour (β 0.06, 95%CI [0.01–0.12]) were associated with a higher change in peak V˙O2. Conclusion While training intensity and volume varied greatly amongst current European CR programs, changes in peak V˙O2 were similar and the effect of training characteristics on these changes were small.

Predictors for one-year outcomes of cardiorespiratory fitness and cardiovascular risk factor control after cardiac rehabilitation in elderly patients: The EU-CaRE study

“…A similar conclusion was drawn by a recent meta-regression analysis, which found exercise intervention intensity to be the only predictive factor for the difference in CRF between randomized exercise-based CR and control groups [ 26 ]. Training intensity was monitored in a subset of patients and its influence on change in peak VO 2 was reported elsewhere [ 27 ].…”

Changes and prognostic value of cardiopulmonary exercise testing parameters in elderly patients undergoing cardiac rehabilitation: The EU-CaRE observational study

“…CPET parameters were determined at the core lab in Bern by an automated procedure on raw data files using MATLAB (vers. R2017b, MathWorks ® , United States), as describe previously [ 11 , 20 ]. One experienced operator (TM) performed extensive visual quality control using Wassermann’s 9-panel plot and in case of doubtful quality, a second operator (MW) was consulted.…”

“…All ventilatory thresholds (VT 1 and VT 2 ) were visually determined by one single investigator (TM). Interrater reliability was determined in a random subset of 200 CPETs, in which thresholds were determined by a second experienced investigator (MW) blinded also to patients and centres as well as to thresholds set by the other investigator [ 20 ]. The respiratory exchange ratio (RER) as measure for exertion was determined by dividing VCO 2 by VO 2 .…”

Frailty in Acute and Chronic Coronary Syndrome Patients Entering Cardiac Rehabilitation

“…However, it is still uncertain whether these improvements may be obtained even in frail elderly patients in CR [ 101 ]. Notably, the EU-CaRE multicenter study aimed at comparing the intensity of CR training and peak oxygen consumption (peak VO 2 ) changes associated to CR programs among European centers [ 102 ]. Interestingly, although participants underwent training sessions above anaerobic threshold (AT), peak VO 2 had a greater improvement; however, a clear association between training intensity and peak VO 2 improvement was not systematically detected, especially in elderly patients performing submaximal exercises (RER < 1.1) (i.e., half of study cohort) [ 103 ].…”