Chronotropic incompetence was prevalent in 79.1% of cardiac rehab patients but did not significantly affect improvement in 6-minute walking distance during rehabilitation.
Does chronotropic incompetence affect exercise capacity and the change in exercise capacity during cardiac rehabilitation in patients with cardiovascular disease?
Chronotropic incompetence is highly prevalent in patients undergoing cardiac rehabilitation but does not significantly impair the improvement in exercise capacity during the rehabilitation program.
Absolute Event Rate: 0% vs 0%
Abstract Background/Introduction Chronotropic incompetence (CI) is frequent in patients with cardiovascular disease due to the disease itself or factors such as medication or cardiac devices. There might as well be an influence of surgical procedures leading to CI. Even though some studies have shown a relevant influence in defined subgroups of cardiovascular disease patients (e.g. heart failure with reduced ejection fraction), there is still a gap of evidence regarding many other entities of cardiovascular diseases, especially for patients after cardiac surgery. In clinical practice CI is often underestimated. Since clinical practice can influence CI in different aspects (e.g. medication type and dosage, pacemaker settings), a better understanding of CI is essential. Purpose Our aim was to investigate CI, exercise capacity and change in exercise capacity during CR. Methods In a retrospective single center cohort-study, we analyzed data of patients admitted for inpatient exercise-based cardiac rehabilitation (CR) between December 2022 and June 2024. We included all patients with available exercise-ECG data and defined the chronotropic index as follows: (maximal heartrate (HR)-resting HR)/(220-age-resting HR). CI was defined as a chronotropic index lower than 0.8. We assessed exercise performance by distance reached in the 6-minute walking test (6MWD), and compared the change in 6MWD between chronotropic incompetent and non-chronotropic incompetent patients using Hodges-Lehmann estimator. We performed logistic regression for CI and linear regression for the chronotropic index. We adjusted for possible confounders (first model: age, sex, second model: age, sex COPD, Hb, LVEF, duration of hospitalization, surgery pre CR). Results Of the 666 patients 527 (79.1%) were chronotropic incompetent. Median age of this population was 64 years (quartiles 57– 71) with 76.7% of the patients being admitted after surgical procedures (see Table 1). There was no significant difference in the exercise-performance change between patients with and without CI, but the total 6MWD at discharge was significantly longer in patients without CI compared to patients with CI (median difference 63m (95% Confidence Interval 41m; 85m)) (see Figure 1). In a continuous model of the chronotropic index there was a significant effect from the chronotropic index on the performance in the 6MWD at discharge, but no effect on the change in the 6MWD. After adjusting for possible confounders, there was no significant effect to the 6MWD change. In the subgroup of patients admitted after cardiac or vascular surgery we found no significant effect by type of surgical access (open vs minimal invasive) or type of surgery (coronary artery bypass graft vs valve surgery) after adjusting for age and sex. Conclusion CI was frequent in patients in CR, but did not have a significant effect with change in 6MWD during CR.
Albus et al. (Sat,) reported a other. Chronotropic incompetence was prevalent in 79.1% of cardiac rehab patients but did not significantly affect improvement in 6-minute walking distance during rehabilitation.