Improvement in VO_2peak predicts readmissions for cardiovascular disease and mortality in patients undergoing cardiac rehabilitation

Abstract

Background Improvement in exercise capacity is a main goal of cardiac rehabilitation but the effects are often lost at long-term follow-up and thus also the benefits on prognosis. We assessed whether improvement in VO2peak during a cardiac rehabilitation programme predicts long-term prognosis. Methods and results We performed a retrospective analysis of 1561 cardiac patients completing cardiac rehabilitation in 2011–2017 in Copenhagen. Mean age was 63.6 (11) years, 74% were male and 84% had coronary artery disease, 6% chronic heart failure and 10% heart valve replacement. The association between baseline VO2peak and improvement after cardiac rehabilitation and being readmitted for cardiovascular disease and/or all-cause mortality was assessed with three different analyses: Cox regression for the combined outcome, for all-cause mortality and a multi-state model. During a median follow-up of 2.3 years, 167 readmissions for cardiovascular disease and 77 deaths occurred. In adjusted Cox regression there was a non-linear decreasing risk of the combined outcome with higher baseline VO2peak and with improvement of VO2peak after cardiac rehabilitation. A similar linear association was seen for all-cause mortality. Applying the multi-state model, baseline VO2peak and change in VO2peak were associated with risk of a cardiovascular disease readmission and with all-cause mortality but not with mortality in those having an intermediate readmission for cardiovascular disease. Conclusion VO2peak as well as change in VO2peak were highly predictive of future risk of readmissions for cardiovascular disease and all-cause mortality. The predictive value did not extend beyond the next admission for a cardiovascular event.

Impact of cardiorespiratory fitness changes in cardiac rehabilitation

“…Only a few studies have examined the effect of change in CRF on clinical outcomes using the gold standard method of directly measured CRF by respiratory gas exchange analysis. Although there are methodological differences between studies, the findings of Mikkelsen et al 4 are consistent with those of Martin et al in coronary artery disease patients, 5 Bakker et al in chronic heart failure patients, 6 and population-based studies in apparently healthy adult men and women. [7][8][9] Similarly, many studies have demonstrated the importance of maintaining or improving CRF in reducing the risk of adverse clinical outcomes using indirect estimates of CRF.…”

“…Mikkelsen et al demonstrated that directly measured peak VO 2 as well as a change in peak VO 2 over time were highly predictive of risk for future readmissions for CVD and all-cause mortality in a large cohort of CVD patients undergoing cardiac rehabilitation. 4 Importantly, the prognostic power of the change in peak VO 2 with serial testing was independent of baseline peak VO 2 and clinical history.…”

Relationship between average daily rehabilitation time and decline in instrumental activity of daily living among older patients with heart failure: A preliminary analysis of a multicenter cohort study, SURUGA-CARE

“…Increasing functional capacity is important to improve healthy life expectancy and reduce hospital readmissions [ 3 ]. Maintaining the ability to perform activities of daily living (ADLs) is also associated with favorable prognosis in older HF patients [ 4 , 5 ].…”

Retrospective analysis of exercise capacity in patients with coronary artery disease after percutaneous coronary intervention or coronary artery bypass graft

“…Exercise capacity, which is assessed based on peak oxygen uptake (peak VO 2 ), is considered the gold standard for assessing aerobic exercise intensity and is generally used in formulating a safe, effective, and individualized exercise prescription for CR and return to work and daily activity recommendations [ [15] , [16] , [17] ]. Peak VO 2 is highly related to morbidity and mortality in CVD populations [ [18] , [19] , [20] ]. Furthermore, Peak VO 2 was also expressed as metabolic equivalent (MET, 1 MET = 3.5 ml⋅kg −1 ⋅min −1 VO 2 ).…”