Effect of Exercise-Based Cardiac Rehabilitation on Cardiorespiratory Fitness in Adults with Congenital Heart Disease

Background:The purpose of this study was to investigate whether patients with adult congenital heart disease(ACHD)benefit from exercise-based cardiac rehabilitation(CR)short-and long-term with regard to improvement of cardiorespiratory fitness.Methods:Cardiopulmonary exercise tests(CPET)completed by ACHD patients between January 2000 and October 2019 were analysed retrospectively.Linear mixed models were performed for peak oxygen consumption(VO_(2))with patients as random effect and age,sex,disease classification,preceding surgery(≤3 months)and preceding CR(≤4 weeks for short term and>4 weeks for long term)as fixed effects.Results:1056 CPETs of 311 ACHD patients with simple(7),moderate(188)or great(116)complexity heart defects were analysed.The 59 patients who completed a CR(median age 27 yrs,38%females)increased peak VO_(2)from before to after CR by a median of 2.7(IQR–0.6 to 5.5)ml/kg/min.However,in the multivariate mixed model,peak VO_(2)was non-significantly increased short-term after CR(β0.8,95%CI–0.7 to 2.4),not maintained long-term after CR(β0.0,95%CI–1.7 to 1.6)but significantly reduced after surgery(β–5.1,95%CI–7.1 to–3.1).The 20 CR patients after surgery increased their peak VO_(2)by 6.2(IQR 3.6–9.5)ml/kg/min,while the 39 CR patients without preceding surgery increased it by 0.9(IQR–1.5 to 3.1)ml/kg/min.Conclusions:The increase in peak VO_(2)with CR was mainly due to recovery from surgical intervention.The small independent benefit from CR was not maintained long-term,highlighting the potential to improve current CR concepts in ACHD populations.