Changes in functional capacity after a contemporary cardiac rehabilitation program: results from the ReCardio national registry

Abstract Objective The objective of this study is to evaluate the clinical characteristics and changes in functional capacity of patients completing contemporary cardiac rehabilitation (CR) programs across Spain, using data from the prospective, multicentre ReCardio national registry. Methods We conducted a prospective, multicentre, cross-sectional registry including consecutive adult patients with ischaemic heart disease (acute coronary syndrome, chronic coronary syndrome, or prior coronary revascularization) who completed a CR program in seven Spanish centres between October 2024 and October 2025. Each centre enrolled the first five consecutive eligible patients attending their discharge visit every month. Data were pseudonymized and captured in a unified web-based platform, enabling structured data entry, semantic interoperability through SNOMED CT, and optional natural-language processing for automated variable extraction. This interim analysis included 77 patients that performed a cardiopulmonary exercise test. An external independent company performed the statistical analysis. Continuous variables were summarized as mean ± SD or median (IQR), and categorical variables as frequencies and percentages. Paired comparisons between baseline and discharge metrics were conducted using the Wilcoxon paired-samples test. Results Participation in a comprehensive CR program resulted in significant improvements in functional capacity. Mean peak oxygen consumption (VO2 peak) increased from 23.4 ± 5.8 at start of CR to 25.6 ± 6.1 ml/kg/min at end of CR, reflecting a mean gain of +2.1 ml/kg/min (p 0.001). This gain is equivalent to nearly 1 MET, representing a clinically relevant enhancement in aerobic capacity. The percentage of predicted VO2 also improved significantly, rising from 97.4 ± 21.0% at start of CR to 102.0 ± 25.1% at end of CR (mean change +4.6%, p 0.001). Among patients who began CR with a predicted VO2 80%, 50% improved above this threshold at end of CR, highlighting the capacity of CR programs to reverse low-baseline functional performance. RER and VE/VCO2 slope values were recorded at both time points, with trends indicating physiological improvement, although between-time differences did not reach statistical significance. Conclusions Patients participating in contemporary CR programs in Spain already show a generally preserved baseline functional capacity as assessed by VO2 peak during maximal cardiopulmonary exercise testing at start of CR. Despite these favourable starting values, participation in a comprehensive, exercise-based CR program was associated with additional clinically meaningful improvements in aerobic fitness, including an improvement in VO2 peak approaching 1 MET at end of CR. These results highlight the sustained value of exercise based CR in enhancing functional capacity even among patients with good initial performance.For image description, please refer to the figure legend and surrounding text.