Functional capacity and risk of major cardiovascular events in a kidney transplant recipients: a medium to long term follow-up cohort study

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Kidney transplant recipients (KTRs) have an increased cardiovascular risk and lower cardiorespiratory fitness (CRF). This is associated with increased all-cause mortality and can drastically reduce quality of life. Therefore, assessment of functional capacity and consequently an individualized physical exercise prescription are important respectively for prognostic and therapeutic purposes. Purpose Evaluate whether functional capacity, expressed as maximum oxygen consumption (VO2peak/Kg) and physical activity level are independent determinants of the risk of major cardio-vascular events (MACEs) in a KTRs population in the medium to long term. Methods In this retrospectively cohort study, 168 KTRs transplanted between 2014 and 2018 were enrolled. They underwent to a complete medical evaluation, a cardiopulmonary exercise testing and GPAQ questionnaire 3-12 months after transplantation. Laboratory blood samples and drug therapy data were collected. The average follow-up period was 6,13 ± 1,63 years. In July 2022, an anamnestic questionnaire (in order to investigate MACEs) and GPAQ questionnaire were submitted by telephone to all patients. Cox regression analyses were performed to evaluate predictors of MACEs adjusting for potential confounders. Results During the study, MACEs occurs in 15 patients (8.93%). Subjects who underwent MACE had a functional capacity significantly lower than those who had no events. Moreover, patients with MACE also had levels of physical activity significantly reduced compared with the ones without events (Table I). Data shows that VO2peak/Kg is a protective marker for risk of MACEs (Hazard Ratio 0.836; 95%CI= 0.715-0.978; p=0.025), independently of gender, age, hypertension, dyslipidaemia, obesity, diabetes mellitus, eGFR, physical activity level and presence of major cardiovascular events before transplantation. Moreover, classifying severity of functional capacity reduction through reference values reported for a matched healthy population, rate of MACEs significantly increases in groups of patients with worse CRF compared to healthy subjects (p=0.027). Conclusions In KRTs, better functional capacity after transplantation seems to be an independent modifiable protective factor for MACEs in the medium to long term. Cardiopulmonary exercise testing should thus be recommended for cardiovascular screening, evaluation of CRF and tailored exercise prescription to reduce the risk of major cardiovascular events.