Abstract
Background: Despite growing interest in cardio-oncology rehabilitation (CORE), data on cardiopulmonary exercise testing (CPX/CPET) in Japanese cancer patients remain scarce.
Methods and Results: We reviewed 440 CPX examinations at Toranomon Hospital (2018–2023) and identified 37 tests from 28 patients with active cancer and cardiovascular problems. CPX parameters included peak oxygen uptake (peak V̇O2), anaerobic threshold (AT), ventilatory efficiency (V̇E vs. V̇CO2slope), and metabolic equivalents (METs). Patients were classified into those with cancer therapy-related cardiac dysfunction (CTRCD or subclinical CTRCD) and those without. Various anticancer agents had been used, with anthracycline exposure more frequent in the CTRCD group. No patient received rehabilitation before CPX. Median age was 60 years; 68% female. Cancers included breast (n=17), lymphoma (n=5), leukemia (n=3), and others. Cardiovascular problems comprised CTRCD/subclinical CTRCD (n=15), ischemic heart disease (n=2), and others. Median peak V̇O2was 14.7 mL/kg/min (63% predicted), with 43% below the prognostic threshold of 14 mL/kg/min. Median AT was 10.9 mL/kg/min and V̇E vs. V̇CO2slope 30.7, indicating reduced cardiorespiratory function. No significant differences were observed between the CTRCD and non-CTRCD groups. In 4 patients with serial CPX, exercise capacity changes did not always parallel left ventricular ejection fraction.
Conclusions: In cancer patients with cardiovascular problems, CPX revealed reduced exercise tolerance beyond cardiac function. These findings highlight the need for individualized rehabilitation inform future CORE protocols.
