Introduction: Organ transplantation is the best treatment for patients with end-stage organ failure. However they usually suffer from multiple co-morbidities due to original disease and side effects of immunosuppressive therapies. Exercise is well-known for improving cardiovascular function and physical fitness. Sports competition, supported by regular training, brings about physiological benefits, improves quality of life, enhances confidence and reduces anxiety and depression. World Transplant Game (WTG) is a bi-annual international sports event for transplant recipients, with 14 sports ranging from low to high exercise intensity. Cardiac incidents including arrest had been reported during the games. Currently there is no consensus on the usefulness of any screening test to assess the cardiopulmonary fitness for sports competition in asymptomatic post-transplant patients. In Hong Kong, we derived a structured submaximal stress test for WTG participants to assess their exercise capacity and recommend choice of sports accordingly. The objective of this study is to  evaluate the outcome of a structured submaximal stress test for the Hong Kong team of WTG 2019.
Methodology: This is a retrospective observational study. A structured submaximal stress test was carried out before registration. All heart and lung recipients, and liver, kidney and bone marrow transplant recipients older than 50 and opted to compete for moderate to high intensity sports were included. Resting blood pressure, pulse rate and 12-lead electrocardiogram (ECG) were recorded before testing. Modified Bruce protocol was adopted, during which heart rate (HR), blood oxygen saturation (SpO2) and rate of perceived exertion (RPE) were closely monitored. Participants whose exercise capacity exceeded the metabolic equivalent (MET) requirement for their target sports would proceed to join the game; while those who failed would be referred for a formal standard cardiac stress ECG test or advised to choose sports with lower intensity.
Results: 21 participants (mean age = 55.8 years, 9 males, 12 females) were evaluated for data analysis. 7 of the 21 (33.3%) subjects failed to attain the required exercise capacity for their target sports. 2 switched to lower intensity sports while the other 5 proceeded to standard cardiac stress test. Among these 5 patients, two had abnormal exercise ECG and switched to lower intensity sports. The other 3 with normal exercise ECG, were given advice or switched to lower intensity sports. No one withdrew from competition. No cardiac event was noted during the game.
Conclusion: Structured submaximal stress test is a cost-effective screening test for asymptomatic post-organ transplant recipients to help choosing the suitable sports event according to their physical capacity. Standard cardiac stress test should be done if the screening test is abnormal to ensure safety of the transplant athletes in competing sports.