SAFETY OF EXERCISE TESTING AND EXERCISE TRAINING FOR CARDIAC PATIENTS, IN A SUPERVISED, COMMUNITY-BASED CARDIAC REHABILITATION PROGRAMME

G. Pepera^1,2, P. Bromley², I. Iliadis¹, G. Sandercock²

Background: Exercise is well recognised as a tool for assessment, prevention and management of cardiovascular disease. Cardiac patients are encouraged to join in supervised exercise cardiac rehabilitation programmes after cardiac risk stratification based on their functional capacity test performance. However, there was no information in the literature concerning the safety of exercise testing and training in long-term maintenance community-based cardiac rehabilitation (CR) settings.

Purpose: To verify to what extent a recommended exercise testing protocol (shuttle walking test) and an exercise training session are safe for a mixed cohort of CR patients during a long-term maintenance programme.

Methods: Overall 33 cardiac patients underwent ambulatory electrocardiogram monitoring during the MSWT (n=11; mean age: 67.2±6.9 years – testing group) and exercise training (n=22; mean age: 66.3±8.6 years – training group). During assessment, testing group patients were required to walk up and down a 10 m course at increasing speeds using the 15 level MSWT; training group patients were required to participate in an exercise-based CR programme. All of them were regular members of long-term maintenance community-based CR. A cardiologist verified the presence or absence of a cardiovascular event. Frequency of the cardiovascular events was reported for the two groups. Patients were divided into an event-free subgroup and a cardiac event subgroup. Differences in functional capacity between the two subgroups were examined using a two-sample t-test. A chi-square test was performed to determine associations between incidences of cardiovascular events with poor functional capacity (distance walked in MSWT<450 m).

Results: No major cardiovascular event related to hospitalisation was detected in testing or training group. The most clinically important event was silent myocardial ischaemia, which occurred in 27.3% of the testing group patients, and in 18% of the training group patients. There was no significant difference in functional capacity between the event-free subgroup and the subgroup with cardiovascular events in both testing and training groups (p>0.05). A chi-square test showed no significant association between poor functional capacity and risk for cardiovascular events in either testing group or training group [Testing group: x2 (11)=0, p=0.99, phi=0.24; Training group: x2 (22)=2.1, p=0.15, phi=-0.42]. Among patients with poor functional capacity, minor cardiovascular events were found in half of those who were assessed during exercise testing with the MSWT, and in all of those who were assessed during exercise training.

Conclusion(s): The results confirm that there is no risk of major cardiovascular events during exercise testing with the MSWT or exercise training in long-term maintenance CR patients. This is probably due to the overall good functional capacity of patients involved in programmes designed for CR maintenance. Poor functional capacity does not seem to be associated with the risk of a cardiac event during exercise. It is suggested that the MSWT and exercise training can be carried out safely in supervised long-term maintenance CR settings.

Implications: Poor functional capacity is not shown to be associated with the risk of a cardiac event during exercise. Supervised exercise testing and training are accompanied only by minor cardiovascular events and they can be carried out safely in community-based CR settings.

Funding, acknowledgements: No funding to declare

Keywords: cardiac rehabilitation, safety, exercise

Topic: Cardiorespiratory

Did this work require ethics approval? Yes

Institution: University of Essex

Committee: University of Essex Ethics Committee, the National Research Ethics Service (NRES)

Ethics number: 09/H0305/102