Study objective: To evaluate the true magnitude of benefit from enhanced external counterpulsation (EECP) by determining the effect of EECP on Canadian Cardiovascular Society (CCS) angina class in patients with chronic stable angina.
Design: Meta-analysis of 13 prospective studies that evaluated patients with stable angina and reported adequate data on CCS angina class.
Patients: A total of 949 adult patients with stable angina who underwent EECP treatment.
Measurements and main results: A systematic literature search of studies published between 1950 and February 2009 was performed. Studies were included for meta-analysis if they were reported in the English language, included human subjects, had a prospective study design, and reported adequate data on CCS angina class. The EECP treatment consisted of 35 sessions-1 hour/day, 5 days/week, for 7 weeks. Improvement in angina class was reported as the weighted proportion of patients improving by at least one CCS class from before to after EECP treatment. Heterogeneity was assessed by performing subgroup analyses and using the Cochran Q statistic. Publication bias was assessed by inspection of funnel plots and the Egger bias statistic. Among the 13 studies incorporating 949 patients, angina class was reduced by at least one CCS score in 86% of the patients (95% confidence interval 82-90%, Q statistic p=0.008]. Inspection of funnel plots showed some asymmetry, but the Egger bias statistic showed no publication bias (p=0.97).
Conclusion: The results of our meta-analysis call for further long-term studies to determine the place of EECP therapy in the management of chronic stable angina. Currently, EECP therapy should be considered for patients with stable angina who are refractory to or not suitable for invasive therapy and/or medical management.