Predictors of benefit in angina patients one year after completing enhanced external counterpulsation: initial responders to treatment versus nonresponders.

Enhanced external counterpulsation (EECP) has been shown to reduce Canadian Cardiovascular Society angina class. This study examines the factors that affect the reduction at 1 year, especially in patients who do not demonstrate an initial response. The data of 2,007 consecutive patients enrolled in the International EECP Patient Registry were analyzed. After 36.6 +/- 4.9 h of EECP, angina was reduced by at least one class in 82.7%. At 1 year, 35.4% of initial nonresponders and 70.6% of responders remained improved by at least one angina class and free of major adverse cardiovascular events. Multivariate predictors of 1-year benefit are initial response to treatment (odds ratio 4.5, 95% CI 3.5-5.8), baseline angina class compared with class IV (odds ratios: class I 2.1, CI 0.93-4.81; class II 0.62, CI 0.43-0.87; class III 0.80, CI 0.62-1.01) and no history of congestive heart failure (odds ratio 1.41, CI 1.14-1.74).