Background Enhanced external counterpulsation (EECP) is an effective noninvasive treatment for refractory angina which is mainly used for patients (pts) who are not candidates for further invasive revascularization. This report examines whether pts who have the option of further invasive revascularization (CR) demonstrate a comparable initial and sustained 2-year response to EECP as those who are not candidates for revascularization (NCR).
Methods Consecutive angina pts enrolled in the International EECP Patient Registry were grouped by potential for further revascularization. Baseline demographics were recorded and outcomes were tracked for 2 years post EECP. Statistical analysis was by chi-square test, t test and Kaplan-Meier survival methods. Significance was defined as p<0.05.
Results There were 1,335 NCR pts and 204 CR pts. CR were significantly younger (64.3 ± 11.3 vs. 66.7 ± 10.7 years), with more recently diagnosed CAD (10.8 ± 9.1 vs. 11.6 ± 8.2 years) and had less severe angina (CCS class III/IV 83.3% vs. 91.8%). They were less likely to have prior CABG (55.2% vs 74%), CHF (16.9% vs 35.1%), LVEF<35% (10.9% vs 21%), multivessel disease (64.8% vs 80.7%), or DM (32.8% vs 44.2%). The two groups received the same course of EECP treatment and responded comparably. Immediately post EECP, only 23.6% of CR and 25.2% of NCR remained in CCS class III/IV, with 73.5% of CR and 77.6% of NCR improving one or more CCS angina class. At 2 years both CR and NCR demonstrated preserved and comparable reductions in angina class (16.3% vs 22.7% remained in class III/IV; with 48.2% vs 48.3% in class I or with no angina). Frequency of angina episodes per week and nitroglycerin use were reduced similarly in both groups post EECP and at 2-year follow-up. The NCR group had higher major adverse cardiovascular events (31.3% vs 25.7%) due to a significantly higher mortality (11.0% vs 6.2%) and myocardial infarction (9.3% vs. 5.4%). Exacerbation of CHF (10.1% vs 2.5%) was also significantly more frequent in NCR pts.
Conclusions EECP effectively provided comparable sustained relief from angina in CAD pts regardless of their candidacy for further revascularization. However NCR patients presented with a more severe clinical profile at baseline, which was reflected in increased mortality and episodes of CHF in follow-up.