Improvement of regional myocardial and coronary blood flow reserve in a patient treated with enhanced external counterpulsation: evaluation by nitrogen-13 ammonia PET.

Enhanced external counterpulsation (EECP) is a noninvasive treatment for chronic stable angina, which works by recruiting and developing the coronary collateral vessels. Coronary perfusion and coronary flow reserve (CFR) were evaluated by nitrogen-13 (13N) ammonia positron emission tomography (PET) in a patient who had undergone EECP. The patient, who had 3-vessel coronary artery disease, required a percutaneous transluminal coronary angioplasty (PTCA) for the right coronary artery. The PTCA was successful, but 6 months later he again felt chest oppression. The coronary angiography showed re-stenosis at the PTCA site, and other progressive coronary stenosis. The patient was again treated with EECP for 35 h. The 13N-ammonia PET was performed both at baseline and during dipyridamole provocation, before and after EECP treatment. Coronary perfusion of each myocardial wall increased at the baseline (anterior: 0.52-0.75; septal: 0.48-0.66; lateral: 0.61-0.68; inferior: 0.46-0.57 ml min(-1) g(-1), and the CFRs in the septal and inferior walls (septal: 2.07-2.15; inferior: 1.99-2.06) also increased after the treatment. Thus, the EECP treatment improved both coronary perfusion at baseline and CFR, which suggests that it may be one of the choices for treatment of angina.