Intracoronary ergonovine testing among 505 consecutive Japanese patients with angina-like chest pain and unobstructed coronary artery disease.

Intracoronary ergonovine (ER) testing is useful for the detection of epicardial spasm (ES) and coronary microvascular spasm (CMS). We retrospectively analyzed the incidence of ES and CMS in consecutive Japanese patients with unobstructed coronary artery disease. From January 1991 to February 2019, we performed intracoronary ER testing of 1196 patients. Among these patients, a total of 505 consecutive patients (207 women, mean age 64 ± 11 years) who underwent first diagnostic angiography for suspected myocardial ischemia and had unobstructed coronary arteries (< 50%) were enrolled. Resting chest pain was reported by 229 patients, exertional chest pain was reported by 62 patients, exertional and resting chest pain was reported by 61 patients, and another chest symptom (not typical chest pain but suspected to be myocardial ischemia) was reported by 153 patients. ES was defined as ≥ 90% stenosis and usual chest symptoms and ischemic ECG changes, while CMS was defined as < 75% stenosis (no epicardial spasm) and usual chest symptoms and ischemic ECG changes. We performed intracoronary ER testing on both coronary arteries in 86% (432/505) of all subjects. Overall, ES was found in 82 patients (16%), whereas CMS was revealed in 12 patients (2%). In patients with ES, women made up 9%, and 70% of the patients had resting chest pain. In contrast, women composed 67% (8/12) of those with CMS, and 5 patients with CMS had another chest symptom. Ventricular fibrillation was observed in two patients who had sinus rhythm after thump version or cardiac resuscitation. However, we observed no irreversible complications during ER testing. CMS was recognized in only 2% of consecutive Japanese patients with unobstructed coronary artery disease by intracoronary ER testing, whereas ES was revealed in 16% of those patients. CMS was often observed in women.