Multivessel versus single vessel spasm, as assessed by the intracoronary acetylcholine provocation test, in Korean patients.

1. Coronary artery spasm (CAS) is known to be a major cause of myocardial ischaemia. Multivessel coronary spasm (MVS) in particular is likely to induce more severe and prolonged myocardial ischaemia than single vessel spasm (SVS). 2. In the present study, a total of 1082 consecutive patients without significant coronary artery disease who underwent an acetylcholine (ACh) provocation test between March 2004 and April 2009 were investigated. Patients were divided into three groups: an MVS group (n = 275), an SVS group (n = 376) and a non-CAS group (n = 431). Differences in clinical and angiographic characteristics following the ACh provocation test were evaluated between the MVS, SVS and non-CAS groups. 3. At baseline, patients in the MVS group had the highest prevalence of peripheral artery disease (PAD), hyperlipidaemia, smoking and old age, as well as the highest triglyceride levels. Calcium channel blockers were most frequently prescribed in MVS patients before the ACh test. During the ACh test, the highest prevalence of chest pain, ischaemic electrocardiogram changes, baseline spasms and diffuse and severe spasms were observed in the MVS group. The response rate to lower ACh doses that induce CAS was also higher in the MVS group. Multivariate analysis showed that the presence of PAD (odds ratio (OR) 2.0; P = 0.006) and baseline spasm (OR 1.4; P = 0.045) were independent predictors of ACh-induced MVS. 4. In conclusion, ischaemic symptoms, diffuse and severe spasm and baseline spasm were more frequently associated with MVS patients, suggesting more intensive medical therapies and close clinical follow up would be required for this patient group.