One of Six Patients with Non-Ischemic Heart Disease Exhibit Provoked Coronary Spasms: Non-Ischemic Heart Disease Associated with Ischemia?

OBJECTIVE: The majority of cardiologists do not perform spasm provocation tests in patients with non-ischemic heart disease (non-IHD) or non-obstructive coronary artery disease (non-ob-CAD). We herein examined the frequency of provoked spasms in non-IHD and non-ob-CAD patients, including those with atypical chest pain (Aty), valvular heart disease (Val), hypertrophic cardiomyopathy (HCM), congestive heart failure (CHF), and others (Oth). METHODS & RESULTS: We performed acetylcholine (ACh) spasm provocation tests over a period of 22 years (1991-2012) among 1,440 patients, including 981 IHD and 459 non-IHD subjects. A total of 43 patients with significant organic stenosis were excluded, and the remaining 416 patients with non-IHD or non-ob-CAD disease were assessed. ACh was injected in incremental doses of 20/50/80 μg into the right coronary artery (RCA) and 20/50/100/(200) μg into the left coronary artery (LCA). Positive coronary spasms were defined as transient luminal narrowing of >99%. Positive coronary spasms were noted in 17.3% of the non-IHDs patients (72/416), compared to 11.4% (15/132), 19% (8/42), 16.7% (5/30), 23.9% (16/67), and 19.3% (28/145), in the patients in the Aty, Val, HCM, CHF, and Oth groups, respectively. The rate of positive provoked spasms was higher in men than women, although not significantly [20.6% (46/223) vs. 13.4% (26/193), ns], and significantly higher in the late period (2001-2012) than in the early period (1991-2000) (36.8% vs. 7.0%, p<0.001). CONCLUSION: Physicians should perform spasm provocation tests in patients with IHD as well as non-IHD with non-ob-CAD, as one of six non-IHD patients in this study exhibited provoked coronary spasms.