One of six patients with non-ischemic heart disease exhibit provoked coronary spasms: non-ischemic heart disease associated with ischemia?

Abstract

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). 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). 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.