Provoked Coronary Spasm and Acute Coronary Syndromes⁎⁎Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.

Abstract

Although coronary artery spasm (CAS) has been linked with acute coronary syndromes (ACS) and vulnerable plaque (1), thrombosis (2), percutaneous coronary intervention (PCI), and stenting (3-7), very limited attention is given to CAS in the current era. This may be related to assumptions that the frequency of CAS is decreasing and if present it will be eliminated with calcium antagonist (8) or nitrate use. However, concerns about adverse outcomes in hypertensive and angina patients over the past decade have diminished calcium antagonist use, particularly in ACS. Long-acting nitrates, once a standard discharge order, are not recommended discharge medications in recent ACS guidelines (9 -11). Important to the perception that CAS is decreasing is the lack of testing to detect spasm as a possible mechanism for ACS when other causes are not apparent. Except for Prinzmetal angina and cocaine use, CAS testing is either not mentioned (9,10) or is given only a IIb recommendation (11) among patients without obstructive coronary artery disease (CAD) in recent guidelines. Therefore, among ACS patients the frequency of CAS was unknown, and it was uncertain whether it was simply a mediator of ischemia among other factors, a marker predicting adverse outcome, or both. See pages 518 and 523This is the setting for 2 provocative reports on coronary spasm in ACS published in this issue of the Journal. Using a prospective cohort design, Wakabayashi et al. (12) tested consecutive Japanese patients for CAS 10 to 20 days after acute myocardial infarction (MI) treated by PCI. Spasm was provoked in about 70% of cases, and almost one-half of these had an event (death, ACS, or revascularization) over follow-up. Spasm was provoked in the majority of arteries examined; occurring in approximately 70% of infarct-related arteries and about one-half of noninfarct-related arteries.Finding CAS in these latter cases indicates that spasm was not related to vascular injury associated with the PCI. Provoked spasm was an independent predictor of adverse outcome, and although exploratory, their analysis suggests that CAS may be linked with early nonobstructive vulnerable plaque as a precursor to recurrent ACS in multiple arteries rather than only the infarct-related lesion. Ong et al. (13) continued this theme of spasm testing in ACS patients without obstructive lesions. Spasm was provoked in approximately 50% of these marker-positive (electrocardiographic [ECG] and/or biochemical) Caucasian cases. Interestingly, smoking history, long recognized as a risk condition for spasm (14), was present in only about one-fourth of these cases and did not differ significantly comparing those with and without spasm. This also held true for other factors previously linked with CAS, such as female gender and hypertension.Although these data, indicating a very high frequency of multivessel CAS in ACS patients possibly linked with adverse outcomes, are very interesting, there are some limitations. The Wakabayashi et al. (12) study conclusions would be stronger if the o...

The Vanishing Stenosis: ST Elevation Myocardial Infarction and Rhythm Disturbance due to Coronary Artery Spasm—Case Report and Review of the Literature

“…28% (138 of 488) had no demonstrable culprit lesion, and of these 86% underwent acetylcholine provocation testing. 49% ( n  = 42) demonstrated evidence of significant coronary spasm defined as a reduction in vessel calibre of at least 75% [1]. …”

What Causes Myocardial Infarction in Women Without Obstructive Coronary Artery Disease?

“…Several recent reports have identified provoked coronary artery spasm in 50% to 70% of ACS patients without obstructive CAD. 9 Interestingly, despite prior reports among more clinically stable patients showing higher frequencies of coronary spasm in women versus men, these new reports in ACS patients did not link coronary artery spasm with sex.…”