Coronary Artery Spasm as a Cause of Acute Coronary Syndrome
About one in two ACS patients without artery occlusion exhibited vasospasm.
Coronary artery spasm is a potential cause of ischemia, but what is the incidence of spasm in patients who present to emergency departments with suspected acute coronary syndrome (ACS)? In this European study, investigators studied 488 consecutive patients with suspected ACS (defined as acute chest pain associated with ischemic changes on electrocardiogram or cardiac biomarker elevations) who underwent angiography.
In 138 patients (28%), epicardial coronary angiography did not reveal clear culprit lesions: 22 patients received alternative diagnoses (e.g., myocarditis) without spasm testing; 30 did not undergo spasm testing for various reasons; and 86 underwent provocative testing with intracoronary acetylcholine to see whether spasm (defined as a 75% constriction), associated with reproduction of symptoms, could be provoked. Spasm was confirmed in 42 patients. Among the 86 tested patients, cardiac enzyme levels generally were normal and were similar in patients with and without coronary spasm.
Comment: In this largely white cohort, angiography detected no culprit lesions in roughly one in four patients with suspected ACS. Of those who underwent acetylcholine challenges, almost half exhibited inducible vasospasms. As an editorialist notes, this study lacks outcome data to tell us whether vasospasm is associated with adverse outcomes in these patients and whether routine testing and treatment for spasm would be helpful in improving outcomes. However, clinicians should remember to consider vasospasm as an alternative diagnosis in patients with suspected ACS, especially when angiography reveals no clear culprit lesions.
Published in Journal Watch General Medicine September 30, 2008
Citation(s): Ong P et al. Coronary artery spasm as a frequent cause of acute coronary syndrome: The CASPAR (Coronary Artery Spasm in Patients With Acute Coronary Syndrome) study. J Am Coll Cardiol 2008 Aug 12; 52:523