Clinical impact of coronary artery spasm in patients with no significant coronary stenosis in acute coronary syndromes

Abstract

Background and objective: To clarify the clinical features of coronary artery spasm (CAS) with no significant coronary stenosis in patients with suspected acute coronary syndrome (ACS) in real practice. Methods: This is a retrospective observational study of patients with suspected ACS (n = 645) based on symptoms, electrocardiographic changes, and/or positive cardiac biomarkers and vasospastic angina (VSA, n = 90). ACS patients were divided into two groups: (1) organic ACS (n = 515), culprit lesion ≥75% coronary stenosis with/without thrombosis; (2) spastic ACS (n = 70), coronary stenosis <75%, either with positive acetylcholine (ACh) test (n = 51) or without ACh test but verified spontaneous spasm (n = 19). The study compared clinical characteristics among organic ACS, spastic ACS, and VSA. Results: One hundred and thirty suspected ACS patients had a coronary organic stenosis <75% (130/645, 20%). Seventy of those patients (70/130, 54%) were confirmed to have CAS, and these accounted for 11% of all ACS patients (70/645). The rate of cigarette smoking was highest in the spastic ACS. No spastic ACS patients died during their hospital stay or after discharge, whereas acute myocardial infarction occurred in 19%, aborted sudden cardiac death in 6%, multivessel spasm was provoked in 78%, and diffuse spasm was more frequently provoked than in the VSA group (82% vs. 62%). Conclusions: CAS is not a rare cause of ACS. Although the prognosis of spastic ACS is good, there are occasional critical cases. An initial differential diagnosis including an ACh test is thus important to decide the treatment strategy of ACS.

A Case of Vasospastic Angina Involving Erosion and Thrombus within the Spastic Segment Detected by Coronary Angioscopy

“…Thrombus formation due to coronary spasms has been reported as one of the mechanisms responsible for ACS without plaque rupture [2][3][4], with the findings of the present case supporting the presence of coronary spasm-induced thrombus formation.…”

“…In cases with coronary plaque rupture, coronary spasm may cause plaque rupture mediated by the external force of the coronary spasm itself; and this relationship was confirmed in an autopsy case report [7]. On the other hand, coronary erosions without plaque rupture are thought to contribute to coronary spasminduced thrombus formation [2][3][4]. Using CAS, Etuda et al [5] reported that intracoronary abnormalities, such as intracoronary hemorrhage, intimal flap, thrombus, or ulcers, were present in 40% of cases with variant angina, which is thought to be a type of angina with a high coronary spasm activity.…”

“…Further, thrombus formation is most commonly caused by plaque rupture [1]. Conversely, ACS without plaque rupture has been reported [2], and coronary spasm has been considered one of the causes of ACS without plaque rupture [2][3][4]. However, a little is known regarding the relationship between coronary spasm and thrombus formation [5,6].…”

Prognosis of Patients With Non–ST-Segment–Elevation Myocardial Infarction and Nonobstructive Coronary Artery Disease

“…[5][6][7] The pathophysiology of troponin elevation in these patients is not completely understood. 8,9 Potential explanations include rupture of a mild plaque with endogenous thrombolysis before angiography; coronary artery spasm 10 ; mismatch between oxygen demand and supply, resulting in myonecrosis without plaque rupture as in type-2 myocardial infarction (MI) 11 ; and noncoronary causes of myocardial injury such as myocarditis. Regardless of the cause, the finding of nonocclusive coronary artery disease (CAD) in patients with NSTEACS and troponin elevation remains a diagnostic and therapeutic dilemma for the treating physician.…”

Malondialdehyde-Modified Low Density Lipoprotein as Oxidative-Stress Marker in Vasospastic Angina Patients

“…VSA is always accompanied by the possibility of ACS, 44) AMI, fatal arrhythmia, and CPA. 19,20) It is not rare that a first time attack causes a critical situation in the emergency room.…”