Clinical efficacy of aspirin with identification of intimal morphology by optical coherence tomography in preventing event recurrence in patients with vasospasm-induced acute coronary syndrome

Canadian Cardiovascular Society/Canadian Women's Heart Health Alliance Clinical Practice Update on Myocardial Infarction With No Obstructive Coronary Artery Disease (MINOCA)

Myocardial infarction with no obstructive coronary artery disease (MINOCA) represents 6%-15% of all acute coronary syndromes, and women are disproportionately represented. MINOCA is an encompassing preliminary diagnosis, and emerging evidence supports a more expansive comprehensive diagnostic and therapeutic clinical approach. The current clinical practice update summarizes the latest evidence regarding the epidemiology, clinical presentation, and diagnostic evaluation of MINOCA. A cascaded approach to diagnostic workup is outlined for clinicians, for noninvasive and invasive diagnostic pathways, depending on clinical setting and local availability of diagnostic modalities. Evidence concerning the nonpharmacological and pharmacological treatment of MINOCA are presented and summarized according to underlying cause of MINOCA, with practical tips on the basis of expert opinion, outlining a real-life, evidence-based, comprehensive approach to management of this challenging condition.

A Rare Encounter: Unstable Vasospastic Angina Induced by Thyrotoxicosis

Coronary artery vasospasm plays a crucial role in the prevalence of unstable angina. Despite common misdiagnosis, there is limited evidence on this topic. Here, we present a rare case of unstable vasospastic angina in a female with severe thyrotoxicosis. Case Report: A 62-year-old female patient was admitted to the cardiac intensive care unit due to crushing chest pain at rest. The patient exhibited ischemic changes on the ECG with a normal troponin I level. Recurrent chest pain prompted urgent coronary angiography, revealing generalized vasospasm of all coronary artery branches including the left main coronary artery. Intracoronary nitroglycerin injection partially alleviated the vasospasm; however, there was a persistent stenosis in the left main artery. Subsequent intravascular ultrasound demonstrated an anatomically normal left main artery. Post-procedure, laboratory tests revealed undetectable levels of thyroid-stimulating hormone and thyroid hormones above the detectable level. The patient was initiated on methimazole and discharged symptom-free, expecting a good prognosis under conservative management. Conclusions: Clinically significant coronary vasospasm triggered by thyrotoxicosis remains a rarity in clinical practice, often posing diagnostic challenges. This case emphasizes the significance of intracoronary nitroglycerin and intravascular ultrasound in discerning the etiology of coronary lesions seen on angiography. We advocate for these techniques to optimize invasive coronary artery diagnostics, enabling the selection of the appropriate treatment strategies and improving long-term prognosis.

Healed plaque erosion as a cause of recurrent vasospastic angina: a case report

Background

Recurrent vasospastic angina sometimes occurs. Fresh thrombi have been known to arise without plaque rupture at coronary spasm sites due to blood flow stagnation and intimal erosion caused by vasospasms. The relationship between recurrence of vasospastic angina and thrombus formation remains unclear.

Case summary

A 67-year-old man presented with sudden chest pain at rest. Electrocardiography and coronary angiography indicated vasospastic angina. His chest pain persisted despite the administration of benidipine, isosorbide mononitrate, nicorandil, and nifedipine. Coronary angiography performed one month after initial presentation showed stenosis refractory to isosorbide administration. Optical coherence tomography revealed a healed plaque, and a stent was deployed. The patient remained symptom-free at 1-year follow-up.

Discussion

Prolonged coronary vasospasm with limited coronary blood flow could induce total occlusion of the coronary artery, and acute thrombus formation, which resulted in healed plaque erosion. When vasospastic angina cannot be controlled, rapidly progressive stenosis caused by healed plaque erosion could be its underlying cause and mechanism. This report indicates that antiplatelet therapy may be a preventive option for future recurrent vasospastic angina, especially in those caused by healed plaques.

Impact of aspirin use on clinical outcomes in patients with vasospastic angina: a systematic review and meta-analysis

OBJECTIVES

The use of aspirin to prevent cardiovascular disease in vasospastic angina (VSA) patients without significant stenosis has yet to be investigated. This study aimed to investigate the efficacy of aspirin use among VSA patients.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Web of Science and Cochrane Central Register of Controlled Trials were searched for relevant information prior to October 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Aspirin use versus no aspirin use (placebo or no treatment) among VSA patients without significant stenosis.

DATA EXTRACTION AND SYNTHESIS

Two investigators extracted the study data. ORs and 95% CIs were calculated and graphed as forest plots. The Newcastle-Ottawa Quality Assessment Scale tool and Begg's funnel plot were used to assess risk of bias.

RESULTS

Four propensity-matched cohorts, one retrospective analysis and one prospective multicentre cohort, in total comprising 3661 patients (aspirin use group, n=1695; no aspirin use group, n=1966) were included in this meta-analysis. Aspirin use and the incidence of major cardiovascular adverse events with follow-up of 1-5 years were not significantly correlated (combined OR=0.90, 95% CI: 0.55 to 1.68, p=0.829, I²=82.2%; subgroup analysis: OR=1.09, 95% CI: 0.81 to 1.47, I²=0%). No significant difference was found between aspirin use and the incidence of myocardial infarction (OR=0.62, 95% CI: 0.09 to 4.36, p=0.615, I²=73.8%) or cardiac death (OR=1.73, 95% CI: 0.61 to 4.94, p=0.444, I²=0%) during follow-up.

CONCLUSION

Aspirin use may not reduce the risk of future cardiovascular events in VSA patients without significant stenosis.

PROSPERO REGISTRATION NUMBER

CRD42020214891.

The impact of antiplatelet therapy on patients with vasospastic angina: A multicenter registry study of the Japanese Coronary Spasm Association

BACKGROUND

Antiplatelet therapy (APT) is generally used in patients with coronary artery disease. However, for patients with vasospastic angina (VSA), the impact of APT is not fully understood.

METHODS

In a multicenter registry study of the Japanese Coronary Spasm Association (n = 1429), patients with or without APT were compared. The primary endpoint was major adverse cardiac events (MACEs), defined as cardiac death, non-fatal myocardial infarction, unstable angina, heart failure and appropriate ICD (Implantable cardioverter defibrillator) shock. Propensity score matching and a multivariable cox proportional hazard model were used to adjust for selection bias for treatment and potential confounding factors.

RESULTS

In the whole population, 669 patients received APT, while 760 patients did not receive APT. Patients with APT had a greater prevalence of comorbidities, such as hypertension, diabetes, dyslipidemia and smoking, than those without APT. The prevalences of previous myocardial infarction, spontaneous ST changes, significant organic stenosis and medications including calcium channel blocker, nitrate, statin and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker were greater in patients with APT than those without APT. After propensity matching (n = 335 for both groups), during the median follow-up period of 32 months, the incidence rate of MACE was comparable between the patients with and without APT (P = 0.24). MACEs occurred in 5.7% of patients with APT and in 3.6% of those without APT (P = 0.20). All-cause death occurred in 0.6% of patients with APT and 1.8% of those without APT (p = 0.16).

CONCLUSION

In this multicenter registry study, anti-platelet therapy exerted no beneficial effects for VSA patients.