Search

[Display omitted] [ABSTRACT FROM AUTHOR]

Background—Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a puzzling clinical entity with no previous evaluation of the literature. This systematic review aims to (1) quantify the prevalence, risk factors, and 12-month prognosis in patients with MINOCA, and (2) evaluate potential pathophysiological mechanisms underlying this disorder. Methods and Results—Quantitative assessment of 28 publications using a meta-analytic approach evaluated the prevalence, clinical features, and prognosis of MINOCA. The prevalence of MINOCA was 6% [95% confidence interval, 5%-7%] with a median patient age of 55 years (95% confidence interval, 51-59 years) and 40% women. However, in comparison with those with myocardial infarction associated with obstructive coronary artery disease, the patients with MINOCA were more likely to be younger and female but less likely to have hyperlipidemia, although other cardiovascular risk factors were similar. All-cause mortality at 12 months was lower in MINOCA (4.7%; 95% confidence interval, 2.6%-6.9%) compared with myocardial infarction associated with obstructive coronary artery disease (6.7%, 95% confidence interval, 4.3%-9.0%). Qualitative assessment of 46 publications evaluating the underlying pathophysiology responsible for MINOCA revealed the presence of a typical myocardial infarct on cardiac magnetic resonance imaging in only 24% of patients, with myocarditis occurring in 33% and no significant abnormality in 26%. Coronary artery spasm was inducible in 27% of MINOCA patients, and thrombophilia disorders were detected in 14%. Conclusions—MINOCA should be considered as a working diagnosis with multiple potential causes that require evaluation so that directed therapies may improve its guarded prognosis. [ABSTRACT FROM AUTHOR]

Background: Suspected myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) occurs in [almost equal to]5% to 10% of patients with MI referred for coronary angiography. The prognosis of these patients may differ to those with MI and obstructive coronary artery disease (MI-CAD) and those without a MI (patients without known history of MI [No-MI]). The primary objective of this study is to evaluate the 12-month all-cause mortality of patients with MINOCA. Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the terms "MI," "nonobstructive," "angiography," and "prognosis" were searched in PubMed and Embase databases from inception to December 2018, including original, English language MINOCA studies with >100 consecutive patients. Publications with a heterogeneous cohort, unreported coronary stenosis, or exclusively focusing on MINOCA-mimicking conditions, were excluded. Unpublished data were obtained from the MINOCA Global Collaboration. Data were pooled and analyzed using Paule-Mandel, Hartung, Knapp, Sidik & Jonkman, or restricted maximum-likelihood random-effects meta-analysis methodology. Heterogeneity was assessed using Cochran's Q and I2 statistics. The primary outcome was 12-month all-cause mortality in patients with MINOCA, with secondary comparisons to MI-CAD and No-MI. Results: The 23 eligible studies yielded 55 369 suspected MINOCA, 485 382 MI-CAD, and 33 074 No-MI. Pooled meta-analysis of 14 MINOCA studies accounting for 30 733 patients revealed an unadjusted 12-month all-cause mortality rate of 3.4% (95% CI, 2.6%-4.2%) and reinfarction (n=27 605; 10 studies) in 2.6% (95% CI, 1.7%-3.5%). MINOCA had a lower 12-month all-cause mortality than those with MI-CAD (3.3% [95% CI, 2.5%-4.1%] versus 5.6% [95% CI, 4.1%-7.0%]; odds ratio, 0.60 [95% CI, 0.52-0.70], P <0.001).> P =0.09). Conclusions: In the largest contemporary MINOCA meta-analysis to date, patients with suspected MINOCA had a favorable prognosis compared with MI-CAD, but statistically nonsignificant trend toward worse outcomes compared to those with No-MI. Registration: URL: https://www.crd.york.ac.uk/PROSPERO/ ; Unique identifier: CRD42020145356. * Myocardial infarction with nonobstructive coronary arteries accounts for 5% to 10% of acute myocardial infarctions. These presentations are considered benign and many of these patients are often dismissed as 'false positive' myocardial infarcts. * In the largest contemporary meta-analysis to date, patients with suspected myocardial infarction with nonobstructive coronary arteries had significant cardiovascular events at 12 months with all-cause mortality of 3.4%, had a favorable prognosis compared to myocardial infarction with obstructive coronary artery disease, but worse prognosis compared with those without known history of myocardial infarction. [ABSTRACT FROM AUTHOR]

Introduction: Patients with Troponin positive Non-Obstructive Coronary Arteries (TpNOCA) warrant further investigation to elucidate the ischemic or non-ischemic cause of the suspected acute myocardial infarct (AMI) presentation. Patients clinically diagnosed with an underlying ischemic cause are subsequently referred to as MI with Non-Obstructive Coronary Arteries (MINOCA). This study evaluates the 2-year major adverse cardiac events (MACE) of MINOCA and secondly compares the outcomes of MINOCA patients with smooth coronaries and minor CAD. Methods: Consecutive patients undergoing angiography for AMI were captured in the Coronary Angiogram Database of South Australia (CADOSA) registry. Patients were categorised as TpNOCA based on the universal criteria for MI and absence of obstructive stenosis (<50%). TpNOCA patients diagnosed with a non-ischemic pathology (e.g. myocarditis) were excluded and the remaining MINOCA patients were categorised as minor CAD (stenosis <50%) or smooth coronaries (0% stenosis). The 2-year MACE (all-cause mortality and readmission for MI, angina, heart failure or stroke) was extracted from administrative data sets. Results: Between 2012-15, 6,811 angiographic procedures were undertaken for AMI, and 13% (882) were classified as TpNOCA, of which, 37% (322) were identified as MINOCA. MINOCA patients were: aged 60±16 yrs, 60% females, 57% hypertensive, 52% with hyperlipidaemia, 30% smokers and 20% with diabetes. Minor CAD was evident in 49% (157). Compared to MINOCA with minor CAD, those with smooth coronaries were younger (58±16 vs. 62±15 yrs p<0.05) and less likely to be females (52% vs 68%, p<0.05). Overall MACE at 2 years was 27% comprising of 3.7% mortality and 26% readmissions. The MACE was similar for MINOCA patients with smooth coronaries and minor CAD (24% vs 31%, OR 0.73, 95%CI 0.45-1.2, p>0.05, age adjusted) although a trend towards lower readmissions in the smooth coronaries group was observed (21% vs 30%, OR 0.64, 95%CI 0.4-1.1, p=0.09, age adjusted). Conclusions: Clinical outcomes in MINOCA warrant further scrutiny with 1 in 4 patients experiencing MACE within 2 years. Larger studies are needed to identify patients at high risk for adverse outcomes so secondary prevention strategies can be optimised. [ABSTRACT FROM AUTHOR]