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The incidence of left ventricular (LV) thrombus following acute myocardial infarction has markedly declined in recent decades caused by advancements in reperfusion and antithrombotic therapies. Despite this, embolic events remain the most feared complication of LV thrombus necessitating systemic anticoagulation. Mechanistically, LV thrombus development depends on Virchow's triad (ie, endothelial injury from myocardial infarction, blood stasis from LV dysfunction, and hypercoagulability triggered by inflammation, with each of these elements representing potential therapeutic targets). Diagnostic modalities include transthoracic echocardiography with or without ultrasound-enhancing agents and cardiac magnetic resonance. Most LV thrombi develop within the first 2 weeks post-acute myocardial infarction, and the role of surveillance imaging appears limited. Vitamin K antagonists remain the mainstay of therapy because the efficacy of direct oral anticoagulants is less well established. Only meager data support the routine use of prophylactic anticoagulation, even in high-risk patients., Competing Interests: Funding Support and Author Disclosures Dr Giustino has received honoraria from Bristol Myers Squibb. Dr Halperin has performed consulting activities with Bayer HealthCare, Boehringer Ingelheim, and Ortho-McNeil-Janssen; and has served on the Steering Committee of the CATALYST trial, sponsored by Abbott. Dr Sharma has received consulting fees or honoraria from Abbott, Boston Scientific, Abiomed, and Cardiovascular Systems, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022. Published by Elsevier Inc.)

Myocardial bridging (MB) is a congenital coronary anomaly in which a segment of the epicardial coronary artery traverses through the myocardium for a portion of its length. The muscle overlying the artery is termed a myocardial bridge, and the intramyocardial segment is referred to as a tunneled artery. MB can occur in any coronary artery, although is most commonly seen in the left anterior descending artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB associated with ischemic symptomatology. The advent of contemporary functional and anatomic imaging modalities, both invasive and noninvasive, have dramatically improved our understanding of dynamic pathophysiology associated with MBs. This review provides a contemporary overview of epidemiology, pathobiology, diagnosis, functional assessment, and management of MBs., Competing Interests: Funding Support and Author Disclosures Dr Sharma has received consultant fees from Abbott Vascular, Boston Scientific, and Cardiovascular Systems, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study investigated the relationship between low wall shear stress (WSS) and severe endothelial dysfunction (EDFx)., Background: Local hemodynamic forces such as WSS play an important role in atherogenesis through their effect on endothelial cells. The study hypothesized that low WSS independently predicts severe EDFx in patients with coronary artery disease (CAD)., Methods: Forty-four patients with CAD underwent coronary angiography, fractional flow reserve, and endothelial function testing. Segments with >10% vasoconstriction after acetylcholine (Ach) infusion were defined as having severe EDFx. WSS, calculated using 3-dimensional angiography, velocity measurements, and computational fluid dynamics, was defined as low (<1 Pa), intermediate (1 to 2.5 Pa), or high (>2.5 Pa)., Results: Median age was 52 years, 73% were women. Mean fractional flow reserve was 0.94 ± 0.06. In 4,510 coronary segments, median WSS was 3.67 Pa. A total of 24% had severe EDFx. A higher proportion of segments with low WSS had severe EDFx (71%) compared with intermediate WSS (22%) or high WSS (23%) (p < 0.001). Segments with low WSS demonstrated greater vasoconstriction in response to Ach than did intermediate or high WSS segments (-10.7% vs. -2.5% vs. +1.3%, respectively; p < 0.001). In a multivariable logistic regression analysis, female sex (odds ratio [OR]: 2.44; p = 0.04), diabetes (OR: 5.01; p = 0.007), and low WSS (OR: 9.14; p < 0.001) were independent predictors of severe EDFx., Conclusions: In patients with nonobstructive CAD, segments with low WSS demonstrated more vasoconstriction in response to Ach than did intermediate or high WSS segments. Low WSS was independently associated with severe EDFx., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)