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ABSORB Japan
Published in Yoshinobu Onuma, Patrick W.J.C. Serruys, Bioresorbable Scaffolds, 2017
ABSORB Japan was a prospective, multicenter, randomized, single-blind, active-controlled clinical trial in which 400 patients undergoing coronary stent implantation from 38 investigational sites in Japan were randomized in a 2:1 ratio to treatment with the Absorb everolimus-eluting BVS or the XIENCE Prime/Xpedition CoCr-EES (both Abbott Vascular, Santa Clara, CA). Patients were eligible if they were ≥20 years of age and had evidence of myocardial ischemia (stable angina, unstable angina, or silent ischemia). We excluded patients with left ventricular ejection fraction <30%, estimated glomerular filtration rate <30 mL/min/1.73 m2, recent myocardial infarction, and those at high bleeding risk. The study allowed treatment of up to two de novo native lesions in separate epicardial coronary arteries. Key angiographic inclusion criteria included reference vessel diameter ≥2.5 to ≤3.75 mm, lesion length ≤24 mm and percent diameter stenosis (DS) ≥50% to <100%. Key angiographic exclusion criteria included left main or ostial location; excessive vessel tortuosity or extreme lesion angulation; heavy calcification proximal to or within the target-lesion; myocardial bridge; restenotic lesion; target vessel containing thrombus; and bifurcation lesion with side branch ≥2 mm in diameter, requiring protection guidewire or dilatation (Figure 6.5.1a).
Cardiac Hypertrophy, Heart Failure and Cardiomyopathy
Published in Mary N. Sheppard, Practical Cardiovascular Pathology, 2022
The striking and still largely unexplained feature is a very marked variation in the macroscopic autopsy appearances between cases. This is even true of members of one family who all carry the same gene mutation. Family-to-family variation is even more pronounced. As already described, asymmetric hypertrophy of the interventricular septum (seeFig. 5.37) with the free wall being macroscopically normal is the commonest phenotypic presentation. Ratios of septal width to posterior wall thickness in the left ventricle exceed a ratio of 2:1. The septal asymmetry is best appreciated in short-axis transverse sections of the ventricles. Such tissue slices also show a characteristic whorled cut surface macroscopically reflecting the muscle bundle disarray and fibrosis. The structural heterogeneity in HCM is considerable, with no single pattern of LVH regarded as typical, almost one third have mild wall thickening localized to a single segment, including the apical form that appears most commonly in Japanese people. Less common forms involve the midventricular level and apical septal areas complicated occasionally by left ventricular aneurysms and thrombi. Distribution of LV wall thickening shows no direct linkage to outcome, although distal hypertrophy is obviously not associated with left ventricular outflow obstruction. There may also be concentric hypertrophy with a greatly reduced chamber (Fig. 5.42). Myocardial bridge, i.e. a deep intramyocardial course of the left anterior descending coronary artery, is much more frequent in HCM than in the normal heart. In 30% of cases, the heart may be normal in weight and wall thickness so a normal appearing heart does not rule out HCM.25
Coronary arterial anatomy: Normal, variants, and well-described collaterals
Published in Debabrata Mukherjee, Eric R. Bates, Marco Roffi, Richard A. Lange, David J. Moliterno, Nadia M. Whitehead, Cardiovascular Catheterization and Intervention, 2017
John P. Erwin, Evan L. Hardegree, Gregory J. Dehmer
One of the most common variations in the course of a coronary artery occurs when a segment of the epicardial artery dips into the myocardium, resulting in the overlying myocardium compressing the artery during systole.[51] The muscle overlying the intramyocardial segment is called a myocardial bridge and the artery coursing through the myocardium is called a tunneled artery. The most frequent site of bridging is the mid-segment of the LAD. A typical muscular bridge in this segment is 10-20 mm long and 2-4 mm thick, but segments up to 50 mm in length have been observed. Muscular bridges may exist over diagonal arteries, the left main, LCx, marginal branches, and the RCA. Angiographic studies show a prevalence of bridging varying from 0.5% to 7.5% of studies, whereas autopsy studies show a prevalence as high as 60% in the LAD and 6% to 50% in other vessels.[52,53] Factors such as the length of the tunneled segment, the degree of systolic compression, and the heart rate have all been postulated to explain the dif- ference between angiographic and autopsy studies. In addi- tion, for systolic narrowing to occur, the external muscular compressive force must exceed the arterial pressure and the intrinsic arterial wall stiffness. During angiography, the increased intraluminal pressure related to the contrast injection may diminish the appearance of systolic com- pression and thus the appreciation of a myocardial bridge. Anatomic variation in bridges also exists. Arteries located in the atrioventricular groove (proximal RCA and LCx) may be surrounded by scattered muscular fibers continuous with the atrial myocardium and may have systolic compres- sion, but these are referred to as myocardial loops rather than classic myocardial bridges. Also, arteries such as an obtuse marginal branch or ramus located over the free wall of the LV may dive into the myocardium and not resurface.
Focus on cardiometabolic risk factors
Published in Acta Cardiologica, 2023
Glucagon-like peptide-1 receptor agonists (GLP-1RAs), a group of novel antidiabetic agents, demonstrated beneficial cardiovascular effects in recent large, placebo-controlled randomised clinical trials (RCTs) [18]. In patients with type 2 diabetes mellitus, treatment with GLP-1RAs does not significantly affect the risk for major cardiac arrhythmias [19]. The abnormal composition of the gut microbiota is linked to the pathogenesis and propagation of CVD and CVD risk factors. Nagarajan’s review discussed various aspects of the interaction between the microbiome and the immune system in order to reveal causative links relating dysbiosis and autoimmune diseases with special emphasis on rheumatic heart disease [20]. Hypothyroidism can result in decreased cardiac output, increased systemic vascular resistance, decreased arterial compliance, and atherosclerosis. Subclinical hypothyroidism is a highly prevalent disease worldwide but remains challenging to diagnose. The influence of subclinical thyroid dysfunction on the heart and cardiovascular system has been much less studied, necessitating additional studies [21]. Beta-blockers block are widely prescribed for angina, heart failure and some heart rhythm disorders, and to control blood pressure. In patients with myocardial bridge, beta-blockers have a beneficial effect on left ventricular function [22].
Decision making in anomalous aortic origin of a coronary artery
Published in Expert Review of Cardiovascular Therapy, 2023
Hitesh Agrawal, Alexandra Lamari-Fisher, Keren Hasbani, Stephanie Philip, Charles D. Fraser, Carlos M. Mery
The AAOCA literature includes many retrospective single-center studies, most of them with limited follow-up [65,71–75]. One of the largest single-center retrospective studies by the Stanford group included 115 patients that underwent repair of AAOCA [65]. Of these, approximately 50% had pre-operative ischemia, 30% were asymptomatic, and 20% had other congenital heart defects requiring surgery. In general, an unroofing was performed for patients with an intramural segment. For those that had no intramural segment, if there were two separate coronary ostia, a coronary translocation was performed, and if there was a single coronary ostium, a pulmonary artery translocation procedure was undertaken. There were no operative mortalities. One patient required early revision for residual narrowing and four patients had postcardiotomy syndrome. At 6 years follow-up, there were no deaths but two patients required reintervention after unroofing. One had a coronary translocation for persistent symptoms and was then found to have a myocardial bridge for continuing symptoms. Another patient had a repeat intervention to unroof a myocardial bridge.
Applications of computational fluid dynamics to congenital heart diseases: a practical review for cardiovascular professionals
Published in Expert Review of Cardiovascular Therapy, 2021
Gianluca Rigatelli, Claudio Chiastra, Giancarlo Pennati, Gabriele Dubini, Francesco Migliavacca, Marco Zuin
Myocardial bridges (MB) were assessed by Javadzadegan et al. [23] using CFD, by dividing patient-specific myocardial bridge models (n = 10) by length. A direct relationship between myocardial bridge length and hemodynamic perturbations emerged in this study. Long myocardial bridge length seems to be associated with lower WSS and higher residence time in the proximal segment to the bridge, and a higher WSS and shorter residence time within the bridge, as compared to short length. More recently Sharzehee M et al. [24] showed that increasing the MB length (by 140%) only had significant impact on the pressure drop in the severe MB (39% increase at the exercise). However, increasing the stenosis length dramatically increased the pressure drop in both moderate and severe stenoses at all flow rates (31% and 93% increase at the exercise, respectively). Both CFD and experimental results confirmed that the MB had a higher maximum and a lower mean pressure drop in comparison with the stenosis, regardless of MB/stenosis severity.