Quantitative analysis of the relationship between the myocardial bridge and the FAI of pericoronal fat on computed tomography

We performed this cohort study to investigate whether the myocardial bridge (MB) affects the fat attenuation index (FAI) and to determine the optimal cardiac phase to measure the volume and the FAI of pericoronary adipose tissue (PCAT). The data of 300 patients who were diagnosed with MB of the left anterior descending (LAD) coronary artery were retrospectively analyzed. All of patients were divided into the MB group and the MB with atherosclerosis group. In addition, 104 patients with negative CCTA results were enrolled as the control group. There was no significant difference between FAI values measured in systole and diastole (P > 0.05). There was no significant difference in FAI among the MB group, the MB with atherosclerosis group, and the control group (P > 0.05). In MB with atherosclerosis group, LAD stenosis degree (< 50%) (OR = 0.186, 95% CI 0.036-0.960; P = 0.045) and MB located in the distal part of LAD opening (OR = 0.880, 95% CI 0.789-0.980; P = 0.020) were protective factors of FAI value. A distance (from the LAD opening to the proximal point of the MB) of 29.85 mm had the highest predictive value for abnormal FAI [area under the curve (AUC), 0.798], with a sensitivity of 81.1% and a specificity of 74.6%.

Prevalence and characteristics of coronary artery fistulas among 20 259 patients undergoing invasive coronary angiography

BACKGROUND

Coronary artery fistula (CAF) is a rare coronary anomaly. This study aimed to investigate the prevalence, clinical features, and imaging characteristics of CAF among patients undergoing coronary angiography (CAG).

METHOD

This was a retrospective study including 20 259 consecutive patients (12 458 were male) who underwent CAG at our institution from September 2018 to March 2023. Electronic angiography records were reviewed, and a total of 86 (0.42%) CAF patients were enrolled and analyzed.

RESULT

Of the 86 CAF patients, 42 (49%) were male. Thus, the prevalence of CAF for males and females was 0.34% and 0.56%, respectively. Arrhythmia, left ventricular (LV) hypertrophy, LV dilation, and LV systolic dysfunction were observed in 38, 25, 10 and 5 cases, respectively. Among the 86 CAF patients, a total of 117 CAFs were detected. 61 (71%) patients had a single CAF, and the remaining 25 (29%) patients had multiple CAFs. Of the 117 CAFs, the most common origins and terminations were the left anterior descending artery (n = 50) and the pulmonary artery (n = 73), respectively. The CAF diameters were greatly varied, ranging from unmeasurable to 7.8 mm, and 22 (18%) CAFs were larger than 3 mm.

CONCLUSION

In the present study, the prevalence of CAF was 0.42% with a female predilection. Arrhythmia, LV remodeling and dysfunction were common. Seventy-one percent of patients had a single CAF. The left anterior descending artery and the pulmonary artery were the most common origin and termination of CAFs, respectively. Most CAFs were small, and 18% of CAFs were larger than 3 mm.

Risk of sports-related sudden cardiac death in women

Sudden cardiac death (SCD) is a tragic incident accountable for up to 50% of deaths from cardiovascular disease. Sports-related SCD (SrSCD) is a phenomenon which has previously been associated with both competitive and recreational sport activities. SrSCD has been found to occur 5-33-fold less frequently in women than in men, and the sex difference persists despite a rapid increase in female participation in sports. Establishing the reasons behind this difference could pinpoint targets for improved prevention of SrSCD. Therefore, this review summarizes existing knowledge on epidemiology, characteristics, and causes of SrSCD in females, and elaborates on proposed mechanisms behind the sex differences. Although literature concerning the aetiology of SrSCD in females is limited, proposed mechanisms include sex-specific variations in hormones, blood pressure, autonomic tone, and the presentation of acute coronary syndromes. Consequently, these biological differences impact the degree of cardiac hypertrophy, dilation, right ventricular remodelling, myocardial fibrosis, and coronary atherosclerosis, and thereby the occurrence of ventricular arrhythmias in male and female athletes associated with short- and long-term exercise. Finally, cardiac examinations such as electrocardiograms and echocardiography are useful tools allowing easy differentiation between physiological and pathological cardiac adaptations following exercise in women. However, as a significant proportion of SrSCD causes in women are non-structural or unexplained after autopsy, channelopathies may play an important role, encouraging attention to prodromal symptoms and family history. These findings will aid in the identification of females at high risk of SrSCD and development of targeted prevention for female sport participants.

Myocardial bridges: A meta-analysis

Myocardial bridges are anatomical entities characterized by myocardium covering segments of coronary arteries. In some patients, the presence of a myocardial bridge is benign and is only incidentally found on autopsy. In other patients, however, myocardial bridges can lead to compression of the coronary artery during systolic contraction and delayed diastolic relaxation, resulting in myocardial ischemia. This ischemia in turn can lead to myocardial infarction, ventricular arrhythmias and sudden cardiac death. Myocardial bridges have also been linked to an increased incidence of atherosclerosis, which has been attributed to increased shear stress and the presence of vasoactive factors. Other studies however, demonstrated the protective roles of myocardial bridges. In this study, using systematic review and a meta-analytical approach we investigate the prevalence and morphology of myocardial bridges in both clinical imaging and cadaveric dissections. We also discuss the pathophysiology, clinical significance, and management of these anatomical entities.

Bridging the Gap in a Rare Cause of Angina

Myocardial bridging occurs when coronary arteries run intramurally. Episodes of tachycardia can cause a dynamic obstruction that extends into diastole, compromising coronary filling time, and subsequently leading to ischaemia. Myocardial ischaemia, acute coronary syndrome, coronary spasm, myocardial stunning, arrhythmia, takotsubo cardiomyopathy, and sudden cardiac death have all been reported with bridging. Atherosclerotic plaques develop proximally in the bridge due to low shear stress and high oscillatory wall-flow. Factors affecting atherosclerotic build-up include disrupted flow patterns (particularly flow recirculation, which exacerbates LDL internalisation), cell adhesion and monocyte adhesion to the endothelium. Endothelial health depends on arterial flow patterns, given that the vessel reacts differently to various flow types, as confirmed in 3D simulations. Medication is the first-line therapy, while surgical de-roofing and coronary bypass are reserved for severe stenosis. Distinguishing physiological arterial compression from pathological stenosis is essential. Deeper bridges correlating with recurrent angina with an instantaneous wave-free ratio ≤0.89 or fractional flow reserve ≤0.80 are treated.

Invasive assessment of myocardial bridging in patients with angina and no obstructive coronary artery disease

AIMS

Angina and no obstructive coronary artery disease (ANOCA) is common. A potential cause of angina in this patient population is a myocardial bridge (MB). We aimed to study the anatomical and haemodynamic characteristics of an MB in patients with ANOCA.

METHODS AND RESULTS

Using intravascular ultrasound (IVUS), we identified 184 MBs in 154 patients. We evaluated MB length, arterial compression, and halo thickness. MB muscle index (MMI) was defined as MB length×halo thickness. Haemodynamic testing of the MB was performed using an intracoronary pressure/Doppler flow wire at rest and during dobutamine stress. We defined an abnormal diastolic fractional flow reserve (dFFR) as ≤0.76 during stress. The median MB length was 22.9 mm, arterial compression 30.9%, and halo thickness 0.5 mm. The median MMI was 12.1. Endothelial and microvascular dysfunction were present in 85.4% and 22.1%, respectively. At peak dobutamine stress, 94.2% of patients had a dFFR ≤0.76 within and/or distal to the MB. MMI was associated with an abnormal dFFR.

CONCLUSIONS

In select patients with ANOCA who have an MB by IVUS, the majority have evidence of a haemodynamically significant dFFR during dobutamine stress, suggesting the MB as being a cause of their angina. A comprehensive invasive assessment of such patients during coronary angiography provides important diagnostic information that can guide management.

Sex differences in non-obstructive coronary artery disease

Ischaemic heart disease is a leading cause of morbidity and mortality in both women and men. Compared with men, symptomatic women who are suspected of having myocardial ischaemia are more likely to have no obstructive coronary artery disease (CAD) on coronary angiography. Coronary vasomotor disorders and coronary microvascular dysfunction (CMD) have been increasingly recognized as important contributors to angina and adverse outcomes in patients with no obstructive CAD. CMD from functional and structural abnormalities in the microvasculature is associated with adverse cardiac events and mortality in both sexes. Women may be particularly susceptible to vasomotor disorders and CMD due to unique factors such as inflammation, mental stress, autonomic, and neuroendocrine dysfunction, which predispose to endothelial dysfunction and CMD. CMD can be detected with coronary reactivity testing and non-invasive imaging modalities; however, it remains underdiagnosed. This review focuses on sex differences in presentation, pathophysiologic risk factors, diagnostic testing, and prognosis of CMD.

Gender Differences in Types, Frequency, Clinical Manifestations and Atherosclerotic Burden of Coronary Artery Anomalies

BACKGROUND

Although not well established; gender may play a role in the incidence, clinical manifestations, and atherosclerotic burden of Coronary Artery Anomalies (CAAS). Our aim is to investigate the impact of gender on coronary artery anomalies.

METHODS

All coronary angiograms performed at the University Heart Center Zurich, Switzerland, between January 2000 and December 2016 were investigated. Those of anomalous origin, course and termination (fistula) were included in the analysis with the exclusion of coronary artery aneurysms and myocardial bridges.

RESULTS

Out of the original 39577 angiographic studies that included 28550 males and 11026 females, Coronary Artery Anomalies (CAAS) were documented in 130 (0.32%) patients of whom 69.2% (n=90) and 30.8%(n=40) were males and females respectively. However, the overall prevalence of coronary anomalies amongst both genders did not differ (0.32% vs 0.36%, P = 1) and so were the basic characteristics except for hypertension, which was more prevalent in females (P = 0.03644). The most prevalent anomaly overall was (left circumflex artery from right coronary artery/sinus), which was present in (n=47, 36.2%). No impact of gender on the incidence of individual anomalies except for Right Coronary Artery (RCA) originating from Left Circumflex Artery (LCX), which was only documented in men (P = 0.0000116). On the other hand malignant CAAS presented equally with a proportion of 10% for both genders (P = 1). Although males outnumbered females in terms of atherosclerotic burden in CAAS this was statistically not significant (P = 0.331).

CONCLUSION

Both genders have a similar impact on the overall prevalence, clinical manifestations and atherosclerotic burden of CAAs. Anomaly of RCA originating from LCX occurred more frequently in males than females.

Cardiovascular consequences of myocardial bridging: A meta-analysis and meta-regression

Myocardial bridging, a congenital abnormality in which a coronary artery tunnels through the myocardial fibres was usually considered a benign condition. Many studies suggested a potential hemodynamic significance of myocardial bridging and some, usually case reports, implied a possible correlation between it and various cardiovascular pathologies like acute myocardial infarction, ventricular rupture, life-threatening arrhythmias, hypertrophic cardiomyopathy, apical ballooning syndrome or sudden death. The main objective of this article is to evaluate whether myocardial bridging may be associated with significant cardiac effects or if it is strictly a benign anatomical variation. To this purpose, we performed a meta-analysis (performed using the inverse variance heterogeneity model) and meta-regression, on scientific articles selected from three main databases (Scopus, Web of Science, Pubmed). The study included 21 articles. MB was associated with major adverse cardiac events - OR = 1.52 (1.01–2.30), and myocardial ischemia OR = 3.00 (1.02–8.82) but not with acute myocardial infarction, cardiovascular death, ischemia identified using imaging techniques, or positive exercise stress testing. Overall, myocardial bridging may have significant cardiovascular consequences (MACE, myocardial ischemia). More studies are needed to reveal/refute a clear association with MI, sudden death or other cardiovascular pathologies.

Myocardial Bridging: A Meta-Analysis of Prevalence

The main objective of this article was to analyze prevalence data about myocardial bridging (MB) in published studies. To this purpose, we performed a meta-analysis of studies published in English literature that contained data about the prevalence of MB and its anatomical characteristics. The overall prevalence was 19% (CI: 17-21%); autopsy studies revealed an overall prevalence of 42% (CI: 30-55%), CT studies 22% (CI: 18-25%), and coronary angiography 6% (CI: 5-8%). Most bridges were located on the left anterior descending artery (82% overall, 63% on autopsy studies), had a mean thickness of 2.47 mm and a mean length of 19.3 mm. In conclusion, autopsy studies should be the gold standard in evaluating the actual prevalence of myocardial bridges, while in vivo high-resolution CT scanning should be preferred to coronary angiography studies.

Understanding the Role of Sex in Heart Valve and Major Vascular Diseases

Cardiovascular disease (CVD) is the major cause of mortality in the elderly population. The cost of CVD treatment and surgeries was over $300 billion in the United States alone in 2010, making this disorder a critical healthcare issue. Many studies have suggested sex as a risk factor for heart valve and major vascular diseases, such as aortic valve stenosis, mitral prolapse and regurgitation, atherosclerosis, coronary artery disease, and abdominal aortic aneurysm. Unfortunately, only a handful of studies have illustrated the role of sex in the etiology and progression of these disorders. Moreover, knowledge of biomolecular factors that affect these diseases in men and women is very limited. Numerous clinical studies have revealed obvious differences in the prevalence of these diseases between the sexes. These reports were supported by a few molecular and cellular physiology studies that associated this difference to sex and sex hormones. In particular, male sex has commonly been identified as a risk factor for majority of heart valve and vascular diseases, whereas females have been identified as higher risk for certain disorders as well. In addition, menopause is a critical issue that turns the tables against women and enhances complications in their cardiovascular structure due to hormonal change. In this review, major vascular and heart valve diseases for which sex is associated as a risk factor have been reviewed to highlight the importance of this risk factor in CVDs.

The clinical anatomy of the coronary arteries

There are a manifold number of variations and anomalies of the origin and course of coronary arteries described in the literature. The incidence of such variations in the general population is reported to range between 0.3 and 1.6 %. Although uncommon, they may be benign or produce symptoms ranging from mild dyspnea to sudden cardiac death, and have been associated with an increased risk of accelerated atherosclerosis and perfusion defects. Thus, in order to effectively utilize the increasing number of therapeutic options available for treating coronary artery diseases, an appreciation of the likely normal and variable arrangements of the coronary arteries is essential. This review will describe the normal anatomy of the coronary arteries as well as the common variations with potential clinical effects.