Sex-dependent association between coronary vessel dominance and cardiac syndrome X: a case-control study

Examining the Influence of Gender, Age, and Dominance on the Caliber of Normal Coronary Arteries in the South Indian Population

Background The diameter of coronary arteries serves as a potential predictor of coronary artery diseases (CADs) that can lead to sudden death. Factors such as gender, age, and coronary artery dominance play a role in influencing the size of normal coronary arteries. The outcome of coronary interventions, to a certain extent, depends on luminal size. Given the considerable variability in luminal size within the normal population, establishing the baseline size of normal coronary arteries in a specific population can aid in estimating the severity of coronary disease and predicting the outcome of interventional procedures. The current study focuses on estimating the luminal diameter of normal coronary arteries within the context of age, gender, and cardiac dominance in the South Indian population. Methods A retrospective study was conducted utilizing coronary angiograms with normal findings from 453 patients, comprising 257 males and 196 females, with a mean age of 54.66±10.66 years. These patients attended the outpatient service of the Cardiology Department at Amrita Institute of Medical Sciences, Kochi, a quaternary care center, between 2015 and 2017. The luminal diameter of coronary arteries is represented as mean±SD in millimeters. Results In the present study, we noted that the largest coronary artery was the left main coronary artery (LMCA, 3.59±0.58 mm), followed by the left anterior descending artery (LAD, 3.50±0.52 mm), the left circumflex artery (LCX, 3.31±0.57 mm), and the right coronary artery (RCA, 3.18±0.57 mm). We further broke down the statistics to evolve a gender pattern. In the raw comparison of data, the luminal size of coronary arteries in males was greater than in females, and statistical significance was noted in all except LAD. In males, the largest coronary artery was LMCA (3.70±0.60 mm), followed by LAD (3.54±0.48 mm), LCX (3.36±0.58 mm), and RCA (3.25±0.62 mm). In females, no significant size difference was observed between LMCA (3.45±0.53 mm) and LAD (3.46±0.55 mm). Females exhibited an increase in the size of LMCA with advancing age. Regardless of right or left cardiac dominance, LMCA was consistently larger than RCA in both genders. However, in cases of co-dominance, only males demonstrated significantly larger LMCA. Conclusion Precise knowledge of the size of normal coronary arteries and their influence by gender, age, and dominance can be crucial for the comprehensive evaluation of CADs and the success of interventional procedures.

The Association of Severe Coronary Tortuosity and Non-Obstructive Coronary Artery Disease

Background and Objectives: There is an increasing interest in the coronary tortuosity as a novel pathophysiological mechanism of ischemia in coronary artery disease without significant obstruction, but there are a lack of studies to confirm this relationship in the clinical setting. The aim of our study was to evaluate the association of severe coronary tortuosity and the potential role of coronary blood supply dominance in the appearance of myocardial ischemia in patients with non-obstructive coronary artery disease (non-CAD), compared to patients with obstructive coronary artery disease (CAD). Materials and Methods: The study enrolled 131 participants (71 male and 60 female), recruited among patients referred to cardiologists due to angina symptoms with ischemic alterations established by cardiac stress tests, as well as those admitted to the hospital for acute coronary syndrome. Results: Mean age of recruited patients was 61.6 (±10.1) years. According to the coronary angiography, they were divided into two groups: non-obstructive and obstructive CAD (77 and 54, respectively). There were significantly more women (61% vs. 24%, p < 0.001) in the non-CAD group. Both tortuous coronary arteries (50.6% vs. 14.8%, p < 0.001) and left coronary dominance (37.7% vs. 16.7%, p = 0.006) were more frequent in the non-CAD group compared to the CAD group. Female sex (OR = 17.516, p = 0.001), tortuous coronary arteries (OR = 7.962, p = 0.006) and left dominance of blood supply were significant predictors for non-CAD. Conclusions: Non-obstructive CAD is common among patients, especially women, who are referred for coronary angiography. Severe coronary artery tortuosity is the strongest independent predictor of non-obstructive CAD, followed by female gender and left coronary dominance.

Association between coronary dominance and acute inferior myocardial infarction: a matched, case-control study

Background

Previous studies have found a connection between left coronary artery dominance and worse prognoses in patient with acute coronary syndrome, which remains a predominant cause of morbidity and mortality globally. The aim of this study was to investigate whether coronary dominance is associated with the incidence of acute inferior myocardial infarction (MI).

Methods

Between January 2011 and November 2014, 265 patients with acute inferior MI and 530 age-matched and sex-matched controls were recruited for a case-control study in the Second Affiliated Hospital of Xi’an Jiaotong University in Xi’an, China. All participants underwent coronary angiography. The exclusion criteria included history of coronary artery bypass graft surgery, chronic or systemic diseases (including hepatic failure, kidney failure, hypothyroidism and Grave’s disease), ventricular fibrillation, and known allergy to iodinated contrast agent. Patients with left- or co-dominant anatomies were placed into the LD group and those with right-dominant anatomy were included in the RD group. The association of acute inferior MI and coronary dominant anatomy were assessed using multivariable conditional logistic regression, and to estimate the odds ratio (OR) and 95% confidence interval (95%CI).

Results

Distributions of right dominance were significantly different between the acute inferior MI group and control group (94.0% vs. 87.9%, P = 0.018). Univariable conditional logistic regression revealed that right dominance may be a risk factor for the incident acute inferior MI (OR: 2.137; 95% CI: 1.210–3.776; P = 0.009). After adjusting for baseline systolic blood pressure, heart rate, smoking status, diabetes mellitus, hypertension, hyperlipidaemia, and family history of coronary artery disease, results of multivariate conditional logistic regression showed that right dominance was associated with the incidence of acute inferior MI (OR: 2.396; 95% CI: 1.328–4.321; P = 0.004).

Conclusions

Right coronary dominance may play a disadvantageous role in the incidence of acute inferior MI. However, further studies are needed to verify our findings, especially with regard to the underlying mechanisms.

NONOBSTRUCTIVE CORONARY ARTERY DISEASE - CLINICAL RELEVANCE, DIAGNOSIS, MANAGEMENT AND PROPOSAL OF NEW PATHOPHYSIOLOGICAL CLASSIFICATION

SUMMARY – New data gathered from large clinical trials indicate that nonobstructive coronary artery disease (non-CAD) is a clinical entity that should not be ignored. It is estimated that 50% of female population undergoing coronarography are diagnosed with non-CAD. There is also an increase in the prevalence of non-CAD in both genders, which is probably due to gradual expanding of clinical indications for angiography in patients with angina. Furthermore, considering the increased mortality risk established recently, a prognosis of non-CAD is not benign as previously thought. However, the concept and definition of non-CAD remains elusive causing difficulties in diagnosis and treatment. One of the major shortcomings is the exclusion-based diagnosis of non-CAD. Furthermore, treatment of non-CAD still presents a great challenge and optimal therapy is yet to be determined. There are two major hypotheses explaining the pathophysiological mechanisms of non-CAD, i.e. ischemic hypothesis based on abnormal microvascular dysfunction and non-ischemic one based on altered pain perception. This review encompasses a broader spectrum of pathophysiological mechanisms of non-CAD, and proposes a new way of classification based on the major disorder involved: type I (ischemic mechanisms) and type II (non-ischemic mechanisms), depending on which mechanism predominates. Hopefully, this would provide new insights in the understanding of this disorder, thus leading to accurate and early diagnosis and successful treatment, especially considering the increased mortality risk in these patients.

Accuracy of exercise tolerance test in the diagnosis of coronary artery disease in patients with left dominant coronary circulation

Background

Exercise is a physiologic stress that helps the physicians to clarify the presence or absence of cardiovascular disease which may be obscure at rest. Although it is sensitive, its specificity is affected by several parameters, such as some metabolic conditions, some structural heart diseases, and some baseline electrocardiogram abnormalities. Currently, the relationship between coronary dominance and accuracy of EET is not examined. Therefore, this study was conducted to determine the potential impact of coronary dominance on the accuracy of EET.

Methods

In this retrospective study, data were gathered from 720 patients from four medical centers. The pattern of dominancy was determined, and the coronary dominance pattern of the patients who had normal angiograms despite abnormal EETs was compared to that from all the patients.

Results

Among the patients who had a normal angiogram despite an abnormal EET, 27% were left dominant while the frequency of left dominancy in the whole population of the study was only 10.9% (P = 0.013). There were no significant differences in baseline characteristics, such as age and sex, between the two studied groups.

Conclusion

The results indicated that the presence of left dominance in patients who had normal angiograms despite an abnormal EET was significantly higher than general population. Therefore, left dominance may be considered a confounding factor for EET, producing false positive results.