Diagnosis of coronary microvascular dysfunction - Present status

The diagnosis and treatment of women with recurrent cardiac ischemia and normal coronary arteries

Cardiac disease is the leading cause of death in women. Among women with recurrent chest pain, abnormal electrocardiograms, and/or stress tests who undergo coronary angiography, as many as 50% have normal or <50% coronary artery obstructive disease. Pharmacologic stress assessment of coronary artery flow reserve in these women frequently demonstrates an inability to increase blood flow to >2.5 times normal flow. Contributory factors include abnormal epicardial or microvascular reactivity, microvascular remodeling or rarefaction, autonomic dysfunction, or coronary plaque rupture/erosion. Assessment is necessary of serum biomarkers and coronary artery flow reserve, fractional flow reserve, microvascular resistance, and epicardial/microvascular spasm. Aggressive treatment of women with positive tests is necessary because these women have an increased incidence of recurrent chest pain, repeated hospitalizations and coronary angiograms, and cardiac death.

Coronary calcium scoring as first-line test to detect and exclude coronary artery disease in patients presenting to the general practitioner with stable chest pain: protocol of the cluster-randomised CONCRETE trial

INTRODUCTION

Identifying and excluding coronary artery disease (CAD) in patients with atypical angina pectoris (AP) and non-specific thoracic complaints is a challenge for general practitioners (GPs). A diagnostic and prognostic tool could help GPs in determining the likelihood of CAD and guide patient management. Studies in outpatient settings have shown that the CT-based coronary calcium score (CCS) has high accuracy for diagnosis and exclusion of CAD. However, the CT CCS test has not been tested in a primary care setting. In the COroNary Calcium scoring as fiRst-linE Test to dEtect and exclude coronary artery disease in GPs patients with stable chest pain (CONCRETE) study, the impact of direct access of GPs to CT CCS will be investigated. We hypothesise that this will allow for early diagnosis of CAD and treatment, more efficient referral to the cardiologist and a reduction of healthcare-related costs.

METHODS AND ANALYSIS

CONCRETE is a pragmatic multicentre trial with a cluster randomised design, in which direct GP access to the CT CCS test is compared with standard of care. In both arms, at least 40 GP offices, and circa 800 patients with atypical AP and non-specific thoracic complaints will be included. To determine the increase in detection and treatment rate of CAD in GP offices, the CVRM registration rate is derived from the GPs electronic registration system. Individual patients' data regarding cardiovascular risk factors, expressed chest pain complaints, quality of life, downstream testing and CAD diagnosis will be collected through questionnaires and the electronic GP dossier.

ETHICS AND DISSEMINATION

CONCRETE has been approved by the Medical Ethical Committee of the University Medical Center of Groningen.

TRIAL REGISTRATION NUMBER

NTR 7475; Pre-results.

Relationship Between Plasma Total Homocysteine Levels and Mean Corrected TIMI Frame Count in Patients with Acute Myocardial Infarction

Objective

To explore the relationship between the plasma total homocysteine (tHcy) levels and slow coronary flow (SCF) measured by mean corrected TIMI frame count (CTFC) in patients with acute myocardial infarction (AMI).

Methods

Ninety-one patients with primary myocardial infarction were enrolled in this study. The quantitative measurement of coronary blood flow was performed using the mean CTFC method. Plasma tHcy levels were determined using enzymatic assay from venous blood samples. Multivariable linear regression models indicated were used to estimate the effect size (β) of plasma tHcy levels on mean CTFC levels.

Results

Compared with patients with the mean CTFC ≤23.61 frames per second (FPS) group, there were increased plasma tHcy levels in patients of the second, third and highest mean CTFC quartiles (P < 0.001). Linear regression models indicated that plasma tHcy levels were positively associated with mean CTFC levels (adjusted-β per SD increase: 1.96, 95% CI 1.20 to 2.73, P < 0.001). Compared to the tHcy ≤12.30 μmol/L group, the third and highest tHcy-quartile groups had higher mean CTFC levels (adjusted-β: 2.52, 95% CI 0.39 to 4.65, P = 0.023; adjusted-β: 5.07, 95% CI 2.98 to 7.16, P < 0.001, respectively; P for trend <0.001). Moreover, this positive relationship was modified by diabetes mellitus (P-value for interaction was 0.046).

Conclusion

We found a positive relationship between plasma tHcy levels and mean CTFC levels in patients with AMI. Moreover, diabetes mellitus played an interactive role in this positive association between the plasma tHcy levels and mean CTFC levels.

Ten things to know about ten imaging studies: A preventive cardiology perspective ("ASPC top ten imaging")

Knowing the patient's current cardiovascular disease (CVD) status, as well as the patient's current and future CVD risk, helps the clinician make more informed patient-centered management recommendations towards the goal of preventing future CVD events. Imaging tests that can assist the clinician with the diagnosis and prognosis of CVD include imaging studies of the heart and vascular system, as well as imaging studies of other body organs applicable to CVD risk. The American Society for Preventive Cardiology (ASPC) has published "Ten Things to Know About Ten Cardiovascular Disease Risk Factors." Similarly, this "ASPC Top Ten Imaging" summarizes ten things to know about ten imaging studies related to assessing CVD and CVD risk, listed in tabular form. The ten imaging studies herein include: (1) coronary artery calcium imaging (CAC), (2) coronary computed tomography angiography (CCTA), (3) cardiac ultrasound (echocardiography), (4) nuclear myocardial perfusion imaging (MPI), (5) cardiac magnetic resonance (CMR), (6) cardiac catheterization [with or without intravascular ultrasound (IVUS) or coronary optical coherence tomography (OCT)], (7) dual x-ray absorptiometry (DXA) body composition, (8) hepatic imaging [ultrasound of liver, vibration-controlled transient elastography (VCTE), CT, MRI proton density fat fraction (PDFF), magnetic resonance spectroscopy (MRS)], (9) peripheral artery / endothelial function imaging (e.g., carotid ultrasound, peripheral doppler imaging, ultrasound flow-mediated dilation, other tests of endothelial function and peripheral vascular imaging) and (10) images of other body organs applicable to preventive cardiology (brain, kidney, ovary). Many cardiologists perform cardiovascular-related imaging. Many non-cardiologists perform applicable non-cardiovascular imaging. Cardiologists and non-cardiologists alike may benefit from a working knowledge of imaging studies applicable to the diagnosis and prognosis of CVD and CVD risk - both important in preventive cardiology.

Prevalence of microvascular angina among patients with stable symptoms in the absence of obstructive coronary artery disease: a systematic review

Our purpose was to perform a systematic review to assess the prevalence of microvascular angina (MVA) among patients with stable symptoms in the absence of obstructive coronary artery disease (CAD). We performed a systematic review of the literature to group the prevalence of MVA, based on diagnostic pathways and modalities. We defined MVA using three definitions: (i) suspected MVA using non-invasive ischaemia tests; proportion of patients with non-obstructive CAD among patients with symptoms and a positive non-invasive ischaemia test result, (ii) suspected MVA using specific modalities for MVA; proportion of patients with evidence of impaired microvascular function among patients with symptoms and non-obstructive CAD, and (iii) definitive MVA; proportion of patients with positive ischaemia test results among patients with an objectified impaired microvascular dysfunction. We further examined the ratio of women-to-men for the different groups. Of the 4547 abstracts, 20 studies reported data on MVA prevalence. The median prevalence was 43% for suspected MVA using non-invasive ischaemia test, 28% for suspected MVA using specific modalities for MVA, and 30% for definitive MVA. Overall, more women were included in the studies reporting sex-specific data. The women-to-men ratio for included participants was 1.29. However, the average women-to-men ratio for the MVA cases was 2.50. In patients with stable symptoms of ischaemia in the absence of CAD, the prevalences of suspected and definitive MVA are substantial. The results of this study should warrant cardiologists to support, promote and facilitate the comprehensive evaluation of the coronary microcirculation for all patients with symptoms and non-obstructive CAD.

Cardiovascular Complications in Patients with Turner's Syndrome

Turner's or Turner syndrome (TS) is the most prevalent chromosomal abnormality in live female births. Patients with TS are predisposed to an increased risk of cardiovascular diseases (CVD), mainly due to the frequently observed congenital structural cardiovascular defects, such as valvular and aortic abnormalities (coarctation, dilatation, and dissection). The increased prevalence of cardiometabolic risk factors, such as arterial hypertension, insulin resistance, diabetes mellitus, dyslipidaemia, central obesity, and increased carotid intima-media thickness, also contribute to increased morbidity and mortality in TS patients. Menopausal hormone therapy (MHT) is the treatment of choice, combined with growth hormone (GH). Although MHT may, in general, ameliorate CVD risk factors, its effect on CVD mortality in TS has not yet been established. The exact effect of GH on these parameters has not been clarified. Specific considerations should be provided in TS cases during pregnancy, due to the higher risk of CVD complications, such as aortic dissection. Optimal cardiovascular monitoring, including physical examination, electrocardiogram, CVD risk factor assessment, and transthoracic echocardiography, is recommended. Moreover, the cardiac magnetic resonance from the age of 12 years is recommended due to the high risk of aortic aneurysm and other anatomical vascular complications.

False-positive stress echocardiograms: Predictors and prognostic relevance

BACKGROUND

Recent studies indicate that the pretest likelihood of significant coronary artery disease (CAD) (≥50% luminal stenosis) is over-estimated and that the frequency and severity of positive stress tests have been decreasing. This suggests an increased prevalence of false-positive (FP) stress tests. The aims of this retrospective study were to investigate the predictors of FP stress echocardiography (SE) and to compare the outcomes of patients with FP results to those with true-positive (TP) results.

METHODS

Patients who underwent SE between 2013 and 2017 in a tertiary-care center were reviewed. Included were patients aged ≥40years who had cardiac catheterization (CC) within 1year of the index stress test. SE was considered FP if a new or worsening wall motion abnormality was present in the absence of significant corresponding CAD.

RESULTS

Of the 5100 patients with SE, 1069 satisfied inclusion criteria. A total of 305 patients had positive SE results; of which 162 (53%) were FP. Logistic regression revealed that female gender (p=0.009), the absence of diabetes (p=0.03), the absence of a personal history of CAD (p=0.004), and lower stress WMSI (p=0.03) were independently associated with FP results. Patients with FP results on SE had similar all-cause mortality to those with TP results.

CONCLUSIONS

Accounting for predictors of FP findings on SE could improve the interpretation of SE results and limit the use of unnecessary CC. Furthermore, patients with FP results on SE could benefit from aggressive risk factor control and careful clinical follow-up.

Insulin resistance linked to subtle myocardial dysfunction in normotensive Turner syndrome young patients without structural heart diseases

Background Turner syndrome (TS) patients have increased cardiovascular risk. This cardiovascular risk is famously attributed to structural abnormalities of the left side of the heart such as aortic stenosis and aortic coarctation. However, due to insulin resistance and subsequent pathogenic mechanisms, normotensive TS patients without structural abnormalities may develop varying degrees of myocardial dysfunction. The aim of this research was to examine the role of speckle tracking echocardiography in early detection of Turner cardiomyopathy and to correlate this myocardial dysfunction with measures of insulin resistance. Methods This cross-sectional case control study included 30 children with TS and 30 age-matched healthy controls. TS patients were excluded if: hypertensive, with major structural abnormalities of the heart or other systemic diseases that may affect myocardial function. Conventional speckle tracking echocardiography and glucose-insulin ratio were performed for all study subjects. Results Routine echocardiographic parameters of left ventricular systolic function were similar in cases and controls while global longitudinal and circumferential strain (GLS and GCS) were lower in patients with TS than controls: (-13.2±1.1 vs. -18.3±2.4, p-value<0.000) and (-11.3±1.1 vs. -16.3±2.1, p-value<0.000), respectively. Fasting glucose:insulin ratio (FGIR) proved to be the best predictor of myocardial dysfunction in TS patients by multivariate analysis. Conclusions This study points towards the potential role of two-dimensional (2D) speckle tracking echocardiography in early detection of subtle systolic myocardial dysfunction in TS patients. It also points towards the implication of insulin resistance in precipitation of the observed dysfunction in TS patients.

Management standards for stable coronary artery disease in India

Coronary artery disease (CAD) is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD) is characterised by episodes of transient central chest pain (angina pectoris), often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS) is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.