Does metabolic syndrome predict significant angiographic coronary artery disease?

IntroductionMetabolic syndrome (MS) is an independent predictor of acute cardiovascular events. However, few studies have addressed the relationship between MS and stable angiographic coronary artery disease (CAD), which has a different pathophysiological mechanism. We aimed to study the independent predictors for significant CAD, and to analyze the impact of MS (by the AHA/NHLBI definition) on CAD.MethodsWe prospectively included 300 patients, mean age 64 ± 9 years, 59% male, admitted for elective coronary angiography (suspected ischemic heart disease), excluding patients with known cardiac disease. All patients underwent assessment of demographic, anthropometric, and laboratory data and risk factors, and subsequently underwent coronary angiography.ResultsIn the study population, 23.0% were diabetic, 40.5% had MS (and no diabetes) and 36.7% had neither diagnosis. Significant CAD was present in 51.3% of patients. CAD patients were older and more frequently male and diabetic, with increased triglycerides and glucose and lower HDL cholesterol. Abdominal obesity was also less prevalent. MS was not associated with the presence of CAD (OR 0.94, 95% CI 0.59–1.48, p=0.778). Of the MS components, the most important predictors of CAD were increased glucose and triglycerides. Abdominal obesity was associated with a lower risk of CAD. In a multivariate logistic regression model for CAD, independent predictors of CAD were age, male gender, glucose and triglycerides. Body mass index had a protective effect.ConclusionsAlthough MS is associated with cardiovascular events, the same was not found for stable angiographically proven CAD. Age, gender, diabetes and triglycerides are the most influential factors for CAD, with abdominal obesity as a protective factor.     

Non-traditional biomarkers of atherosclerosis in stable and unstable coronary artery disease, do they differ?

BACKGROUND: Biomarkers of atherosclerosis are emerging as a potential tool for assessment of coronary artery disease (CAD) patients. As acute coronary syndrome (ACS), and stable CAD are distinguished in their pathophysiology it is conceivable that they are also characterized by different biomarkers of atherosclerosis. METHODS: We systematically reviewed the literature for clinical studies of several non-traditional biomarkers of atherosclerosis reflecting various pathophysiological processes, namely macrophage-activity, oxidative-stress, tissue remodeling, and thrombosis in ACS and stable CAD to determine whether circulating biomarkers are differently expressed/predict outcome in these two clinical conditions. RESULTS: Macrophage-activity (monocyte chemoattractant protein-1, neopterin), tissue-remodeling (matrix metalloproteinase-9) and thrombosis (tissue-factor) related biomarkers were consistently elevated in ACS compared to stable CAD, in accordance with the pathophysiological role of these mediators in plaque rupture, characterizing ACS. Thus, these biomarkers may be applicable for diagnosis of ACS. Additionally, neopterin was consistently shown to predict outcome in both stable and ACS patients and myeloperoxidase was strongly shown to predict outcome in ACS, implying for their potential role in risk stratification of these patients. CONCLUSIONS: As ACS and stable CAD are characterized by different pathophysiological processes, it appears that the biomarkers that are associated with them are differently expressed in these two clinical conditions     

Bilirubin in coronary artery disease: Cytotoxic or protective?

Bilirubin has traditionally been considered a cytotoxic waste product.However,recent studies have shown bilirubin to have anti-oxidant,anti-inflammatory,vasodilatory,anti-apoptotic and anti-proliferative functions.These properties potentially confer bilirubin a new role of protection especially in coronary artery disease(CAD),which is a low grade inflammatory process exacerbated by oxidative stress.In fact,recent literature reports an inverse relationship between serum concentration of bilirubin and the presence of CAD.In this article,we review the current literature exploring the association between levels of bilirubin and risk of CAD.We conclude that current evidence is inconclusive regarding the protective effect of bilirubin on CAD.A causal relationship between low serum bilirubin level and increased risk of CAD is not currently established.     

Does angina vary with the menstrual cycle in women with premenopausal coronary artery disease?

OBJECTIVE—To determine whether angina in women with established coronary heart disease varies with changes in hormone concentrations during the menstrual cycle.
DESIGN—Subjects were prospectively studied once a week for four weeks.
SETTING—Cardiology outpatient department of tertiary referral centre.
SUBJECTS—Nine premenopausal women, mean (SEM) age 38.89 (2.18) years, with established coronary heart disease, symptomatic angina, and a positive exercise test.
MAIN OUTCOME MEASURE—Myocardial ischaemia as determined by time to 1 mm ST depression during symptom limited exercise testing. Position in the menstrual cycle was established from hormone concentrations.
RESULTS—The early follicular phase, when oestradiol and progesterone concentrations were both low, was associated with the worst exercise performance in terms of time to onset of myocardial ischaemia, at 290 (79) seconds; the best performance (418 (71) seconds) was when oestrogen concentrations were highest in the mid-cycle (p < 0.05). Similar trends were observed in other measured variables. Progesterone concentrations did not influence exercise performance.
CONCLUSIONS—During the menstrual cycle myocardial ischaemia was more easily induced when oestrogen concentrations were low. This may be important for timing the assessment and evaluating treatment in women with coronary heart disease.


Keywords: myocardial ischaemia; exercise testing; oestradiol; progesterone     

“Obesity paradox” in coronary artery disease

Obesity used to be among the more neglected public health problems, but has unfolded as a growing medical and socioeconomic burden of epidemic proportions. Morbid obesity is linked to traditional cardiovascular risk factors like, hypertension, hyperlipidemia and diabetes, and suspected to incur increased morbidity and mortality in the Western and even third world populations. This patient cohort is also at greater risk to develop coronary artery disease. Recent population-based registries revealed that 43% and 24% of all cases of coronary revascularization were carried out in overweight and obese patients, respectively. However, despite evidence of a positive correlation between obesity and increased cardiovascular morbidity, some authors have described a better clinical outcome in overweight and obese patients, a phenomenon they coined “obesity paradoxon”. Thus, there is an ongoing debate in light of conflicting data and the possibility of confounding bias causing misconception and challenging the “obesity paradox”. In this review article we present the current evidence and throughly discuss the validity of the “obesity paradoxon” in a variety of clinical settings.     

Is FFR-CT a “game changer” in the diagnostic management of stable coronary artery disease?

The introduction of fractional flow reserve computed tomography (FFR-CT) that is performed from static coronary CT angiography datasets may open new horizons in the diagnostic management of patients with suspected coronary artery disease. FFR-CT has a high sensitivity and moderate specificity in identifying ischemia in intermediate coronary stenoses. It has been demonstrated that this technology has the potential to significantly reduce the number of invasive coronary angiograms and the rate of normal coronary angiograms that are not followed by an intervention. Furthermore, initial data indicate that FFR-CT may predict the hemodynamic effect of stenting and even of bypass surgery. Thus, FFR-CT, with its capacity to serve as an effective gatekeeper before invasive angiography and the option to virtually predict the success of revascularization, constitutes a completely new concept in managing patients with stable angina pectoris. Before this exciting technology can enter clinical practice, however, some evident limitations need to be overcome and significantly more data concerning accuracy and influence on clinical and economic outcome parameters need to be generated.     

Does electron beam computer tomography provide added value in the diagnosis of coronary artery disease?

PURPOSE OF REVIEW: Electron beam computer tomography (EBCT) is increasingly being used to diagnose coronary artery disease (CAD) in the asymptomatic patient. The aim of this review is to assess the current findings concerning EBCT in the diagnosis and prognostication of CAD. RECENT FINDINGS: Review of the English language peer-reviewed medical literature for EBCT was done with emphasis on the diagnosis and prognosis of CAD. SUMMARY: The goal of risk stratification is to limit aggressive and costly care to group of high-risk patients. EBCT has been used to track the progression of coronary atherosclerosis periodically. Studies have shown that the calcium score will increase from 18 to 22% per year and depends on the age, sex and renal function. Patients with end-stage renal disease have much higher counts. Because it is cheap and noninvasive, EBCT has been used to assess the effects of medications on velocity of increase in the calcium scores. There is concern about radiation for its use long term to assess the calcium score increase over a long period of time.     

Severity of coronary artery disease in type 2 diabetes mellitus: Does the timing matter?

AimThe aim of our study was to compare the angiographic changes in 53 nondiabetic patients, 54 type 2 diabetic patients of less than 5 years of duration, 41 patients with 5–10 years of diabetes, and 27 with more than 10 years of diabetic duration.MethodsIn this cross-sectional study, 175 patients, who underwent coronary angiogram for the evaluation of the coronary artery disease (CAD), were recruited. Based on the angiographic findings, syntax score, vessel score, and coronary collaterals grading were analyzed. The biochemical analysis was done by using the auto analyzer.ResultsA significant increase in the mean syntax score (p = 0.019), vessel score (p = 0.007), and coronary collateral grade (p = 0.008) was observed in the patients with 5–10 years of diabetes when compared to those with less than 5 years of diabetic duration. There was no significant difference in the mean syntax score (p = 0.979), vessel score (p = 0.299), and collateral grade (p = 0.842) between the patients with 5–10 years and more than 10 years of diabetes. The difference in the mean syntax score (p = 0.791), vessel score (p = 0.098), and collateral grade (p = 0.661) between the nondiabetic and the patients with less than 5 years of diabetes was not significant.ConclusionA significant structural change in the coronary arteries was found among the patients with 5–10 years of diabetes.