Twenty-first century epidemiology of dyslipidemia in Greece: EMENO national epidemiological study.

BACKGROUND: Greece was recently reclassified from low- to medium-risk country in terms of cardiovascular disease, with 27% of cardiovascular deaths attributed to hypercholesterolemia. EMENO nationwide survey (2013-2016) assessed the epidemiology of dyslipidemia in the general population in Greece. METHODS: A random sample of adults was drawn by multistage stratified random sampling based on 2011 census. Standardized questionnaires and blood tests for total cholesterol (TC), low-density (LDL-C), and high-density lipoprotein cholesterol (HDL-C), and triglycerides were used. Hypercholesterolemia was defined as TC ≥ 240/200 mg/dL and/or the use of lipid-lowering drugs, hyper-LDL-cholesterolemia as LDL-C ≥160/130/100 mg/dL and/or the use of drugs, hypo-HDL-cholesterolemia as HDL-C <40 mg/dL, and hypertriglyceridemia as triglycerides ≥150 mg/dL. Weighted analysis was applied to adjust for study design, age/sex distribution discrepancies between sample and population and nonresponse. RESULTS: Of 6,006 individuals recruited, 4,298 were analyzed (mean [SD] age 49.2 [18.5] years, men 48.5%, BMI 28.2 [5.7] kg/m2). Mean TC, LDL-C, HDL-C, and TG were 193.9 [44.4], 118.5 [37.6], 49.1 [14.9], and 130.8 [94.4] mg/dL, respectively. The prevalence of hypercholesterolemia was 27.6/52.4% for thresholds ≥240/200 mg/dL, and of hyper-LDL-cholesterolemia was 26.3/46.7/74% for thresholds ≥160/130/100 mg/dL, with no differences between sexes. The prevalence of hypo-HDL-cholesterolemia was 27.5% (men/women 38.1/17.5%, p < 0.001) and of hypertriglyceridemia was 27.8% (men/women 32.6/23.4%, p < 0.001). Lipid-lowering drugs were used by 14.1% of the participants (men/women 12.6/15.6%, p < 0.001). CONCLUSIONS: More than 50% of adults in Greece have some type of dyslipidemia (mainly TC ≥ 200 mg/dL) and 14% are treated. Nationwide programmes are needed to manage dyslipidemia and halt the increasing rate of cardiovascular disease in Greece.

Phytosterol supplementation does not affect plasma antioxidant capacity in patients with metabolic syndrome.

Several studies have observed decreased levels of lipophilic antioxidants after supplementation with phytosterols and stanols. The aim of this study was to examine the effect of phytosterol supplementation on plasma total antioxidant capacity in patients with metabolic syndrome. In a parallel arm, randomized placebo-controlled design, 108 patients with metabolic syndrome were assigned to consume yogurt beverage which provided 4 g of phytosterols per day or yogurt beverage without phytosterols. The duration of the study was 2 months and the patients in both groups followed their habitual westernized type diet. Blood samples were drawn at baseline and after 2 months, and the total antioxidant capacity of plasma was measured using the ferric reducing antioxidant power of plasma and oxygen radical absorbance capacity assays. After 2 months of intervention, plasma total antioxidant capacity did not differ between and within the intervention and the control groups. Phytosterol supplementation does not affect plasma antioxidant status.

Association of MT1A haplotype with cardiovascular disease and antioxidant enzyme defense in elderly Greek population: comparison with an Italian cohort.

Metallothioneins (MT), the antioxidant zinc-binding proteins, seem to mediate cardioprotection. It has been postulated that zinc homeostasis and MT function may be altered, as a consequence of oxidative stress, in cardiovascular disease (CVD), with a potential implication of MT genetic polymorphisms. The present study explores the role of +647A/C and +1245A/G MT1A polymorphisms on the susceptibility to CVD, zinc status and enzyme antioxidant activity, in the Greek and Italian populations. The country selection was based on the lower zinc status and the reduced zinc dietary intake in Greece than in Italy despite the similar Mediterranean dietary pattern. A total of 464 old, healthy control subjects and 369 old CVD patients more than 70 years of age were studied. Logistic regression model indicated that +1245 MT1A G+ genotype significantly increased the risk of CVD in Greece (34.4% vs. 23.2%; odds ratio=1.88, 95% confidence interval=1.14-3.08; P=.013) but not in Italy. Haplotype analysis showed an increment of CG haplotype frequency in CVD Greek patients (17.4% vs. 10.6%, P<.05). Differential country-related frequency distribution was also recorded. Applying a multivariate regression model, +647/+1245 MT1A haplotype was associated with a modulation of enzyme antioxidant activities in both countries. Decreased plasma zinc and reduced intracellular Zn release, as well as increased enzyme antioxidant activity, were more apparent in Greek healthy donors than in Italy. In conclusion, +1245 MT1A polymorphism and +647/+1245 MT1A haplotype are implicated in CVD in Greece but not in Italy, suggesting a role of gene-diet interaction in the disease predisposition.

Association of the 894G>T polymorphism in the endothelial nitric oxide synthase gene with risk of acute myocardial infarction.

BACKGROUND: This study was designed to investigate the association of the 894G>T polymorphism in the eNOS gene with risk of acute myocardial infarction (AMI), extent of coronary artery disease (CAD) on coronary angiography, and in-hospital mortality after AMI. METHODS: We studied 1602 consecutive patients who were enrolled in the GEMIG study. The control group was comprised by 727 individuals, who were randomly selected from the general adult population. RESULTS: The prevalence of the Asp298 variant of eNOS was not found to be significantly and independently associated with risk of AMI (RR = 1.08, 95%CI = 0.77-1.51, P = 0.663), extent of CAD on angiography (OR = 1.18, 95%CI = 0.63-2.23, P = 0.605) and in-hospital mortality (RR = 1.08, 95%CI = 0.29-4.04, P = 0.908). CONCLUSION: In contrast to previous reports, homozygosity for the Asp298 variant of the 894G>T polymorphism in the eNOS gene was not found to be associated with risk of AMI, extent of CAD and in-hospital mortality after AMI.

The prognostic value of a QRS score during exercise testing.

BACKGROUND: Values of a QRS score have been positively related to the number of narrowed coronary arteries and to the extent of myocardial ischemia in radionuclide imaging techniques. HYPOTHESIS: This study was conducted to evaluate the potential prognostic information of abnormal values of this QRS score during treadmill exercise testing in patients with established coronary artery disease (CAD). METHODS: In all, 309 patients (258 men, 51 women, mean age 56.1 +/- 10.0 years) with documented CAD, underwent a treadmill exercise test and coronary arteriography at baseline. Subsequently, they were prospectively followed to a maximum of 36 months (mean follow-up 23 +/- 13 months, median 25 months). RESULTS: During the follow-up period, 20 patients (6.5%) died from acute myocardial infarction. Abnormal QRS score values were found to be significantly and independently associated with cardiac mortality (QRS < or = -4: relative risk 11.7; 95% confidence interval = 2.5-55.4; p = 0.002). CONCLUSIONS: Taking into consideration the importance of exercise testing in the management of ischemic heart disease, the use of this QRS score could be of clinical value in predicting the outcome of patients with documented CAD.

Exercise-induced prolongation of the infarct-related Q-waves as a marker of myocardial viability in the infarcted area.

OBJECTIVE: It is known that exercise-induced ischemia in patients with coronary artery disease (CAD) may produce QRS prolongation in the surface electrocardiogram (ECG). To investigate the presence of exercise-induced Q-wave prolongation in patients with single-vessel CAD and Q-wave myocardial infarction (MI), in association with the presence of reversible perfusion defects during thallium scintigraphy in the infarcted area. METHODS: 107 consecutive patients (89 males, mean age 56+/-8 years) were evaluated. All patients underwent coronary arteriography, maximal treadmill exercise testing and thallium-201 scintigraphy. Q-wave duration was measured both before exercise testing and during maximal heart rate from 12-lead ECGs recorded with a paper speed of 50 mm/s. RESULTS: Only 57 out of the 107 studied patients showed reversible perfusion defects in the infarcted area during thallium scintigraphy. Q-wave duration was significantly increased from the resting to the stress ECG (DeltaQ-wave duration) in patients with reversible perfusion defects in the infarcted areas (10+/-13 ms), but not in patients with fixed defects in the infarcted zone (-2.0+/-5 ms, p<0.01). The sensitivities and the specificities of Q-wave prolongation, ST segment elevation, and the combination of ST segment elevation with ST segment depression in the reciprocal leads for the detection of myocardial viability in the infarcted area were 82%, 48%, 29% and 88%, 50%, and 90%, respectively. CONCLUSIONS: Exercise-induced Q-wave prolongation is demonstrated in those patients with single-vessel CAD and a recent MI who show reversible perfusion defects in thallium scintigraphy. Exercise-induced Q-wave prolongation was found to be a sensitive and specific ECG marker for the detection of myocardial viability in the infarcted area.

A QRS score versus ST-segment changes during exercise testing: which is the most reliable ischaemic marker after myocardial revascularisation?

BACKGROUND: The diagnostic ability of exercise testing based on ST-segment changes is low for the detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA) or ischaemia after bypass surgery (CABG). The aim of this study was to improve the diagnostic accuracy of exercise testing in patients with a history of PTCA or CABG, with the implementation of a QRS score. METHODS: We studied 128 post-PTCA patients (aged 49 +/- 8 years) and 104 post-CABG patients (aged 54 +/- 8 years), who had either positive exercise tests with or without angina, or negative exercise tests with continuing angina-like symptoms, and underwent cardiac catheterisation. RESULTS: The univariate risk ratio of exercise-induced ST-segment deviation to detect restenosis was 3.05 (p = 0.005) and 0.83 (p = 0.690) in group A and group B patients, respectively. The univariate risk ratios of abnormal QRS score values to detect restenosis were 32.1 (p < 0.001) and 18.8 (p < 0.001) for group A and group B patients, respectively. The univariate risk ratios of the combination of exercise-induced ST-segment changes and of abnormal QRS score values to detect restenosis was 9.43 (p < 0.001) and 3.77 (p < 0.044) for group A and group B patients, respectively. The value of the area under the ROC curves is higher for the QRS score in group A patients, group B patients and for the whole study population. CONCLUSIONS: QRS score values significantly improve the diagnostic ability of ST-segment change-based exercise testing, for the assessment of restenosis after PTCA or ischaemia after CABG.

Improved myocardial performance during repetitive exercise testing: the role of extracellular superoxide dismutase activity in a model of exercise-induced myocardial preconditioning.

BACKGROUND: The aim of this study was to investigate whether endogenous antioxidant defense is involved in adaptation to myocardial ischemia in patients with coronary artery disease and severe exercise-induced myocardial ischemia. METHODS: Fifty patients, aged 50 to 72 years (mean, 58 +/- 6 years), with positive exercise test results underwent 4 treadmill exercise tests. Thallium-201 scintigraphy was performed during the first and the fourth testing. The second, the third, and the fourth tests were performed the next day. The time interval between the second and the third test was 15 minutes, and between the third and the fourth test, the interval was 45 minutes. Extracellular superoxide dismutase activity was measured just before and at the peak of the first and the fourth exercise test. RESULTS: The patients were divided in 2 groups according to the extent of myocardial ischemia at peak exercise of the fourth test compared with the first test. Most of the patients studied (37/50) showed improved myocardial performance during the last of the sequential exercise tests, as demonstrated with the studied exercise parameters and the extent of myocardial ischemia in thallium-scintigraphy. Extracellular superoxide dismutase activity before the last exercise test was found to be significantly increased only in the patients who had improved myocardial performance at the last of the sequential exercise tests. CONCLUSION: The beneficial effects of sequential episodes of exercise-induced myocardial ischemia seem to be strongly related to extracellular superoxide dismutase activity. Although there is still lack of direct evidence, our data support the theory that the favorable adaptation to repetitive exercise may represent an aspect of the clinical relevance of ischemic preconditioning in humans.

Significance of exercise-induced ST changes in leads aVR, V5, and V1. Discrimination of patients with single- or multivessel coronary artery disease.

BACKGROUND: It is known that exercise-induced ST-segment elevation in lead V1 (V1-E) detects left anterior descending (LAD) stenosis. It was also postulated that ST elevation in aVR and simultaneous ST depression in V5 (aVR-E + V5-D) is a marker of ischemia due to significant stenosis of the LAD in patients with single-vessel disease. HYPOTHESIS: This study was undertaken to investigate the significance of the concomitant appearance of both electrocardiographic (ECG) ischemic markers, and of each of them alone during exercise, to detect either LAD stenosis as single-vessel coronary artery disease (CAD), or multivessel CAD involving LAD stenosis. METHODS: A total of 196 consecutive patients (152 men and 44 women, mean age 54 +/- 7 years) with at least one of these ECG markers, who underwent treadmill exercise testing with the Bruce protocol and coronary arteriography, were studied. RESULTS: Patients were divided into three groups. In Group A (83 patients with V1-E + aVR-E & V5-D), 93% of patients with single-vessel disease had significant LAD stenosis (p<0.001), whereas 75% of patients with double-vessel disease had significant stenoses of the LAD and the left circumflex (LCx) coronary arteries (p<0.01). In Group B (97 patients with aVR-E & V5-D but without V1-E), 43% of patients with single-vessel disease had significant LAD stenosis (p<0.08), whereas 85% of patients with double-vessel disease had significant stenoses of the LAD and the right coronary artery (RCA) (p<0.01). In Group C (16 patients with only V1-E), 60% of patients with single-vessel disease had significant LAD stenosis (p<0.05), whereas 75% of patients with double-vessel disease had significant LAD and LCx stenoses (p<0.05). CONCLUSIONS: The concomitant appearance of exercise-induced ST elevation in lead V1, ST elevation in lead aVR, and ST depression in lead V5, as well as the isolated appearance of ST elevation in lead V1 detect significant LAD stenosis as single-vessel disease, or significant stenoses of LAD and LCx arteries in patients with double-vessel disease, whereas the appearance of ST elevation in aVR & ST depression in V5 but without ST elevation in V1 correlates strongly with significant LAD and RCA stenoses and usually indicates double-vessel disease.

P wave analysis indices in young healthy men: data from the digital electrocardiographic study in Hellenic Air Force Servicemen (DEHAS).

P wave analysis from the 12-lead ECG is a recent contribution of noninvasive electrocardiology. P wave analysis indices (maximum and minimum P wave duration, P wave dispersion [Pdis = Pmax-Pmin], adjusted P wave dispersion [APdis = Pdis/square root of measured leads], summated P wave duration [Psum], standard deviation of P wave duration [Psd], mean P wave duration [Pmean]) can predict atrial arrhythmias. However, the definitions of all these indices are based on few studies. The aim of this analysis was to define normal values of these indices and the examine possible associations between P wave indices and clinical variables. The study included 1,353 healthy men, 24 +/- 3 years of age, who answered a questionnaire and underwent a detailed physical examination and a digitized 12-lead surface ECG. All P wave indices were analyzed by two independent investigators. Mean values of the ECG indices were: Pmax: 96 +/- 11 ms, Pmin: 57 +/- 9 ms, Pdis: 38 +/- 10 ms, Psum: 924 +/- 96 ms, Psd: 12 +/- 3, APdis: 11 +/- 3 ms, and Pmean: 77 +/- 8 ms. Age was significantly related with Pmax (r = 0.277, P < 0.01), Pmin (r = 0.255, P < 0.001), Psum (r = 0.074, P < 0.01), and Pmean (r = 0.074, P < 0.01). All ECG indices were significantly associated with the R-R interval, and among each other. This study defined normal indices of wave duration and correlations among them. These markers may play an important predictive role in patients with atrial conduction abnormalities.