Renin-angiotensin-aldosterone system gene polymorphisms and coronary artery disease: detection of gene-gene and gene-environment interactions.

OBJECTIVE: The objective of this study was to explore the association between coronary artery disease and genetic polymorphisms of the renin-angiotensin-aldosterone system (RAAS) pathway. In addition, we examined the interactions between demographic and lifestyle risk factors (environmental factors including age, sex, smoking status, alcohol intake) and RAAS polymorphisms on disease risk. METHODS: A total of 1089 subjects who underwent coronary angiography were enrolled in this study. Eight RAAS polymorphisms were genotyped in this population: the G2350A (rs4343) polymorphism in exon 17 of the angiotensin converting enzyme (ACE) gene, 1166A→C (rs5186) and 573C/T (rs5182) in the angiotensin II type 1 receptor (AGTR1) gene, the -344C→T transversion (rs1799998) in the aldosterone synthase (CYP11B2) gene, and the G-217A (rs5049), G-6A (rs5051), M235T (rs699; T4072C), and T174M (rs4762; C3889T) polymorphisms in the angiotensinogen (AGT) gene. Subjects with coronary heart disease were defined as those with at least 50% stenosis in at least one major coronary artery, and, the severity of coronary atherosclerosis was defined by the Gensini scoring system. RESULTS: Compared to the subjects with AA genotype, the subjects with AG + GG genotype of rs1799998 had significant lower gensini score (p=0.029). After adjusting for age, gender, cigarette smoking, and alcohol intake status, the AG genotype (OR 0.717 95%CI 0.541-0.950, p=0.021) and the AG + GG genotype (OR 0.730 95%CI 0.559-0.954, p=0.021) distributions of rs1799998 were significantly different between the cases and controls compare to the AA genotype. Subjects with three at-risk loci had increased risk of coronary artery disease compared to subjects carrying 0 or 1 risk-associated polymorphism (OR [95% CI]:1.579 [1.077-2.316], p=0. 019), and the significance of the association was not reduced after adjusting for age, sex, cigarette smoking, or alcohol intake (adjusted OR [95% CI]: 1.673 [1.116-2.507], p=0.013). The results of multifactor-dimensionality reduction analysis revealed an interaction effect of CYP11B2 -344C→T, age, and smoking status on the risk of coronary heart disease (training OR [95% CI]: 3.7685 [2.8463-4.9895], p<0.0001; testing OR [95% CI]: 2.7583 [1.2038-6.3203], p=0.015). CONCLUSIONS: Subjects who carried the G allele of the rs1799998 polymorphism significantly associated with coronary heart disease and severity of coronary atherosclerosis estimated by the Gensini score in the whole population of the study. And, multiple RAAS gene polymorphisms are associated with coronary artery disease. The interaction of the CYP11B2 -344C→T polymorphism (rs1799998), age, and smoking status is also associated with enhanced risk of coronary artery disease.

Time distribution of the onset of chest pain in subjects with acute ST-elevation myocardial infarction: an eight-year, single-center study in China.

OBJECTIVE: The objective of this study was to explore the time distribution patterns of the onset of chest pain in subjects with acute ST-elevation myocardial infarction in a Chinese population. METHODS: A total of 1467 patients with acute ST-elevation myocardial infarction were enrolled from 2003 to 2010. The hourly, daily, monthly, seasonal and day-of-week fluctuations in the prevalence of acute ST-elevation myocardial infarction were analyzed. RESULTS: A peak was found between the morning hours of 07:31 and 08:30. A second peak was observed between 14:31 and 15:30, and a third peak was found between 23:31 and 00:30 (p<0.001). The monthly maximum was recorded in November and the minimum was in April (p<0.001). The number of daily cases was greatest in autumn and lowest in the spring (p = 0.001). Day-of-the-week variations of ST-elevation acute myocardial infarction were not found, except in patients more than 75-years-old. CONCLUSIONS: Periodic variations in the frequency of ST-elevation acute myocardial infarction in Chinese patients showed significant differences with regard to diurnal, monthly and seasonal patterns. The exact mechanisms underlying these circadian variations require further study.

Severity of coronary atherosclerosis is an independent predictor of the left ventricular ejection fraction.

1. We studied the association between the level of the left ventricular ejection fraction and the severity of coronary atherosclerosis. 2. The study population consisted of 850 consecutive patients who underwent coronary angiography for suspected or known coronary atherosclerosis. Anthropometric measurements including the body mass index, blood pressure, blood lipids, blood glucose and leucocyte count were taken. The severity of coronary atherosclerosis was defined by the Gensini score. 3. When the level of the left ventricular ejection fraction was examined as a categorical variable classified by quartile values, subjects with a high left ventricular ejection fraction level had significantly lower Gensini scores than those with a low left ventricular ejection fraction level (P=0.000). Spearman's correlation analysis suggested that the left ventricular ejection fraction was significantly negatively associated with Gensini score (r= -0.213, P=0.000). Multiple stepwise linear regression analysis showed that the Gensini score was significantly independently associated with the left ventricular ejection fraction level (ß= -0.194, P=0.000). Furthermore, multivariable stepwise logistic regression analysis showed that the Gensini score was the independent risk factor for dysfunction of left ventricular ejection (OR=2.048, 95% CI=1.517-2.763). 4. The severity of coronary atherosclerosis was defined by the Gensini score. This was a strong and statistically highly significant predictor of the left ventricular ejection fraction level and dysfunction of left ventricular ejection independent of other major risk factors including age, body mass index, blood pressure, fasting blood glucose, blood lipid and leucocyte count.

Association of serum sodium concentration with coronary atherosclerosis in China: follow-up study.

AIM: The aim of this study was to test the hypothesis that lower serum sodium may be associated with increased cardiovascular events and all-cause mortality by means of long-term follow-up of subjects with coronary atherosclerosis in a prospective, hospital-based epidemiological study in China. METHODS: A prospective, hospital-based epidemiological design was used. The study population consisted of 1069 consecutive patients who were scheduled to undergo coronary angiography for suspected or known coronary atherosclerosis. The severity of coronary atherosclerosis was defined using Gensini's score system. Age, sex-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the quartiles of serum sodium concentration were estimated with Cox proportional hazard models, using quartile 1 as the reference. Cox proportional hazard models were also constructed to estimate the hazard ratios and 95% confidence intervals for all-cause mortality and final end-point events by serum sodium quartile and to adjust for potentially confounding variables. Multivariate models were adjusted for the following variables: age, sex, smoking status, alcohol consumption, body mass index, blood pressure, potassium, chloride, total cholesterol, triglycerides, fasting blood glucose, urea, creatinine, uric acid, and Gensini's score. RESULTS: During the median 2.86 years (3011.66 person-years) of follow-up, 176 final end-point events were documented. These events included 79 deaths and 97 readmissions for coronary heart disease. There was a statistically significant inverse association of serum sodium with all-cause mortality (P<0.001). After full adjustment comparing the highest serum sodium quartile to the lowest, there was a non-significant inverse association with all-cause mortality, with an adjusted hazard ratio (95% CI) of 0.67 (0.25-1.80). After adjustment for age and sex, the hazard ratio and 95% CI for final end-point events across increasing quartiles of serum sodium concentration were 1.00, 0.85 (0.59-1.22), 0.52 (0.34-0.82), and 0.31 (0.19-0.49). After full adjustment comparing the highest serum sodium quartile to the lowest, there was a statistically significant inverse association with final end-point events, with an adjusted hazard ratio (95% CI) of 0.46 (0.26-0.81). CONCLUSION: The serum sodium concentration showed a statistically significant negative association with coronary events and all-cause mortality in subjects with coronary atherosclerosis; the actual mechanism underlying this association needs further study.