Susceptibility genes for coronary heart disease and myocardial infarction

Coronary heart disease and its main complication, myocardial infarction is leading cause of death worldwide. Over the past years, much progress has been made in the pharmacotherapy of major risk factors like dyslipidemias, diabetes mellitus and hypertension. The targeting of coronary risk factors coupled with advances in the management of coronary artery disease has improved patient survival. However, the incidence of cardiovascular disease is projected to continue to rise and the identification of individuals at risk should improve beyond the traditional models of global risk factor scoring. In the past few years, important progresses have been made in the area of genomics, especially with the completion of the human genome-sequencing Consortium of 2004, proteomics and imaging. This progress will promote a better understanding of cardiovascular risk assessments and disease prediction, thus allowing earlier preventive strategies to prevent and improve cardiovascular outcomes. These genomic advances have improved characterization of disease pathology especially at the molecular level with the discovery and introduction of genetic markers, single nucleotide polymorphisms (SNPs), and haplotype blocks.     

Susceptibility genes for coronary heart disease and myocardial infarction

Coronary heart disease and its main complication, myocardial infarction is leading cause of death worldwide. Over the past years, much progress has been made in the pharmacotherapy of major risk factors like dyslipidemias, diabetes mellitus and hypertension. The targeting of coronary risk factors coupled with advances in the management of coronary artery disease has improved patient survival. However, the incidence of cardiovascular disease is projected to continue to rise and the identification of individuals at risk should improve beyond the traditional models of global risk factor scoring. In the past few years, important progresses have been made in the area of genomics, especially with the completion of the human genome-sequencing Consortium of 2004, proteomics and imaging. This progress will promote a better understanding of cardiovascular risk assessments and disease prediction, thus allowing earlier preventive strategies to prevent and improve cardiovascular outcomes. These genomic advances have improved characterization of disease pathology especially at the molecular level with the discovery and introduction of genetic markers, single nucleotide polymorphisms (SNPs), and haplotype blocks.     

Risk of new myocardial infarction in middle-aged men with manifest coronary heart disease.

Men incuring coronary heart disease (CHD) during surveillance of an employed population were studied for risk factors associated with additional myocardial infarctions. The coronary-prone Type A behavior pattern measured by a test score, number of cigarettes smoked daily, and serum cholesterol were significantdiscriminators between the 67 men with recurrent CHD and the 220 with but a single clinical CHD event. Diastolic blood pressure and fasting serum triglycerides were not significant discriminators. Statistical analyses directed to possible sources of bias occasioned by the combined retrospective-prospective study design revealed that these problems are negligible and do not alter the findings observed. Type A score appears relatively unaffected by whether the measure was made before or after the initial CHD event. Multivariable discriminant function equations showed Type A score to be the strongest single predictor of recurrent CHD among the variables available. Number of cigarettes smoked and serum cholesterol accounted for additional variance. Future field trials for the secondary prevention of myocardial infarction would be strengthened by consideration of the possible role of Type A behavior.     

心理应激性心肌缺血与中青年女性冠心病的研究

中青年女性发生冠心病的预后不如男性好，这种现象不能用已经证实的传统的心血管疾病危险因素完全解释。心理应激作为新的危险因素，被广泛证实可诱发可逆的心肌缺血，称之为心理应激性心肌缺血。在缺血性心脏病患者中，心理应激性心肌缺血发生率高且可加重预后转归。与男性患者相比，中青年女性更容易发生心理应激性心肌缺血。最新的研究数据表明微循环障碍可能在中青年女性心理应激性心肌缺血的发生中扮演重要角色。这篇文章首次综述心理应激性心肌缺血与中青年女性冠心病的研究进展。     

The incidence and prognosis of unrecognized myocardial infarction in the Honolulu, Hawaii, Heart Program

The incidence of clinically unrecognized myocardial infarctions among 7331 Japanese-American men in Hawaii, aged 45 to 68 years and free of coronary heart disease at entry, was studied on the basis of electrocardiographic changes between successive examinations during 6 years of follow-up. The proportion of asymptomatic myocardial infarction accounted for 33% of transmural (Q-wave) myocardial infarctions identified by temporal changes on electrocardiogram and 22% of all nonfatal infarctions ascertained by either repeated examinations or hospital surveillance. The 10-year prognosis of unrecognized infarction, in terms of mortality from all causes, cardiovascular disease, and coronary heart disease, was worse (with risk ratios of 1.5 to 1.7) than that of recognized infarction, even after adjusting for age and other possible determinants, although the differences were not statistically significant. These findings suggest that regular health check-ups with an electrocardiogram would be important to detect asymptomatic myocardial infarction and to increase the opportunity of taking secondary preventive measures. However, the conclusion should await further studies based on intervention trials to determine the comparative effects of the secondary prevention on the prognosis of clinically recognized vs unrecognized infarction.     

Relationship of plasma insulin levels to the incidence of myocardial infarction and coronary heart disease mortality in a middle-aged population

Summary The possible role of plasma insulin levels as a risk factor of coronary heart disease has been studied in a population of 7246 non diabetic, working men, aged 43–54 years, initially free from heart disease, and followed for 63 months on average. 128 new coronary heart disease events (non fatal myocardial infarction and coronary related deaths) were detected during this period. The annual risk is analysed by a multivariate model including age, serum cholesterol and triglycerides, blood pressure, smoking, obesity, plasma glucose and insulin fasting and 2 hours after a 75 g oral glucose load. It is shown that the fasting plasma insulin level and the fasting insulin-glucose ratio are positively associated with risk independent of the other factors. The same variables, 2 hours after the glucose load are also positively associated with risk but their contributions are not significant in the multivariate analysis. It is concluded that high insulin levels may constitute an independent risk factor for coronary heart disease complications in middle aged non diabetic men.     

Sex steroids and heart rate variability in men with coronary artery disease after myocardial infarction

The role of sex steroids in coronary artery disease (CAD) has been studied for years. In patients after myocardial infarction autonomic nervous system dysfunction has been described. Heart rate variability (HRV) analysis is one of the method of autonomic nervous system evaluation. The aim of the study was to evaluate correlations between sex steroids and HRV in 88 men (aged 36-73, av. 53 yrs), with the history of MI, with angiographically documented CAD. In all the patients 24-hour Holter monitoring was performed to assess HRV time domain parameters: SDNN, SDNNI, SDANN, rMSSD, pNN50. Levels of testosterone and estradiol were measured in two subsequent blood samples, taken with 30 min interval. Free testosterone index as well as estradiol/testosterone ratio were assessed. For statistics r-Spearman test was used. Positive correlations were found between testosterone and SDNN (r = 0.38, p = 0.03), testosterone and rMSSD (r = 0.51, p = 0.002) and between testosterone and pNN50 (r = 0.45, p = 0.007). Since rMSSD and pNN50 are parameters describing parasympathetic activity, our results suggest that in CAD men with the history of myocardial infarction, testosterone may influences the function of autonomic nervous system promoting parasympathetic dominance. It can be favorable for the circulatory system function.     

Prediction of missed myocardial infarction among symptomatic outpatients without coronary heart disease

Background

Missed diagnoses of acute myocardial infarction (AMI) in the ambulatory setting can cause patient suffering and malpractice litigation. Multiple algorithms have been developed to detect the presence of coronary heart disease (CHD) or acute coronary ischemia.

Methods

We performed a case-control study of patients with no prior history of CHD presenting to outpatient practices with potential cardiac ischemia. Malpractice claims files were used to identify 18 cases of patients with missed AMIs. For each case, we identified 3 control patients who had office visits for chest pain during the same month and assessed the association of 4 different prediction tools with missed AMI.

Results

The 18 cases of missed AMI had a 39% 1-month mortality rate. Cases were more likely than controls to be men (67% vs 26%, P = .001), to be smokers (88% vs 39%, P < .001), and to have low HDL cholesterol (39 mg/dL vs 59 mg/dL, P < .001) and elevated total cholesterol (236 mg/dL vs 213 mg/dL, P = .01). A Framingham risk score predicting a 10-year risk of CHD ≥10% and a positive score using the Goldman risk predictor were associated with an increased risk of missed AMI (odds ratio 5.7, 95% CI 1.8-18.4 for Framingham risk score; odds ratio 7.2, 95% CI 1.4-36.8 for Goldman risk predictor).

Conclusions

Among ambulatory patients with possible cardiac ischemia and no prior CHD, multiple algorithms may be useful for improvement of risk stratification.     

早发冠心病心肌梗死型与非心肌梗死型危险因素差异分析

目的探讨早发冠心病中心肌梗死型与非心肌梗死型的危险因素差异。方法回顾性分析2004年1月至2009年12月在沈阳医学院附属奉天医院心血管内科住院并确诊的45岁及以下冠心病患者165例,分为急性心肌梗死(AMI)组和非AMI组。对两组患者的相关临床资料及危险因素进行统计分析。结果 AMI组吸烟史比例、男性比率、血浆纤维蛋白原及D-二聚体均高于非AMI组,差异有统计学意义(P<0.05),两组的血脂异常率、血小板计数(PLT)、血小板压积、凝血酶原时间(PT)、国际标准化比值(INR)和活化部分凝血活酶时间(APTT)的差异无统计学意义。结论吸烟、男性性别、血脂水平异常是早发冠心病重要危险因素;血浆纤维蛋白原水平增高对于预测早发冠心病心肌梗死可能具有一定的临床意义。     

Atypical presentation and unrecognized myocardial infarction

de Torbal et al.¹ reported on the incidence of recognizedand unrecognized myocardial infarction in patients aged 55 andolder. I would like to draw attention to     

21 year trends in incidence of myocardial infarction and mortality from coronary disease in middle-age

The aim of this study is to describe the 21 year trends in myocardialinfarction among middle-aged inhabitants in the city of Turku,in southwestern Finland. Since 1972 the coronary register in Turku has monitored acutecoronary events leading to hospital admission or death, firstaccording to the methods of the World Heath Organization HeartAttack Register Study, and since 1982 according to the methodsof the WHO MONICA. From 1972 to 1992 we registered 7374 events of suspected myocardialinfarction, of which 6045 events occurring in inhabitants ofTurku aged 35–64 years, fulfilled the criteria for myocardialinfarction. Within 28 days, 2266 coronary events proved fatal.During the 21-year period, the incidence of definite myocardialinfarction fell by 55% in men and by 62% in women, and coronarymortality fell by 66 and 81%, respectively. From 1972 to 1982,total mortality and coronary mortality decreased in parallel.Later on, the decrease in total mortality levelled off, eventhough coronary mortality fell still steeper, because mortalityfrom external causes of death increased. The favourable long-term trends reflect favourable changes intotal cholesterol and blood pressure in the middle-aged population,and the improvement in the treatment of myocardial infarction.Further efforts are needed to enhance this trend, but also toreduce total mortality among middle-aged people. (Eur Heart J 1996; 17: 1495–1502)     

Trends in acute myocardial infarction coronary heart disease death in the United States

Coronary heart disease accounted for 489,171 deaths in 1990. Age-adjusted death rates decreased faster between 1976 and 1990 for white men than for white women or blacks. Out of hospital death rates for coronary heart disease decreased in the 1980s. Hospital fatality rates for acute myocardial infarction continued a long-term decrease through 1990. Trends in risk factors and invasive procedures support the conclusion that risk factor reduction has resulted in reduced incidence of acute myocardial infarction and sudden coronary death and that improvements in medical care have resulted in a continued decrease in acute myocardial infarction fatalities and overall coronary deaths.