ABCA1 polymorphisms and prognosis after myocardial infarction in young patients

High-density cholesterol (HDL) levels are affected by genetic influences and certain behaviors. Low levels of HDL-C are considered as an independent risk factor for premature coronary heart disease. In patients with Tangier disease, characterised by low HDL levels, mutations in the ATP binding cassette transporter have been described. We have analysed three polymorphisms of the ABCA1 gene (-477C/T, R219 K, and I883M) in a cohort of young male survivors of myocardial infarction in order to know their influence in long-term prognosis. In premature heart disease, knowing prognosis factors is specially relevant.     

对急性心肌梗死患者应用血管造影肾动脉狭窄患病率分析

目的 调查了解急性心肌梗死患者粥样硬化性肾动脉狭窄(ARAS)的患病率.方法 采用2008年8月至2009年3月,北京安贞医院28病区231例急性心肌梗死患者在接受冠状动脉造影时接受选择性肾动脉造影的病历资料进行分析.结果 肾动脉正常者149例,ARAS(≥50%)53例(占入选患者22.9%),单侧ARAS 36例(左、右侧各18例,共占入选患者15.6%),双侧ARAS 17例(占入选患者7.4%).经logistic回归分析,年龄、高血压、缺血性脑卒中和血清肌酐异常是ARAS预测因素,而冠状动脉病变血管支数不是ARAS预测因素.结论 部分急性心肌梗死患者同时合并ARAS;对于合并有前述预测因素者,在冠状动脉造影时有必要作肾动脉造影.     

Effect of diltiazem on coronary reactive hyperemia in patients with flow-limiting coronary artery stenosis

The acute effects of diltiazem on coronary reactive hyperemia were studied in 12 patients with flow-limiting coronary stenosis. Reactive hyperemia was elicited by injection of 8 ml contrast medium into the left coronary artery, while coronary sinus blood flow and left ventricular and aortic pressures were continuously recorded. Relative magnitude of hyperemia was estimated by the ratio of coronary flow at peak hyperemia to baseline flow (hyperemic ratio). Coronary resistance was calculated as the ratio between mean aortic pressure minus left ventricular mean diastolic pressure and coronary sinus blood flow. The 12 patients studied had flow-limiting coronary stenosis since their hyperemic ratio was significantly restrained when compared to that of seven control subjects (1.45 +/- 0.17 vs 2.02 +/- 0.24, respectively; p less than 0.001). The intravenous infusion of diltiazem (0.30 mg X kg-1) reduced heart rate, mean aortic pressure, and myocardial oxygen consumption (all p less than 0.001). After diltiazem the hyperemic ratio was blunted when compared to the basal state (1.36 +/- 0.15 vs 1.45 +/- 0.17, respectively; p less than 0.05), and hyperemia volume was reduced (-33%; p less than 0.001). The decrease in coronary resistance at peak hyperemia was also reduced from -30 +/- 8% to -25 +/- 8% (p less than 0.05). We conclude that diltiazem blunts coronary reactive hyperemia in patients with demonstrated flow-limiting coronary stenosis. This reduction of coronary flow response to a hyperemic stimulus could favorably influence blood flow distribution in patients with significant coronary stenosis.     

阿托伐他汀对ST段抬高型急性心肌梗死患者急诊PCI术后无复流现象的影响

目的:探讨长期应用阿托伐他汀对冠状动脉介入治疗(PCI)术后无复流发生率的影响。方法:入选对象均为ST段抬高型急性心肌梗死(STEMI)患者,接受急诊PCI治疗且至少口服阿托伐他汀10mg/d3个月以上者入选阿托伐他汀组,未服用任何调脂药物者入选对照组,连续入选,至每组60例为止。PCI术中根据TI-MI血流分级法(TFG)、TIMI计帧法(cTFC)评价冠状动脉血流。术后24h进行实时心肌声学造影检查,计算心肌灌注缺损计分指数(CSI)及室壁运动计分指数(WMSI)。术后30min及24h记录心电图,观察ST段抬高最显著导联ST段回落的情况。术前、术后24h采取静脉血测定血浆高敏C反应蛋白(Hs-CRP)及sICAM-1水平。结果:阿托伐他汀组TIMI3级血流者显著多于对照组(P<0.05),而cTFC显著低于对照组(P<0.01)。阿托伐他汀组与对照组相比CSI(1.22±0.33:1.37±0.42,P<0.05),WMSI(1.53±0.40:1.71±0.38,P<0.05)均显著降低。术后30min阿托伐他汀组ST段回落≥50%者显著多于对照组(P<0.05),术后24h差异无统计学意义。术前、术...     

Diabetic patients after myocardial infarction

Diabetes mellitus is not just another risk factor for cardiovascular events; it per se defines maximal risk for target organ damage including the cardiovascular system. Diabetes is one of the main drivers in the race towards a higher incidence in cardiovascular disease worldwide. In addition, it is also one of the often unrecognized predecessors of myocardial infarction and sudden cardiac death. About three quarters of patients post-MI show impaired glucose tolerance or full blown diabetes. The MONICA/KORA data have shown that the higher risk for mortality and morbidity in diabetics is maintained past the first event. However, the STENO-2 trial has shown that consequently managing diabetes and concomitant cardiovascular risk factors can significantly reduce the risk for cardiovascular events in this high-risk group.     

Mortality after myocardial infarction in patients with diabetes mellitus

See article on page 1577Diabetes mellitus (diabetes), in particular type 2 diabetes, constitutes one of the largest emerging threats to health in the 21st century. It is estimated that by 2030 as many as 360 million people world wide will be affected.¹The cause of death in those with diabetes is dominated by coronary heart disease, accompanied by increased rates of stroke and peripheral vascular disease: so called macrovascular complications. At least two‐thirds of deaths are attributable to these cardiovascular diseases and their sequelae.² A true picture of the extent of macrovascular complications is obscured, however, by inaccurate death certification³ and diagnostic criteria⁴ based on the development of microvascular complications (retinopathy, neuropathy, nephropathy). The Euro Heart⁵ Survey demonstrated that if one applied oral glucose tolerance tests to those presenting with all forms of acute coronary syndrome, two‐thirds display impaired glucose regulation.In the USA, although the overall mortality rate associated with coronary heart disease has declined over the past 20 years, this trend has not been reflected in a decline of mortality rates in patients with diabetes.⁶ Results published in this issue of Heart from the Swedish registry on coronary care (RIKS‐HIA) confirm this trend (see article on page 1577).⁷ After a myocardial infarction (MI), patients with diabetes had an increased mortality rate compared with non‐diabetic patients. Moreover, despite the existence of treatments which may benefit diabetic patients disproportionately, the relative hazard of mortality in diabetic patients has improved little compared with non‐diabetic patients between the time periods 1995–8 and 1999–2002. These observations give us a glimpse of the vast epidemic that is approaching, if not upon us.     

Syphilitic coronary stenosis,with myocardial infarction

The protocols of 6,225 consecutive autopsies at the Charity Hospital of New Orleans during the past five years were reviewed in order to ascertain the incidence of myocardial infarction secondary to syphilitic coronary stenosis. Three such patients were found. These comprised 1.6 per cent of all cases of myocardial infarction. A review of the literature revealed nine other patients with myocardial infarction caused by syphilis.The average age of the patients with syphilitic coronary stenosis was forty-five years. Both arteries were involved in the majority of cases. Among the patients with coronary stenosis, the white to colored ratio was about one to six, and the female to male ratio was about one to three and a half. The blood Wassermann reaction was positive in 96.3 per cent of the patients with coronary stenosis. The average weight of the hearts with coronary stenosis alone was 413 grams, whereas patients who had had coronary stenosis and aortic regurgitation, hypertension, or both, had an average heart weight of 680 grams.A case of myocardial infarction secondary to syphilitic coronary stenosis was described to illustrate the clinical picture.     

无并发症的前壁和下壁急性心肌梗死的交感神经活动研究

研究表明[1-3],急性心肌梗死（AMI）后早期即可发生交感高活动性,但是二者间是否存在差异尚难定论.     

KCNJ11 polymorphisms and sudden cardiac death in patients with acute myocardial infarction

PURPOSE: Patients with an acute myocardial infarction (AMI) are of high risk to develop ischemia-induced ventricular arrhythmias, leading to sudden cardiac death (SCD) in about one third of all AMI patients. The individual susceptibility to ischemia-induced arrhythmias may be modified by polymorphisms in genes encoding ion channels. The cardiac ATP-dependent potassium channel (K(ATP)) current is generated by ion channels encoded by the KCNJ11 gene and the SUR2a gene. Opening of the K(ATP) channel during ischemia results in action potential shortening in various studies and may therefore influence the outcome of AMI patients. METHODS: Using a three-primer strategy, we sequenced the complete coding and adjacent 5' and 3' sequences of the intronless KCNJ11 gene (1.3 kb) prospectively in two groups. Patients of group 1 (n = 84) survived three or more transmyocardial infarctions without developing any ventricular arrhythmias. Patients of group 2 died suddenly from their first myocardial infarction (n = 86), most of them witnessed SCDs. RESULTS: We identified a total of six known polymorphisms (K23E, A190A, L267V, L270V, I337V, and K281K) and two new polymorphisms (L267L, 3'UTR +62 G/A). The allele, genotype, and haplotype frequencies did not differ between the two groups. All polymorphisms were found to be in Hardy-Weinberg equilibrium. In addition, we identified two novel missense mutations in a highly conserved region of the gene in two patients of group 2 (P266T and R371H) with yet unknown functional consequences. CONCLUSION: In this study of AMI patients, SCD was not related to polymorphisms in the KCNJ11 gene.     

Interventions in diabetic patients after myocardial infarction

Occurrence of a first acute myocardial infarction (AMI) is associated with further increase in risk of cardiovascular events. This risk is further increase is disproportionate in diabetics, who suffer from very high mortality short and long term after AMI. Factors responsible for the increased risk are only partially understood. Additional, properly designed, prospective epidemiological studies are needed for a better understanding of complicated diabetic macrovascular disease after the occurrence of the first event. These studies are also needed for designing interventional trials that target factors that carry the highest risk of new events. Published studies provide some insight into the issue of efficacy of blood pressure, cholesterol and blood glucose lowering strategies in the diabetic population. It remains unclear how important is the control of triglyceride concentration or other risk factors during various stages of recovery after AMI. The main reason is the lack of clinical trials. Evidence-based approach to patients with diabetes and AMI indicates the importance of tight control of cholesterol, blood pressure and blood glucose concentration. Although other risk factors have not been extensively studied, it is reasonable to assume that other major risk factors, such as hypertriglyceridemia, should be targeted as well. In the meantime, more data need to be collected from prospective epidemiological and interventional protocols, if better control over the cardiovascular risk in this high-risk population is to be achieved.     

Repolarization duration in patients with conduction disturbances after myocardial infarction

This study compared different measurements of repolarization duration in patients after infarction with and without conduction disturbances and evaluated the prognostic significance of repolarization parameters for predicting mortality in patients with conduction abnormalities. The study population consisted of 3,282 patients after recent myocardial infarction. Repolarization duration was measured using Bazett QTc and JTc (QTc minus QRS) and Rautaharju QT and JT(RR) formulas. All-cause mortality was the end point of the predictive models. In 259 patients with conduction disturbances, 76 (2.3%) had indeterminate ventricular conduction disturbances, 126 (3.8%) had right bundle branch block, and 47 (1.4%) had left bundle branch block. Patients with left bundle branch block demonstrated excessive prolongation of the QTc interval, which was not observed when using the JT(RR) interval. There were no significant differences in repolarization duration by gender in patients with conduction abnormalities. Repolarization parameters were uniformly dichotomized at the 75th percentile (QTc interval >490 ms, JTc interval >360 ms, QT(RR,QRS) interval >433 ms, JT(RR) interval >359 ms) to determine their prognostic significance for predicting mortality. After adjustment for significant clinical predictors of mortality, the hazard ratios were 1.65 for QTc interval (p = 0.062), 1.46 for JTc interval (p = 0.168), 1.71 for QT(RR,QRS) interval (p = 0.043), and 1.70 for JT(RR) interval (p = 0.044)(.) In conclusion, patients with left bundle branch block, right bundle branch block, or indeterminate ventricular conduction disturbances show longer repolarization duration than patients without these conduction disturbances, and QT(RR,QRS) and JT(RR) intervals reflect better than QTc repolarization duration in patients with conduction disturbances. QT(RR) and JT(RR) intervals significantly and independently predict mortality in patients after infarction with conduction disturbances.     

急性心肌梗死经皮冠状动脉介入治疗后心肌灌注的方法评价

目的　联合应用TIMI心肌灌注分级 (TMP)、校正的TIMI画面记帧 (CTFC)、心电图ST段变化 (sumSTR)方法评价急性心肌梗死 (AMI)急诊经皮冠状动脉介入治疗 (PCI)后心肌灌注程度 ,探讨心肌灌注程度对临床预后的影响。方法　 77例AMI患者PCI后即刻采用TMP CTFC、TMP sumSTR、CTFC sumSTR三种联合方法评价心肌灌注程度 ,PCI术后 1个月检查双核素心肌灌注显像 ,记录 6个月心脏事件。结果　评价心肌灌注程度 ,与双核素心肌灌注显像对比 ,TMP sumSTR敏感性 86 7%、特异性 85 7%、准确性 86 2 % ;TMP CTFC敏感性 80 %、特异性 77 1%、准确性 78 5 % ;多变量回归分析TMP 0 / 1级 sumSTR <30 %为 6个月心脏事件的独立危险因子 (OR=2 1 5 ,95 %可信区间 2 7～ 6 5 7,P =0 0 0 3) ;Kaplan Meier分析曲线显示TMP sumSTR方法评价的心肌灌注不良组 6个月心脏事件高于心肌灌注良好组 (P <0 0 5 )。结论　TMP sumSTR、TMP CTFC能更好的评价心肌灌注程度 ;TMP sumSTR可预测 6个月心脏事件。     

Myocardial viability in patients with Q wave myocardial infarction and no residual ischemia.

BACKGROUND. Coronary revascularization in patients with persistent angina after myocardial infarction reduces the incidence of recurrent angina pectoris and myocardial infarction and improves left ventricular function. The results of revascularization after a Q wave myocardial infarction when there is no residual ischemia may depend on myocardial viability. METHODS AND RESULTS. To determine whether there was viable myocardium in the infarct area in the absence of clinical and scintigraphic evidence of myocardial ischemia, 15 asymptomatic patients with a Q wave myocardial infarction, no redistribution on stress 201Tl test, and single-vessel disease (greater than 70% stenosis) with persistent anterograde blood flow were randomized to percutaneous transluminal coronary artery angioplasty (PTCA) or conservative medical treatment. After 2 months of follow-up, mean coronary blood flow measured by Doppler catheter in the infarct-related artery was higher in the PTCA treatment group (33 +/- 6 ml/min, n = 8) than in the conservative treatment group (16 +/- 4 ml/min, n = 7; p less than 0.05 between groups). The 201Tl pathological-to-normal ratios measured on postexercise images did not change in patients treated conservatively during the follow-up period (delta = +1.1 +/- 2.2%; NS from baseline) but increased significantly in patients treated by PTCA (delta = +8.5 +/- 2.3%; p less than 0.01 from baseline; p less than 0.05 between groups). Segmental wall motion improved on left ventricular angiography 2 months after PTCA (delta = +11.5 +/- 2.2%; p less than 0.001 from baseline) significantly more than in the conservative treatment group (delta = +4.1 +/- 1.4%; p less than 0.05 between both groups). Improvements of 201Tl ratios and segmental wall motion indexes correlated significantly (r = 0.73, p = 0.002). The mild improvement of global left ventricular ejection fraction measured in the PTCA treatment group did not differ significantly from changes in the conservative treatment group. CONCLUSIONS. Successful angioplasty of the stenotic infarct artery in patients with a Q wave myocardial infarction and no residual ischemia improved coronary flow, 201Tl uptake in the infarct area, and regional wall motion. Therefore, myocardial viability may last several weeks, as long as residual blood flow persists in the infarct-related artery. Optimal assessment of viability by imaging techniques should identify patients who are most likely to benefit from revascularization.