Increased aortic pulse and fractional pulse pressures in patients with cardiac syndrome X

BACKGROUND: Angina with normal coronary arteries, cardiac syndrome X, is a diagnosis of exclusion. The exact mechanism of this clinical syndrome remains unclear. Although the prognosis is as good as equal to that of the normal population, symptoms related to the syndrome largely impair quality of life. Aortic pulse and fractional pulse pressures are strong and independent indicators of the risk of coronary heart disease. An increase in these hemodynamic parameters is significantly associated with the presence of coronary artery disease in men and women. METHODS AND RESULTS: We evaluated aortic pulse and fractional pulse pressures of patients with cardiac syndrome X and control subjects, and investigated the relation between the two groups. One hundred and twenty-six patients with cardiac syndrome X with a mean age of 53.1 +/- 9.5 years and 76 patients without the syndrome with a mean age of 53.1+/-11.2 years were studied consecutively from May 2004 to May 2005. Aortic systolic, diastolic, mean and pulse pressures were measured and the fractional pulse pressure was calculated (aortic pulse pressure/mean pressure). Aortic pulse and fractional pulse pressures were significantly higher in the cardiac syndrome X group than in the control group (51 +/- 13 mmHg and 43+/-9 mmHg, p < 0.001; 0.54 +/- 0.11 and 0.47 +/- 0.08, p < 0.001, respectively). All patients were classified into tertiles of aortic pulse pressure level to evaluate whether aortic pulse pressure was associated with the presence of cardiac syndrome X in the study. The multiple-adjusted odds ratio of the risk of cardiac syndrome X was 6.72 (95% CI 2.76-16.37) for tertile 2 and 29.94 (95% CI 5.59-160.44) for tertile 3 of aortic pulse pressure level compared with tertile 1. In addition, all patients were divided into two groups as lower and higher levels of aortic fractional pulse pressure. The multiple-adjusted OR of the risk of cardiac syndrome X was 4.09 (95% CI 2.05-8.15) for the higher group compared with the lower group of aortic fractional pulse pressure level. CONCLUSION: Ascending aorta pulse and fractional pulse pressures are significantly associated with the presence of cardiac syndrome X and these associations are independent of age and other cardiovascular risk factors.     

Metabolic syndrome negatively impacts early patency of saphenous vein grafts

BACKGROUND: Coronary artery bypass grafting has been performed for a long period utilizing saphenous vein grafts, the fate of which might be crucial to prognosis following the operation. Metabolic syndrome, on the other hand, has become an increasingly important part of cardiovascular practice. We examined whether there was any negative effect of metabolic syndrome on saphenous vein graft patency in a relatively short term (< or =5 years). METHODS: Coronary angiograms of 314 consecutive patients (mean age 62.6+/-8.5 years), having at least one saphenous vein bypass graft within the last 5 years, were evaluated. RESULTS: One hundred and twenty-one patients (group 1) had either an occluded saphenous vein graft or a saphenous vein graft with a significant lesion, and 193 patients (group 2) had patent saphenous vein grafts. Metabolic syndrome was present in 46.2% of all patients (n=145), in 57% of patients in group 1 and in 39.4% of patients in group 2 (P=0.002). Having metabolic syndrome increased the risk of saphenous vein graft occlusion or having a significant lesion on saphenous vein grafts by 2.04-folds. In multivariable logistic regression, smoking (P=0.015, odds ratio=1.88), metabolic syndrome (P=0.019, odds ratio=1.81) and diabetes mellitus (P=0.048, odds ratio=1.36) were found to be associated with poor venous graft fate in the relatively short-term period after bypass. CONCLUSION: Metabolic syndrome seems to impact saphenous vein graft patency negatively in the relatively short term.     

冠状动脉旁路移植术序贯和单一静脉桥通畅率荟萃分析

目的:比较冠状动脉旁路移植术(CABG)后序贯和单一大隐静脉桥通畅率。方法:检索PUBMED、EMBASE、The Cochrane Library及中国生物医学文献数据库。文献纳入标准:两组患者分别行序贯和单一大隐静脉CABG术;前瞻性或回顾性队列研究,须满足非随机研究方法组制定的队列研究特征;运用冠状动脉造影或超高速CT检查旁路移植术至少1个月以后桥血管通畅情况。文献纳入、数据提取和文献质量评定均由两名研究者独立完成。运用Rev Man5.0和Stata10.0软件进行数据处理,合并相对危险度(RR)作为分析统计量,95%可信区间(CI)为判断结果标准。结果:12篇文献纳入本研究。序贯桥梗阻风险低于单一桥(13.56%vs.19.18%,RR=0.67,95%CI:0.60~0.74);序贯桥中侧侧吻合梗阻风险低于端侧吻合(9.58%vs.14.07%,RR=0.52,95%CI:0.34~0.80);序贯桥和单一桥中端侧吻合梗阻风险,差异无统计学意义(14.07%vs.13.61%,RR=0.85,95%CI:0.68~1.06)。结论:CABG后大隐静脉序贯桥中长期通畅率优于单一桥,序贯桥中侧侧吻合口通畅率优于端侧吻合口,序贯桥和单一桥端侧吻合口通畅率无差别。     

Factors affecting early graft patency after coronary grafts

From June 1984 to December 1987, an early postoperative angiographic study was performed in 247 patients who underwent isolated coronary artery bypass surgery. The average age of these patients was 58.6 years, range 31 to 75 years. Preoperatively 50.8% of patients had myocardial infarction and 43.2% of them had unstable angina before surgery. Early coronary artery bypass angiogram was performed in 683 grafts (2.76 grafts per patient): 74 internal mammary artery grafts and 609 saphenous vein grafts. The distribution, location and type of the stenosis, distal coronary artery diameter, segmental myocardial contractility, and distal angiographic coronary filling are analyzed with a matching statistical method. Multivariate analysis showed significant predictors of early graft occlusion to be right coronary and circumflex artery, poor or non visible distal angiographic filling, coronary arteries smaller than 1.5 mm. The univariate analysis associates as risk factors hypokinetic or akinetic territories and multiple stenosis coronary arteries. It can be concluded that the early angiographic study demonstrate that coronary arteries with multiple stenosis, poor distal angiographic filling, smaller than 1.5 mm in diameter, coronary arteries perfusing hypokinetic or akinetic territories and the right coronary and left circumflex artery grafts have significantly lower early cumulative patency rates.     

Saphenous vein bypass grafts: Long-term patency and effect on the native coronary circulation

The long-term durability of saphenous vein bypass grafts and their effect on existing intrinsic coronary artery disease remain ill defined. Therefore, sequential catheterization studies were performed in patients selected for study solely on the basis of documentation of a patent graft at an earlier study performed three to nine months postoperatively; at that time 29 patent grafts were demonstrated in 20 patients. Fifteen to 36 months postoperatively (average 22 months), 27 grafts were unchanged, 1 manifested minimal luminal irregularities and 1 was occluded. In one additional patient, studied 4 months and $\text{4}\text{1}\text{2}\text{years}$ postoperatively, the graft was widely patent and had good distal runoff at the second study.Sequential coronary arteriograms revealed that progression of disease to complete occlusion occurred in 24 percent of vessels with severe lesions proximal to a patent graft, whereas progression of disease distal to a graft anastomosis was uncommon. Of 25 vessels not receiving grafts, disease progressed in 5 (20 percent). Grafts that are patent 3 months after operation appear to remain patent for at least 2 to 3 years, and their presence does not unduly accelerate the disease process involving the native coronary arteries.     

大隐静脉序贯桥行冠状动脉螺旋CT的中期随访结果

目的：评价冠状动脉旁路移植术中应用大隐静脉序贯桥的中期临床效果。方法: 对37例冠状动脉粥样硬化性心脏病患者以大隐静脉序贯桥行冠状动脉旁路移植术,其中男25例,女12例,年龄45-69岁,不稳定性心绞痛患者23例,陈旧性心肌梗塞患者10例,急性心肌梗塞患者4例,于术后2年行冠状动脉螺旋CT随访。结果：37例病人中,35例全部血管桥均通畅,有2例病人乳内动脉桥路通畅,大隐静脉血管桥闭塞,未予介入或手术干预。结论:大隐静脉序贯桥中期随访通畅率良好,虽有“一闭俱闭”的风险,但大多数不会导致心肌梗死。     

静脉桥病变的介入治疗及临床预后观察

目的:本文针对不同部位桥血管病变的介入特点及临床预后进行比较探讨。方法:入选2005年12月至2011年12月,行静脉桥血管(SVG)介入治疗的患者68例。共73处SVG病变,其中位于主动脉-静脉桥开口14处,体部病变39处,远端病变20处。随访联合终点事件包括:急性心肌梗死,靶血管闭塞及再狭窄(TVF),心源性死亡。结果:平均桥血管病变发生时间为冠状动脉搭桥术后(6.72±4)年。1年以内的发生的桥血管病变大部分为远端吻合口病变(54.5%)。经皮冠状动脉介入术的介入成功率为94.5%,以体部病变成功率最高达100%,主动脉-静脉桥开口的成功率最低为85.7%。远端保护器应用在体部病变中应用比率最高(30.8%,P<0.01),远端吻合口病变所需支架直径最小(3.26±0.57)mm,P<0.05。主动脉-静脉桥开口病变所需支架的后扩张压力最大(17.8±2.3)atm(1atm=101.325 kPa),P<0.05。平均随访24.37个月,共发生终点事件17例(23.3%)。以主动脉-静脉桥开口最为多见6例(42.9%)。结论:SVG的经皮介入治疗可行,主动脉-静脉桥开口病变的介入成功率较低,远期预后较差。     

Routine intraoperative angiography improves the early patency of coronary grafts performed on the beating heart

OBJECTIVES: The techniques of performing coronary revascularization without cardiopulmonary bypass are rapidly evolving. However, concern remains regarding the accuracy of coronary artery anastomoses performed on the beating heart. This report reviews the use of intraoperative angiography in the critical appraisal of "off-pump" coronary artery bypass graft (CABG) surgery. PATIENTS: Intraoperative angiography was performed in 24 consecutive patients undergoing CABG surgery without cardiopulmonary bypass. In all, 24 left internal mammary artery (LIMA) grafts and 18 saphenous vein bypass grafts were assessed for patency, anastomosis quality, distal and proximal runoff, and correct placement. RESULTS: All of the saphenous vein-to-coronary artery anastomoses were widely patent, although two patients (8%) required revision of their LIMA grafts on the basis of angiographic findings. CONCLUSION: Intraoperative angiography permits the surgeon to immediately appraise the CABG and to revise, if necessary, any graft abnormality, thus potentially eliminating the need for early repeated surgery. The practice of routine intraoperative angiography is likely to improve the outcome of CABG surgery on the beating heart.     

Histochemical examination of energy metabolism in aortic vein grafts in rats

The duration of the presumed metabolic depression of syngeneic vena cava to aorta transplants was determined in rats and the site and type of energy metabolism in the vein grafts assessed. The aerobic metabolic activity was measured from the histochemical reactivity of the enzymes, succinate dehydrogenase and cytochrome oxidase, and the anaerobic activity by staining with lactate dehydrogenase. The activity of the hexose-monophosphate shunt was assessed by the histochemical demonstration of glucose-6-phosphate dehydrogenase. Sixteen hours after grafting a pronounced metabolic depression was noted. Recovery occurred 24 hours after transplantation. The most intense staining was from lactate dehydrogenase in the vein grafts and in the non-transplanted veins. At the end of the observation period of four months the grafts were definitely more strongly stained than the non-transplanted veins, with most of the activity in the thickened intima. This layer had a metabolic profile resembling that of the media of the adjacent aorta.     

A reappraisal of the factors affecting early patency of aortocoronary saphenous vein bypass grafts. Current experience with extensive revascularization employing sequential grafting techniques

A number of factors potentially influencing the patency rates of aortocoronary bypass grafts were investigated in a consecutive series of 50 patients by control angiography at 28 +/- 26 days and by univariate and multivariate analysis of a selected set of clinical, surgical and angiographic predictors. There were 234 anastomoses in this series, a mean of 4.7 per patient (range 1 to 9), 215 of which were connected to sequential vein grafts. After surgery, 40 patients were treated with anticoagulants and/or platelet inhibitors. Of the 234 coronary anastomoses studied, 219 were patent (93.6%). Coronary artery diameter, patient's age and previous myocardial infarction were shown to be independent predictors of increased risk of anastomotic occlusion. Arteries less than 1.5 mm in diameter had a patency rate of 84.9%, versus 96.1% for vessels 1.5 mm or larger (p = 0.009). The use of side-to-side anastomoses with sequential grafts seemed to counterbalance the unfavourable effect of small arterial size. Patients aged 65 or older had a lower probability of having all their grafts patent than younger patients did (50 vs 89%, p = 0.01). Patients with previous myocardial infarction similarly had a lower probability of having all their grafts patent compared to patients without previous infarction (68 vs 95%, p less than 0.05); this correlation was explained by a more frequent occlusion rate of grafts directed to fibrotic left ventricular areas. The effect of anticoagulants and of platelet-inhibitors was favourable, but did not reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heart rate dependence of aortic pulse wave velocity at different arterial pressures in rats

Arterial stiffness, as measured by aortic pulse wave velocity (PWV), is an independent marker of cardiovascular disease and events in both healthy and diseased populations. Although some cardiovascular risk factors, such as age and blood pressure, show a strong association with PWV, the association between heart rate (HR) and PWV is not firmly established. Furthermore, this association has not been investigated at different arterial blood pressures. To study effects of HR on aortic PWV at different mean arterial pressures (MAPs), adult (12 weeks; n=7), male, anesthetized Sprague-Dawley rats were randomly paced at HRs of between 300 and 450 bpm, at 50-bpm steps. At each pacing step, aortic PWV was measured across a physiological MAP range of 60 to 150 mmHg by infusing sodium nitroprusside and phenylephrine. When compared at the same MAP, increases in HR resulted in significant increases in PWV at all of the MAPs >80 mmHg (ANOVA, P<0.05), with the greatest significant change of 6.03±0.93% observed in the range 110 to 130 mmHg. The positive significant association between HR and PWV remained when PWV was adjusted for MAP (ANOVA, P<0.001). These results indicate that HR dependency of PWV is different at higher pressures than at lower pressures and that HR may be a confounding factor that should be taken into consideration when performing analysis based on PWV measurements.     

Effect of suloctidil on tomographically quantitated platelet accumulation in Dacron aortic grafts

Platelet deposition contributes to the thrombotic and embolic complications of prosthetic materials in man. To determine if the investigational platelet inhibitory drug suloctidil (200 mg 3 times daily) reduces platelet deposition on Dacron aortic grafts, a randomized, double-blind, crossover trial was conducted in 12 men with grafts that had been in place more than 9 months. Platelet deposition in the graft was assessed by quantitative analysis of planar images obtained at 24, 48 and 72 hours after injection of indium-111-labeled platelets. Also, a tomographic method of imaging and quantitating labeled platelet deposition in the graft was developed. Tomographic imaging was performed at 24 and 72 hours after platelet injection and was quantitated by a graft/blood ratio that compared indium-111 platelet activity in summed 1.8-cm-thick transaxial tomographic slices of the aortic graft to indium-111 platelet activity in well-counted whole blood. Compared with placebo, suloctidil failed to decrease the tomographic graft/blood ratio at 24 hours (6.2 +/- 1.3 vs 5.7 +/- 0.8) and 72 hours (11.4 +/- 2.9 vs 10.7 +/- 2.2). Similarly, the graft/blood ratio determined by planar imaging was not different between placebo and suloctidil therapy at 24 hours (1.7 +/- 0.3 vs 1.6 +/- 0.2), 48 hours (2.2 +/- 0.4 vs 2.4 +/- 0.4) or 72 hours (2.6 +/- 0.5 vs 2.8 +/- 0.5) after labeled platelet injection. Thus, suloctidil does not significantly reduce platelet deposition on chronically implanted Dacron grafts in humans.