Coronary collateral circulation in coronary artery disease and systemic hypertension

The extent and functional capacity of coronary collateral circulation in patients with systemic hypertension has not been elucidated. In the present study, 313 patients with coronary artery disease were studied to evaluate coronary collateral circulation in relation to the presence of systemic hypertension and left ventricular hypertrophy. Patients had greater than or equal to 95% diameter luminal obstruction of either the left anterior descending or the right coronary artery. Patients were classified into 2 groups: The hypertensive group consisted of 61 patients, mean age 55 +/- 9 years, with systemic hypertension, and the normotensive group consisted of 252 patients, mean age 53 +/- 8 years, without hypertension. The hypertensive group had more severe angina pectoris and less history of healed myocardial infarction than the normotensive group (p less than 0.001). Left ventricular wall thickness was 1.26 +/- 0.1 cm in the hypertensive and 1.03 +/- 0.06 cm in the normotensive group (p less than 0.001). The hypertensive group had more extensive coronary collateral circulation than the normotensive group (p less than 0.01). There was a positive relation between coronary collateral circulation and left ventricular wall thickness (p less than 0.001). These results indicate that patients with systemic hypertension and coronary artery disease have an increase in coronary collateral circulation corresponding to the degree of left ventricular wall thickness.     

Coronary collateral perfusion in patients with coronary artery disease: effect of metoprolol.

BACKGROUND: The use of ultrathin Doppler angioplasty guidewires has made it possible to measure collateral flow quantitatively. Pharmacologic interventions have been shown to influence collateral flow and, thus, to affect myocardial ischaemia. METHODS: Twenty-five patients with coronary artery disease undergoing PTCA were included in the present analysis. Coronary flow velocities were measured in the ipsilateral (n = 25) and contralateral (n = 6; two Doppler wires) vessels during PTCA with and without i.v. adenosine (140 microg/kg.min) before and 3 min after 5 mg metoprolol i.v., respectively. The ipsilateral Doppler wire was positioned distal to the stenosis, whereas the distal end of the contralateral wire was in an angiographically normal vessel. The flow signals of the ipsilateral wire were used to calculate the collateral flow index (CFI). CFI was defined as the ratio of flow velocity during balloon inflation divided by resting flow. RESULTS: Heart rate and mean aortic pressure decreased slightly (ns) after i.v. metoprolol. The collateral flow index was 0.25+/-0.12 (one fourth of the resting coronary flow) during the first PTCA and 0.27+/-0.14 (ns versus first PTCA) during the second PTCA, but decreased with metoprolol to 0.16+/-0.08 (p<0.0001 vs. baseline) during the third PTCA. CONCLUSIONS: Coronary collateral flow increased slightly but not significantly during maximal vasodilatation with adenosine but decreased in 23 of 25 patients after i.v. metoprolol. Thus, there is a reduction in coronary collateral flow with metoprolol, probably due to an increase in coronary collateral resistance or a reduction in oxygen demand.     

慢性心肌缺血中侧支循环作用的研究

目的:运用冠脉造影和非介入性方法研究冠状动脉慢性闭塞多支病变(Chronic Occlusive Multivessle Disease)中侧支循环与临床状况及表示侧支循环状况的临床指标。方法:选择既往无心肌梗塞、有稳定型和不稳定型心绞痛病史,冠脉造影示至少一支冠脉完全闭塞并有多支病变的病人,根据CAG判断侧支循环的分级情况,病人被分为侧支良好组(A组:侧支循环2．3级)和侧支不良组(B组:侧支循环0,1级),对两组患者临床特征进行对比分析。结果:40例冠脉慢性闭塞多支病变患者中侧支良好的有28例(A组),侧支不良的有12例(B组)。心绞痛病程(>3个月)在A组中占96．4％,在B组中占66．6％,B组明显少于A组(P<0．05)。异常Q波的出现率两组分别为28．5％(A组),66．6％(B组),B组明显高于A组(P<0．05)。室壁运动正常者A组占39．2％,明显高于B组的10％(P<0．01)。左室射血分数(LVEF)A组明显高于B组(50±8．0:44．8±5．5,P<0．05)。结论:病程较短,有异常Q波,室壁运动异常,左室射血分数<50％者提示侧支循环不佳。     

Pravastatin promotes coronary collateral circulation in patients with coronary artery disease

BACKGROUND: Previous studies suggested that hydroxymethylglutaryl coenzyme A reductase inhibitor (statin) promotes collateral circulation in ischemic limbs of rabbits. The present study was designed to determine the association between treatment with pravastatin and the development of coronary collateral circulation as assessed by the Rentrop Score in patients with coronary artery disease (CAD) in a case-control study. DESIGN: The study included patients who had one (1-V), two (2-V) or three (3-V) significantly stenosed vessels. Patients who did and did not receive pravastatin were defined as case participants (n = 42) and control participants (n = 100), respectively. RESULTS: The case participants included a higher percentage of 3-V patients with a Rentrop Score 1 compared to the control participants but there was no difference among 1-V and 2-V patients, suggesting that pravastatin was associated with coronary collateral circulation independent of the number of stenosed vessels. Patients with 3-V disease who were treated with pravastatin were most likely [odds ratio (confidence interval), 17.4 (4.4-115)] to develop collateral circulation, as assessed by multiple logistic regression analysis. CONCLUSIONS: Treatment with pravastatin was associated with the development of collateral circulation in patients with CAD, suggesting that such action constitutes part of the pleiotropic effects of statin.     

Coronary collateral quantitation in patients with coronary artery disease using intravascular flow velocity or pressure measurements

Objectives. This study evaluated two methods for the quantitative measurement of collaterals using intracoronary (IC) blood flow velocity or pressure measurements.Background. The extent of myocardial necrosis after coronary artery occlusion is substantially influenced by the collateral circulation. So far, qualitative methods have been available to assess the human coronary collateral circulation, thus restraining the conclusive investigation of, for example, therapies to promote collateral development.Methods. Fifty-one patients with a coronary artery stenosis to be treated by percutaneous transluminal coronary angioplasty (PTCA) were investigated using IC PTCA guidewire-based Doppler and pressure sensors positioned distal to the stenosis. Simultaneous measurements of aortic pressure, IC velocity and pressure distal to the stenosis during and after PTCA provided the variables for calculating collateral flow indices (CFI_vand CFI_p) that express collateral flow as a fraction of flow via the patent vessel. Both CFI_vand CFI_pwere compared with conventional methods for collateral assessment, among them ST-segment changes >1 mm on IC and surface electrocardiogram (ECG) at PTCA. Also, CFI_vand CFI_pwere compared with each other.Results. In 11 patients without ECG signs of ischemia during PTCA (sufficient collaterals), relative collateral flow amounted to 46% as determined by Doppler and pressure wire. Patients with insufficient collaterals (n = 40) had relative collateral flow values of 18%. Using a threshold of CFI = 30%, sufficient and insufficient collaterals could be diagnosed with 100% sensitivity and 93% specificity by IC Doppler, and 75% sensitivity and 92% specificity by IC pressure measurements. The agreement between Doppler and pressure measurements was good: CFI_v= 0.08 + 0.8 CFI_p, r = 0.80, p = 0.0001.Conclusions. Intracoronary flow velocity or pressure measurements during routine PTCA represent an accurate and, at last, quantitative method for assessing the coronary collateral circulation in humans.     

冠状动脉痉挛致心脏骤停患者的临床特征和长期预后

目的探讨冠状动脉（简称冠脉）痉挛致心脏骤停患者的临床特征及长期预后。方法回顾性分析2000年11月至2013年6月间冠脉痉挛致心脏骤停患者,经冠脉造影等检查排除冠脉疾病及其他心脏疾病,长期随访患者的治疗和预后。结果共入选13例（男／女,10／3）,该队列的吸烟率及高血压患病率较高,心室颤动是导致心脏骤停最常见的心律失常。给予钙离子拮抗剂和／或长效硝酸酯类药物治疗,3例行埋藏式心脏复律除颤器（ICD）植入。经平均71（3—296）个月随访,1例发生心源性猝死,其余12例未再发生心脏骤停和ICD放电等事件。结论冠脉痉挛可导致致命性心律失常。长期、规律的药物治疗有利于其预后。     

冠心病患者冠状动脉侧支循环形成的相关因素

目的:探讨冠状动脉侧支循环形成的意义及影响侧支循环形成的相关因素。方法:冠状动脉造影中发现有侧支循环形成者47例作为研究组,以病变程度相同但无侧支循环形成者58例作为对照组;同时超声心动图检查病变局部室壁运动情况。结果:侧支循环形成与糖尿病、吸烟呈负相关,与服用他汀类药物呈正相关,而与性别、年龄、胸痛时间、有无高血压病、有无高脂血症、家族史、冠状动脉病变支数、服用ACEI类、硝酸酯类药物无关。结论:侧支循环多出现在病变严重的冠心病患者,糖尿病、吸烟是侧支循环形成的不利因素,服用他汀类药物能促进侧支循环形成;糖尿病患者即使形成侧支循环,对心功能的保护作用也较差。     

Hematological parameters and coronary collateral circulation in patients with stable coronary artery disease

BACKGROUND:

Although hematological parameters have been associated with prognosis in patients with various cardiovascular diseases, their relationship with coronary collateral (CC) circulation in patients with stable coronary artery disease (CAD) is unknown.

OBJECTIVE:

To investigate the relationship between hematological parameters and CC vessel development in patients with stable CAD.

METHODS:

A total of 96 patients who underwent coronary angiography were retrospectively enrolled. All study participants had at least one occluded major coronary artery. Development of CCs was classified using the method of Rentrop. Rentrop grades of 0 and 1 indicate poor CCs, whereas grades 2 and 3 indicate good CCs. Hematological parameters, including mean platelet volume (MPV) and neutrophil/lymphocyte (N/L) ratio, were measured. Multivariate logistic regression analysis was performed to identify independent variables.

RESULTS:

The MPV and N/L ratio were significantly higher in the poor CC group compared with the good CC group. Negative correlations were found in the analyses comparing Rentrop score with MPV and N/L ratio (r=−0.274; P=0.012 and r=−0.339; P=0.001, respectively). In multivariate analysis, the N/L ratio was independently related to CC circulation (OR 0.762 [95% CI 0.587 to 0.988]; P=0.04).

CONCLUSION:

The results suggest that N/L ratio and MPV are associated with poor CCs, and a high N/L ratio is a significant predictor of poor CC development in patients with stable CAD.     

Coronary artery ectasia--a variant of occlusive coronary arteriosclerosis.

In a study of 1000 consecutive coronary arteriograms, 12 patients (all men) had coronary artery ectasia. Ectasia was found most frequently in the circumflex or right coronary artery. Only 1 patient had ectasia in the left anterior descending coronary artery. In 11 patients, ectasia of one artery was associated with severe stenosis or occlusion of other vessels, typical of arteriosclerosis. Histology from an ectatic segment in one of this group showed changes of severe arteriosclerosis with extensive intimal fibrosis and destruction of the media. One patient had a mixed collagen vascular disease. Measurement of coronary sinus flow in 2 patients with coronary artery ectasia showed flows in the range of patients with non-ectatic coronary artery disease. At cardiac surgery flows down the graft to ectatic arteries were in the same range as in grafts to non-ectatic vessels. Patients with coronary artery ectasia should be anticoagulated.     

Coronary artery spasm and its relationship to exercise in patients without severe coronary obstructive disease

Coronary artery spasm is reported to occur with exercise. In patients without severe coronary atherosclerosis, the evidence for exercise-induced coronary artery spasm is limited. Three patients with positive exercise tests but no severe coronary atherosclerosis are presented. Coronary artery spasm was provoked and verified by angiography in all three, but coronary angiography during exercise failed to demonstrate spasm. The literature is reviewed and the value of a routine protocol for evaluation is discussed.     

Coronary collateral development in swine after coronary artery occlusion.

We have quantified the development of the coronary collateral circulation in the pig. The collateral circulation was induced to grow by placing an ameroid occluder on the left circumflex coronary artery. Two to 16 weeks after ameroid placement, the coronary collateral circulation was identified after the injection of several colors of a silicone polymer into the coronary arteries and the aorta. We identified intercoronary and extracardiac collaterals and quantified their number, location, size, and wall thickness. Intercoronary collaterals grew to a level that represents a 14-fold increase in normal collateral blood flow under resting conditions compared with the values in an animal not subjected to coronary artery occlusion. Extracardiac collaterals could potentially supply approximately 30% of resting flow. The sources of the extracardiac collaterals were the bronchial and internal mammary arteries. Coronary collateral morphometry and DNA synthesis in the pig heart also were examined. Coronary collaterals had significantly less smooth muscle than did normal arterioles. This may account, in part, for the reduced response of the coronary collaterals to vasodilators. We observed intense DNA synthesis in endothelial and smooth muscle cells in the first 2 or 3 weeks of ischemia. However, DNA synthesis rapidly ceased after this time, coincident with coronary collateral reserve values (ischemic/nonischemic regional blood flow ratios during maximal vasodilation) reaching their maximum level. This suggests that failure of the vessels to continue proliferating accounts for the occurrence of the plateau in blood flow levels.