Coronary Collaterals In Patients Research Articles

Functional vascular endothelial growth factor gene polymorphisms and diabetes: Effect on coronary collaterals in patients with significant coronary artery disease

Vascular endothelial growth factor (VEGF) plays a pivotal role in angiogenesis. This study tested the association between functional VEGF +405 C>G (rs2010963), -2578C>A (rs699947) polymorphisms, and coronary collaterals in patients with coronary artery disease (CAD). The collateral scoring system developed by Rentrop was used to classify 393 patients according to their collaterals as either "poor" (grades 0 and 1) or "good" (grades 2 and 3). Gene polymorphisms were analyzed by TaqMan assay. The frequency of +405C and -2578A alleles was higher in the good collaterals group (p=0.007 and 0.005, respectively). For the +405C>G allele, the odds ratio (OR) of good collaterals for CC to GG genotype was 2.54 (p=0.003). For the -2578A allele, the OR of good collaterals for AA to CC genotype was 2.31 (p=0.038). Univariate and logistic regression analysis found 2 polymorphisms in the additive model for associations with collateral development: +405C>G (p=0.005 and 0.010) and -2578C>A (p=0.006 and 0.006). The VEGF +405C>G polymorphism and DM revealed an interactive effect on collateral development (p=0.027). The VEGF +405C>G and -2578C>A polymorphisms might be novel genetic factors affecting collateral development in Chinese patients.

Plasma cathepsin L and its extracellular matrix cleavage product—endostatin play useful roles in predicting poor coronary collaterals in patients with coronary artery disease

Plasma cathepsin L and its extracellular matrix cleavage product—endostatin play useful roles in predicting poor coronary collaterals in patients with coronary artery disease

Assessment of the presence and extent of coronary collateralization by coronary computed tomographic angiography in patients with total occlusions

Coronary computed tomography angiography (CTA) may be helpful to manage patients with chronic coronary occlusions. The aim of this study was to determine the sensitivity and specificity of CTA to detect the presence and extent of coronary collaterals as compared to invasive coronary angiography (ICA). We retrospectively evaluated 26 patients who underwent both coronary CTA and ICA within 3 weeks and demonstrated a total coronary occlusion (TIMI grade 0) in one of the major coronary arteries. CTA was performed using a 64-slice multidetector CT. The presence, and extent of collateralization was assessed by two blinded observers using the Rentrop classification for ICA. CTA accurately identified the presence and location of all 26 total occlusions. The presence of any collaterals was accurately detected in 21/23 patients [sensitivity 91% (CI: 71-98%)] and the absence in three patients [specificity 100% (CI: 29%-100%)]. The sensitivity of coronary CTA to identify patients with collateralization increased from 91 to 94% (CI: 71-99%) and 100% (CI: 59-100%) for collaterals Rentrop grade 2 and 3 in ICA, respectively. Coronary CTA accurately detects the presence of any coronary collateralization in patients with total occlusions. Although CT technology is currently limited in the assessment of individual collaterals and smaller vessels, it may be helpful in the management of patients with total occlusions.

The prognostic significance of coronary collaterals in patients with ischemic heart disease: An essential response to ischemia

The prognostic significance of coronary collaterals in patients with ischemic heart disease: An essential response to ischemia

Effect of Chronic Sustained‐Release Dipyridamole on Myocardial Blood Flow and Left Ventricular Function in Patients With Ischemic Cardiomyopathy

Dipyridamole increases adenosine levels and augments coronary collateralization in patients with coronary ischemia. This pilot study tested whether a 6-month course of sustained-release dipyridamole/aspirin improves coronary flow reserve and left ventricular systolic function in patients with ischemic cardiomyopathy. Six outpatients with coronary artery disease and left ventricular ejection fraction (LVEF) <40% were treated with sustained-release dipyridamole 200 mg/aspirin 25 mg twice daily for 6 months. Myocardial function and perfusion, including coronary sinus flow at rest and during intravenous dipyridamole-induced hyperemia, were measured using velocity-encoded cine magnetic resonance stress perfusion studies at baseline, 3 months, and 6 months. There was no change in heart failure or angina class at 6 months. LVEF increased by 39%+/-64% (31.0%+/-13.3% at baseline vs 38.3%+/-10.7% at 6 months; P=.01), hyperemic coronary sinus flow increased more than 2-fold (219.6+/-121.3 mL/min vs 509.4+/-349.3 mL/min; P=.01), and stress-induced relative myocardial perfusion increased by 35%+/-13% (9.4%+/-3.4% vs 13.9%+/-8.5%; P=.004). Sustained-release dipyridamole improved hyperemic myocardial blood flow and left ventricular systolic function in patients with ischemic cardiomyopathy.

Relation of C-Reactive Protein to Coronary Collaterals in Patients With Stable Angina Pectoris and Coronary Artery Disease

The heterogeneity in the degree of collateralization among patients with coronary artery disease (CAD) is poorly understood. We sought to determine whether chronic subclinical inflammation is related to coronary collateral development in patients with chronic stable angina pectoris and obstructive CAD. High-sensitivity C-reactive protein (CRP) levels were measured in 177 patients with stable angina pectoris before coronary angiography. Multivariable logistic regression revealed an inverse graded association between CRP and the presence of coronary collaterals (Rentrop grade 1 to 3). Compared with patients in the first CRP tertile, the adjusted odds ratio for the presence of coronary collaterals was 0.70 (95% confidence interval, 0.33 to 1.52; p = 0.45) for patients in the second CRP tertile and 0.33 (95% confidence interval, 0.15 to 0.75; p = 0.008) for patients in the third CRP tertile (p for trend = 0.008). In conclusion, an inverse graded association exists between CRP and the presence of coronary collaterals in patients with stable angina pectoris.

Coronary collateral circulation: The effects of smoking and alcohol

Objective The presence or absence of coronary collaterals is of vital importance during acute ischemia. Smoking and alcohol have been suggested to play a role, but data are scarce. We examined the extent to which smoking and alcohol use affect the presence of coronary collateral circulation. Methods Cross-sectional study in 242 patients, admitted for elective PTCA. Smoking was defined as past or current. Packyears were calculated and categorized into never-smokers (reference-category): <10, 10–19, 20–29, and ≥30 packyears. Alcohol consumption was defined as past or current, and categorized into never-users (reference-category): <1, 1–10, 11–20, and ≥21 units per week (UPW). Collaterals were graded with Rentrop's classification. Coronary collateral presence was defined as Rentrop-grade ≥1. Results Current smoking (odds ratio (OR) 4.17; 95% confidence interval (CI) 1.79–9.71) was positively associated, while packyears of smoking was not related. Current alcohol intake showed a J-shaped tendency with coronary collateral presence, while past moderate alcohol consumption was inversely associated (OR 0.19; 95% CI 0.04–0.98). Conclusions Smoking and (to some extent) alcohol use are associated with collateral presence. The results support the view that life-style factors may affect the formation of coronary collaterals in patients with ischemic cardiac disease.

Circulating Endothelial Progenitor Cells and Coronary Collaterals in Patients with Non-ST Segment Elevation Myocardial Infarction

Background: Endothelial progenitor cells (EPCs) are bone marrow-derived cells that are augmented in response to ischemia and incorporated into neovascularization sites. We sought to determine whether circulating EPCs are related to collateral formation following non-ST segment elevation myocardial infarction (NSTEMI). Methods: Twenty patients who underwent percutaneous coronary intervention (PCI) within a week of NSTEMI were divided into two groups: patients without collaterals (coll–, n = 10) and patients with Rentrop grade 3–4 collaterals (coll+, n = 10). Blood samples were drawn before PCI and 24 ± 2 h after PCI. EPC colonies were grown from peripheral blood mononuclear cells, characterized, and counted. Using flow cytometry the percentage of cells coexpressing vascular endothelial growth factor receptor-2 and CD133 was determined. Results: The coll+ group had higher degree of culprit vessel stenosis and lower initial thrombolysis in myocardial infarction flow grade. The relative number of EPCs before PCI was significantly higher in the coll+ group than in the coll– group (1.49 ± 0.9% vs. 0.77 ± 0.4%, p = 0.045). There were no significant intergroup differences in the number of EPC colony-forming cells. The number of EPC colonies increased in the coll– group after PCI (9.5 ± 4.8 to 14.0 ± 5.9/10⁶ cells, p = 0.01). Conclusions: This study supports an association between circulating EPC levels and collateral formation in patients with an NSTEMI.

Prognostic Significance of Coronary Collaterals in Patients With Coronary Heart Disease Having Percutaneous Transluminal Coronary Angioplasty

We examined the presence and extent of coronary collaterals as a prognostic determinant of cardiovascular outcome in a prospective case-cohort study of 655 patients admitted for elective coronary angioplasty. In patients with ischemic heart disease, the angiographic presence of coronary collaterals may mark an unfavorable prognosis, particularly in relatively high-risk patients.

Presence of the Metabolic Syndrome Does Not Impair Coronary Collateral Vessel Formation in Patients With Documented Coronary Artery Disease

The metabolic syndrome confers an increased risk for cardiovascular morbidity and mortality. The presence of coronary collaterals may have beneficial effects during myocardial ischemia and may improve cardiovascular outcome in patients with coronary artery disease. Impaired collateral formation could be one of the reasons for the increased cardiovascular risk in patients with the metabolic syndrome. The aim of the present study was to determine the influence of the metabolic syndrome and insulin resistance on the presence of coronary collaterals. We conducted a cross-sectional study in 227 patients referred for elective percutaneous transluminal coronary angioplasty to the University Medical Centre Utrecht. The metabolic syndrome was diagnosed according to Adult Treatment Panel III, and homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) were used to quantify insulin resistance. Coronary collaterals were graded with Rentrop's classification. Rentrop grade >/=1 indicated the presence of collaterals. Results were adjusted for age, sex, and severity of coronary artery disease. A total of 103 patients (45%) were diagnosed with the metabolic syndrome. There was no association between the metabolic syndrome and the presence of coronary collateral formation (odds ratio [OR] 1.2 [95% CI 0.7-2.0]). Also, the degree of insulin resistance was not related to the presence of coronary collaterals. The OR for HOMA-IR (highest versus lowest tertile) was 0.7 (0.3-1.5) and for QUICKI (lowest versus highest tertile) 0.8 (0.4-1.6). The metabolic syndrome and insulin resistance are not related to the presence of coronary collaterals in patients with documented coronary artery disease.

Coronary collaterals: an important and underexposed aspect of coronary artery disease.

Important risk factors for cardiovascular disease (CVD) have been identified, but they fail to explain why some patients with atherosclerosis become symptomatic and have recurrent symptomatic disease, and others do not. Apart from the extent of coronary atherosclerosis (among other factors), the sensitivity of organs to episodes of ischemia is probably of importance. An organ may be less sensitive to episodes of ischemia if supplied with sufficient blood flow by well-developed collateral vessels. Unfortunately, some organs or even some individuals do not appear to have well-developed collateral vessels, if developed at all. At present, it is not clear why there are differences between individuals in their capability of developing a sufficient collateral circulation. The potential of individuals to develop coronary collateral circulation has so far been largely neglected but may play a major role in determining myocardial vulnerability. In the present article, we propose why coronary collaterals are important, and why this individual potential to develop collaterals should be considered an additional indicator of cardiac vulnerability. Also, we review determinants that play a role in collateral coronary blood supply. Coronary collaterals, or “natural bypasses,” are anastomotic connections without an intervening capillary bed between portions of the same coronary artery and between different coronary arteries (Figure 1).1 Collateral circulation potentially offers an important alternative source of blood supply when the original vessel fails to provide sufficient blood.2 Timely enlargement of collaterals may even avoid transmural myocardial infarction (MI) and death in symptomatic patients.3 As early as in 1956, Baroldi et al4 demonstrated the presence at birth of mostly corkscrew-shaped collaterals in normal human hearts, with a lumen diameter of 20 to 350 μm and lengths ranging from 1 or 2 cm to 4 or 5 cm. In hearts with typical findings of coronary disease at autopsy, …

Bradycardia is associated with development of coronary collateral vessels in humans.

The development of mature coronary collateral vessels in patients with obstructive coronary artery disease (CAD) decreases the ischemic myocardial burden. Chronic bradycardia has been shown to stimulate formation of collateral vessels in experimental models. To test our hypothesis that CAD patients with bradycardia would have better developed collateral circulation than would members of a control group. A retrospective study examining the relationship between bradycardia and the development of coronary collateral vessels in patients with obstructive CAD. Admission electrocardiograms and rhythm tracings obtained during angiography of all patients presenting to the cardiac catheterization laboratory were screened from January to October 1997. Angiograms for patients with heart rates < or = 50 beats/min were reviewed. An equivalent number of consecutive patients with heart rates > or = 60 beats/min served as controls. Patients with acute myocardial infarction, with rhythms other than sinus, and without high grade obstructive CAD (< 70% stenosis) were excluded from the study. The study population consisted of 61 patients, 30 having heart rates < or = 50 beats/min (group A), and 31 controls with heart rates > or = 60 beats/min (group B). A significantly greater proportion of patients in group A than of matched controls was demonstrated to have developed collaterals (97 versus 55% in group B, P < 0.005). The mean collateral grades were 1.66 and 0.95 for subjects in groups A and B, respectively (P < 0.001). CAD patients with bradycardia are more likely (odds ratio 24, 95% confidence interval 5-146) to have angiographic coronary collaterals than are those with higher heart rates. Results of this study demonstrate that there is an association between bradycardia and growth of collateral vessels in patients with obstructive CAD. Bradycardic agents may be useful for promoting development of coronary collaterals in patients with atherosclerotic disease.

Coronary collaterals in patients with normal and impaired left ventricular systolic function

One hundred and twenty consecutive patients with significant coronary artery disease, normal left ventricular systolic function and coronary collaterals (group A) were compared to 120 patients with the same characteristics but with left ventricular systolic dysfunction (group B). No significant differences were found between the two groups on age, hypertension, diabetes mellitus and smoking. The left ventricular end diastolic pressure was 16±7 in group A, and 24±9 in group B ( P<0.01). The number of diseased vessels was similar in both groups. More completely occluded vessels were found in group B (155 vs. 101 in group A). No significant difference was detected between the two groups in the distribution of the diseased vessels. In both groups, the richest collateral supply was to the right coronary artery, followed by collaterals to the left anterior descending. The poorest supply was to the left circumflex. In conclusion, patients with normal and abnormal left ventricular systolic function have similar coronary collateral characteristics.

Role of coronary collaterals in patients with coronary artery disease

Role of coronary collaterals in patients with coronary artery disease

Study of Coronary Collaterals in Patients with Stable Angina

Background: Coronary collateral circulation is an alternative source of blood supply to the myocardium in coronary atherosclerotic disease. They provide adequate flow to the major epicardial branches of the coronary artery. Indicator of cardiac ischemia like stable angina pectoris may determine the presence of coronary collateral circulation.Methods and results: In this prospective observational cross sectional study, 150 patients with stable angina pectoris with or without MI (myocardial infarction) and or coronary intervention were enrolled. Presence of coronary collaterals in coronary angiogram was defined as Rentrop grade &gt; 1. Patients were divided into two groups. Group A patients having Rentrop grade 0 and Group B patients are with collateral circulation, having Rentrop grade 1-3. Patients are compared in these groups. Total (63%) patients with stable angina were in Group B with coronary collateral circulation and only (37%) patients with stable angina pectoris were in Group A without collaterals.Conclusions: The incidence of development of coronary collaterals was significantly higher in patients with stable angina pectoris. DOI: 10.3329/uhj.v6i2.7245University Heart Journal Vol. 6, No. 2, July 2010 pp.61-64

The current status of nitrites in the treatment of coronary artery disease

The nitrites remain the cornerstone of treatment in the anginal syndrome despite unresolved questions regarding their mechanism of action. Although increase in coronary blood flow probably occurs in all subjects, this change is transient; and the effectiveness of nitrites in angina may be related to preferential effects on collateral vessels in which an increase of flow may not be reflected in total coronary flow as usually measured. The beneficial effects of nitrites in angina might also be explained on the basis of a reduction in left ventricular work and therefore oxygen requirements. The newer nitrates have not displaced the use of nitroglycerin in the treatment or prevention of acute anginal attacks. The question of whether chronic usage of nitrites can enhance the development of coronary collaterals in patients with angina remains unanswered. Although nitrites have traditionally been felt to be contraindicated in the presence of acute myocardial infarction, experiments involving coronary artery obstruction with ischemia have suggested that collateral blood flow may be enhanced by these agents if arterial blood pressure does not decline markedly. A number of hemodynamic studies have demonstrated enhanced left ventricular function after nitrites, supporting the clinical experience of their effectiveness in relieving paroxysmal nocturnal dyspnea. Further studies of a quantitative physiological nature are needed to evaluate the effects of nitrites on regional blood flow and metabolism within the myocardium, particularly in the presence of ischemia.