Coronary collateral circulation: the effects of smoking and alcohol

Impact of smoking on outcomes following endovascular therapy for acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Smoking represents a leading risk factor for acute ischemic stroke (AIS). Previous literature has described a "smoking paradox", wherein smokers experience better outcomes following intravenous thrombolysis for AIS. It is unclear whether such a phenomenon exists in smokers undergoing endovascular therapy (EVT) for AIS. To assess outcomes in smokers following EVT for AIS, we conducted a systematic review and meta-analysis.

METHODS

Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Embase Web of Science, and Scopus. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0-2, thrombolysis in cerebral infarction (TICI) score 2b-3, symptomatic intracranial hemorrhage (sICH), and mortality. We calculated mean difference (MD), pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI).

RESULTS

Eight studies with 2633 patients comprised our analysis. On average, smokers were 10.14 years (MD  =  10.14, [95% CI  =  -14.49 to -5.79], P-value < 0.001) younger than non-smokers. Smokers achieved mRS 0-2 (OR =  1.82, [95% CI, 1.34-2.48], P-value < 0.001) and TICI 2b-3 (OR =  1.61, [95% CI, 1.19-2.19], P-value  =  0.002) at a higher rate than non-smokers. sICH rates were comparable between smokers and non-smokers (OR =  1.07, [95% CI, 0.62-1.85], P-value  =  0.81). Smokers had a lower rate of 90-day mortality than non-smokers (OR =  0.54, [95% CI, 0.41-0.71], P-value < 0.001).

CONCLUSIONS

In this meta-analysis of eight studies, we found that smokers with AIS undergoing EVT experienced better 90-day outcomes and higher rates of TICI 2b-3. This may be due to baseline differences between smokers and non-smokers, but future studies should explore alternative reasons that could explain this relationship between smoking and AIS treated with EVT.

Cardiogenic Shock Does Not Portend Poor Long-Term Survival in Patients Undergoing Primary Percutaneous Coronary Intervention

Although a strong association of cardiogenic shock (CS) with in-hospital mortality in patients with acute coronary syndrome (ACS) is well established, less attention has been paid to its prognostic influence on long-term outcome. We evaluated the impact of CS in 1173 patients undergoing primary percutaneous coronary interventions between 1997 and 2009. Patients were followed up until the primary study endpoint (cardiovascular mortality) was reached. Within the entire study population, 112 (10.4%) patients presented with CS at admission. After initial survival, CS had no impact on mortality (non-CS: 23.5% vs. CS: 24.0%; p = 0.923), with an adjusted hazard ratio of 1.18 (95% CI: 0.77–1.81; p = 0.457). CS patients ≥ 55 years (p = 0.021) with moderately or severely impaired left ventricular function (LVF; p = 0.039) and chronic kidney disease (CKD; p = 0.013) had increased risk of cardiovascular mortality during follow-up. The present investigation extends currently available evidence that cardiovascular survival in CS is comparable with non-CS patients after the acute event. CS patients over 55 years presenting with impaired LVF and CKD at the time of ACS are at increased risk for long-term mortality and could benefit from personalized secondary prevention.

Enhanced Thrombin Generation Is Associated with Worse Left Ventricular Scarring after ST-Segment Elevation Myocardial Infarction: A Cohort Study

Acute myocardial infarction (AMI) is associated with heightened thrombin generation. There are limited data relating to thrombin generation and left ventricular (LV) scarring and LV dilatation in post-MI LV remodeling. We studied 113 patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PPCI) (n = 76) or pharmaco-invasive management (thrombolysis followed by early PCI, n = 37). Endogenous thrombin potential (ETP) was measured at baseline, 1 month and 6 months. Cardiovascular magnetic resonance imaging was performed at baseline and 6 months post-MI. Outcomes studied were an increase in scar change, which was defined as an increase in left ventricular infarct size of any magnitude detected by late gadolinium enhancement, adverse LV remodeling, defined as dilatation (increase) of left ventricular end-diastolic volume (LVEDV) by more than 20% and an increase in left ventricular ejection fraction (LVEF). The mean age was 55.19 ± 8.25 years and 91.2% were men. The baseline ETP was similar in the PPCI and pharmaco-invasive groups (1400.3 nM.min vs. 1334.1 nM.min, p = 0.473). Each 10-unit increase in baseline ETP was associated with a larger scar size (adjusted OR 1.020, 95% CI 1.002–1.037, p = 0.027). Baseline ETP was not associated with adverse LV remodeling or an increase in LVEF. There was no difference in scar size or adverse LV remodeling among patients undergoing PPCI vs. pharmaco-invasive management or patients receiving ticagrelor vs. clopidogrel. Enhanced thrombin generation after STEMI is associated with a subsequent increase in myocardial scarring but not LV dilatation or an increase in LVEF at 6 months post-MI.

Traditional Cardiovascular Risk Factors and Coronary Collateral Circulation: A Meta-Analysis

Objective: Patients with well-developed coronary collateral circulation (CC) usually have low mortality, improved cardiac function, and reduced infarct size. Currently, there is conflicting evidence on the association between traditional cardiovascular risk factors (diabetes, hypertension, and smoking habit) and CC.

Design: We performed a meta-analysis of case-control studies to better understand such associations.

Data Sources: We searched the MEDINE, EMBASE, and Science Citation Index databases to identify relevant studies.

Eligibility Criteria for Selecting Studies: Case control studies reporting data on risk factors (smoking habit, hypertension, and diabetes mellites) in comparing cases between poor CC and well-developed CC groups. Well-developed CC was the primary outcome of this meta-analysis

Data Extraction and Synthesis: Relevant data were extracted by two independent investigators. We derived pooled odds ratios (ORs) with random effects models. We performed quality assessments, publication bias, and sensitivity analysis to ensure the reliability of our results.

Results: In total, 18 studies that had 4,746 enrolled patients were analyzed. Our results showed that hypertension and smoking habit did not (OR = 0.94, 95% CI: 0.75–1.17, p = 0.564 and OR = 1.00, 95% CI: 0.84–1.18, p = 0.970, respectively), and diabetes did (OR = 0.50, 95% CI: 0.38–0.67, p = 0.00001) affect the development of CC.

Conclusion: Unlike hypertension and smoking habit, diabetes was associated with poor CC formation.

Trial Registration Number:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=87821, identifier: CRD42018087821.

Metabolic syndrome and its components reduce coronary collateralization in chronic total occlusion: An observational study

Background

Metabolic syndrome (MetS) is an independent risk factor for the incidence of cardiovascular diseases. We investigated whether or to what extent MetS and its components was associated with coronary collateralization (CC) in chronic total occlusion (CTO).

Methods

This study involved 1653 inpatients with CTO. Data on demographic and clinical characteristics were collected by cardiovascular doctors. The CC condition was defined by the Rentrop scoring system. Subgroup analysis, mixed model regression analysis, scoring systems and receiver operating characteristic (ROC) curve analysis were performed.

Results

Overall, 1653 inpatients were assigned to the poor CC group (n = 355) and good CC group (n = 1298) with or without MetS. Compared to the good CCs, the incidence of MetS was higher among the poor CCs for all patients. Poor collateralization was present in 7.6%, 14.2%, 19.3%, 18.2%, 35.6% and 51.1% of the six groups who met the diagnostic criteria of MetS 0, 1, 2, 3, 4 and 5 times, respectively. For multivariable logistic regression, quartiles of BMI remained the risk factors for CC growth in all subgroups (adjusted OR = 1.755, 95% CI 1.510–2.038, P < 0.001 all patients; adjusted OR = 1.897, 95% CI 1.458–2.467, P < 0.001 non-MetS; and adjusted OR = 1.814, 95% CI 1.482–2.220, P < 0.001 MetS). After adjustment for potential confounding factors, MetS was an independent risk factor for CC growth in several models. Assigning a score of one for each component, the AUCs were 0.629 (95% CI 0.595–0.662) in all patients, 0.656 (95% CI 0.614–0.699) in MetS patients and 0.569 (95% CI 0.517–0.621) in non-MetS patients by receiver operating characteristic analysis.

Conclusions

MetS, especially body mass index, confers a greater risk of CC formation in CTO. The value of scoring systems should be explored further for CTO.

Visceral fat index: a novel predictor for coronary collateral circulation

Objective This study was designed to investigate the role of visceral adiposity along with other clinical parameters in predicting poor coronary collateral circulation (CCC) among patients with severe obstructive coronary artery disease (CAD). Subjects and methods A total of 135 patients with severe obstructive CAD and good (n = 70) or poor (n = 65) CCC were included. Data on angiographically detected CCC, the quality criteria for CCC (Rentrop scores) and visceral fat index (VFI) obtained via bioelectrical impedance were compared between good and poor CCC groups. Independent predictors of poor CCC, the correlation between VFI and Rentrop score and the role of VFI in the identification of CCC were analyzed. Results A significant negative correlation was noted between VFI and Rentrop scores (r = -0.668, < 0.001). The presence of hypertension (OR 4.244, 95% CI 1.184 to 15.211, p = 0.026) and higher VFI (OR 1.955, 95% CI 1.342 to 2.848, p < 0.001) were shown to be independent predictors of an increased risk for poor CCC. ROC analysis revealed a VFI > 9 (AUC [area under the curve] (95% CI): 0.898 (0.834-0.943), p < 0.0001) to be a potential predictor of poor CCC with a sensitivity of 95.38% and specificity of 85.71%. Conclusion In conclusion, our findings revealed comorbid hypertension and higher VFI to significantly predict the risk of poor CCC in patients with severe obstructive CAD.

Spontaneous coronary collateral recruitment in patients with recurrent ST elevation myocardial infarction (STEMI)

The spontaneous recruitment of acute coronary collaterals in the setting of an ST elevation myocardial infarction (STEMI) is seen frequently in those patients undergoing primary percutaneous coronary intervention (pPCI) and is associated with improved clinical outcomes. However, it is unknown whether in patients who present with a recurrent STEMI, the degree of collateral recruitment remains the same as in the index procedure. We reviewed all patients presenting to our tertiary centre with a STEMI undergoing primary or rescue percutaneous coronary intervention (PCI) from July 2010 until December 2018. We identified patients who presented with a recurrent STEMI following their index procedure. We defined patients with poor collateral recruitment as Rentrop grade 0 or 1, whilst patients with robust collateral recruitment as Rentrop grade 2 or 3. Of the 1795 patients who were identified, there were 27 cases in 25 patients who presented with a repeat STEMI following their index procedure. The median time between cases was 12.8 days (IQR 2.3-589.5 days). Compared to the index case, there was no statistically significant difference in the degree of collateral recruitment in recurrent presentations (Z = - 0.378, p = 0.70). In those patients presenting more than 6 months following the index procedure, the median time between cases was 654.5 days (IQR 479.5-1151.9). There was no difference in the degree of collateral recruitment in recurrent presentations (Z = 0.000, p = 1.0). Cases which had poorer collateral recruitment in recurrent presentations were less likely to be current smokers (0% vs 50%, p < 0.001) and less likely to have diabetes (0% vs 27.3%, p < 0.05) The recruitment of spontaneous coronary collaterals remains constant in recurrent STEMI presentations suggesting an innate biological process rather than merely a manifestation of alteration of haemodynamic blood flow. Further investigations to identify these processes is required.

Blood Group Types O and Non-O Are Associated With Coronary Collateral Circulation Development

Blood group types are associated with coronary artery disease. However, data are scarce about the impact of blood group types on coronary collateral circulation. In this study, we aimed to investigate the relationship between the blood group types and coronary collateral circulation. Two hundred and twelve patients who underwent coronary angiography in our department and had a stenosis of ≥ 90% in at least one major epicardial vessel were included in our study. Collateral degree was graded according to Rentrop-Cohen classification. After grading, patients were divided into poor coronary collateral circulation (Rentrop grade 0 and 1) and good coronary collateral circulation (Rentrop 2 and 3) groups. The ABO blood type of all participants was determined. The incidence rates of O blood group type were significantly higher in the good coronary collateral group compared to the poor collateral group (37.9% vs 17.1%, P < .001). The O type blood group was an independent predictor of good coronary collateral circulation (odds ratio = 1.83, 95% confidence interval = 1.56-6.18, P = .015). Coronary collateral circulation is associated with blood group types. The O blood group predicts good coronary collateral development among patients with coronary artery disease.

Risk factors for cardiac rupture complicating myocardial infarction: a PRISMA meta-analysis and systematic review

Cardiac rupture (CR) is a complication of acute myocardial infarction (AMI) that is associated with a high mortality rate. This study aimed to identify the risk factors for CR in patients with AMI. Medline, Cochrane, EMBASE, and Google Scholar databases were searched for relevant literature published through September 16, 2018. Eligible studies included patients with AMI and compared factors between patients with and without CR. Sixteen studies were identified and included in the meta-analysis. Results revealed that female gender (pooled OR=2.72, 95% CI 2.04 to 3.63, p<0.001), older age (pooled difference in means=6.91, 95% CI 4.20 to 9.62, p<0.001), infarction at left anterior descending coronary artery (LAD) (pooled OR=1.85, 95% CI 1.03 to 3.32, p=0.039), and anterior wall infarction (pooled OR=1.87, 95% CI 1.30 to 2.68, p=0.001) were associated with increased risk of CR, whereas history of MI, smoking, and multivessel disease were associated with reduced risk of CR. Patients treated with primary percutaneous coronary intervention (PCI) had reduced risk of CR, while patients who had received any thrombolysis had increased risk of CR. In conclusion, results of systematic review and meta-analysis of existing literature suggest that risk factors for CR in patients with AMI include female gender, older age, new-onset MI, non-smoking status, LAD infarction, anterior wall infarction, and single-vessel disease. Furthermore, treatment with primary PCI may help reduce the risk for CR, while thrombolysis might increase the risk for CR.

Traditional cardiovascular risk factors and coronary collateral circulation: Protocol for a systematic review and meta-analysis of case-control studies

BACKGROUND

Well-developed coronary collateral circulation usually results in fewer infarct size, improved cardiac function, and fewer mortality. Traditional coronary risk factors (diabetes, hypertension, and smoking) have some effects on coronary collateral circulation. However, the association between these risk factors and coronary collateral circulation are controversial. Given the confusing evidences regarding traditional cardiovascular risk factors on coronary collateral circulation, we performed this meta-analysis protocol to investigate the relationship between traditional risk factors of coronary artery disease and coronary collateral circulation.

METHODS

MEDINE, EMBASE, and Science Citation Index will be searched to identify relevant studies. The primary outcomes of this meta-analysis are well-developed coronary collateral circulation. Meta-analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) of traditional coronary risk factors (diabetes, smoking, hypertriton). Pooled ORs were computed as the Mantel-Haenszel-weighted average of the ORs for all included studies. Sensitivity analysis, quality assessment, publication bias analysis, and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) will be performed to ensure the reliability of our results.

RESULTS

This study will provide a high-quality synthesis of current evidence of traditional risk factors on collateral circulation.

CONCLUSION

This conclusion of our systematic review and meta-analysis will provide evidence to judge whether traditional risk factors affects coronary collateral circulation.Ethics and dissemination: Ethical approval is not required because our systematic review and meta-analysis will be based on published data without interventions on patients. The findings of this study will be published in a peer-reviewed journal.

Reduced coronary collateralization in type 2 diabetic patients with chronic total occlusion

BACKGROUND

The extent of coronary collateral formation is a primary determinant of the severity of myocardial damage and mortality after coronary artery occlusion. Type 2 diabetes mellitus (T2DM) represents an important risk factor for impaired collateral vessel growth. However, the mechanism of reduced coronary collateralization in type 2 diabetic patients remains unclear.

METHODS

With the reference to the recent researches, this review article describes the pathogenic effects of T2DM on collateral development and outlines possible clinical and biochemical markers associated with reduced coronary collateralization in type 2 diabetic patients with chronic total occlusion (CTO).

RESULTS

Diffuse coronary atherosclerosis in T2DM reduces pressure gradient between collateral donor artery and collateral recipient one, limiting collateral vessel growth and function. An interaction between advanced glycation end-products and their receptor activates several intracellular signaling pathways, enhances oxidative stress and aggravates inflammatory process. Diabetic condition decreases pro-angiogenic factors especially vascular endothelial growth factor and other collateral vessel growth related parameters. Numerous clinical and biochemical factors that could possibly attenuate the development of coronary collaterals have been reported. Increased serum levels of glycated albumin, cystatin C, and adipokine C1q tumor necrosis factor related protein 1 were associated with poor coronary collateralization in type 2 diabetic patients with stable coronary artery disease and CTO. Diastolic blood pressure and stenosis severity of the predominant collateral donor artery also play a role in coronary collateral formation.

CONCLUSIONS

T2DM impairs collateral vessel growth through multiple mechanisms involving arteriogenesis and angiogenesis, and coronary collateral formation in patients with T2DM and CTO is influenced by various clinical, biochemical and angiographic factors. This information provides insights into the understanding of coronary pathophysiology and searching for potential new therapeutic targets in T2DM.

Coronary collateralization shows sex and racial-ethnic differences in obstructive artery disease patients

Background

Coronary collateral circulation protects cardiac tissues from myocardial infarction damage and decreases sudden cardiac death. So far, it is unclear how coronary collateralization varies by race-ethnicity groups and by sex.

Methods

We assessed 868 patients with obstructive CAD. Patients were assessed for collateral grades based on Rentrop grading system, as well as other covariates. DNA samples were genotyped using the Affymetrix 6.0 genotyping array. To evaluate genetic contributions to collaterals, we performed admixture mapping using logistic regression with estimated local and global ancestry.

Results

Overall, 53% of participants had collaterals. We found difference between sex and racial-ethnic groups. Men had higher rates of collaterals than women (P-value = 0.000175). White Hispanics/Latinos showed overall higher rates of collaterals than African Americans and non-Hispanic Whites (59%, 50% and 48%, respectively, P-value = 0.017), and especially higher rates in grade 1 and grade 3 collateralization than the other two populations (P-value = 0.0257). Admixture mapping showed Native American ancestry was associated with the presence of collaterals at a region on chromosome 17 (chr17:35,243,142-41,251,931, β = 0.55, P-value = 0.000127). African ancestry also showed association with collaterals at a different region on chromosome 17 (chr17: 32,266,966-34,463,323, β = 0.38, P-value = 0.00072).

Conclusions

In our study, collateralization showed sex and racial-ethnic differences in obstructive CAD patients. We identified two regions on chromosome 17 that were likely to harbor genetic variations that influenced collateralization.

Vascular endothelial growth factor and hypoxia-inducible factor-1α gene polymorphisms and coronary collateral formation in patients with coronary chronic total occlusions

Introduction:

We evaluated the association between two single nucleotide polymorphisms of the vascular endothelial growth factor gene and one of the hypoxia-inducible factor-1α gene and the degree of coronary collateral formation in patients with a coronary chronic total occlusion.

Methods:

Totally, 98 patients with symptomatic coronary artery disease and a chronic total occlusion observed during coronary angiography were recruited. Genotyping of two vascular endothelial growth factor promoter single nucleotide polymorphisms (−152G>A and −165C>T) and the C1772T single nucleotide polymorphism of hypoxia-inducible factor-1α were performed using polymerase chain reaction and restriction fragment length polymorphism analysis. The presence and extent of collateral vessel filling was scored by blinded observers using the Rentrop grade.

Results:

We found no association between the vascular endothelial growth factor −152G>A, −165C>T and hypoxia-inducible factor-1α −1772C>T with the presence and filling of coronary collateral vessels. A history of percutaneous coronary intervention and transient ischaemic attack/cerebrovascular accident were associated with the presence of enhanced collateral vessel formation following binary logistic regression analysis.

Conclusion:

The study findings suggest that coronary collateral formation is not associated with the tested polymorphic variants of vascular endothelial growth factor and hypoxia-inducible factor-1α in patients with symptomatic coronary artery disease and the presence of a chronic total occlusion.

Change in left ventricular systolic function in patients with ST elevation myocardial infarction: Evidence for smoker's paradox or pseudo-paradox?

Background

The ‘smoker's paradox’ refers to the observation of favorable prognosis in current smokers following an acute ST elevation myocardial infarction (STEMI) in the era of fibrinolysis, however, several STEMI studies have demonstrated conflicting results in patients undergoing primary percutaneous coronary intervention (p-PCI).

Objective

Aim of the current study was to evaluate the impact of cigarette smoking on left ventricular function in STEMI patients undergoing p-PCI.

Methods

Our population is represented by 74 first-time anterior STEMI patients undergoing p-PCI, 37 of whom were smokers. We assessed left ventricular function by left ventricular ejection fraction (LVEF) on the second day after admission and at 3-month follow-up. Early predictors of adverse left ventricular remodelling after STEMI treated by p-PCI were examined.

Results

Basal demographics and comorbidities were similar between groups. Although the LVEF during the early phase was higher in smokers compared to non-smokers (44.95 ± 7.93% vs. 40.32 ± 7.28%; p = 0.011); it worsened in smokers at follow-up (mean decrease in LVEF: −2.70 ± 5.95%), whereas it improved in non-smokers (mean recovery of LVEF: +2.97 ± 8.45%). In univariate analysis, diabetes mellitus, peak troponin I, current smoking, and lower TIMI flow grade after p-PCI, pain-to-door time and door-to-balloon times were predictors of adverse left ventricular remodelling. After multivariate logistic regression analysis, smoking at admission, lower TIMI flow grade after p-PCI, the pain-to-door time and door-to-balloon times remained independent predictors of deterioration in LVEF.

Conclusion

True or persistent ‘smoker's paradox’ does not appear to be relevant among STEMI patients undergoing p-PCI. The ‘smoker's paradox’ is in fact a pseudo-paradox. Further studies with larger numbers may be warranted.

Hyperintense Vessels on FLAIR: Hemodynamic Correlates and Response to Thrombolysis

BACKGROUND AND PURPOSE

Hyperintense vessels on baseline FLAIR MR imaging of patients with ischemic stroke have been linked to leptomeningeal collateralization, yet the ability of these to maintain viable ischemic tissue remains unclear. We investigated whether hyperintense vessels on FLAIR are associated with the severity of hypoperfusion and response to thrombolysis in patients treated with intravenous tissue-plasminogen activator.

MATERIALS AND METHODS

Consecutive patients with ischemic stroke with an MR imaging before and within 24 hours of treatment, with proved vessel occlusion and available time-to-maximum maps were included (n = 62). The severity of hypoperfusion was characterized on the basis of the hypoperfusion intensity ratio (volume with severe/mild hypoperfusion [time-to-maximum ≥ 8 seconds / time-to-maximum ≥ 2 seconds]). The hypoperfusion intensity ratio was dichotomized at the median to differentiate moderate (hypoperfusion intensity ratio ≤ 0.447) and severe (hypoperfusion intensity ratio > 0.447) hypoperfusion. Good outcome was defined as a modified Rankin Scale score of ≤2.

RESULTS

Hyperintense vessels on FLAIR were identified in 54 patients (87%). Patients with extensive hyperintense vessels on FLAIR (>4 sections) had higher NIHSS scores, larger baseline lesion volumes, higher rates of perfusion-diffusion mismatch, and more severe hypoperfusion (hypoperfusion intensity ratio). In stepwise backward multivariate regression analysis for the dichotomized hypoperfusion intensity ratio (including stroke etiology, age, perfusion deficit, baseline lesion volume, smoking, and extent of hyperintense vessels on FLAIR), extensive hyperintense vessels on FLAIR were independently associated with severe hypoperfusion (OR, 6.8; 95% CI, 1.1-42.7; P = .04). The hypoperfusion intensity ratio was an independent predictor of a worse functional outcome at 3 months poststroke (OR, 0.2; 95% CI, 0.5-0.6; P < .01).

CONCLUSIONS

Hyperintense vessels on FLAIR are associated with larger perfusion deficits, larger infarct growth, and more severe hypoperfusion, suggesting that hyperintense vessels on FLAIR most likely indicate severe ischemia as a result of insufficient collateralization.

Flk-1/KDR mediates ethanol-stimulated endothelial cell Notch signaling and angiogenic activity

We previously reported that ethanol (EtOH) stimulates endothelial angiogenic activity mediated via a notch- and angiopoietin-1 (Ang-1) pathway. As crosstalk exists between notch and vascular endothelial growth factor (VEGF) signaling, we examined whether the VEGF receptor (VEGFR) Flk-1 (fetal liver kinase 1) mediates EtOH-stimulated notch signaling and angiogenic activity.

METHODS AND RESULTS

Treatment of human coronary artery endothelial cells (HCAECs) with EtOH (1-50 mM, 24 h) dose-dependently increased Flk-1 expression with a maximum increase observed at 25 mM EtOH. Ethanol treatment activated both Flk-1 and Flt-1 (FMS-like tyrosine kinase 1) as indicated by their phosphorylation, and subsequent stimulation of Akt. EtOH activation of Flk-1 was inhibited by the VEGFR inhibitor SU5416. Gene silencing of Flk-1 using small interfering RNA inhibited the EtOH-induced increase in notch receptors 1 and 4 and notch target gene (hairy enhancer of split-related transcription factor 1) mRNA. Knockdown of Flk-1 inhibited EtOH-induced Ang-1/Tie-2 mRNA expression and blocked EtOH-induced HCAEC network formation on Matrigel, a response that was restored by notch ligand, notch ligand delta-like ligand 4, treatment. In vivo, moderate alcohol feeding increased vascular remodeling in mouse ischemic hindlimbs.

CONCLUSIONS

These data demonstrate that EtOH activates Flk-1 and Flt-1 receptors in HCAECs and promotes angiogenic activity via an Flk-1/notch pathway. These effects of EtOH may be relevant to the influence of moderate alcohol consumption on cardiovascular health.

Coronary Collateral Circulation and Cardiovascular Risk Factors: Is There a Paradox?

We sought to determine the association of major cardiovascular risk factors and other comorbidities with the presence or absence of coronary collateral (CC) circulation. All electronic medical records from 2010 to 2011 were retrospectively reviewed. A total of 563 patients were divided into 2 groups: CC present (180) and CC absent (383). Smoking (P = .012, odds ratio [OR] 1.58), hypercholesterolemia (P = .001, OR 2.21), and hypertension (P = .034, OR 1.75) were associated with the presence of CC. Increasing body mass index (BMI, P = .001) and decreasing estimated glomerular filtration rate (eGFR, P = .042) were associated with the absence of CC. On multivariable linear regression analysis, hypercholesterolemia (P = .001, OR 2.28), BMI (P = .012, OR 0.77), and eGFR (P = .001, OR 0.70) were found to be independently associated with CC. Our findings will help predict patient populations more likely to have presence or absence of CC circulation.

Impact of collaterals on successful revascularization in Solitaire FR with the intention for thrombectomy

BACKGROUND AND PURPOSE

Collaterals at angiography before endovascular therapy were analyzed to ascertain the effect on a novel end point of successful revascularization without symptomatic hemorrhage in the Solitaire FR With the Intention for Thrombectomy (SWIFT) study.

METHODS

Collateral grade (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology) on baseline angiography was independently assessed, blind to other data, with statistical analyses delineating the relationship with clinical, laboratory, and imaging parameters.

RESULTS

Angiographic data on collaterals were available in 119 of 144 subjects (mean age, 67±12 years; 52% woman; median National Institutes of Health Stroke Scale, 18 [range, 8-28]). Worse collaterals were noted in subjects with elevated baseline blood glucose (P=0.013) and those with elevated baseline systolic blood pressure (P=0.039). Multivariate predictors of partial or worse collaterals included absence of prior hypertension (odds ratio, 4.049, P=0.012), smoking history (odds ratio, 3.822; P=0.013), and higher blood glucose (odds ratio, 1.017; P=0.022). Collaterals were strongly related to Alberta Stroke Program Early CT Score (ASPECTS) at baseline (0-1: median 8 [3-10]; 2-9 [5-10]; 3-9 [7-10]; 4-9 [8-10]; P<0.001) and 24 hours (0-1: median 1 [0-5]; 2-6 [0-10]; 3-8 [0-10]; 4-8 [4-8]; P<0.001). Better collaterals were linked with Thrombolysis in Cerebral Infarction 2b/3 reperfusion (P=0.019), better median National Institutes of Health Stroke Scale at day 7/discharge (P<0.001), and better day 90 modified Rankin Scale (P<0.001). Better collateral grade was associated with successful revascularization without symptomatic hemorrhage, mean 2.3 (95% confidence interval, 2.1-2.5) versus 1.9 (95% confidence interval, 1.7-2.2), P=0.021.

CONCLUSIONS

Better collaterals were associated with lower glucose, lower blood pressure, smaller baseline infarcts in SWIFT, and greater likelihood of successful revascularization without hemorrhage and good clinical outcomes.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01054560.

Predictors of poor coronary collateral development in patients with stable coronary artery disease: neutrophil-to-lymphocyte ratio and platelets

Objective:

The heterogeneity in the degree of collateralization among patients with coronary artery disease (CAD) remains incompletely understood. We evaluated the predictors of poorly developed coronary collateral circulation (CCC) in patients with stable coronary artery disease.

Methods:

Current study is a retrospective study, consisting of 118 patients with poor CCC and 130 patients with good CCC. We investigated predictors of poor coronary collaterals in a cohort of 248 patients who had high-grade coronary stenosis or occlusion on their angiograms. To classify CCC, we used the Rentrop classification.

Results:

Patients with poorly developed CCC had significantly higher neutrophil-to-lymphocyte ratio (N/L) compared with those with well-developed CCC, (4.2±2.8 vs. 3±3.1, p=0.001), whereas mean platelet volume, red cell distribution width and uric acid were not significantly different. Logistic regression analysis showed that N/L ratio (odds ratio 1.199, 95% confidence interval 1.045-1.375) and serum triglyceride levels [odds ratio (OR)=1.006, 95% confidence interval (CI)=1.001-1.010] were independent predictors of poorly developed CCC.

Conclusion:

An elevated level of N/L ratio is independently associated with a significant impairment in coronary collateralization. Our findings suggest that N/L ratio is an inexpensive, universally available hematological marker for sufficiency of CCC in patients with stable coronary artery disease.

Absence of a 'smoker's paradox' in field triaged ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention

PURPOSE

The 'smoker's paradox' refers to the observation of favorable prognosis in current smokers following an acute myocardial infarction (AMI). Initial positive findings were in the era of fibrinolysis, with more contemporary studies finding conflicting results. We sought to determine the presence of a 'smoker's paradox' in a cohort of ST Elevation Myocardial Infarction (STEMI) patients identified via field triage, treated with primary percutaneous coronary intervention (pPCI).

METHODS

This was a single center retrospective cohort study identifying consecutive STEMI patients presenting for pPCI via field triage. The primary end points were all cause mortality, major adverse cardiac events (MACE), major bleeding, in-hospital cardiac arrest and length of stay (LOS).

RESULTS

A total of 382 patients were included in the study. Current smokers were more likely to be younger (p<0.00001), male (p<0.001) and have fewer comorbidities, including renal impairment (p<0.01) and a history of AMI (p<0.05). Current smokers also had a shorter ischemic time (p<0.05), were less likely to have collateral circulation (p<0.05), and more likely to have signs of pulmonary edema at presentation (p<0.05). There was no difference between smoking groups and all cause mortality (p=0.67), MACE (p=0.49), major bleeding (p=0.49) or in-hospital cardiac arrest (p=0.43). Current smokers had a shorter LOS (p<0.05). In multivariate analysis smoking status did not correlate with primary outcomes.

CONCLUSION

The 'smoker's paradox' does not appear to be relevant among STEMI patients undergoing pPCI, identified via field triage. The previously documented 'smoker's paradox' may have been an indication of patient characteristics and the historical treatment of STEMI with thrombolysis. Further studies with larger numbers may be warranted.

Alcohol and cardiovascular disease--modulation of vascular cell function

Alcohol is a commonly used drug worldwide. Epidemiological studies have identified alcohol consumption as a factor that may either positively or negatively influence many diseases including cardiovascular disease, certain cancers and dementia. Often there seems to be a differential effect of various drinking patterns, with frequent moderate consumption of alcohol being salutary and binge drinking or chronic abuse being deleterious to one’s health. A better understanding of the cellular and molecular mechanisms mediating the many effects of alcohol consumption is beginning to emerge, as well as a clearer picture as to whether these effects are due to the direct actions of alcohol itself, or caused in part by its metabolites, e.g., acetaldehyde, or by incidental components present in the alcoholic beverage (e.g., polyphenols in red wine). This review will discuss evidence to date as to how alcohol (ethanol) might affect atherosclerosis that underlies cardiovascular and cerebrovascular disease, and the putative mechanisms involved, focusing on vascular endothelial and smooth muscle cell effects.

Cardiovascular risk factors and collateral artery formation

Arterial lumen narrowing and vascular occlusion is the actual cause of morbidity and mortality in atherosclerotic disease. Collateral artery formation (arteriogenesis) refers to an active remodelling of non-functional vascular anastomoses to functional collateral arteries, capable to bypass the site of obstruction and preserve the tissue that is jeopardized by ischaemia. Hemodynamic forces such as shear stress and wall stress play a pivotal role in collateral artery formation, accompanied by the expression of various cytokines and invasion of circulating leucocytes. Arteriogenesis hence represents an important compensatory mechanism for atherosclerotic vessel occlusion. As arteriogenesis mostly occurs when lumen narrowing by atherosclerotic plaques takes place, presence of cardiovascular risk factors (e.g. hypertension, hypercholesterolaemia and diabetes) is highly likely. Risk factors for atherosclerotic disease affect collateral artery growth directly and indirectly by altering hemodynamic forces or influencing cellular function and proliferation. Adequate collateralization varies significantly among atherosclerotic patients, some profit from the presence of extensive collateral networks, whereas others do not. Cardiovascular risk factors could increase the risk of adverse cardiovascular events in certain patients because of the reduced protection through an alternative vascular network. Likewise, drugs primarily thought to control cardiovascular risk factors might contribute or counteract collateral artery growth. This review summarizes current knowledge on the influence of cardiovascular risk factors and the effects of cardiovascular medication on the development of collateral vessels in experimental and clinical studies.

Redox-dependent mechanisms in coronary collateral growth: the "redox window" hypothesis

This review addresses the complexity of coronary collateral growth from the aspect of redox signaling and introduces the concept of a "redox window" in the context of collateral growth. In essence, the redox window constitutes a range in the redox state of cells, which not only is permissive for the actions of growth factors but also amplifies their actions. The interactions of redox-dependent signaling with growth factors are well established through the actions of many redox-dependent kinases (e.g., Akt and p38 mitogen-activated protein kinase). The initial changes in cellular redox can be induced by a variety of events, from the oxidative burst during reperfusion after ischemia, to recruitment of various types of inflammatory cells capable of producing reactive oxygen species. Any event that "upsets" the normal redox equilibrium is capable of amplifying growth. However, extremes of the redox window, oxidative and reductive stresses, are associated with diminished growth-factor signaling and reduced activation of redox-dependent kinases. This concept of a redox window helps to explain why the clinical trials aimed at stimulating coronary collateral growth, the "therapeutic angiogenesis trials," failed. However, understanding of redox signaling in the context of coronary collateral growth could provide new paradigms for stimulating collateral growth in patients.

Gender-related differences in the prevalence of cardiovascular disease risk factors and their correlates in urban Tanzania

Background

Urban areas in Africa suffer a serious problem with dual burden of infectious diseases and emerging chronic diseases such as cardiovascular diseases (CVD) and diabetes which pose a serious threat to population health and health care resources. However in East Africa, there is limited literature in this research area. The objective of this study was to examine the prevalence of cardiovascular disease risk factors and their correlates among adults in Temeke, Dar es Salaam, Tanzania. Results of this study will help inform future research and potential preventive and therapeutic interventions against such chronic diseases.

Methods

The study design was a cross sectional epidemiological study. A total of 209 participants aged between 44 and 66 years were included in the study. A structured questionnaire was used to evaluate socioeconomic and lifestyle characteristics. Blood samples were collected and analyzed to measure lipid profile and fasting glucose levels. Cardiovascular risk factors were defined using World Health Organization criteria.

Results

The age-adjusted prevalence of obesity (BMI ≥ 30) was 13% and 35%, among men and women (p = 0.0003), respectively. The prevalence of abdominal obesity was 11% and 58% (p < 0.0001), and high WHR (men: >0.9, women: >0.85) was 51% and 73% (p = 0.002) for men and women respectively. Women had 4.3 times greater odds of obesity (95% CI: 1.9–10.1), 14.2–fold increased odds for abdominal adiposity (95% CI: 5.8–34.6), and 2.8 times greater odds of high waist-hip-ratio (95% CI: 1.4–5.7), compared to men. Women had more than three-fold greater odds of having metabolic syndrome (p = 0.001) compared to male counterparts, including abdominal obesity, low HDL-cholesterol, and high fasting blood glucose components. In contrast, female participants had 50% lower odds of having hypertension, compared to men (95%CI: 0.3–1.0). Among men, BMI and waist circumference were significantly correlated with blood pressure, triglycerides, total, LDL-, and HDL-cholesterol (BMI only), and fasting glucose; in contrast, only blood pressure was positively associated with BMI and waist circumference in women.

Conclusion

The prevalence of CVD risk factors was high in this population, particularly among women. Health promotion, primary prevention, and health screening strategies are needed to reduce the burden of cardiovascular disease in Tanzania.