Validation of improved vessel-specific leads (VSLs) for detecting acute myocardial ischemia.

BACKGROUND: Existing criteria recommended by ACC/ESC for identifying patients with ST elevation myocardial infarction (STEMI) from the 12-lead ECG perform with high specificity (SP), but low sensitivity (SE). In our previous studies, we found that the SE of ischemia detection can be markedly improved without any loss of SP by calculating, from the 12-lead ECG, ST deviation in 3 "optimal" vessel-specific leads (VSLs). Our original VSLs, based on ΔST body-surface potential maps (BSPMs), have been modified by using the more appropriate J-point BSPMs at peak ischemia (without subtraction of pre-occlusion distributions). The aim of the present study was to compare the performance of these new VSLs with that achieved by the STEMI criteria used in current practice. METHODS: Two independent datasets of 12-lead ECGs were used: the STAFF III dataset acquired during ischemic episodes caused by balloon inflation in LAD (n=35), RCA (n=47), and LCx (n=17) coronary arteries, and the Glasgow dataset comprising admission 12-lead ECGs of 116 patients who were hospitalized for chest pain and underwent contrast-enhanced cardiac MRI that confirmed AMI in 58 patients (50%). RESULTS: We found that, in the STAFF III dataset, the detection of ischemic state by the STEMI criteria attained SE/SP of 60/97%, whereas SE/SP values of VSLs were 72/98%. In the Glasgow dataset, STEMI criteria yielded SE/SP of 43/98%, whereas the VSLs improved SE/SP to 60/98%. The most significant increase in diagnostic performance appeared in patients with LCx coronary artery occlusion: in STAFF III data (n=17) SE achieved by STEMI criteria was improved by the VSLs from 35% to 71%; in Glasgow data (n=12) SE of 31% achieved by STEMI criteria was improved by the VSLs to 69%. CONCLUSION: In our study population, existing ACC/ESC STEMI criteria complemented by the new VSLs yielded much improved sensitivity of ischemia detection without any detrimental effect on specificity. This finding needs to be corroborated on a larger chest-pain patient population with typical prevalence of acute ischemia presented to the emergency rooms.

The relationship between anthropometric indexes of adiposity and vascular function in the FATE cohort.

OBJECTIVE: Numerous indexes of adiposity have been proposed and are currently in use in clinical practice and research. However, the correlation of these indexes with measures of vascular health remain poorly defined. This study investigated which measure of adiposity is most strongly associated with endothelial function. DESIGN AND METHODS: Data from the Firefighters And Their Endothelium (FATE) study was used. The relationships between three measures of vascular function: flow-mediated dilation (FMD), hyperemic velocity time integral (VTI), and hyperemic shear stress (HSS), and five measures of adiposity: BMI, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and body adiposity index (BAI) were tested. Univariate comparisons were made, and subsequently models adjusted for traditional risk factors were constructed. RESULTS: A total of 1,462 male firefighters (mean age 49 ± 9) without cardiovascular disease comprised the study population. No measure of adiposity correlated with FMD; all five measures of adiposity were negatively correlated with VTI and HSS (P values <0.0001), with WHtR most strongly correlated with VTI, and WC most strongly correlated with HSS (both P < 0.05). In models including all five measures of obesity simultaneously, BMI, WC, and WHtR were all predictive of HSS (all P values <0.05), and BMI and WHR were both predictive of VTI (P values <0.05). CONCLUSIONS: Anthropometric measures of adiposity may help refine estimations of atherosclerotic burden. BMI was most consistently associated with endothelial dysfunction, but measures of adiposity that reflect distribution of mass were additive.

Microvascular function predicts cardiovascular events in primary prevention: long-term results from the Firefighters and Their Endothelium (FATE) study.

BACKGROUND: Biomarkers of atherosclerosis may refine clinical decision making in individuals at risk of cardiovascular disease. The purpose of the study was to determine the prognostic significance of endothelial function and other vascular markers in apparently healthy men. METHODS AND RESULTS: The cohort consisted of 1574 men (age, 49.4 years) free of vascular disease. Measurements included flow-mediated dilation and its microvascular stimulus, hyperemic velocity, carotid intima-media thickness, and C-reactive protein. Cox proportional hazard models evaluated the relationship between vascular markers, Framingham risk score, and time to a first composite cardiovascular end point of vascular death, revascularization, myocardial infarction, angina, and stroke. Subjects had low median Framingham risk score (7.9%). Cardiovascular events occurred in 71 subjects (111 events) over a mean follow-up of 7.2±1.7 years. Flow-mediated dilation was not associated with subsequent cardiovascular events (hazard ratio, 0.92; P=0.54). Both hyperemic velocity (hazard ratio, 0.70; 95% confidence interval, 0.54 to 0.90; P=0.006) and carotid intima-media thickness (hazard ratio, 1.45; confidence interval, 1.15 to 1.83; P=0.002) but not C-reactive protein (P=0.35) were related to events in a multivariable analysis that included Framingham risk score (per unit SD). Furthermore, the addition of hyperemic velocity to Framingham risk score resulted in a net clinical reclassification improvement of 28.7% (P<0.001) after 5 years of follow-up in the intermediate-risk group. Overall net reclassification improvement for hyperemic velocity was 6.9% (P=0.24). CONCLUSIONS: In men, hyperemic velocity, the stimulus for flow-mediated dilation, but not flow-mediated dilation itself was a significant risk marker for adverse cardiovascular outcomes. The prognostic value was additive to traditional risk factors and carotid intima-media thickness. Hyperemic velocity, a newly described marker of microvascular function, is a novel tool that may improve risk stratification of lower-risk healthy men.

Cardiometabolic effects of rosiglitazone in patients with type 2 diabetes and coronary artery bypass grafts: A randomized placebo-controlled clinical trial.

OBJECTIVES: To assess the efficacy and safety of rosiglitazone on saphenous vein graft (SVG) atherosclerosis prevention and on modification of the global cardiometabolic risk profile. METHODS AND RESULTS: This was a double-blind, randomized, placebo-controlled, multicenter trial which enrolled 193 post-CABG patients with type 2 diabetes. Atherosclerosis changes in one SVG were assessed with intravascular ultrasound at baseline and at 12 months. Serial cardiometabolic assessments were performed. At baseline, both groups had mean HbA(1C)<7%, LDL-cholesterol (LDL-C)<2.3 mmol/l, HDL-cholesterol (HDL-C)>1.0 mmol/l and blood pressure<130/75 mmHg. After 12 months, plaque volume in SVG had increased (median [interquartile range]) by 7.7 mm(3) (-17.2 to 37.9) in the placebo group and decreased by 0.3mm(3) (-19.1 to 22.3) in the rosiglitazone group (P=0.22). Compared to placebo, rosiglitazone treated patients had a higher (mean + or - SD) body weight (89 + or - 15 kg vs. 84 + or - 15 kg, P=0.02) at the end of the study, mostly related to an increment in subcutaneous adipose tissue. Rosiglitazone treated patients also displayed further improvements in glycemic control compared to placebo (HbA(1C): 6.4 + or - 0.7% vs. 7.0 + or - 0.9%, P<0.001) as well as in several cardiometabolic parameters such as lipids (HDL-C: 1.16 + or - 0.28 mmol/l vs. 1.06 + or - 0.23 mmol/l, P=0.003), inflammatory profile (C-reactive protein: 0.92 mg/l [0.51-1.56] vs. 1.37 mg/l [0.79-3.08], P=0.02), and adiponectin levels (11.1 microg/ml [8.19-17.9] vs. 4.65 microg/ml [3.27-7.15], P<0.001). There was no significant difference in the incidence of serious adverse cardiovascular events. However, more patients in the rosiglitazone group had peripheral oedema (33% vs. 18%, P=0.0019). CONCLUSION: After a 12-month follow-up, we found no evidence for a statistically significant effect of rosiglitazone on SVG atherosclerosis whereas significant effects on glycemic control and on the cardiometabolic risk profile appeared to be modulated in part by changes in subcutaneous adiposity.

Intensive multifactorial intervention for stable coronary artery disease: optimal medical therapy in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial.

OBJECTIVES: This paper describes the medical therapy used in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial and its effect on risk factors. BACKGROUND: Most cardiovascular clinical trials test a single intervention. The COURAGE trial tested multiple lifestyle and pharmacologic interventions (optimal medical therapy) with or without percutaneous coronary intervention in patients with stable coronary disease. METHODS: All patients, regardless of treatment assignment, received equivalent lifestyle and pharmacologic interventions for secondary prevention. Most medications were provided at no cost. Therapy was administered by nurse case managers according to protocols designed to achieve predefined lifestyle and risk factor goals. RESULTS: The patients (n = 2,287) were followed for 4.6 years. There were no significant differences between treatment groups in proportion of patients achieving therapeutic goals. The proportion of smokers decreased from 23% to 19% (p = 0.025), those who reported <7% of calories from saturated fat increased from 46% to 80% (p < 0.001), and those who walked >or=150 min/week increased from 58% to 66% (p < 0.001). Body mass index increased from 28.8 +/- 0.13 kg/m(2) to 29.3 +/- 0.23 kg/m(2) (p < 0.001). Appropriate medication use increased from pre-randomization to 5 years as follows: antiplatelets 87% to 96%; beta-blockers 69% to 85%; renin-angiotensin-aldosterone system inhibitors 46% to 72%; and statins 64% to 93%. Systolic blood pressure decreased from a median of 131 +/- 0.49 mm Hg to 123 +/- 0.88 mm Hg. Low-density lipoprotein cholesterol decreased from a median of 101 +/- 0.83 mg/dl to 72 +/- 0.88 mg/dl. CONCLUSIONS: Secondary prevention was applied equally and intensively to both treatment groups in the COURAGE trial by nurse case managers with treatment protocols and resulted in significant improvement in risk factors. Optimal medical therapy in the COURAGE trial provides an effective model for secondary prevention among patients with chronic coronary disease. (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation; NCT00007657).

Comparison of new measures of vascular function to flow mediated dilatation as a measure of cardiovascular risk factors.

Although flow-mediated dilatation (FMD) is widely used, the ideal vascular parameter for the measurement of cardiovascular risk is not clear. Recently, it has been proposed that shear stress and blood velocity during hyperemia (VRH) may provide stronger correlations with cardiovascular risk factors than FMD. The aim of this study was to evaluate the relations of VRH and shear stress during reactive hyperemia (SSRH) to FMD and the association of these measures to cardiovascular risk factors in 1,477 men without cardiovascular disease. SSRH and VRH showed weak correlations with FMD in bivariate analysis (r = 0.239, p <0.001, and r = 0.108, p <0.001, respectively). The only cardiovascular risk factor independently associated with FMD was systolic blood pressure (beta = -0.073, p <0.01). In contrast, as the dependent variable, SSRH (R2 for model = 0.107) was independently associated with age, systolic blood pressure, low-density lipoprotein cholesterol, and body mass index. As the dependent variable, VRH was associated with the same risk factors with a slightly weaker R2 value of 0.095. In conclusion, SSRH and simply calculated VRH have stronger associations with cardiovascular risk factors than FMD. This may reflect greater sensitivity of these measures to detect early abnormalities associated with risk factors in a relatively young and healthy population.

Relationship between brachial artery flow-mediated dilatation, hyperemic shear stress, and the metabolic syndrome.

Metabolic syndrome (MetSyn) may predispose to cardiovascular disease (CVD) by causing vascular dysfunction. This study aimed to determine the association of MetSyn with vascular function, as assessed by brachial artery flow-mediated dilatation (FMD) and hyperemic shear stress (HSS). A total of 1,417 male firefighters without established diabetes and CVD were classified for MetSyn, according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP) definition. MetSyn was present in 267 individuals (19%). Although FMD was lower in those with versus without MetSyn (8.1 +/- 4.1 vs 8.7 +/- 4.0%; p = 0.02), this was not significant after adjusting for baseline differences (age, smoking, and brachial artery diameter) (p = 0.2). However, HSS was significantly lower in those with versus without MetSyn (72.0 +/- 27.8 vs 80.9 +/- 24.8 dyne/cm(2); p < 0.001), and there was a significant inverse graded relationship with the number of NCEP criteria present (mean HSS for those with 0, 1, 2, 3, 4, and 5 criteria: 83.2 +/- 22.5, 82.2 +/- 24.7, 76.5 +/- 27.2, 74.3 +/- 27.4, 66.5 +/- 28.4, 67.1 +/- 27.6 dyne/cm(2); p < 0.001 for trend). The individual NCEP criteria of abdominal obesity, systolic hypertension, and impaired fasting glucose were independent predictors for HSS. In conclusion, MetSyn was not associated with impaired FMD. Alternatively, HSS, a measure of microvascular function, was significantly lower in those with MetSyn. Thus, MetSyn may contribute to CVD by causing microvascular dysfunction.

Effects of the antioxidant succinobucol (AGI-1067) on human atherosclerosis in a randomized clinical trial.

BACKGROUND: The antioxidant AGI-1067 was shown to reduce experimental atherosclerosis. The present study originally intended to study restenosis as a primary endpoint but was subsequently modified to primarily investigate the effects of AGI-1067 on coronary atherosclerosis. METHODS AND RESULTS: This placebo-controlled randomized trial assessed the effects of AGI-1067 280 mg qd started before percutaneous coronary intervention (PCI) and administered for 12 months after PCI on atherosclerosis progression as assessed by coronary intravascular ultrasound (IVUS). Among patients with IVUS examinations considered technically adequate both at baseline and follow-up upon central laboratory assessments (n=232), plaque volume was not significantly modified with placebo (least squares mean change: -0.4mm(3), P=0.85 versus baseline), but was significantly reduced by -4.0mm(3) at end of treatment in the AGI-1067 group (P=0.001 versus baseline, P=0.12 versus placebo). LDL-cholesterol varied by -9% and +4% in the placebo and AGI-1067 groups, respectively (P<0.05 between groups), and HDL-cholesterol was reduced by 1% with placebo and 14% with AGI-1067 (P<0.05 between groups). Plasma myeloperoxidase was reduced by 6% with AGI-1067 (P<0.05) but hs-CRP was not significantly different between groups. CONCLUSIONS: Atherosclerosis regression (-4.0mm(3)) was observed in patients treated with AGI-1067, although this was not significantly different from placebo. The anti-inflammatory effect of AGI-1067 is supported by reduced levels of myeloperoxidase.

Optimal medical therapy with or without PCI for stable coronary disease.

BACKGROUND: In patients with stable coronary artery disease, it remains unclear whether an initial management strategy of percutaneous coronary intervention (PCI) with intensive pharmacologic therapy and lifestyle intervention (optimal medical therapy) is superior to optimal medical therapy alone in reducing the risk of cardiovascular events. METHODS: We conducted a randomized trial involving 2287 patients who had objective evidence of myocardial ischemia and significant coronary artery disease at 50 U.S. and Canadian centers. Between 1999 and 2004, we assigned 1149 patients to undergo PCI with optimal medical therapy (PCI group) and 1138 to receive optimal medical therapy alone (medical-therapy group). The primary outcome was death from any cause and nonfatal myocardial infarction during a follow-up period of 2.5 to 7.0 years (median, 4.6). RESULTS: There were 211 primary events in the PCI group and 202 events in the medical-therapy group. The 4.6-year cumulative primary-event rates were 19.0% in the PCI group and 18.5% in the medical-therapy group (hazard ratio for the PCI group, 1.05; 95% confidence interval [CI], 0.87 to 1.27; P=0.62). There were no significant differences between the PCI group and the medical-therapy group in the composite of death, myocardial infarction, and stroke (20.0% vs. 19.5%; hazard ratio, 1.05; 95% CI, 0.87 to 1.27; P=0.62); hospitalization for acute coronary syndrome (12.4% vs. 11.8%; hazard ratio, 1.07; 95% CI, 0.84 to 1.37; P=0.56); or myocardial infarction (13.2% vs. 12.3%; hazard ratio, 1.13; 95% CI, 0.89 to 1.43; P=0.33). CONCLUSIONS: As an initial management strategy in patients with stable coronary artery disease, PCI did not reduce the risk of death, myocardial infarction, or other major cardiovascular events when added to optimal medical therapy. (ClinicalTrials.gov number, NCT00007657 [ClinicalTrials.gov].).

The effect of iron status on vascular health.

The effect of increased iron stores on the progression of atherosclerosis and endothelial health remains inconclusive. This study was designed to evaluate the relationship between hemochromatosis genotypes, serum ferritin levels and presymptomatic vascular abnormalities in a cohort of healthy subjects. Carotid intima-media thickness (CIMT) and brachial flow-mediated vasodilation (FMD) were assessed by high-resolution ultrasound in 907 male (47 +/- 10 years) participants enrolled in the Firefighters and their Endothelium (FATE) study. Analyses of the hemochromatosis C282Y, H63D and S65C alleles were simultaneously determined by a single nucleotide polymorphism (SNP) primer extension method. It was found that brachial FMD was not related to serum ferritin or hemochromatosis genotype status. The presence of a hemochromatosis-associated genotype (n = 18) or heterozygosity for the C282Y genotype (n = 98) was not associated with an increased mean CIMT. After adjustment for conventional risk factors, serum ferritin was also not associated with mean CIMT. In conclusion, neither ferritin nor a hemochromatosis genotype was related to brachial endothelial function or carotid atherosclerosis. The present study does not support the hypothesis that mild to moderately increased iron stores are associated with enhanced atherosclerosis risk.

Folic acid improves endothelial dysfunction in type 2 diabetes--an effect independent of homocysteine-lowering.

Diabetes is associated with endothelial dysfunction, which in part may be related to uncoupling of the endothelial nitric oxide (NO) synthase enzyme, thus reducing the availability of NO. As folates may potentially reverse the uncoupling of NO synthase, we wanted to determine whether folic acid supplementation could modulate endothelial function and markers of inflammation in patients with type 2 diabetes without vascular disease. Nineteen patients with type 2 diabetes were treated with folic acid (10mg/day for 2 weeks) versus placebo in a randomized, placebo-controlled, cross-over study with an 8-week washout period between treatments. Fasting endothelium-dependent flow-mediated dilatation (FMD) of the brachial artery, endothelium-independent nitroglycerin-mediated dilatation (NMD), plasma homocysteine, serum lipids, folate, and inflammatory markers (high-sensitivity C-reactive protein, soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, interleukin-18, tumor necrosis factor-alpha) were assessed after each 2-week treatment period. Folic acid supplementation significantly increased folate levels and lowered plasma homocysteine levels. Folic acid significantly improved FMD compared to placebo (5.8 +/- 4.8% vs 3.2 +/- 2.7%, p = 0.02). There were no significant effects of folic acid supplementation on lipids, NMD, or the inflammatory markers. There was no relationship between the change in homocysteine and the improvement in FMD. Thus, 2 weeks of folic acid supplementation can improve endothelial dysfunction in type 2 diabetics independent of homocysteine-lowering, but does not modulate markers of inflammation.

Improved prediction of early-onset coronary artery disease using APOE epsilon4, BChE-K, PPARgamma2 Pro12 and ENOS T-786C in a polygenic model.

OBJECTIVES: Coronary artery disease (CAD) is often polygenic due to multiple mutations that contribute small effects to susceptibility. Since most prior studies only evaluated the contribution of single candidate genes, we therefore looked at a combination of genes in predicting early-onset CAD [apolipoprotein E (APOE) epsilon4, butyrylcholinesterase (BChE) K, peroxisome proliferator-activated receptor gamma2 (PPARgamma2) Pro12Ala and endothelial nitric oxide synthase (ENOS) T-786C]. DESIGN AND METHODS: We examined the frequencies, individually and in combination, of all four alleles among patients with early-onset CAD (n = 150; <50 years), late-onset CAD (n = 150; >65 years) and healthy controls (n = 150, age range 47-93 years). Differences in the proportion of subjects in each group with the given gene combination were assessed and likelihood ratios (LR) were calculated using logistic regression to combine the results of multiple genes. RESULTS: Early-onset CAD patients had increased, but non-significant, frequencies of PPARgamma2 Pro12/Pro12 (P = 0.39) and ENOS T-786C (P = 0.72), while BChE-K was only significantly higher in early-onset CAD patients compared to controls (P = 0.03). There were significantly more APOE epsilon4 alleles alone (P = 0.02) or in combination with BChE-K (P = 0.02) among early-onset CAD patients compared to late-onset CAD ones or controls. When combined, there was a higher prevalence of all four alleles in early-onset CAD (early-onset CAD patients: 10.7%, late-onset CAD patients: 3.3% and controls: 2.7%, P = 0.01). LR for early-onset CAD for a single allele was relatively small (1.08 for PPARgamma2 to 1.70 for APOE epsilon4). This increased to 2.78 (1.44-5.37) when combining all four alleles, therefore increasing the pre-test probability of CAD from 5% to a post-test probability of 12.7%. CONCLUSIONS: While any single mutation causes only a mildly increased LR (none > 1.7), in combination, the likelihood of early-onset CAD increased to 2.78 with four mutations. The genetics of early-onset CAD appear to be multifactorial, requiring polygenic models to elucidate risk.

Intensity of lipid lowering with statins and brachial artery vascular endothelium reactivity after acute coronary syndromes (from the BRAVER trial).

The time course and differential effects of statin regimens on endothelial function after acute coronary syndromes (ACSs) are unknown and could contribute to the superiority of a more intense strategy. A subset of subjects who were enrolled in the PROVE IT-TIMI 22 trial (n = 50) underwent evaluation of vascular reactivity by high-resolution brachial ultrasound. Endothelium-dependent flow-mediated dilation (FMD) and endothelium-independent sublingual nitroglycerin-mediated dilation (NMD) were measured at baseline and at 48 hours, 1 month, and 4 months after the initiation of 40 mg of pravastatin (n = 26) or 80 mg of atorvastatin (n = 24). After 4 months, low-density lipoprotein cholesterol was decreased by 32% in the atorvastatin group but was not different from baseline after ACS in the pravastatin group. C-reactive protein decreased similarly in the 2 groups. Brachial artery diameters at rest were similar in the 2 groups and at each time point of the trial. FMD and NMD increased significantly after 4 months by 27% and 24%, respectively (p <0.05), with no difference between groups. There was no correlation between the change in FMD and the change in lipids or C-reactive protein. In subjects who had received previous statin therapy (n = 15), there was no significant variation in FMD (p = 0.140) and NMD (p = 0.129). In conclusion, initiation of statin therapy soon after ACS is associated with improvements in endothelium-dependent and independent vascular reactivities after 4 months.

The relationship between soluble CD40 ligand levels and Framingham coronary heart disease risk score in healthy volunteers.

Elevated soluble CD40 ligand (sCD40L) levels are associated with an increased risk of cardiovascular events in patients with acute coronary syndromes and in middle-aged healthy women. However, the relationship between sCD40L and global risk assessment remains unclear. The present study was designed to examine the relationship between sCD40L and Framingham Coronary Heart Disease Risk Scores (FCRS) in healthy middle-aged men. The study population consisted of 400 active and retired male firefighters, with no previous history of cardiovascular disease, as part of the Firefighters and Their Endothelium (FATE) study. FCRS correlated poorly with sCD40L levels (p=0.14). Soluble CD40L concentrations correlated only with total (r=0.105; p=0.035) and LDL cholesterol (r=0.104; p=0.039), and CRP levels (r=0.11; p=0.03). Compared with participants with sCD40L levels <4.36 ng/mL (75th percentile), participants with sCD40L levels >4.36 ng/mL had higher total (p=0.016) and LDL cholesterol (p=0.018), CRP levels (p=0.034) and FCRS (p=0.012). Multivariate analysis revealed that CRP level was the only parameter that independently correlated with the sCD40L levels (p=0.032). This is the first study to evaluate the relationship between sCD40L levels and Framingham global risk assessment in a large cohort of otherwise healthy individuals. We demonstrate that sCD40L levels poorly correlate with both the individual components and the calculated FCRS. Long-term follow-up of the FATE study will shed light on whether the predictive value of sCD40L is independent of Framingham based global risk assessment.

Effects of the acyl coenzyme A:cholesterol acyltransferase inhibitor avasimibe on human atherosclerotic lesions.

BACKGROUND: Inhibition of the acyl coenzyme A:cholesterol acyltransferase (ACAT) enzyme may prevent excess accumulation of cholesteryl esters in macrophages. The ACAT inhibitor avasimibe was shown to reduce experimental atherosclerosis. This study was designed to investigate the effects of avasimibe on human coronary atherosclerosis. METHODS AND RESULTS: This randomized, double-blind, placebo-controlled trial assessed the effects of avasimibe at dosages of 50, 250, and 750 mg QD on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients received background lipid-lowering therapy if necessary to reach a target baseline LDL level <125 mg/dL (3.2 mmol/L). IVUS and coronary angiography were performed at baseline and repeated after up to 24 months of treatment. Approximately equal percentages of patients across groups received concurrent statin therapy (87% to 89%). The mean total plaque volume at baseline was approximately 200 mm3, and the least squares mean change at end of treatment was 0.7 mm3 for placebo and 7.7, 4.1, and 4.8 mm3 for the avasimibe 50, 250, and 750 mg groups, respectively (adjusted P=0.17 [unadjusted P=0.057], 0.37, and 0.37, respectively). Percent atheroma volume increased by 0.4% with placebo and by 0.7%, 0.8%, and 1.0% in the respective avasimibe groups (P=NS). LDL cholesterol increased during the study by 1.7% with placebo but by 7.8%, 9.1%, and 10.9% in the respective avasimibe groups (P<0.05 in all groups). CONCLUSIONS: Avasimibe did not favorably alter coronary atherosclerosis as assessed by IVUS. This ACAT inhibitor also caused a mild increase in LDL cholesterol.

Cross-sectional evaluation of brachial artery flow-mediated vasodilation and C-reactive protein in healthy individuals.

AIMS: The present study was designed to (a) examine the interrelationship between endothelial function and CRP in healthy individuals and (b) evaluate the relationship of each biomarker towards global Framingham risk scores. METHODS AND RESULTS: Brachial artery flow-mediated vasodilatation (FMD), CRP, and traditional cardiovascular risk factors were measured in the Firefighters and Their Endothelium (FATE) study, which recruited 1154 male participants (mean age 47.4+/-9.8 years) with no known history of cardiovascular disease. No relationship was observed between FMD and CRP (p = 0.96). FMD and the Framingham risk score tended to correlate but not significantly (p = 0.07). A lower FMD was related to a higher systolic and diastolic blood pressure (p < 0.001 and p = 0.002, respectively) in the univariate analysis, and higher systolic blood pressure (p = 0.001) in the multivariate analysis. Elevated CRP levels independently correlated most closely with overall Framingham risk score (r = 0.36, p < 0.001) and a weaker although statistically significant relationship was seen with individual traditional cardiovascular risk factors (p < 0.005). CONCLUSIONS: The current study provided evidence that brachial artery FMD had no relationship to CRP in a large cohort of healthy subjects. These observations suggest that the predictive value of CRP may be largely independent of abnormalities in endothelial function. The additive prognostic value of endothelial vasodilator testing remains to be established.

The Canadian study of the sirolimus-eluting stent in the treatment of patients with long de novo lesions in small native coronary arteries (C-SIRIUS).

OBJECTIVES: We assessed the safety and effectiveness of the sirolimus-eluting stent (SES) in treating single de novo long lesions in small native coronary arteries compared to an identical bare metal stent (BMS). BACKGROUND: The SES was previously demonstrated to reduce restenosis significantly. However, patients with long lesions in small vessels have not been well studied and may define a group at very high risk. METHODS: The Canadian Study of the Sirolimus-Eluting Stent in the Treatment of Patients With Long De Novo Lesions in Small Native Coronary Arteries (C-SIRIUS) was a multicenter, randomized, double-blind trial comparing SES versus identical BMS. The primary end point was in-stent minimal lumen diameter (MLD) at eight months. Secondary end points included angiographic restenosis at 8 months, target lesion revascularization (TLR), and major adverse cardiac events (MACE) at 270 days. RESULTS: A total of 100 patients were enrolled at eight Canadian sites. The in-stent MLD at eight months was 2.46 +/- 0.37 mm in the SES compared with 1.49 +/- 0.75 mm in the BMS (a 65% increase, p < 0.001). Angiographic restenosis occurred in 1 of 44 SES patients (2.3%, with no in-stent restenosis) and in 23 of 44 BMS patients (52.3%, p < 0.001). At 270 days, there were two clinically driven TLRs in the SES (4%) and nine in the BMS (18%, p = 0.05). The Kaplan-Meier estimate of freedom from MACE at 270 days was 96.0% for SES patients and 81.7% for BMS patients (p = 0.029). CONCLUSIONS: Patients with long lesions in small vessels are at very high risk of restenosis. In these patients, the SES dramatically reduces the risk of restenosis at eight months, translating into an excellent clinical outcome at nine months.

Effect of cyclooxygenase-2 inhibition with rofecoxib on endothelial dysfunction and inflammatory markers in patients with coronary artery disease.

OBJECTIVES: The aim of this study was to determine whether selective cyclooxygenase-2 (COX-2) inhibition with rofecoxib can modulate endothelial dysfunction and levels of circulating inflammatory markers in patients with established coronary artery disease (CAD). BACKGROUND: Expression of COX-2 is upregulated in atherosclerosis. Thus, it has been hypothesized that COX-2 may contribute to atherogenesis by producing eicosanoids, which mediate vascular inflammation and endothelial dysfunction. METHODS: In a randomized, double-blind, placebo-controlled, parallel-design trial, we studied the vascular effects of rofecoxib on brachial artery vasoreactivity and inflammatory markers in 60 patients with angiographically proven CAD who were taking concomitant low-dose aspirin. Patients were randomly assigned to receive either rofecoxib (25 mg/day; n = 30) or placebo (n = 30) for eight weeks. Brachial artery endothelium-dependent flow-mediated dilation (FMD), endothelium-independent nitroglycerin-mediated dilation (NMD), and inflammatory markers (i.e., high-sensitivity C-reactive protein [CRP], soluble intercellular adhesion molecule-1 [sICAM-1], and soluble interleukin-6 receptor [sIL-6r]) were measured at baseline and after eight-week follow-up. RESULTS: Baseline clinical characteristics were similar in the two groups. After eight weeks of treatment, FMD did not significantly change in either the rofecoxib or placebo group (4.0 +/- 3.0% to 4.0 +/- 3.8% vs. 2.7 +/- 2.7% to 3.1 +/- 2.7%, respectively; p = 0.6 by two-way analysis of variance). Similarly, NMD remained unchanged in both groups. Levels of CRP, sICAM-1, and sIL-6r were not significantly altered in either the rofecoxib or placebo group. CONCLUSIONS: The addition of selective COX-2 inhibition with rofecoxib did not appear to have any favorable or adverse effects on endothelial dysfunction or vascular inflammation in patients with CAD using concomitant low-dose aspirin.

Quantitative assessment of myocardial ischemia by electrocardiographic and scintigraphic imaging.

We calculated distributions of epicardial potentials from body-surface electrocardiograms (ECGs) recorded during controlled myocardial ischemia and compared them with scintigraphic estimates of ischemia's extent/severity. The study population consisted of patients suffering from single-vessel coronary artery disease, referred for elective percutaneous transluminal coronary angioplasty of either the left anterior descending (n=7), the right coronary (n=9), or the left circumflex (n=2) artery. After the target vessel had been dilated, a 1960s "study" inflation was performed with a non-perfusion-type balloon catheter; at its commencement, technetium-99m sestamibi was injected via a femoral-vein catheter, and ECGs were recorded throughout the inflation from 120 leads. Single photon emission computed tomographic imaging was performed one hour after the injection of radionuclide to obtain an "occlusion image", and again one hour after a repeat injection 24 hours later to obtain a "control image"; the latter image was subtracted from the former, to derive a scintigraphic difference map (Delta map). The ECGs were signal-averaged over a 10-s window at preinflation and peak-inflation states, the preinflation averaged complexes were subtracted from the peak-inflation ones to produce body-surface Delta maps, and the corresponding Delta maps of epicardial potentials were calculated by applying the electrocardiographic inverse solution; this procedure is referred to as electrocardiographic imaging. The ECG-derived epicardial Delta maps related spatially to the scintigraphic Delta maps in all patients. The percent areas and surface integrals of positive values in ECG-derived Delta maps were found to be very good single-variable predictors of the extent (r=0.73; p=0.0006) and severity (r=0.72; p=0.0008) of the scintigraphically-estimated perfusion defect; a regression equation using two ECG-derived predictors further improved the agreement with scintigraphic estimates (r=0.81; p=0.0004 for estimates of severity). These findings suggest that noninvasive electrocardiographic imaging might provide quantitative estimates of the extent/severity of myocardial ischemia that agree closely with those provided by scintigraphic techniques.

Relation between butyrylcholinesterase K variant, paraoxonase 1 (PON1) Q and R and apolipoprotein E epsilon 4 genes in early-onset coronary artery disease.

OBJECTIVES: The common K variant of butyrylcholinesterase (BChE-K), an enzyme which metabolizes acetylcholine and organophosphates, has been associated with Alzheimer's disease, especially in the presence of the apolipoprotein E epsilon 4 allele (APOE-epsilon 4). Although APOE-epsilon 4 has been associated with the development of coronary artery disease (CAD), an association between the BChE-K variant and CAD has not been explored. Paraoxonase 1 (PON1), located within HDL, is an enzyme which also metabolizes organophosphates and may be antiatherogenic. The R192 variant of PON1 (PON1-R) has been associated with CAD. DESIGN AND METHODS: To determine whether BChE-K is also associated with premature CAD, we examined the frequency of BChE-K among patients with early-onset CAD (n = 150; < 50 yr) vs. late-onset CAD (n = 150; > 65 yr) by molecular analysis. We also examined the frequency of the PON1-R allele in both groups, and explored whether there was synergism between BChE-K and APOE-epsilon 4, BChE-K and PON1-R or PON1-R and APOE-epsilon 4. RESULTS: The frequency of the BChE-K allele tended to be greater among early-onset CAD patients compared to late-onset CAD patients (41.3% vs. 31.3%; p = 0.07), but without any significant difference between males and females. There was no difference in the prevalence of the PON1-R allele between those with early- or late-onset CAD (46.0% vs. 52.7%; p = 0.25). Twenty-two patients with early-onset CAD had both the BChE-K plus APOE-epsilon 4 alleles (14.7%) compared to 11 late-onset CAD patients (7.3%) (p = 0.04). There was no such association between BChE-K and PON1-R, nor PON1-R and APOE-epsilon 4. CONCLUSIONS: Our study suggests that there is a minor association between BChE-K and early-onset CAD, especially in the presence of the APOE-epsilon 4 allele.