Incidence and Prognostic Implications of Late Bleeding After Myocardial Infarction or Unstable Angina According to Treatment Strategy.

BACKGROUND: Bleeding complications accompanying coronary revascularization are associated with increased mortality; however, few data are available on subsequent bleeding risk. We used administrative data to assess the incidence of late bleeding events in patients with acute coronary syndrome (ACS) according to treatment allocation. METHODS: The cohort and bleeding events were identified through the Canadian Institute for Health Information discharge abstract database. Crude and adjusted odds ratios (ORs) were calculated for index and postindex admission bleeding up to 1 year after discharge. RESULTS: Of 31,941 patients hospitalized with ACS, 7681 (32.4%) patients were treated with medication alone, 3728 (15.2%) underwent angiography without intervention, and 13,075 (53.4%) underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The overall incidence of readmission with bleeding based on administrative codes was low (3.8% for medically treated patients, 2.8% for patients who underwent angiography alone, 2.6% for patients who underwent CABG, and 1.8% for patients who underwent PCI; P < 0.0001). Bleeding codes were mainly gastrointestinal bleeding (52%), but 7.8% were intracranial episodes of bleeding. Patients who received PCI had significantly lower odds of late bleeding compared with medically treated patients (OR, 0.76; 95% CI, 0.62-0.94). Late bleeding during the first year after ACS was associated with mortality (OR, 4.96; 95% CI, 2.47-9.93). CONCLUSIONS: Patients who underwent revascularization procedures had a relatively low risk for late bleeding events after a hospitalization for ACS. Late bleeding events were associated with an increased risk of death.

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.

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.

The differential association between various anthropometric indices of obesity and subclinical atherosclerosis.

BACKGROUND: Recent observational studies have reported differential quantitative relationships between the different anthropometric indices of obesity and risk for cardiovascular (CV) events. Specifically, waist circumference and waist-to-hip ratio (WHR) as crude measures of abdominal obesity were shown to be more predictive of CV events than body mass index (BMI). However, it remains undetermined whether indices of abdominal obesity are also more strongly associated with early subclinical atherosclerosis in asymptomatic individuals. METHODS: The associations between carotid intimal-medial thickness (cIMT) as a validated marker of subclinical atherosclerosis and each of BMI, waist circumference and WHR were compared among 1578 middle-aged men free of clinical CV disease enrolled in the Fire Fighter and Their Endothelium (FATE) study. RESULTS: In univariate analyses, the correlation with cIMT as well as the ability to predict substantially increased atherosclerotic burden (cIMT>75% percentile of the cohort) was strongest for WHR, intermediate for waist circumference, and weakest for BMI (Pearson's coefficient of 0.21, 0.18 and 0.12, respectively; area under the receiver operating characteristics curve [AUC] of 0.65, 0.62 and 0.58, respectively, P<0.01 for differences). Within each traditional BMI category, WHR uniformly outperformed waist circumference in further refining discrimination for increased atherosclerotic burden. In multivariable analyses, WHR consistently demonstrated the strongest graded independent relationship with cIMT, beyond most of the established risk factors of atherosclerosis, and superseded both waist circumference and BMI. CONCLUSION: Our findings support the use of WHR for estimating adiposity-related atherosclerotic burden in clinical practice and in obesity research. Moreover, our study suggests that the increased CV risk associated with abdominal obesity may be mediated in part by the increased anatomic extent of atherosclerotic vascular disease.

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.

The effect of large unilamellar vesicles on vascular function in patients with coronary atherosclerosis.

OBJECTIVE: To evaluate the effect of large unilamellar vesicles (LUVs) infusion on endothelial function. Low-density lipoprotein (LDL) lowering, particularly with statins, results in rapid attenuation of endothelial dysfunction and decreases cardiovascular events. Unique methods of removing cholesterol from the vessel wall are being developed. The effect of LUVs on endothelial function has not been evaluated in humans. METHOD: 75 subjects (mean age 61+/-10 years) with established vascular disease were randomized to receive either 2g, 8 g or matching placebo of LUVs as a weekly intravenous bolus infusion for 4 consecutive weeks. Brachial artery flow-mediated dilation (FMD) and nitroglycerin-mediated dilation was measured at baseline and 1 week after the last infusion. The primary study outcome was the change from baseline in FMD in the active therapy groups combined. Predefined secondary end-points included nitroglycerin-mediated dilation and safety. RESULTS: Active therapy (combined 2g+8 g treatment groups, n=49) did not result in a change in FMD, but did improve nitroglycerin dilation (p<0.05). However, a beneficial effect on both FMD (10.2+/-5.7% vs. 11.8+/-5.5%) and nitroglycerin-mediated dilation (18.1+/-9.3% vs. 21.2+/-8.7%, both p<0.05) was seen in the 2-g group. Infusion of the 8-g dose resulted in significantly higher levels of unesterified cholesterol compared with the other groups during the study period (p<0.01). CONCLUSION: The current study demonstrated no overall effect of LUVs on FMD, however nitroglycerin-mediated dilation was improved. Further studies are required to clarify if there is a dose-dependent effect of this therapy and what its role is in subjects with atherosclerosis.

Modulation of arterial reactivity using amlodipine and atorvastatin measured by ultrasound examination (MARGAUX).

OBJECTIVE: To evaluate the effect of the calcium channel blocker amlodipine on endothelial function in normotensive patients with coronary disease taking concomitant atorvastatin therapy. METHODS AND RESULTS: Atorvastatin was titrated (10-80 mg/day) to maintain LDL-C<2.5 mmol/L and patients were randomized to receive amlodipine (5-10mg/day, n=64) or placebo (n=70) for 12 months. Brachial artery flow-mediated vasodilation (FMD) was assessed using vascular ultrasound. Inflammatory markers were also measured. At 12 months there was a significant decrease in mean low-density lipoprotein cholesterol (LDL-C) (4.4-2.1 mmol/L, P<0.0001), high-sensitivity C-reactive protein (hsCRP) (3.8-2.3mg/L, P<0.0001) and soluble vascular cell adhesion molecule-1 (sVCAM-1) (710-665 ng/mL, P<0.0001) for all patients, compared with baseline. Amlodipine was associated with a mean blood pressure reduction of 8/3 mm Hg (P<0.0001) whereas patients on placebo had no significant change. In the atorvastatin-placebo group, mean FMD increased (7.3-9.5%, P<0.05) with no change in nitroglycerin-mediated dilation. No further benefit on FMD or inflammatory markers was observed with the addition of amlodipine. CONCLUSIONS: Intensive reduction of LDL-C with atorvastatin improves endothelium-dependent vasodilation and reduces markers of inflammation in patients with coronary disease. Amlodipine was not associated with a significant additional benefit on these variables.

Registry data evaluating the effectiveness of drug-eluting stents for the treatment of symptomatic in-stent restenosis.

BACKGROUND: In this new-era of drug-eluting stents (DES) the impact of symptomatic in-stent restenosis (ISR) is diminishing. However, world wide bare-metal stents remain widely used and therefore, it is imperative to establish a simple and effective form of treatment. The objective of this registry database was to evaluate the 'real-world' effectiveness of DES for the treatment of symptomatic bare-metal stent ISR. METHODS: All patients presenting with symptomatic ISR were evaluated between February 2003 and February 2005. Patients had 9-month angiographic follow-up with primary endpoint evaluation of binary restenosis (>50%). Secondary endpoints included in-segment late loss, target lesion revascularization (TLR) and the difference in late loss between sirolimus (n=23) and paciltaxel (n=36) eluting stents. RESULTS: Fifty eight patients with fifty nine ISR lesions were evaluated, 36% of patients had diabetes mellitus. All procedures were performed safely with no adverse peri-procedural events documented. At 9-month follow-up the median in-segment late loss was 0.24 mm (IQR 0.1, 0.53), with a binary restenosis rate of 17%. At long-term follow-up greater than 1 year, the incidence of TLR was 10%. No difference in the angiographic parameter of in-segment late loss was seen between the sirolimus and paclitaxel-eluting stents. CONCLUSIONS: In this cohort of patients with long-term angiographic and clinical follow-up, DES is an effective and safe treatment for symptomatic bare-metal stent ISR.

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.

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.

Relationship between carotid artery intima-media thickness and brachial artery flow-mediated dilation in middle-aged healthy men.

OBJECTIVES: We aimed to determine the relationship between carotid intima-media thickness (IMT) and brachial artery flow-mediated dilation (FMD) in healthy middle-age men. BACKGROUND: Carotid IMT and brachial artery FMD are frequently used as surrogate measures of subclinical atherosclerosis. Whereas carotid IMT identifies early structural abnormalities, brachial artery FMD, considered a bioassay of endothelial function, measures functional vascular integrity. The relationship between carotid IMT and brachial artery FMD has not been well studied. METHODS: We measured traditional risk factors, carotid IMT, and brachial artery FMD in 1,578 middle-aged men without known cardiovascular disease and analyzed the relationship between carotid IMT and brachial FMD. RESULTS: Carotid IMT correlated with age, systolic blood pressure, body mass index, fasting glucose, total and low-density lipoprotein (LDL) cholesterol, and with the overall Framingham risk score (p < 0.001 for all), whereas impaired brachial artery FMD correlated with systolic and diastolic blood pressure (p < 0.01). No relationship was observed between carotid IMT and brachial artery FMD for the entire cohort (r = -0.006, p = 0.82) and in subgroups defined by traditional risk factors or by quintiles of carotid IMT and brachial FMD. CONCLUSIONS: In middle-aged healthy men, there is no significant correlation between carotid IMT and brachial artery FMD. This finding suggests that these are unique, independent surrogates that measure different aspects and stages of early atherosclerosis. Further studies are needed to define their role in clinical research and in cardiovascular risk assessment.

Reaching recommended lipid and blood pressure targets with amlodipine/atorvastatin combination in patients with coronary heart disease.

The effects of combined atorvastatin and amlodipine on blood pressure (BP) and low-density lipoprotein (LDL) cholesterol levels were investigated in 134 patients with documented coronary heart disease treated for 1 year. BP at baseline was 128 +/- 15/79 +/- 9 mm Hg and was controlled by the treating physician; no calcium channel blockers were allowed. Baseline means for plasma cholesterol were 6.4 +/- 1.1 mmol/L (147 +/- 39 mg/dl), triglycerides 2.0 +/- 0.9 mmol/L (177 +/- 88 mg/dl), LDL cholesterol 4.4 +/- 1.0 mmol/L (170 +/- 39 mg/dl), and high-density lipoprotein cholesterol 1.2 +/- 0.3 mmol/L (46 +/- 12 mg/dl). Patients were all given atorvastatin 10 mg, then increased to 80 mg if the LDL cholesterol was <2.5 mmol/L (100 mg/dl). At 3 months, patients were randomized to amlodipine 10 mg or placebo. Plasma LDL cholesterol was decreased by 50%, and the LDL cholesterol target of <2.5 mmol/L was achieved in 81% of the patients. BP targets were achieved in 69% of the atorvastatin + placebo group, versus 96% in the atorvastatin + amlodipine group (p = 0.0002). With use of combination atorvastatin + amlodipine at doses ranging from 10 to 80 mg and 5 to 10 mg, respectively, recommended therapeutic goals were reached in most select subjects with coronary artery disease who were concomitantly receiving aspirin and antihypertensive therapy.

Comparison of endothelial function in young men and women with a family history of premature coronary artery disease.

Endothelial function was evaluated in 34 young men and women with a family history of premature coronary artery disease (CAD) and 28 control subjects. Men with a family history of CAD had significantly impaired flow-mediated, endothelium-dependent vasodilation of the brachial artery compared with controls; however, in women, there was no difference in flow-mediated vasodilation between subjects with a family history and controls.

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.

Vasospasm and myocardial bridge.

Two cases are discussed where vasospasm was induced at the level of myocardial bridges in patients with a recent myocardial infarction. A review of the clinical significance of myocardial bridges is presented. It is hypothesized that myocardial bridges may predispose to vasospasm; therefore, testing for vasospasm in patients with otherwise normal coronary angiograms is suggested.

Depression and prognosis following hospital admission because of acute myocardial infarction.

BACKGROUND: Whether there is an association between depression at the time of acute myocardial infarction and subsequent risk of cardiac complications and death remains controversial. Most studies of this risk factor have been limited to patients of single institutions, and this might account for the varying results. We prospectively evaluated patients admitted to 5 tertiary care and 5 community hospitals and followed them for 1 year to measure the prevalence and prognostic impact of depressive symptoms after acute myocardial infarction. METHODS: Patients were recruited for the study by trained nurse interviewers who had documented acute myocardial infarction within 2-3 days of admission. The nurses collected information from the medical records and asked study subjects to complete the Beck Depression Inventory questionnaire during their stay in hospital and using a mailed questionnaire 30 days, 6 months and 1 year later. We obtained information on vital status for patients lost to follow-up from a central death registry. RESULTS: Of the 587 study subjects, 550 (94%) completed the Beck Depression Inventory at baseline and 191 (35%) had a score of 10 or more, indicating at least mild depression. Rates of depression did not vary over the follow-up period and were similar among patients admitted to tertiary care or community hospitals. Depressed patients were more likely to undergo catheterization (57% v. 47%, 95% confidence interval [CI] around the difference 0.1%-19.6%) and were more likely to undergo percutaneous coronary intervention (32% v. 24%, 95% CI around the difference 0.1%-16.2%) within 30 days of first admission to hospital. Patients with depression on admission had higher rates of a composite of cardiac complications, including recurrent ischemia, infarction or congestive heart failure during their first stay in hospital or readmission for angina, recurrent acute myocardial infarction, congestive heart failure or arrhythmia (adjusted hazard ratio 1.4, 95% CI 1.05-1.86), compared with patients who were not depressed on admission. After 1 year, death rates were higher among patients who were depressed at admission (30 patients, 16%) compared with nondepressed patients (28 patients, 8%), although the difference was not statistically significant (hazard ratio 1.3, 95% CI 0.59-3.05). INTERPRETATION: Depressive symptoms are common after acute myocardial infarction and are associated with a slight increase in risk of in-hospital catheterization and angiography and readmission because of cardiac complications. Death was infrequent, with no statistically significant difference between the 2 groups.

The fate of endothelial function testing: rationale and design of the Firefighters And Their Endothelium (FATE) study.

Endothelial dysfunction plays a pivotal role in the development and progression of atherosclerotic vascular disease. The endothelium is strategically located between blood and vascular smooth muscle, making it both vulnerable to a variety of injurious stimuli but also available for interrogation as a marker of vascular health. Firefighters And Their Endothelium (FATE) is a prospective, longitudinal cohort study designed to assess the relationship between endothelial function, emerging cardiovascular risk factors and ultimately atherosclerotic vascular disease. It is hypothesized that participants with impaired endothelial function will be at increased risk of atherosclerotic complications. This Canadian initiative will recruit 1600 middle-aged participants with no known history of cardiovascular disease to be followed for cardiovascular events over the next decade. Quantitative B-mode ultrasound will be employed to assess endothelial function and subclinical atherosclerosis. This research is designed to redefine the approach to the primary prevention of atherosclerosis.

The T-786-->C mutation in endothelial nitric oxide synthase is associated with hypertension.

Although the pathogenic mechanisms involved in predisposing individuals to hypertension are not well defined, evidence is accumulating that suggests a strong genetic transmission. Animal studies and some clinical investigations have revealed that aberrant NO production may be an important contributing factor. Indeed, a missense mutation in the endothelial NO gene caused by a Glu298Asp alteration has been strongly associated with essential hypertension, coronary artery spasm, and myocardial infarction. Recently, another point mutation caused by a T-786-->C transition in the 5'-flanking region of the endothelial NO synthase gene has been identified and, like the Glu298Asp mutation, is associated with coronary artery spasm. The present study was conducted to determine the effect of the T-786-->C point mutation on hypertension. We investigated the interaction between the endothelial NO synthase T-786-->C polymorphism and blood pressure in a large (n=705) clinically healthy population. Allele frequencies for the T and C alleles were 62% and 38%, translating into 39%, 46% and 15% of the population having the T/T, T/C, and C/C genotypes, respectively, for the T-786-->C point mutation. Subjects with the C/C genotype had significantly higher systolic blood pressures and were 2.16(95% confidence interval, 1.3 to 3.7) more likely to be hypertensive. Therefore, the -786 C/C genotype in NO synthase is a significant contributing factor for increasing the risk of essential hypertension.