Canadian Spontaneous Coronary Artery Dissection Cohort Study: 3-Year Outcomes.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-aged women. OBJECTIVES: We aim to define the long-term natural history of SCAD. METHODS: We performed a multicenter, prospective, observational study of patients with nonatherosclerotic SCAD presenting acutely from 22 North American centers. We recorded baseline demographics, in-hospital characteristics, precipitating and predisposing conditions, angiographic features (adjudicated), in-hospital and 3-year major adverse cardiovascular events (MACE). Cox regression multivariable analysis was performed. RESULTS: We prospectively enrolled 750 consecutive patients with SCAD from June 2014 to June 2018. Mean age was 51.7 ± 10.5 years, 88.5% were women (55.0% postmenopausal); 31.3% presented with ST-segment elevation myocardial infarction, and 68.3% with non-ST-segment elevation myocardial infarction. Precipitating emotional stressor was reported in 50.3%, and physical stressor in 28.9%. Predisposing conditions included fibromuscular dysplasia in 42.9% (56.4% in those with complete screening), peripartum state 4.5%, and genetic disorders 1.6%. Most patients were treated conservatively (84.3%); 14.1% underwent percutaneous coronary intervention (PCI), 0.7% coronary artery bypass graft. At 3.0-year median follow-up, mortality was 0.8%, recurrent MI 9.9% (extension of previous SCAD 3.5%, de novo recurrent SCAD 2.4%, iatrogenic dissection 1.9%), with overall MACE 14.0%. Presence of genetic disorders, peripartum SCAD, and extracoronary fibromuscular dysplasia were independent predictors of 3-year MACE. Patients who underwent PCI at index hospitalization had similar postdischarge MACE compared with no PCI. At 3 years, 80.0% remained on aspirin and 73.5% on beta-blockade. CONCLUSIONS: Long-term mortality and de novo recurrent SCAD was low in our contemporary large SCAD cohort that included low revascularization rate and high use of beta-blockade and aspirin. Genetic disorders, extracoronary fibromuscular dysplasia, and peripartum SCAD were independent predictors of long-term MACE.

Clinical usefulness of lipid ratios to identify men and women with metabolic syndrome: a cross-sectional study.

BACKGROUND: Waist circumference, a metabolic syndrome (MetSy) criterion, is not routinely measured in clinical practice making early identification of individuals with MetSy challenging. It has been argued that ratios of commonly measured parameters such as lipids and lipoproteins may be an acceptable alternative for identifying individuals with MetSy. The objective of our study was to explore clinical utility of lipid ratios to identify men and women with MetSy; and to explore the association between lipid ratios and the number of MetSy components. METHODS: Men and women (N = 797) of Aboriginal, Chinese, European, and South Asian origin (35-60 years), recruited across ranges of body mass index (BMI), with no diagnosed cardiovascular disease (CVD) or on medications to treat CVD risk factors were assessed for anthropometrics, family history of CVD, MetSy components (waist circumference, blood pressure, glucose, triglycerides (TG), high-density-lipoprotein-cholesterol (HDL-C)), low-density-lipoprotein-cholesterol (LDL-C), nonHDL-C, and health-related behaviours. RESULTS: Mean levels of lipid ratios significantly increased with increasing number of MetSy components in men and women (p < 0.05). After adjustment for age, ethnicity, smoking, alcohol consumption, physical activity, family history of CVD and BMI, (and menopausal status in women), all lipid ratios were associated with the number of MetSy components in men and women (Poisson regression, p < 0.001). Compared to the rest of the lipid ratios (ROC curve analysis), TG/HDL-C was best able to discriminate between individuals with and without MetSy (AUC = 0.869 (95% CI: 0.830, 0.908) men; AUC = 0.872 (95% CI: 0.832, 0.912) women). The discriminatory power of TC/HDL-C and nonHDL-C/HDL-C to identify individuals with MetSY was the same (for both ratios, AUC = 0.793 (95% CI: 0.744, 0.842) men; 0.818 (95% CI: 0.772, 0.864) women). Additionally, LDL-C/HDL-C was a good marker for women (AUC = 0.759 (95% CI: 0.706, 0.812)), but not for men (AUC = 0.689 (95% CI: 0.631, 0.748)). Based on a multiethnic sample, we identified TG/HDL-C cut-off values of 1.62 in men and 1.18 in women that were best able to discriminate between men and women with and without MetSY. CONCLUSIONS: Our results indicate that TG/HDL-C is a superior marker to identify men and women with MetSy compared to TC/HDL-C, LDL-C/HDL-C, and nonHDL-C/HDL-C.

The association between "hypertriglyceridemic waist" and sub-clinical atherosclerosis in a multiethnic population: a cross-sectional study.

BACKGROUND: "Hypertriglyceridemic waist" (HTGW) phenotype, an inexpensive early screening tool for detection of individuals at risk for type 2 diabetes and cardiovascular disease was found to be associated with subclinical atherosclerosis in various patient populations such as those with diabetes mellitus, chronic kidney disease, and those infected with human immunodeficiency virus. However, less is known regarding an association between HTGW and subclinical atherosclerosis in the apparently healthy, multiethnic population. Therefore, the aim of the study was to explore the association between HTGW and sub-clinical atherosclerosis in an apparently healthy, multiethnic population; and to investigate whether the effect of HTGW on sub-clinical atherosclerosis persists over and above the traditional atherosclerosis risk factors. METHODS: We studied 809 individuals of Aboriginal, Chinese, European and South Asian origin who were assessed for indices of sub-clinical atherosclerosis (intima-media thickness (IMT), total area and presence of carotid plaques), socio-demographic and lifestyle characteristics, anthropometrics, lipids, glucose, blood pressure, and family history of cardiovascular disease. RESULTS: We found that, compared to individuals without HTGW and after adjusting for age, ethnicity, smoking, and physical activity; men and women with HTGW had a significantly higher: IMT (men: B (95%CI = 0.084 (0.037, 1.133), p < 0.001; women: B (95%CI) = 0.041 (0.006, 0.077), p = 0.020); and total area (men: B (95%CI = 0.202 (0.058, 0.366), p = 0.005; women: B (95%CI) = 0.115 (0.006, 0.235), p = 0.037). The association between HTGW waist and presence of plaques was significant for men (OR (95%CI) = 1.904 (1.040, 3.486), p = 0.037 vs. men without HTGW), but not for women (p = 0.284). Once analyses were adjusted for additional, traditional risk factors for atherosclerosis, the effect of HTGW on sub-clinical atherosclerosis was no longer significant. CONCLUSIONS: In conclusion, HTGW may serve as an early marker of subclinical atherosclerosis in men and women, irrespective of ethnicity. However, once individuals are assessed for all traditional risk factors for atherosclerosis, the additional assessment for HTGW is not warranted.