Atherothrombotic and thrombolytic biomarkers in incident stroke and atrial fibrillation-related stroke: The Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND AND AIMS: Although several biomarkers have been studied in thromboembolic stroke, measuring the balance between thrombus formation and thrombolysis and data on its role in predicting stroke and atrial fibrillation (AF)-related stroke is limited. We sought to assess atherothrombotic biomarkers grouped into composite factors that reflect thrombotic and thrombolytic potential, and the balance between these factors as it relates to incident stroke or transient ischemic attack (TIA) and stroke/TIA in AF. METHODS: A Thrombotic Factor, derived from fibrinogen, plasmin-antiplasmin complex, factor VIII, D-dimer, and lipoprotein(a); and a Thrombolytic Factor, derived from plasminogen and oxidized phospholipids on plasminogen, were evaluated at baseline in 5,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We evaluated the association between these two factors representative of thrombotic and thrombolytic potential and incident stroke/TIA (n = 402), and AF-related stroke/TIA (n = 82) over a median of 13.9 and 3.7 years, respectively. Cox proportional hazard models adjusted for medication use, cardiovascular risk factors and CHA2DS2-VASc score were utilized. Harrell's C-index was estimated to evaluate model performance. RESULTS: In models including both factors, Thrombotic Factor was positively while Thrombolytic Factor was inversely associated with incident stroke/TIA and AF-related stroke/TIA. Incorporating these factors along with the CHA2DS2-VASc in adjusted models resulted in a small improvement in risk prediction of incident stroke/TIA and AF-related stroke/TIA compared to models without the factors (C-index from 0.697 to 0.704, and from 0.657 to 0.675, respectively). CONCLUSIONS: Composite biomarker factors, representative of the balance between thrombotic and thrombolytic propensity, provided an improvement in predicting stroke/TIA beyond CHA2DS2-VASc score.

Smoking-associated Electrocardiographic Abnormalities Predict Cardiovascular Mortality: Insights from NHANES.

Background­: Smoking is associated with arrhythmia and sudden cardiac death, but the biological mechanisms remain unclear. Abnormal electrocardiogram (ECG) durations of ventricular repolarization (QT interval), atrial depolarization (P wave), and atrioventricular depolarization (PR interval and segment), predict cardiac arrhythmia and mortality. Objectives­: To elucidate how smoking affects cardiac excitation, we assessed in a nationally representative sample (NHANES III) associations between cotinine, abnormalities in P duration, PR interval, PR segment, rate-corrected QT (QTc), QRS duration, and JT interval, and long-term mortality. Methods­: We analyzed data from 5,633 adults using survey-weighted multinomial logistic regression to estimate associations between tobacco use (>15 ng/ml serum cotinine) and short (<5th percentile) or long (>95th percentile) ECG intervals, relative to reference (5 - 95th percentile). Results­: After adjustment for demographics, risk factors, and conduction-altering medications, smoking was associated with a higher odds of short PR interval, PR segment, and QRS, and long JT. Broader ECG effects of smoking were also assessed by survey-weighted linear regression of continuous cotinine and ECG intervals, which revealed cotinine inversely associated with PR segment and QTc. Over a 22-year follow-up, many ECG abnormalities predicted cardiovascular mortality in smokers, including long JT, QRS, and QTc, and short QRS. Conclusions­: Smoking increases likelihood for rapid atrioventricular conduction, rapid ventricular depolarization, and slow ventricular repolarization. The ventricular electrophysiologic abnormalities associated with smoking also predict cardiovascular mortality in smokers; however, traditional ECG measures of cardiac risk like QTc can overlook these ventricular defects and their independent predictive value in smokers.

Change in matrix metalloproteinase 2, 3, and 9 levels at the time of and after acute atherothrombotic myocardial infarction.

Elevated measures of matrix metalloproteinases (MMPs) are associated with acute myocardial infarction (MI), but it is not known how long these changes persist post-MI or if these measures differ between atherothrombotic versus non-atherothrombotic MI. MMPs-2, 3, and 9 were measured in 80 subjects with acute MI (atherothrombotic and non-atherothrombotic MI) or stable coronary artery disease (CAD). Measurements were made at, the time of acute MI, and > 3-month following acute MI (quiescent phase). Outcome measures were compared between groups and between time of acute MI and quiescent post-MI follow-up using Wilcoxon's and repeated measures analysis of variance. Forty-nine subjects met the criteria for acute MI with clearly defined atherothrombotic (n = 22) and non-atherothrombotic (n = 12) subsets. Fifteen subjects met criteria for stable CAD. MMP-3 was higher in acute MI versus stable CAD subjects at the time of acute MI: (453 vs. 217 pg/mL, p = 0.010) but not at quiescent phase follow-up (p > 0.05). MMP-9 was higher in acute MI versus stable CAD subjects at the time of acute MI: (412 vs. 168 pg/mL, p = 0.002) but not at the quiescent phase follow-up (p > 0.05). MMP-9 was higher at the time of acute MI versus quiescent phase follow-up in acute MI (412 vs. 213 pg/mL, p = 0.001) and atherothrombotic MI specifically (458 vs. 212 pg/mL, p = 0.001). No difference in MMP-2, 3, or 9 was observed between atherothrombotic versus non-atherothrombotic MI subgroups. MMPs-3 and 9 are significantly elevated in acute MI verses stable CAD subjects at time of acute MI but not different at quiescent phase follow-up. MMP-9 is elevated at the time of acute MI and specifically in acute atherothrombotic MI at time of MI versus quiescent phase follow-up.

Platelet Count and Mean Platelet Volume at the Time of and After Acute Myocardial Infarction.

Platelet count has been shown to be lower and mean platelet volume (MPV) to be higher in acute myocardial infarction (MI). However, it is not known whether these changes persist post-MI or if these measures are able to distinguish between acute thrombotic and non-thrombotic MI. Platelet count and MPV were measured in 80 subjects with acute MI (thrombotic and non-thrombotic) and stable coronary artery disease (CAD) at cardiac catheterization (acute phase) and at >3-month follow-up (quiescent phase). Subjects were stratified using stringent clinical, biochemical, histological, and angiographic criteria. Outcome measures were compared between groups by analysis of variance. Forty-seven subjects met criteria for acute MI with clearly defined thrombotic (n = 22) and non-thrombotic (n = 12) subsets. Fourteen subjects met criteria for stable CAD. No significant difference was observed in platelet count between subjects with acute MI and stable CAD at the acute or quiescent phase. MPV was higher in acute MI (9.18 ± 1.21) compared to stable CAD (8.13 ± 0.66; P = 0.003) at the acute phase but not at the quiescent phase (8.48 ± 0.58 vs 8.94 ± 1.42; P = 0.19). No difference in platelet count or MPV was detected between thrombotic and non-thrombotic subsets at acute or quiescent phases. The power to detect differences in these measures between thrombotic and non-thrombotic subsets was 58%. Higher MPV at the time of acute MI is not observed by 3 months post-MI (quiescent phase). Platelet count and MPV do not differ in subjects with thrombotic versus non-thrombotic MI. Further investigation is warranted to evaluate the utility of these measures in the diagnosis of acute MI.

Risk score overestimation: the impact of individual cardiovascular risk factors and preventive therapies on the performance of the American Heart Association-American College of Cardiology-Atherosclerotic Cardiovascular Disease risk score in a modern multi-ethnic cohort.

AIMS: To evaluate the 2013 American Heart Association (AHA)-American College of Cardiology (ACC)-Atherosclerotic Cardiovascular Disease (ASCVD) risk score among four different race/ethnic groups and to ascertain which factors are most associated with risk overestimation by the AHA-ACC-ASCVD score. METHODS AND RESULTS: The Multi-Ethnic Study of Atherosclerosis (MESA), a prospective community-based cohort, was used to examine calibration and discrimination of the AHA-ACC-ASCVD risk score in 6441 White, Black, Chinese, and Hispanic Americans (aged 45-79 years and free of known ASCVD at baseline). Using univariable and multivariable absolute risk regression, we modelled the impact of individual risk factors on the discordance between observed and predicted 10-year ASCVD risk. Overestimation was observed in all race/ethnic groups in MESA and was highest among Chinese (252% for women and 314% for men) and lowest in White women (72%) and Hispanic men (67%). Higher age, Chinese race/ethnicity (when compared with White), systolic blood pressure (treated and untreated), diabetes, alcohol use, exercise, lipid-lowering medication, and aspirin use were all associated with more risk overestimation, whereas family history was associated with less risk overestimation in a multivariable model (all P < 0.05). CONCLUSION: The AHA-ACC-ASCVD risk score overestimates ASCVD risk among men, women, and all four race/ethnic groups evaluated in a modern American primary prevention cohort. Clinicians treating patients similar to those in MESA, particularly older individuals and those with factors associated with more risk overestimation, may consider interpreting absolute ASCVD risk estimates with caution.

Comparison of coliform contamination in non-municipal waters consumed by the Mennonite versus the non-Mennonite rural populations.

OBJECTIVES: Mennonites reside in clusters, do not use modern sewage systems and consume water from non-municipal sources. The purpose of this study is to assess risk of Escherichia coli exposure via consumption of non-municipal waters in Mennonite versus non-Mennonite rural households. METHODS: Results were reviewed for non-municipal water samples collected by the local health department from Mennonite and non-Mennonite lifestyle households from 1998 through 2012. Water contamination was examined with the help of two study variables: water quality (potable, polluted) and gastrointestinal (GI) health risk (none, low, high). These variables were analyzed for association with lifestyle (Mennonite, non-Mennonite) and season (fall, winter, spring, summer) of sample collection. Data were split into two periods to adjust for the ceiling effect of laboratory instrument. RESULTS: From the entire cohort, 82 % samples were polluted and 46 % samples contained E. coli, which is consistent with high GI health risk. In recent years (2009 through 2012), the presence of total coliforms was higher in non-Mennonites (39 %, P = 0.018) and presence of E. coli was higher in Mennonites (P = 0.012). Most polluted samples were collected during summer (45 %, P = 0.019) and had high GI health risk (51 %, P = 0.008) as compared to other seasons. CONCLUSIONS: Majority of non-municipal waters in this region are polluted, consuming those poses a high GI health risk and contamination is prevalent in all households consuming these waters. An association of E. coli exposure with the Mennonite lifestyle was limited to recent years. Seasons with high heat index and increased surface runoffs were the riskiest to consume non-municipal waters.

Nonalcoholic fatty liver disease and serum lipoproteins: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: While nonalcoholic fatty liver disease (NAFLD) is associated with the metabolic syndrome, it is not known if NAFLD plays an independent role in the atherogenic dyslipidemia phenotype. METHODS AND RESULTS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based prospective cohort study of adults free of clinical cardiovascular disease at enrollment. We tested for a relationship between NAFLD, defined as a liver/spleen (L/S) attenuation ratio of <1 on a non-contrast cardiac CT scan, and multiple measures of fasting serum lipoprotein size, cholesterol and particle concentrations. NAFLD was present in 569 (17%) of 3362 participants. After adjustment for multiple metabolic risk factors, adiposity and measures of insulin resistance (HOMA-IR), NAFLD was independently associated with higher fasting serum triglycerides and lower serum HDL-C. Despite a lack of association with LDL-C, NAFLD was associated with higher LDL particle concentration and lower LDL particle size. Modeling the L/S ratio as a continuous variable, a severity dependent association was observed between atherogenic lipoprotein abnormalities and NAFLD. CONCLUSION: In a large, multi-ethnic, gender balanced cohort, CT-diagnosed NAFLD was associated with the atherogenic dyslipidemia phenotype in a dose dependent fashion. These relationships persisted after adjustment for several metabolic risk factors and HOMA-IR, suggesting a possible independent pathophysiologic role between NAFLD and dyslipidemia.

Omega-3 Fatty acids for cardiovascular disease prevention.

OPINION STATEMENT: Major dietary sources of omega-3 fatty acids are fish containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as nuts, seeds, and vegetable oils containing α-linolenic acid (ALA). Omega-3 fatty acids, especially those derived from marine sources, may be a useful tool for the primary and secondary prevention of cardiovascular disease. Omega-3s exert their cardioprotective effects through multiple mechanisms, including reducing arrhythmias and altering production of prostaglandins, which reduces inflammation and improves platelet and endothelial function. To date, no serious adverse effects of omega-3s have been identified, despite extensive study. In adults, any potential harm from mercury exposure from consuming fish rich in omega-3s is outweighed by the proven cardiovascular benefits of eating fish. Concerns over increased bleeding complications have not materialized despite the increased concomitant use of aspirin and clopidogrel. We recommend one serving (200-400 g) of fatty fish two times per week and a diet that includes foods rich in ALA for the primary prevention of cardiovascular disease. We recommend one serving (200-400 g) of fatty fish or a fish oil supplement containing 900 mg of EPA + DHA every day and a diet rich in ALA for patients with known cardiovascular disease or congestive heart failure.

On-site Night Float by Attending Physicians: A Model to Improve Resident Education and Patient Care.

BACKGROUND: In 2003, the Accreditation Council for Graduate Medical Education instituted common duty hour limits, and in 2008 the Institute of Medicine recommended additional limits on continuous duty hours. Using a night-float system is an accepted approach for adhering to duty hour mandates. OBJECTIVE: To determine the effect of an on-site night-float attending physician on resident education and patient care. METHODS: Night-float residents and daytime ward residents were surveyed at the end of their rotation about the impact of an on-site night-float attending physician on education and quality of patient care. Responses were provided on a 5-point Likert scale ranging from 1, strongly agree, to 5, strongly disagree. RESULTS: Overall, 92 of the 140 distributed surveys were completed (66% response rate). Night-float residents found the night-float attending physician to be helpful with cross-cover issues (mean  =  2.00), initial history and physical examination (mean  =  1.56), choosing appropriate diagnostic tests (mean  =  1.79), developing a treatment plan (mean  =  1.74), and improving overall patient care (mean  =  1.91). Daytime ward residents were very satisfied with the quality of the admission workups (mean  =  1.78), tests and diagnostic procedures (mean  =  1.76), and initial treatment plan (mean  =  1.62) provided by the night-float service. CONCLUSION: A night-float system that includes on-site attending physician supervision can provide a valuable opportunity for resident education and may help improve the quality of patient care.

Blood is thicker than water: the management of hyperviscosity in adults with cyanotic heart disease.

Complications of chronic hypoxia, including erythrocytosis, hyperviscosity, abnormalities of hemostasis, cerebral abscesses, stroke, and endocarditis, are among the most common consequences of cyanotic heart disease in adults. The compensatory erythrocytosis of cyanotic heart disease can become pathologic by causing an increase in blood viscosity, thereby decreasing perfusion and resulting in decreased total oxygen delivery and increased risk of venoocclusive/hyperviscosity syndrome. Treatment of hyperviscosity secondary to erythrocytosis in cyanotic heart disease is controversial. Data is limited but suggest that phlebotomy has the potential to increase exercise capacity, reduce the symptoms of hyperviscosity, and reduce the potential risk of vasoocclusive disease in selected patients with polycythemia secondary to cyanotic heart disease. Unfortunately, repeated phlebotomy can quickly lead to iron deficiency, resulting in microcytic erythrocytes that induce higher viscosity than normocytic erythrocytes, which may increase the risk for venoocclusive events. There are limited data on the use of hydroxyurea to suppress erythrocytosis in this patient population. The authors conclude that until newer approaches to decreasing hematocrit without inducing iron deficiency are shown to be safe and efficacious, phlebotomy should only be used for the acute resolution of hyperviscosity symptoms. In addition, the use of hydroxyurea should be limited to patients with recurrent symptoms.