Association between CK-MB Area Under the Curve and Tranexamic Acid Utilization in Patients Undergoing Coronary Artery Bypass Surgery.

Myonecrosis after coronary artery bypass graft (CABG) surgery is associated with excess mortality. Tranexamic acid (TA), an anti-fibrinolytic agent, has been shown to reduce peri-operative blood loss without increasing the risk of myocardial infarction (MI); however, no large study has examined the association between TA treatment and post-CABG myonecrosis. In the MC-1 to Eliminate Necrosis and Damage in Coronary Artery Bypass Graft Surgery II trial, inverse probability weighting of the propensity to receive TA was used to test for differences among the 656 patients receiving and 770 patients not receiving TA. The primary outcome was creatine kinase MB (CK-MB) area under the curve (AUC) through 24 h. The secondary outcome was 30-day cardiovascular death or MI. Patients who received TA were more frequently female, had a previous MI, heart failure, low molecular weight heparin therapy, on-pump CABG, valvular surgery, and saphenous vein or radial grafts. The median 24-h CK-MB AUC was higher in TA-treated patients [301.9 (IQR 196.7-495.6) vs 253.5 (153.4-432.5) ng h/mL, p < 0.001]. No differences in the 30-day incidence of cardiovascular death or MI were observed (8.7 vs 8.3%, adjusted OR 0.99; 95% CI 0.67-1.45, p = 0.948). In patients undergoing CABG, TA use was associated with a higher risk of myonecrosis; however, no differences were observed in death or MI. Future larger studies should be directed at examining the pathophysiology of TA myonecrosis, and its association with subsequent clinical outcomes.

Premature permanent discontinuation of apixaban or warfarin in patients with atrial fibrillation.

AIMS: The ARISTOTLE (Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation) trial randomised patients with atrial fibrillation at risk of stroke to apixaban or warfarin. We sought to describe patients from ARISTOTLE who prematurely permanently discontinued study drug. METHODS/RESULTS: We performed a posthoc analysis of patients from ARISTOTLE who prematurely permanently discontinued study drug during the study or follow-up period. Discontinuation rates and reasons for discontinuation were described. Death, thromboembolism (stroke, transient ischaemic attack, systemic embolism), myocardial infarction and major bleeding rates were stratified by ≤30 days or >30 days after discontinuation. A total of 4063/18 140 (22.4%) patients discontinued study drug at a median of 7.3 (2.2, 15.2) months after randomisation. Patients with discontinuation were more likely to be female and had a higher prevalence of cardiovascular disease, diabetes, renal impairment and anaemia. Premature permanent discontinuation was more common in those randomised to warfarin than apixaban (23.4% vs 21.4%; p=0.002). The most common reasons for discontinuation were patient request (46.1%) and adverse event (34.9%), with no significant difference between treatment groups. The cumulative incidence of clinical events ≤30 days after premature permanent discontinuation for all-cause death, thromboembolism, myocardial infarction, and major bleeding was 5.8%, 2.6%, 0.9%, and 3.0%, respectively. No significant difference was seen between treatment groups with respect to clinical outcomes after discontinuation. CONCLUSION: Premature permanent discontinuation of study drug in ARISTOTLE was common, less frequent in patients receiving apixaban than warfarin and was followed by high 30-day rates of death, thromboembolism and major bleeding. Initiatives are needed to reduce discontinuation of oral anticoagulation.

Simultaneous Risk Factor Control Using Telehealth to slOw Progression of Diabetic Kidney Disease (STOP-DKD) study: Protocol and baseline characteristics of a randomized controlled trial.

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD) in the United States. Multiple risk factors contribute to DKD development, yet few interventions target more than a single DKD risk factor at a time. This manuscript describes the study protocol, recruitment, and baseline participant characteristics for the Simultaneous Risk Factor Control Using Telehealth to slOw Progression of Diabetic Kidney Disease (STOP-DKD) study. The STOP-DKD study is a randomized controlled trial designed to evaluate the effectiveness of a multifactorial behavioral and medication management intervention to mitigate kidney function decline at 3 years compared to usual care. The intervention consists of up to 36 monthly educational modules delivered via telephone by a study pharmacist, home blood pressure monitoring, and medication management recommendations delivered electronically to primary care physicians. Patients seen at seven primary care clinics in North Carolina, with diabetes and [1] uncontrolled hypertension and [2] evidence of kidney dysfunction (albuminuria or reduced estimated glomerular filtration rate [eGFR]) were eligible to participate. Study recruitment completed in December 2014. Of the 281 participants randomized, mean age at baseline was 61.9; 52% were male, 56% were Black, and most were high school graduates (89%). Baseline co-morbidity was high- mean blood pressure was 134/76 mmHg, mean body mass index was 35.7 kg/m2, mean eGFR was 80.7 ml/min/1.73 m2, and mean glycated hemoglobin was 8.0%. Experiences of recruiting and implementing a comprehensive DKD program to individuals at high risk seen in the primary care setting are provided. TRIAL REGISTRATION: NCT01829256.

Association between trace elements in the environment and stroke risk: The reasons for geographic and racial differences in stroke (REGARDS) study.

The disparities in stroke mortality between blacks and whites, as well as the increased stroke mortality in the "stroke belt" have long been noted. The reasons for these disparities have yet to be fully explained. The association between trace element status and cardiovascular diseases, including stroke, has been suggested as a possible contributor to the disparities in stroke mortality but has not been fully explored. The purpose of this study is to investigate distributions of four trace elements (arsenic, mercury, magnesium, and selenium) in the environment in relation to stroke risk. The study population (N=27,770) is drawn from the Reasons for Geographic and Racial Disparities in Stroke (REGARDS) cohort. Environmental distribution of each trace element was determined using data from the United States Geological Survey (USGS) and was categorized in quartiles. A proportional hazards model, adjusted for demographic data and stroke risk factors, was used to examine the association of interest. The results showed that higher selenium levels in the environment were associated with increased stroke risk, and the hazard ratio for the 4th quartile compared to the 1st quartile was 1.33 (95% CI: 1.09, 1.62). However, there was no statistically significant relationship between environmental arsenic, mercury or magnesium and the risk of stroke. Because of dietary and non-dietary exposure as well as bioavailability, further research using biomarkers is warranted to examine the association between these trace elements and the risk of stroke.

Dichotomizing partial compliance and increased participant burden in factorial designs: the performance of four noncompliance methods.

BACKGROUND: Noncompliance to treatment assignment is an inevitable occurrence in randomized clinical trials (RCTs). Intention to treat (ITT) is generally considered the best method for addressing noncompliance in RCTs. Alternatives to ITT exist, including per protocol (PP), as treated (AT), and instrumental variables (IV). These three methods define participant compliance dichotomously, but partial compliance is a common occurrence in RCTs. By defining a threshold, above which a participant is called a complier, PP, AT and IV can be used, but the resulting loss of information may affect their performance. Trials with factorial designs may experience higher rates of noncompliance due to the heavier burden that participants experience by being assigned to multiple experimental treatments. METHODS: Using simulations, we assessed the performance of ITT, PP, AT, and IV in both the partial compliance setting and in a 2-by-2 factorial design with increased participant burden for those randomized to both active treatments. RESULTS: The bias, mean squared error, and type I error rates of the IV method after dichotomizing partial compliance were heavily inflated. The performance of all four methods depended on the level of noncompliance present, with higher average noncompliance leading to poorer performance. PP and AT showed improved bias and power relative to ITT without inflating the type I error beyond acceptable limits. However, the PP and AT heavily inflated the type I error rates when participant compliance was affected by the participants' general health. CONCLUSIONS: There are consequences for dichotomizing compliance information to make it fit into well-known methods. The results suggest the need for a method of estimating treatment effects that can utilize partial compliance information.

Intake of trans fat and incidence of stroke in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort.

BACKGROUND: Whether elevated intakes of trans fatty acids (TFAs) increase the risk of stroke remains unclear. Except for the Women's Health Initiative-Observational Study, most studies that directly assessed the association between TFA intake and stroke yielded null results. OBJECTIVE: The aim of this study was to investigate the association between TFA intake and stroke incidence. DESIGN: We prospectively investigated the association between TFA intake and stroke incidence in black and white men and women (n = 17,107) from the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort. Participants were recruited between 2003 and 2007 from the continental United States and followed for incident stroke. Diet was assessed by using the Block 1998 food-frequency questionnaire. Cox regression was used to test whether energy-adjusted TFA intake in 1-SD increments was associated with incident stroke. RESULTS: During a median follow-up of 7 y, 479 strokes were identified, including 401 ischemic strokes. Sex modified the association between TFA intake and stroke (P-interaction = 0.06), and thus the results were stratified by sex. In fully adjusted models, a 1-SD (2-g/d) increase in TFA intake was associated with an increased risk of any stroke in men (HR: 1.14; 95% CI: 1.02, 1.28) but not in women (HR: 0.93; 95% CI: 0.79, 1.11). Similarly, our results showed an increased risk of ischemic stroke in men (HR: 1.13; 95% CI: 1.00, 1.28) but not in women (HR: 0.93; 95% CI: 0.77, 1.12). CONCLUSIONS: We show that sex modifies the association between TFA intake and stroke; for every 2-g/d increase in TFA intake, there was a 14% increase in the risk of stroke in men but not in women. Our findings provide further evidence to support the concerted effort to minimize TFAs in the diet.

Intake of trans fat and all-cause mortality in the Reasons for Geographical and Racial Differences in Stroke (REGARDS) cohort.

BACKGROUND: A high intake of trans fatty acids decreases HDL cholesterol and is associated with increased LDL cholesterol, inflammation, diabetes, cancer, and mortality from cardiovascular disease. The relation between trans fat intake and all-cause mortality has not been established. OBJECTIVE: The aim of this study was to determine the relation between trans fat intake and all-cause mortality. DESIGN: We used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study-a prospective cohort study of white and black men and women residing in the continental United States. Energy-adjusted trans fat intake was categorized into quintiles, and Cox-regression was used to evaluate the association between trans fat intake and all-cause mortality. RESULTS: During 7 y of follow-up, there were 1572 deaths in 18,513 participants included in REGARDS. From the first to the fifth quintile of trans fat intake, the mortality rates per 1000 person-years of follow-up (95% CIs) were 12.8 (11.3, 14.5), 14.3 (12.7, 16.2), 14.6 (13.0, 16.5), 19.0 (17.1, 21.1), and 23.6 (21.5, 25.9), respectively. After adjustment for demographic factors, education, and risk factors for mortality, the HRs (95% CIs) for all-cause mortality were 1.00, 1.03 (0.86, 1.23), 0.98 (0.82, 1.17), 1.25 (1.05, 1.48), and 1.24 (1.05, 1.48), respectively (P-trend = 0.004). The population attributable risk due to trans fat intake was 7% (95% CI: 5%, 8%). CONCLUSION: Higher trans fat intake is associated with an increased risk of all-cause mortality.