Oral anticoagulation across diabetic subtypes in patients with newly diagnosed atrial fibrillation: A report from the GARFIELD-AF registry.

AIMS: This study aims to describe both management and prognosis of patients with diabetes mellitus (DM) and newly diagnosed atrial fibrillation (AF), overall as well as by antidiabetic treatment, and to assess the influence of oral anticoagulation (OAC) on outcomes by DM status. METHODS: The study population comprised 52 010 newly diagnosed patients with AF, 11 542 DM and 40 468 non-DM, enrolled in the GARFIELD-AF registry. Follow-up was truncated at 2 years after enrolment. Comparative effectiveness of OAC versus no OAC was assessed by DM status using a propensity score overlap weighting scheme and weights were applied to Cox models. RESULTS: Patients with DM [39.3% oral antidiabetic drug (OAD), 13.4% insulin ± OAD, 47.2% on no antidiabetic drug] had higher risk profile, OAC use, and rates of clinical outcomes compared with patients without DM. OAC use was associated in patients without DM and patients with DM with lower risk of all-cause mortality [hazard ratio 0.75 (0.69-0.83), 0.74 (0.64-0.86), respectively] and stroke/systemic embolism (SE) [0.69 (0.58-0.83), 0.70 (0.53-0.93), respectively]. The risk of major bleeding with OAC was similarly increased in patients without DM and those with DM [1.40 (1.14-1.71), 1.37 (0.99-1.89), respectively]. Patients with insulin-requiring DM had a higher risk of all-cause mortality and stroke/SE [1.91 (1.63-2.24)], [1.57 (1.06-2.35), respectively] compared with patients without DM, and experienced significant risk reductions of all-cause mortality and stroke/SE with OAC [0.73 (0.53-0.99); 0.50 (0.26-0.97), respectively]. CONCLUSIONS: In both patients with DM and patients without DM with AF, OAC was associated with lower risk of all-cause mortality and stroke/SE. Patients with insulin-requiring DM derived significant benefit from OAC.

The importance of the design of observational studies in comparative effectiveness research: Lessons from the GARFIELD-AF and ORBIT-AF registries.

Randomized controlled trials (RCTs) are considered the gold standard for estimating the effectiveness of a treatment. However, in many instances they are impractical to conduct because of time limitations, cost restrictions, or ethical reasons. As a consequence, non-randomized observational studies have an important role in comparative effectiveness and safety research since they can address issues that would not be possible using conventional RCT methodology. Observational studies can be strategically designed to reduce the risk of potential sources of bias by emulating the design principles of an equivalent but ideal randomized trial - the target trial - that would answer the research question of interest. In this article, we review some of the necessary components of observational studies required for valid causal inference within the framework of target trial emulation, so as to avoid common methodological pitfalls of study design. We discuss the assumptions of consistency, time-zero specification, exchangeability and positivity. To illustrate these concepts in a context where existing knowledge is well-established through clinical trials, we evaluate and compare the treatment effects of vitamin K antagonists (VKA) against no VKA (No VKA) on the treatment of atrial fibrillation from two real-world observational studies, namely the GARFIELD-AF and ORBIT-AF registries. Results are compared with those of published RCTs.

Early Risks of Death, Stroke/Systemic Embolism, and Major Bleeding in Patients With Newly Diagnosed Atrial Fibrillation.

BACKGROUND: Atrial fibrillation is associated with increased risks of death, stroke/systemic embolism, and bleeding (incurred by antithrombotic therapy), which may occur early after diagnosis. METHODS: We assessed the risk of early events (death, stroke/systemic embolism, and major bleeding) over 12 months and their relation to the time after diagnosis of atrial fibrillation in 52 014 patients prospectively enrolled in the GARFIELD-AF registry (Global Anticoagulant Registry in the FIELD-Atrial Fibrillation) between March 2010 and August 2016. RESULTS: Over 12 months, 2140 patients died (mortality rate, 4.3; 95% CI, 4.2-4.5 per 100 person-years), of whom 288 (13.5%) died in the first month (6.8; 95% CI, 6.1-7.6). Over 12 months, 657 patients had a stroke/systemic embolism (1.3; 95% CI, 1.2-1.4) and 411 had a major bleeding (0.8; 95% CI, 0.8-0.9). During the first month, the rates (per 100 person-years) of stroke/systemic embolism and major bleed were 2.3 (95% CI, 1.9-2.8) and 1.5 (95% CI, 1.2-1.9), respectively. The elevated 1-month mortality rate was mostly attributable to cardiovascular mortality (3.5; 95% CI, 3.0-4.1), in particular, heart failure, sudden death, and acute coronary syndromes (1.0 [95% CI, 0.8-1.4], 0.6 [95% CI, 0.4-0.8], and 0.5 [95% CI, 0.3-0.8], respectively). Age, heart failure, prior stroke, history of cirrhosis, vascular disease, moderate-to-severe kidney disease, diabetes mellitus, and living in North or Latin America were independent predictors of a higher risk of early death, whereas anticoagulation and living in Europe or Asia were independent predictors of a lower risk of early death. A predictive model developed for the 1-month risk of death had a C-statistic of 0.81 (95% CI, 0.78-0.83). CONCLUSIONS: The increased hazard of early events, in particular, cardiovascular mortality, in newly diagnosed atrial fibrillation points to the importance of comprehensive care for such patients and should alert clinicians to detect warning signs of possible early mortality. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01090362.

Frequency, Regional Variation, and Predictors of Undetermined Cause of Death in Cardiometabolic Clinical Trials: A Pooled Analysis of 9259 Deaths in 9 Trials.

BACKGROUND: Modern cardiometabolic clinical trials often include cardiovascular death as a component of a composite primary outcome, requiring central adjudication by a clinical events committee to classify cause of death. However, sometimes the cause of death cannot be determined from available data. The US Food and Drug Administration has indicated that this circumstance should occur only rarely, but its prevalence has not been formally assessed. METHODS: Data from 9 global clinical trials (2009-2017) with long-term follow-up and blinded, centrally adjudicated cause of death were used to calculate the proportion of deaths attributed to cardiovascular, noncardiovascular, or undetermined causes by therapeutic area (diabetes mellitus/pre-diabetes mellitus, stable atherosclerosis, atrial fibrillation, and acute coronary syndrome), region of patient enrollment, and year of trial manuscript publication. Patient- and trial-level variables associated with undetermined cause of death were identified using a logistic model. RESULTS: Across 127 049 enrolled participants from 9 trials, there were 9259 centrally adjudicated deaths: 5012 (54.1%) attributable to cardiovascular causes, 2800 (30.2%) attributable to noncardiovascular causes, and 1447 (15.6%) attributable to undetermined causes. There was variability in the proportion of deaths ascribed to undetermined causes by trial therapeutic area, region of enrollment, and year of trial manuscript publication. On multivariable analysis, acute coronary syndrome or atrial fibrillation trial (versus atherosclerotic vascular disease or diabetes mellitus/pre-diabetes mellitus), longer time from enrollment to death, more recent trial manuscript publication year, enrollment in North America (versus Western Europe), female sex, and older age were associated with greater likelihood of death of undetermined cause. CONCLUSIONS: In 9 cardiometabolic clinical trials with long-term follow-up, approximately 16% of deaths had undetermined causes. This provides a baseline for quality assessment of clinical trials and informs operational efforts to potentially reduce the frequency of undetermined deaths in future clinical research.

Peripheral blood metabolite profiles associated with new onset atrial fibrillation.

BACKGROUND: Peripheral blood metabolite profiles have yielded mechanistic insights into various cardiovascular disease states. We hypothesized that peripheral blood metabolite profiles would be associated with new onset atrial fibrillation (AF). METHODS AND RESULTS: The study population comprised 1892 patients without AF at baseline, who, as part the MURDOCK Cardiovascular Disease Study molecular profiling cohort (n = 2023), had previously had determination of levels of 69 metabolites from frozen, fasting plasma specimens obtained during coronary angiography. We used Cox proportional hazards models to examine the association of 13 uncorrelated metabolite factors created from these data using principal components analysis (PCA) with new occurrences of AF during a median follow up of 2.8 (0.1-4.9) years. A total of 233 patients developed new AF (12.3%) during follow up. Patients with new onset AF were older (median 67 vs. 60 years); more often white (82 vs. 71%) and male (68 vs. 60%), and had more comorbidities than those who did not develop AF. After adjustment, PCA factor 1 (medium chain acylcarnitines; hazard ratio [HR]: 1.11 [1.01-1.22]), factor 2 (short chain dicarboxylacylcarnitines; HR: 1.21 [1.09-1.34]) and factor 5 (long chain acylcarnitines; HR: 1.19 [1.06-1.34]) were associated with new onset AF. CONCLUSION: Metabolite profiles were associated with new onset AF among patients referred for coronary angiography. Validation of these observations in broader patient populations may provide better mechanistic insight into the development of AF, and may provide new opportunities for prevention and treatment.

Predictors of NOAC versus VKA use for stroke prevention in patients with newly diagnosed atrial fibrillation: Results from GARFIELD-AF.

INTRODUCTION: A principal aim of the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) was to document changes in treatment practice for patients with newly diagnosed atrial fibrillation during an era when non-vitamin K antagonist oral anticoagulants (NOACs) were becoming more widely adopted. In these analyses, the key factors which determined the choice between NOACs and vitamin K antagonists (VKAs) are explored. METHODS: Logistic least absolute shrinkage and selection operator regression determined predictors of NOAC and VKA use. Data were collected from 24,137 patients who were initiated on AC ±â€¯antiplatelet (AP) therapy (NOAC [51.4%] or VKA [48.6%]) between April 2013 and August 2016. RESULTS: The most significant predictors of AC therapy were country, enrolment year, care setting at diagnosis, AF type, concomitant AP, and kidney disease. Patients enrolled in emergency care or in the outpatient setting were more likely to receive a NOAC than those enrolled in hospital (OR 1.16 [95% CI: 1.04-1.30], OR: 1.15 [95% CI: 1.05-1.25], respectively). NOAC prescribing seemed to be favored in lower-risk groups, namely, patients with paroxysmal AF, normotensive patients, and those with moderate alcohol consumption, but also the elderly and patients with acute coronary syndrome. By contrast, VKAs were preferentially used in patients with permanent AF, moderate to severe kidney disease, heart failure, vascular disease, and diabetes and with concomitant AP. CONCLUSION: GARFIELD-AF data highlight marked heterogeneity in stroke prevention strategies globally. Physicians are adopting an individualized approach to stroke prevention where NOACs are favored in patients with a lower stroke risk but also in the elderly and patients with acute coronary syndrome.

Sitagliptin does not reduce the risk of cardiovascular death or hospitalization for heart failure following myocardial infarction in patients with diabetes: observations from TECOS.

BACKGROUND: To examine the effects of the DPP-4i sitagliptin on CV outcomes during and after incident MI in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS). METHODS: TECOS randomized 14,671 participants with type 2 diabetes and atherosclerotic cardiovascular disease (ASCVD) to sitagliptin or placebo, in addition to usual care. For those who had a within-trial MI, we analyzed case fatality, and for those with a nonfatal MI, we examined a composite cardiovascular (CV) outcome (CV death or hospitalization for heart failure [hHF]) by treatment group, using Cox proportional hazards models left-censored at the time of the first within-trial MI, without and with adjustment for potential confounders, in intention-to-treat analyses. RESULTS: During TECOS, 616 participants had ≥ 1 MI (sitagliptin group 300, placebo group 316, HR 0.95, 95% CI 0.81-1.11, P = 0.49), of which 25 were fatal [11 and 14, respectively]). Of the 591 patients with a nonfatal MI, 87 (15%) died subsequently, with 66 (11%) being CV deaths, and 57 (10%) experiencing hHF. The composite outcome occurred in 58 (20.1%; 13.9 per 100 person-years) sitagliptin group participants and 50 (16.6%; 11.7 per 100 person-years) placebo group participants (HR 1.21, 95% CI 0.83-1.77, P = 0.32, adjusted HR 1.23, 95% CI 0.83-1.82, P = 0.31). On-treatment sensitivity analyses also showed no significant between-group differences in post-MI outcomes. CONCLUSIONS: In patients with type 2 diabetes and ASCVD experiencing an MI, sitagliptin did not reduce subsequent risk of CV death or hHF, contrary to expectations derived from preclinical animal models. Trial registration clinicaltrials.gov no. NCT00790205.

Characteristics of patients with atrial fibrillation prescribed antiplatelet monotherapy compared with those on anticoagulants: insights from the GARFIELD-AF registry.

Aims: Current atrial fibrillation (AF) guidelines discourage antiplatelet (AP) monotherapy as alternative to anticoagulants (ACs). Why AP only is still used is largely unknown. Methods and results: Factors associated with AP monotherapy prescription were analysed in GARFIELD-AF, a registry of patients with newly diagnosed (≤6 weeks) AF and ≥1 investigator-determined stroke risk factor. We analysed 51 270 patients from 35 countries enrolled into five sequential cohorts between 2010 and 2016. Overall, 20.7% of patients received AP monotherapy, 52.1% AC monotherapy, and 14.1% AP + AC. Most AP monotherapy (82.5%) and AC monotherapy (86.8%) patients were CHA2DS2-VASc ≥2. Compared with patients on AC monotherapy, AP monotherapy patients were frequently Chinese (vs. Caucasian, odds ratio 2.73) and more likely to have persistent AF (1.32), history of coronary artery disease (2.41) or other vascular disease (1.67), bleeding (2.11), or dementia (1.81). The odds for AP monotherapy increased with 5 years of age increments for patients ≥75 years (1.24) but decreased with age increments for patients 55-75 years (0.86). Antiplatelet monotherapy patients were less likely to have paroxysmal (0.67) or permanent AF (0.57), history of embolism (0.56), or alcohol use (0.90). With each cohort, AP monotherapy declined (P<0.0001), especially non-indicated use. AP + AC and no antithrombotic therapy were unchanged. However, even in 2015 and 2016, about 50% of AP-treated patients had no indication except AF (71% were CHA2DS2-VASc ≥2). Conclusion: Prescribing AP monotherapy in newly diagnosed AF has declined, but even nowadays a substantial proportion of AP-treated patients with AF have no indication for AP. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362.

Secondary Prevention of Cardiovascular Disease in Patients With Type 2 Diabetes Mellitus: International Insights From the TECOS Trial (Trial Evaluating Cardiovascular Outcomes With Sitagliptin).

BACKGROUND: Intensive risk factor modification significantly improves outcomes for patients with diabetes mellitus and cardiovascular disease. However, the degree to which secondary prevention treatment goals are achieved in international clinical practice is unknown. METHODS: Attainment of 5 secondary prevention parameters-aspirin use, lipid control (low-density lipoprotein cholesterol <70 mg/dL or statin therapy), blood pressure control (<140 mm Hg systolic, <90 mm Hg diastolic), angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, and nonsmoking status-was evaluated among 13 616 patients from 38 countries with diabetes mellitus and known cardiovascular disease at entry into TECOS (Trial Evaluating Cardiovascular Outcomes With Sitagliptin). Logistic regression was used to evaluate the association between individual and regional factors and secondary prevention achievement at baseline. Cox proportional hazards regression analysis was used to determine the association between baseline secondary prevention achievement and cardiovascular death, myocardial infarction, or stroke. RESULTS: Overall, 29.9% of patients with diabetes mellitus and cardiovascular disease achieved all 5 secondary prevention parameters at baseline, although 71.8% achieved at least 4 parameters. North America had the highest proportion (41.2%), whereas Western Europe, Eastern Europe, and Latin America had proportions of ≈25%. Individually, blood pressure control (57.9%) had the lowest overall attainment, whereas nonsmoking status had the highest (89%). Over a median 3.0 years of follow-up, a higher baseline secondary prevention score was associated with improved outcomes in a step-wise graded relationship (adjusted hazard ratio, 0.60; 95% confidence interval, 0.47-0.77 for those patients achieving all 5 measures versus those achieving ≤2). CONCLUSIONS: In an international trial population, significant opportunities exist to improve the quality of cardiovascular secondary prevention care among patients with diabetes mellitus and cardiovascular disease, which in turn could lead to reduced risk of downstream cardiovascular events. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00790205.

Apixaban following acute coronary syndromes in patients with prior stroke: Insights from the APPRAISE-2 trial.

BACKGROUND AND PURPOSE: Patients with prior stroke are at greater risk for recurrent cardiovascular events post-acute coronary syndromes (ACS) and may have a different risk/benefit profile with antithrombotic therapy than patients without prior stroke. METHODS: We studied 7391 patients with ACS from APPRAISE-2, stratified by the presence or absence of prior stroke. Baseline characteristics and outcomes of cardiovascular death, myocardial infarction (MI), or stroke were compared between groups. Interactions between prior stroke, treatment assignment (apixaban vs placebo), and outcomes were tested before and after multivariable adjustment with Cox proportional hazards models. RESULTS: A total of 902 patients (12%) had prior stroke. Those with prior stroke were older (69 vs 67 years), had more hypertension (91% vs 77%), peripheral vascular disease (22% vs18%), and impaired renal function (38% vs 30%) but less diabetes (44% vs 48%) than those without prior stroke. Patients with prior stroke vs no prior stroke had higher unadjusted rates of cardiovascular death (4.8% vs 4.0%), MI (11.2% vs 7.1%), and ischemic stroke (3.2% vs 0.9%). Patients with prior stroke assigned to apixaban had similar rates of the composite of cardiovascular death, MI, or stroke compared with those assigned to placebo (HR 1.39; 95% CI 0.92-2.08). Patients without prior stroke assigned to apixaban had similar rates of cardiovascular death, MI, or ischemic stroke compared with those assigned to placebo (HR 0.87; 95% CI 0.73-1.04; P-interaction=.041). Median follow-up was 240 days. CONCLUSIONS: Patients with prior stroke are at higher risk for recurrent cardiovascular events post-ACS and had a differential risk/benefit profile with oral anticoagulation.

Discharge timing and outcomes after uncomplicated non-ST-segment elevation acute myocardial infarction.

BACKGROUND: Length of stay after non-ST-segment elevation myocardial infarction (NSTEMI) continues to decrease, but information to guide duration of hospitalization is limited. METHODS: We used landmark analyses, in which the landmark defined potential days of discharge, to estimate complication rates on the first day the patient would have been out of the hospital, and estimated associations between timing of discharge and 30-day and 1-year event-free survival after discharge among NSTEMI patients. RESULTS: Among 20,410 NSTEMI patients, median length of stay was 7 (4, 12) days; 3,209 (15.7%) experienced a cardiac complication on days 0 to 2 and 1,322 (6.5%) were discharged without complications during hospital days 0 to 2. At the start of day 3, 15,879 patients (77.8%) were still hospitalized without complications. Of these, 1,689 (10.6%) were discharged event-free on day 3. Adjusted event-free survival rates of death or myocardial infarction from day 4 to 30 days after among the 1,689 patients was 99.1% compared with 93.1% for the 14,190 who remained hospitalized at the end of day 3. For 1-year mortality, these rates were 98.1% and 96.4%, respectively. Among 13,334 patients hospitalized without complications at the start of day 4, 1,706 were discharged event-free that day. Adjusted survival rates among these patients, compared with those still hospitalized at the end of day 4, were 98.0% versus 93.7% for 30-day death or myocardial infarction and 97.8% versus 96.1% for 1-year mortality. CONCLUSIONS: Patients with NSTEMI who had no serious complications during the first 2 hospital days were at low risk of subsequent short- and intermediate-term death or ischemic events.

Safety of ticagrelor in patients with baseline conduction abnormalities: A PLATO (Study of Platelet Inhibition and Patient Outcomes) analysis.

BACKGROUND: Although bradyarrhythmias have been observed with ticagrelor and its use with advanced atrioventricular block is not recommended, questions arise regarding its use in patients with mild conduction abnormalities. The objectives were to compare rates of clinically relevant arrhythmias in relation to any mild baseline conduction abnormality in patients with acute coronary syndrome randomized to ticagrelor versus clopidogrel. METHODS: We included all subjects in the electrocardiographic (ECG) substudy of the Platelet Inhibition and Patient Outcomes trial, excluding those with missing baseline ECG or with a pacemaker at baseline (N = 15,460). Conduction abnormality was defined as sinus bradycardia, first-degree atrioventricular block, hemiblock, or bundle-branch block. The primary arrhythmic outcome was the composite of any symptomatic brady- or tachyarrhythmia, permanent pacemaker placement, or cardiac arrest through 12 months. RESULTS: Patients with baseline conduction abnormalities (n = 4,256, 27.5%) were older and more likely to experience the primary arrhythmic outcome. There were no differences by ticagrelor versus clopidogrel in the composite arrhythmic end point in those with baseline conduction disease (1-year cumulative incidence rate: 17% for both study arms; hazard ratio: 0.99 [0.86-1.15]) or without baseline conduction disease (1-year cumulative incidence rate: clopidogrel 12.8% vs ticagrelor 12.4%; hazard ratio: 0.98 (0.88-1.09). There were also no statistically significant differences between ticagrelor and clopidogrel in the rates of bradycardic (or any individual arrhythmic) events in patients with baseline conduction abnormalities. CONCLUSIONS: Ticagrelor compared to clopidogrel did not increase arrhythmic events even in subjects with acute coronary syndrome who present with mild conduction abnormalities on their baseline ECG.

Risk Profile and 1-Year Outcome of Newly Diagnosed Atrial Fibrillation in Japan　- Insights From GARFIELD-AF.

BACKGROUND: Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective non-interventional study of stroke prevention in patients with newly diagnosed non-valvular AF (NAVF) that is being conducted in 35 countries. Methods and Results: A total of 52,081 patients with a new diagnosis of NVAF were enrolled prospectively in GARFIELD-AF. Of these, 4859 (9.3%) were recruited in Japan (2010-2016). In cohort 1 (2010-2011), few patients were on non-vitamin K antagonist oral anticoagulants (NOAC) globally. From cohort 2 onwards (2011-2016), however, there was a rapid increase in NOAC use around the globe, especially in Japan. By the last year of enrolment (2015-2016), 67.9% of patients in Japan and 43.1% of patients globally were on NOAC±antiplatelet therapy (AP). In Japan and globally, 17.0% and 12.2% of patients, respectively, did not receive stroke prevention treatment. Few patients in Japan (5.7%) received AP only. Compared with the other countries, the unadjusted rates of all-cause mortality and major bleeding were low, while rates of stroke/systemic embolism were similar after 1 year of follow-up. CONCLUSIONS: GARFIELD-AF continues to provide important information on the homogeneity and heterogeneity of baseline characteristics and treatment patterns in patients with newly diagnosed NVAF. This diversity reflects the differences in outcomes in Japan compared with the rest of the world.

Association of standard clinical and laboratory variables with red blood cell distribution width.

BACKGROUND: Red blood cell distribution width (RDW) strongly predicts clinical outcomes among patients with coronary disease and heart failure. The factors underpinning this association are unknown. METHODS: In 6,447 individuals enrolled in the Measurement to Understand the Reclassification of Disease of Cabarrus/Kannapolis (MURDOCK) Study who had undergone coronary angiography between 2001 and 2007, we used Cox proportional hazards modeling to examine the adjusted association between RDW and death, and death or myocardial infarction (MI). Multiple linear regression using the R(2) model selection method was then used to identify clinical factors associated with variation in RDW. RESULTS: Median follow-up was 4.2 (interquartile range 2.3-5.9) years, and the median RDW was 13.5% (interquartile range 12.9%-14.3%, clinical laboratory reference range 11.5%-14.5%). Red blood cell distribution width was independently associated with death (adjusted hazard ratio 1.13 per 1% increase in RDW, 95% CI 1.09-1.17), and death or MI (adjusted hazard ratio 1.12, 95% CI 1.08-1.16). Twenty-seven clinical characteristics and laboratory measures were assessed in the multivariable linear regression model; a final model containing 18 variables explained only 21% of the variation in RDW. CONCLUSIONS: Although strongly associated with death and death or MI, only one-fifth of the variation in RDW was explained by routinely assessed clinical characteristics and laboratory measures. Understanding the latent factors that explain variation in RDW may provide insight into its strong association with risk and identify novel targets to mitigate that risk.

Renal failure in patients with ST-segment elevation acute myocardial infarction treated with primary percutaneous coronary intervention: Predictors, clinical and angiographic features, and outcomes.

BACKGROUND: Among patients presenting with ST-segment elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PCI), the associations between clinical outcomes and both baseline renal function and the development of acute kidney injury (AKI) have not been reported in a trial population with unselected baseline renal function. METHODS: Patients enrolled in the APEX-AMI trial who underwent primary PCI for the treatment of STEMI were categorized according to (a) baseline renal function and (b) the development of AKI. Patient characteristics, clinical outcomes, and treatment patterns were analyzed according to baseline renal function and the development of AKI. A prediction model for AKI after primary PCI for STEMI was also developed. RESULTS: A total of 5,244 patients were included in this analysis and stratified according to baseline estimated glomerular filtration rate (eGFR) (milliliters per minute per 1.73 m(2)) of >90, 60 to 90, 30 to 59, or <30 or as dialysis dependent. Patients with lower eGFR were older, more often female, and less often treated with evidence-based medicines and had worse angiographic outcomes and higher mortality. The rates of AKI for patients with a baseline eGFR of >90, 60 to 90, 30 to 59, and <30 were 2.5%, 4.1%, 8.1%, and 1.6%, respectively (P < .0001). The strongest predictors of AKI were age and presenting in Killip class III or IV. CONCLUSIONS: Among patients undergoing primary PCI for STEMI, impaired renal function at presentation and development of post-PCI AKI were highly associated with worse clinical and angiographic outcomes, including death. The risk of developing AKI was low and only modestly associated with baseline renal function.

Pooled analysis of adverse event collection from 4 acute coronary syndrome trials.

BACKGROUND: Adverse event collection in randomized clinical trials establishes drug safety. Although costly and regulated, it is rarely studied. METHODS: Adverse event data from 4 clinical trials (APPRAISE-2, PLATO, TRACER, TRILOGY ACS) comprising 48,118 participants with acute coronary syndromes were pooled to compare patterns and determinants of reporting. Events were classified as serious (SAE) or nonserious (AE) from hospital discharge to 1 year; study end points were excluded. RESULTS: In total, 84,901 events were reported. Of those, 12,266 (14.4%) were SAEs and 72,635 (85.6%) were AEs. Of all participants, 7,823 (16.3%) had SAEs, 18,124 (37.7%) had only AEs, and 22,171 (46.1%) had neither. Nonserious adverse events were distributed across system organ classes: general disorders (11%), infection (10%), gastrointestinal (10%), respiratory (9%), cardiovascular (8.4%), and other (35%). Serious adverse events had a higher proportion of cardiovascular causes (14.0%). Event reporting was highest after hospital discharge, decreasing rapidly during the following 3 months. In a Cox proportional hazards model, chronic obstructive pulmonary disease (hazard ratio 1.58, 95% CI 1.44-1.74), heart failure (1.55, 1.40-1.70), older age, and female sex were independent predictors of more SAEs, whereas enrollment in Eastern Europe (0.63, 0.58-0.69) or Asia (0.84, 0.75-0.94) were independent predictors of fewer SAEs. CONCLUSIONS: Half of all participants reported adverse events in the year after acute coronary syndrome; most were AEs and occurred within 3 months. The high volume of events, as well as the variation in SAE reporting by characteristics and enrollment region, indicates that efforts to refine event collection in large trials are warranted.

Release kinetics of circulating cardiac myosin binding protein-C following cardiac injury.

Diagnosis of myocardial infarction (MI) is based on ST-segment elevation on electrocardiographic evaluation and/or elevated plasma cardiac troponin (cTn) levels. However, troponins lack the sensitivity required to detect the onset of MI at its earliest stages. Therefore, to confirm its viability as an ultra-early biomarker of MI, this study investigates the release kinetics of cardiac myosin binding protein-C (cMyBP-C) in a porcine model of MI and in two human cohorts. Release kinetics of cMyBP-C were determined in a porcine model of MI (n = 6, pigs, either sex) by measuring plasma cMyBP-C level serially from 30 min to 14 days after coronary occlusion, with use of a custom-made immunoassay. cMyBP-C plasma levels were increased from baseline (76 ± 68 ng/l) at 3 h (767 ± 211 ng/l) and peaked at 6 h (2,418 ± 780 ng/l) after coronary ligation. Plasma cTnI, cTnT, and myosin light chain-3 levels were all increased 6 h after ligation. In a cohort of patients (n = 12) with hypertrophic obstructive cardiomyopathy undergoing transcoronary ablation of septal hypertrophy, cMyBP-C was significantly increased from baseline (49 ± 23 ng/l) in a time-dependent manner, peaking at 4 h (560 ± 273 ng/l). In a cohort of patients with non-ST segment elevation MI (n = 176) from the SYNERGY trial, cMyBP-C serum levels were significantly higher (7,615 ± 4,514 ng/l) than those in a control cohort (416 ± 104 ng/l; n = 153). cMyBP-C is released in the blood rapidly after cardiac damage and therefore has the potential to positively mark the onset of MI.

Challenges and solutions to pre- and post-randomization subgroup analyses.

Subgroup analyses are commonly performed in the clinical trial setting with the purpose of illustrating that the treatment effect was consistent across different patient characteristics or identifying characteristics that should be targeted for treatment. There are statistical issues involved in performing subgroup analyses, however. These have been given considerable attention in the literature for analyses where subgroups are defined by a pre-randomization feature. Although subgroup analyses are often performed with subgroups defined by a post-randomization feature--including analyses that estimate the treatment effect among compliers--discussion of these analyses has been neglected in the clinical literature. Such analyses pose a high risk of presenting biased descriptions of treatment effects. We summarize the challenges of doing all types of subgroup analyses described in the literature. In particular, we emphasize issues with post-randomization subgroup analyses. Finally, we provide guidelines on how to proceed across the spectrum of subgroup analyses.

Extent, location, and clinical significance of non-infarct-related coronary artery disease among patients with ST-elevation myocardial infarction.

IMPORTANCE: Little information exists about the anatomical characteristics and clinical relevance of non-infarct-related artery (IRA) disease among patients with ST-segment elevation myocardial infarction (STEMI). OBJECTIVES: To investigate the incidence, extent, and location of obstructive non-IRA disease and compare 30-day mortality according to the presence of non-IRA disease in patients with STEMI. DESIGN, SETTING, AND PARTICIPANTS: Retrospective study of patients pooled from a convenience sample of 8 independent, international, randomized STEMI clinical trials published between 1993 and 2007. Follow-up varied from 1 month to 1 year. Among 68,765 patients enrolled in the trials, 28,282 patients with valid angiographic information were included in this analysis. Obstructive coronary artery disease was defined as stenosis of 50% or more of the diameter of a major epicardial artery. To assess the generalizability of trial-based results, external validation was performed using observational data for patients with STEMI from the Korea Acute Myocardial Infarction Registry (KAMIR) (between November 1, 2005, and December 31, 2013; n = 18,217) and the Duke Cardiovascular Databank (between January 1, 2005, and December 31, 2012; n = 1812). MAIN OUTCOMES AND MEASURES: Thirty-day mortality following STEMI. RESULTS: Overall, 52.8% (14,929 patients) had obstructive non-IRA disease; 29.6% involved 1 vessel and 18.8% involved 2 vessels. There was no substantial difference in the extent and distribution of non-IRA disease according to the IRA territory. Unadjusted and adjusted rates of 30-day mortality were significantly higher in patients with non-IRA disease than in those without non-IRA disease (unadjusted, 4.3% vs 1.7%, respectively; risk difference, 2.7% [95% CI, 2.3% to 3.0%], P < .001; and adjusted, 3.3% vs 1.9%, respectively; risk difference, 1.4% [95% CI, 1.0% to 1.8%], P < .001). The overall prevalence and association of non-IRA disease with 30-day mortality was consistent with findings from the KAMIR registry (adjusted, 3.6% for patients with non-IRA disease vs 2.5% in those without it; risk difference, 1.1% [95% CI, 0.6% to 1.7%]; P < .001), but not with the Duke database (adjusted, 4.7% with non-IRA disease vs 4.3% without it; risk difference, 0.4% [95% CI, -1.4% to 2.2%], P = .65). CONCLUSIONS AND RELEVANCE: In a retrospective pooled analysis of 8 clinical trials, obstructive non-IRA disease was common among patients presenting with STEMI, and was associated with a modest statistically significant increase in 30-day mortality. These findings require confirmation in prospectively designed studies, but raise questions about the appropriateness and timing of non-IRA revascularization in patients with STEMI.