Direct Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: Patient-Level Network Meta-Analyses of Randomized Clinical Trials With Interaction Testing by Age and Sex

BACKGROUND

Direct oral anticoagulants (DOACs) are preferred over warfarin for stroke prevention in atrial fibrillation. Meta-analyses using individual patient data offer substantial advantages over study-level data.

METHODS

We used individual patient data from the COMBINE AF (A Collaboration Between Multiple Institutions to Better Investigate Non-Vitamin K Antagonist Oral Anticoagulant Use in Atrial Fibrillation) database, which includes all patients randomized in the 4 pivotal trials of DOACs versus warfarin in atrial fibrillation (RE-LY [Randomized Evaluation of Long-Term Anticoagulation Therapy], ROCKET AF [Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation], ARISTOTLE [Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation], and ENGAGE AF-TIMI 48 [Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48]), to perform network meta-analyses using a stratified Cox model with random effects comparing standard-dose DOAC, lower-dose DOAC, and warfarin. Hazard ratios (HRs [95% CIs]) were calculated for efficacy and safety outcomes. Covariate-by-treatment interaction was estimated for categorical covariates and for age as a continuous covariate, stratified by sex.

RESULTS

A total of 71 683 patients were included (29 362 on standard-dose DOAC, 13 049 on lower-dose DOAC, and 29 272 on warfarin). Compared with warfarin, standard-dose DOACs were associated with a significantly lower hazard of stroke or systemic embolism (883/29 312 [3.01%] versus 1080/29 229 [3.69%]; HR, 0.81 [95% CI, 0.74-0.89]), death (2276/29 312 [7.76%] versus 2460/29 229 [8.42%]; HR, 0.92 [95% CI, 0.87-0.97]), and intracranial bleeding (184/29 270 [0.63%] versus 409/29 187 [1.40%]; HR, 0.45 [95% CI, 0.37-0.56]), but no statistically different hazard of major bleeding (1479/29 270 [5.05%] versus 1733/29 187 [5.94%]; HR, 0.86 [95% CI, 0.74-1.01]), whereas lower-dose DOACs were associated with no statistically different hazard of stroke or systemic embolism (531/13 049 [3.96%] versus 1080/29 229 [3.69%]; HR, 1.06 [95% CI, 0.95-1.19]) but a lower hazard of intracranial bleeding (55/12 985 [0.42%] versus 409/29 187 [1.40%]; HR, 0.28 [95% CI, 0.21-0.37]), death (1082/13 049 [8.29%] versus 2460/29 229 [8.42%]; HR, 0.90 [95% CI, 0.83-0.97]), and major bleeding (564/12 985 [4.34%] versus 1733/29 187 [5.94%]; HR, 0.63 [95% CI, 0.45-0.88]). Treatment effects for standard- and lower-dose DOACs versus warfarin were consistent across age and sex for stroke or systemic embolism and death, whereas standard-dose DOACs were favored in patients with no history of vitamin K antagonist use (P=0.01) and lower creatinine clearance (P=0.09). For major bleeding, standard-dose DOACs were favored in patients with lower body weight (P=0.02). In the continuous covariate analysis, younger patients derived greater benefits from standard-dose (interaction P=0.02) and lower-dose DOACs (interaction P=0.01) versus warfarin.

CONCLUSIONS

Compared with warfarin, DOACs have more favorable efficacy and safety profiles among patients with atrial fibrillation.

Reexamination of the Embolic Stroke of Undetermined Source Concept

Occult atrial fibrillation (AF) is a leading cause of stroke of unclear cause. The optimal approach to secondary stroke prevention for these patients remains elusive. The term embolic stroke of undetermined source (ESUS) was coined to describe ischemic strokes in which the radiographic features demonstrate territorial infarcts resembling those seen in patients with confirmed sources of embolism but without a clear source of embolism detected. It was assumed that patients with ESUS had a high rate of occult AF and would benefit from treatment with direct oral anticoagulants, which are at least as effective as vitamin K antagonists for secondary stroke prevention in patients with AF, but with a much lower risk of intracerebral hemorrhage. Two recent large randomized trials failed to show superiority of direct oral anticoagulants over aspirin in ESUS patients. These findings prompt a reexamination of the ESUS concept, with the goal of improving specificity for detecting patients with a cardioembolic cause. Based on the negative trial results, there is renewed interest in the role of long-term cardiac monitoring for AF in patients who fit the current ESUS definition, as well as the clinical implication of detecting AF. Ongoing trials are exploring these questions. Current ESUS definitions do not accurately detect the patients who should be prescribed direct oral anticoagulants, potentially because occult AF is less common than expected in these patients and/or anticoagulants may be less beneficial in patients with ESUS but no AF than they are for patients with stroke with established AF. More specific criteria to identify patients who may be at higher risk for occult AF and reduce their risk of subsequent stroke have been developed and are being tested in ongoing clinical trials.

The Non-Vitamin K Antagonist Oral Anticoagulants in Heart Disease: Section V—Special Situations

Non-vitamin K antagonist oral anticoagulants (NOACs) include dabigatran, which inhibits thrombin, and apixaban, betrixaban, edoxaban and rivaroxaban, which inhibit factor Xa. In large clinical trials comparing the NOACs with the vitamin K antagonist (VKA) warfarin, dabigatran, apixaban, rivaroxaban and edoxaban were at least as effective for stroke prevention in atrial fibrillation and for treatment of venous thromboembolism, but were associated with less intracranial bleeding. In addition, the NOACs are more convenient to administer than VKAs because they can be given in fixed doses without routine coagulation monitoring. Consequently, the NOACs are now replacing VKAs for these indications, and their use is increasing. Although, as a class, the NOACs have a favourable benefit–risk profile compared with VKAs, choosing among them is complicated because they have not been compared in head-to-head trials. Therefore, selection depends on the results of the individual trials, renal function, the potential for drug–drug interactions and preference for once- or twice-daily dosing. In addition, several ‘special situations’ were not adequately studied in the dedicated clinical trials. For these situations, knowledge of the unique pharmacological features of the various NOACs and judicious cross-trial comparison can help inform prescription choices. The purpose of this position article is therefore to help clinicians choose the right anticoagulant for the right patient at the right dose by reviewing a variety of special situations not widely studied in clinical trials.

Management and outcomes of patients with atrial fibrillation and a history of cancer: the ORBIT-AF registry

Aims

The presence of cancer can complicate treatment choices for patients with atrial fibrillation (AF) increasing both the risk of thrombotic and bleeding events.

Methods and results

Using data from Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, we aimed to characterize AF patients with cancer, to describe their management and to assess the association between cancer and cardiovascular (CV) outcomes. Among 9749 patients, 23.8% had history of cancer (57% solid malignancy, 1.3% leukaemia, 3.3% lymphoma, 40% other type, and 2.2% metastatic cancer). Patients with history of cancer were older, more likely to have CV disease, CV risk factors, and prior gastrointestinal bleeding. No difference in antiarrhythmic and antithrombotic therapy was observed between those with and without cancer. Patients with history of cancer had a significantly higher risk of death (7.8 vs. 4.9 deaths per 100 patient-years follow-up, P = 0.0003) mainly driven by non-CV death (4.2 vs. 2.4 per 100 patient-years follow-up; P = 0.0004) and higher risk of major bleeding (5.1 vs. 3.5 per 100 patient-years follow-up; P = 0.02) compared with non-cancer patients; no differences were observed in risks of strokes/non-central nervous system embolism (1.96 vs. 1.48, P = 0.74) and CV death (2.89 vs. 2.07, P = 0.35) between the two groups.

Conclusion

A history of cancer is common among AF patients with up to one in four patients having both. Antithrombotic therapy, rates of cerebrovascular accident, other thrombotic events and cardiac death were similar in AF patients with or without a history of cancer. Patients with cancer, however, were at higher risk of major bleeding and non-CV death.

Mineralocorticoid Receptor Antagonism in Patients With Atrial Fibrillation: Findings From the ORBIT-AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) Registry

Background

Mineralocorticoid receptor antagonist (MRA) therapy may be beneficial to patients with atrial fibrillation (AF), but little is known about their use in patients with AF and subsequent outcomes.

Methods and Results

In order to better understand MRA use and subsequent outcomes, we performed a retrospective cohort study of the contemporary ORBIT‐AF (Outcomes Registry for Better Informed Treatment of Atrial Fibrillation) registry. AF progression and cardiovascular outcomes were compared using propensity‐matched Cox proportional hazards modeling according to MRA use at baseline and new MRA use at follow‐up versus patients with no MRA use. Among 7012 patients with nonpermanent AF, 320 patients were taking MRA at enrollment, and 416 patients initiated MRA use during follow‐up. The mean patient age was 72.5 years, 56.3% were men, and 70.4% had paroxysmal AF. Among all patients taking MRAs, 434 (59.0%) had heart failure, 655 (89.0%) had hypertension, and 380 (51.6%) had both. After adjustment, new MRA use was not associated with reduced AF progression (hazard ratio, 1.18; 95% confidence interval, 0.88–1.58; P=0.27) but showed a trend towards lower risk of stroke, transient ischemic attack, or systemic embolism (hazard ratio, 0.17; 95% confidence interval, 0.02–1.23; P=0.08). Results were similar for a comparison of new MRA users and baseline MRA users compared with nonusers.

Conclusions

In community‐based outpatients with AF, the majority of MRA use was for heart failure and hypertension. MRA use also trended towards lower adjusted stroke risk. Future studies should test the hypothesis that MRA use may decrease the risk of stroke in patients with AF.

Highlights from the Tenth International Symposium of Thrombosis and Anticoagulation (ISTA X), September 22 and 23, 2017, Salvador, Bahia, Brazil

To discuss and share knowledge about advances in the care of patients with thrombotic disorders, the Tenth International Symposium of Thrombosis and Anticoagulation was held in Salvador, Bahia, Brazil, on September 22 and 23, 2017. This scientific program was developed by clinicians for clinicians and was promoted by two major clinical research institutes-the Brazilian Clinical Research Institute and the Duke Clinical Research Institute of the Duke University School of Medicine. Comprising academic presentations and open discussion, the symposium had as its primary goal to educate, motivate, and inspire internists, cardiologists, hematologists, and other physicians by convening national and international visionaries, thought-leaders, and dedicated clinician-scientists. This paper summarizes the symposium proceedings.

Comprehensive risk reduction in patients with atrial fibrillation: Emerging diagnostic and therapeutic options

There are exciting new developments in several areas of atrial fibrillation (AF) management that carry the hope of improving outcomes in AF patients. This paper is an executive summary that summarises the proceedings from the 3rd AFNET/EHRA consensus conference on atrial fibrillation, held in Sophia Antipolis from November 7th to 9th 2010, shortly after the release of the new ESC guidelines on AF. The conference was jointly organised by the German Atrial Fibrillation competence NETwork (AFNET) and the European Heart Rhythm Association (EHRA). This executive summary report covers four sections: 1. Risk factors and risk markers for AF, 2. Pathophysiological classification of AF, 3. Relevance of monitored AF duration for AF-related outcomes, and 4. Perspectives and needs for implementing better antithrombotic therapy.

Bleeding risk assessment and management in atrial fibrillation patients

In this executive summary of a Consensus Document from the European Heart Rhythm Association, endorsed by the European Society of Cardiology Working Group on Thrombosis, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in atrial fibrillation (AF) patients. The main aim of the document was to summarise ‘best practice’ in dealing with bleeding risk in AF patients when approaching antithrombotic therapy, by addressing the epidemiology and size of the problem, and review established bleeding risk factors. We also summarise definitions of bleeding in the published literature. Patient values and preferences balancing the risk of bleeding against thromboembolism as well as the prognostic implications of bleeding are reviewed. We also provide an overview of published bleeding risk stratification and bleeding risk schema. Brief discussion of special situations (e.g. periablation, peri-devices such as implantable cardioverter defibrillators [ICD] or pacemakers, presentation with acute coronary syndromes and/or requiring percutanous coronary interventions/stents and bridging therapy) is made, as well as a discussion of the prevention of bleeds and managing bleeding complications. Finally, this document puts forwards consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Anticoagulation for valvular heart disease in community-based practice

Little is known about patients who receive oral anticoagulation for valvular heart disease (VHD) in community-based practice. It was this study’s objective to describe the characteristics, management, and outcomes of patients anticoagulated for VHD, compared to patients anticoagulated for atrial fibrillation (AF). We used a nationally-representative cohort of community-based anticoagulation care in the United States. Data collected included indications for therapy, demographics, selected comorbid conditions, international normalised ratio (INR) target ranges, INR control, and clinical outcomes. We identified 1,057 patients anticoagulated for VHD (15.6% of the overall cohort) and 3,396 patients anticoagulated for AF (50.2%). INR variability was similar between the two groups (0.64 vs. 0.69, p = 0.80). Among patients with aortic VHD, for whom a standard (2–3) target INR range is recommended, 461 (84%) had a high target range (2.5–3.5), while 95 (16%) had a standard target range. VHD patients had a higher rate of major haemorrhage compared to AF patients (3.57 vs. 1.78 events per 100 patient-years, incidence rate ratio 2.02, 95% CI 1.33 – 3.06). The rate of stroke/systemic embolus was similar between groups (0.67 vs. 0.97 events per 100 patient-years, incidence rate ratio 0.71, 95% CI 0.32 – 1.57). In our community-based study, approximately 15.6% of patients receiving warfarin were anticoagulated for VHD. VHD patients achieved similar anticoagulation control to patients with AF, as measured by INR variability. Nevertheless, the rate of major haemorrhage was elevated among VHD patients compared to AF patients; this finding requires further investigation.

Disclaimer: The opinions expressed in this manuscript do not necessarily represent the views or policies of the United States Department of Veterans Affairs.

Factors associated with non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with new-onset atrial fibrillation: Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation II (ORBIT-AF II)

BACKGROUND

Several non-vitamin K antagonist oral anticoagulant (NOAC) alternatives to warfarin are available for stroke prevention in atrial fibrillation (AF). We aimed to describe the factors associated with selection of NOACs versus warfarin in patients with new onset AF.

METHODS

The ORBIT-AF II study is a national, US, prospective, observational, cohort study of anticoagulation treatment in patients with AF receiving NOACs or warfarin in the United States from 2013 to 2016. We measured factors associated with oral anticoagulant selection in 4,670 patients recently diagnosed with AF.

RESULTS

At baseline, 1,169 (25%) patients were started on warfarin and 3,501 (75%) on NOACs: of these latter, 259 (6%) were started on dabigatran, 1858 (40%) on rivaroxaban, and 1384 (30%) on apixaban. Those receiving NOACs were slightly younger patients (median age 71 vs 72, P<.0001); were less likely to have prior stroke (5.3% vs 8.6%; P<.0001) or prior bleeding (2.7% vs 4.4%; P=.005); had better kidney function (mean estimated glomerular filtration rate 91 mL/min vs 80 mL/min, P<.0001); and had fewer patients at high stroke risk (CHA₂DS₂-VASc score [Congestive heart failure, Hypertension, Age ≥75years, Diabetes mellitus, Prior stroke, transient ischemic attack {TIA}, or thromboembolism,Vascular disease, Age 65-74years, Sex category {female}] ≥2 in 86% vs 93%; P<.0001). In multivariable analysis, factors associated with NOAC selection versus warfarin included renal function, prior stroke or valve replacement, rhythm control AF management strategy, treatment by a cardiologist, and higher patient education level.

CONCLUSIONS

In contemporary clinical practice, up to three-fourths of patients with new-onset AF are now initially treated with a NOAC for stroke prevention. Those selected for NOAC treatment had lower stroke and bleeding risk profiles, were more likely treated by cardiologists, and had higher socioeconomic status.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01701817.

Comparative effectiveness of venous thromboembolism prophylaxis options for the patient undergoing total hip and knee replacement: a network meta-analysis

Essentials Despite trial data, guidelines have not endorsed direct oral Xa inhibitors above other options. We provide profiles of venous thromboembolism and hemorrhage risk for 12 options. Direct oral Xa inhibitors had a favorable profile compared with low-molecular-weight heparin. Other options did not have favorable profiles compared with low-molecular-weight heparin.

SUMMARY

Background There are numerous trials and several meta-analyses comparing venous thromboembolism (VTE) prophylaxis options after total hip and knee replacement (THR and TKR). None have included simultaneous comparison of new with older options. Objective To measure simultaneously the relative risk of VTE and hemorrhage for 12 prophylaxis options. Methods We abstracted VTE and hemorrhage information from randomized controlled trials published between January 1990 and June 2016 comparing 12 prophylaxis options. We then constructed networks to compute the relative risk for each option, relative to once-daily dosing with low-molecular-weight heparin (LMWH) Low. Results Main: Relative to LMWH Low, direct oral Xa inhibitors had the lowest risk of total deep vein thrombosis (DVT)-asymptomatic and symptomatic- (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.35-0.57), translating to 53-139 fewer DVTs per 1000 patients. Vitamin K antagonists (VKAs) titrated to International Normalized Ratio [INR] 2-3 predicted 56% more DVT events (OR, 1.56; 95% CI, 1.14-2.14). Aspirin performed similarly (OR, 0.80; 95% CI, 0.34-1.86), although small numbers prohibit firm conclusions. Direct oral Xa inhibitors did not lead to significantly more bleeding (OR, 1.21; 95% CI, 0.79-1.90). Secondary: Relative to LMWH Low, direct oral Xa inhibitors prevented 4-fold more symptomatic DVTs (OR, 0.25; 95% CI, 0.13-0.47). Conclusions Relative to LMWH Low, direct oral Xa inhibitors had a more favorable profile of VTE and hemorrhage risk, whereas VKAs had a less favorable profile. The profile of other agents was not more or less favorable. Clinicians should consider these profiles when selecting prophylaxis options.

Family history of atrial fibrillation is associated with earlier-onset and more symptomatic atrial fibrillation: Results from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry

BACKGROUND

We addressed whether patients with a family history of atrial fibrillation (AF) were diagnosed as having AF earlier in life, were more symptomatic, and had worse outcomes compared with those without a family history of AF.

METHODS

Using the ORBIT-AF, we compared symptoms and disease characteristics in those with and without a family history of AF. A family history of AF was defined as AF in a first-degree family member and obtained by patient self-reporting. Multivariable Cox proportional hazard analyses were performed to compare the incidence of cardiovascular outcomes, AF progression, all-cause hospitalization, and all-cause death.

RESULTS

Among 9,999 patients with AF from 176 US outpatient clinics, 1,481 (14.8%) had a family history of AF. Relative to those without, those with a family history of AF developed AF 5 years earlier on average (median age 65 vs 70 years, P < .01), with less comorbidity, and had more severe AF-related symptoms. No differences were found between the 2 groups in the risk of AF progression (adjusted hazard ratio [HR] 0.98, 95% CI 0.85-1.14), stroke, non-central nervous system embolism, or transient ischemic attack (adjusted HR 0.95, 95% CI 0.67-1.34), all-cause hospitalization (adjusted HR 1.03, 95% CI 0.94-1.12), and all-cause death (adjusted HR 1.05, 95% CI 0.86-1.27).

CONCLUSIONS

Patients with a family history of AF developed AF at a younger age, had less comorbidity, and were more symptomatic. Once AF developed, no significantly increased risks of AF progression and thromboembolism were associated with a family history of AF compared with no family history.

Increased Heart Rate Is Associated With Higher Mortality in Patients With Atrial Fibrillation (AF): Results From the Outcomes Registry for Better Informed Treatment of AF (ORBIT-AF)

BACKGROUND

Most patients with atrial fibrillation (AF) require rate control; however, the optimal target heart rate remains under debate. We aimed to assess rate control and subsequent outcomes among patients with permanent AF.

METHODS AND RESULTS

We studied 2812 US outpatients with permanent AF in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation. Resting heart rate was measured longitudinally and used as a time-dependent covariate in multivariable Cox models of all-cause and cause-specific mortality during a median follow-up of 24 months. At baseline, 7.4% (n=207) had resting heart rate <60 beats per minute (bpm), 62% (n=1755) 60 to 79 bpm, 29% (n=817) 80 to 109 bpm, and 1.2% (n=33) ≥110 bpm. Groups did not differ by age, previous cerebrovascular disease, heart failure status, CHA2DS2-VASc scores, renal function, or left ventricular function. There were significant differences in race (P=0.001), sinus node dysfunction (P=0.004), and treatment with calcium-channel blockers (P=0.006) and anticoagulation (P=0.009). In analyses of continuous heart rates, lower heart rate ≤65 bpm was associated with higher all-cause mortality (adjusted hazard ratio [HR], 1.15 per 5-bpm decrease; 95% CI, 1.01 to 1.32; P=0.04). Similarly, increasing heart rate >65 bpm was associated with higher all-cause mortality (adjusted HR, 1.10 per 5-bpm increase; 95% CI, 1.05 to 1.15; P<0.0001). This relationship was consistent across endpoints and in a broader sensitivity analysis of permanent and nonpermanent AF patients.

CONCLUSIONS

Among patients with permanent AF, there is a J-shaped relationship between heart rate and mortality. These data support current guideline recommendations, and clinical trials are warranted to determine optimal rate control.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/. Unique identifier: NCT01165710.

Design and rationale for RE-VERSE AD: A phase 3 study of idarucizumab, a specific reversal agent for dabigatran

Idarucizumab, a Fab fragment directed against dabigatran, produced rapid and complete reversal of the anticoagulation effect of dabigatran in animals and in healthy volunteers. The Study of the REVERSal Effects of Idarucizumab in Patients on Active Dabigatran (RE-VERSE AD™) is a global phase 3 prospective cohort study aimed at investigating idarucizumab in dabigatran-treated patients who present with uncontrollable or life-threatening bleeding, and in those requiring urgent surgery or intervention. We describe the rationale for, and design of the trial (clinicaltrials.gov NCT02104947).

Abstract 283: Association of Body Mass Index with Outcomes in Patients with Atrial Fibrillation: Results From the ORBIT-AF Registry

Introduction: Higher body mass index (BMI) is an independent risk factor for incident atrial fibrillation (AF). However, its impact on management strategies and clinical outcomes among patients with prevalent AF is unclear.

Methods: The study cohort included patients with AF enrolled in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) registry from June 2010 through August 2011. Participants with BMI > 18.5 kg/m2 were stratified into normal (18.5 - 25 kg/m2), overweight (25 - 30 kg/m2), Class I obese (30 - 35 kg/m2), Class II obese (35 - 40 kg/m2), and Class III obese (>40 kg/m2) categories. Unadjusted and adjusted Cox frailty models were constructed to assess the categorical and continuous association of BMI with AF progression, mortality, and incidence of thromboembolic events.

Results: We evaluated 9,606 patients with AF (mean age: 74 + 11 years; 42% women) from 174 US ORBIT participating practices. Patients in the higher BMI categories were younger and had a higher prevalence of comorbidities such as diabetes, hypertension, and obstructive sleep apnea. AF symptom burden was greatest among patients in extreme BMI categories. Proportional use of anticoagulation, antiarrhythmic drugs, and invasive rhythm control strategies was significantly greater among patients in higher BMI categories. Rates for mortality and stroke/non-CNS embolism decreased in a near linear fashion across successively higher BMI categories (P<0.001; Table). After multivariable adjustment, higher BMI categories were associated with lower risk for mortality (p = 0.0002), with the lowest risk observed among overweight patients [Hazard Ratio (HR) (95% CI): 0.65 (0.54 - 0.79) ref. group: normal weight]. For every 5-kg/m2 increase in BMI, the odds of risk-adjusted mortality were 6% lower [HR (95% CI): 0.94 (0.89 - 0.98)]. In contrast, the association between BMI and risk for stroke/non-CNS embolism was significant on unadjusted analysis (P <0.001) but attenuated after adjustment for risk factors (P = 0.78; Table). No significant association was observed between BMI and AF progression rates in either unadjusted (P = 0.35) or adjusted analyses (P = 0.17).

Conclusion: Among patients with AF, higher BMI was associated with a greater use of anticoagulation, rhythm control strategies, and lower mortality risk.

Abstract 179: Ischemic Stroke in Atrial Fibrillation: 30-day Outcomes and Factors Associated with Severity

Background and Hypothesis: Ischemic stroke (IS) in atrial fibrillation (AF) is associated with high mortality. Inflammation, endothelial dysfunction, and hypercoagulability, in addition to blood stasis in the left atrium, play a critical role in thrombogenesis in AF. Hyperglycemia and chronic kidney disease (CKD) are potent triggers for inflammation, oxidative stress, and thrombogenesis. Statins have been shown to possess anti-inflammatory, anti-oxidant, and anti-thrombotic properties. Accordingly, we assessed the hypothesis that statin use may modulate stroke severity in AF.

Methods: Consecutive IS admissions were identified from 2006-2010. All events were subject to CT or MRI and assessed for functional independence at discharge using modified Rankin scale (mRS). AF was confirmed by ECG at presentation or within the prior 6 months in all cases. Covariates were abstracted from the medical record. To account for confounding by treatment, we used multivariable logistic regression analysis adjusted using inverse probability weighting.

Results: We identified 1,030 AF-related IS; mean age was 77, 56% were female, mean CHA 2 DS 2 VASC score was 4.8 designating high baseline stroke risk. IS resulted in severe neurological deficit or death (mRS ≥ 4) for 69%; 21% died within 30-days. Severe stroke was associated with older age, diabetes, dementia, prior ischemic stroke, prior venous thromboembolism, and CKD (Table). Baseline statin use was associated with a 33% reduced risk of sustaining a severe stroke.

Conclusion: Strokes in AF are associated with high morbidity and mortality. Clinical markers of thrombophilia, including prior IS, DVT, and PE, were significantly associated with severe strokes. Diabetes and CKD independently increased this risk. Statin use resulted in less severe outcomes. Advancing our basic understanding of these interrelated thrombogenic pathways will inform clinical interventions to reduce these devastating outcomes.

Abstract 100: Influence of Race on Presentation, Treatment, and Outcome Among Patients With Atrial Fibrillation-related Ischemic Stroke

Background: Blacks have been underrepresented (<2% of 71,683) in recent atrial fibrillation (AF) trials of novel anticoagulants vs. warfarin. Blacks with AF have also been underrepresented in stroke cohort studies from which the stroke risk prediction rules are derived.

Objective: We examined whether there exist racial differences in presentation, treatment, and outcome among patients with AF-related ischemic stroke (IS).

Methods: Consecutive IS were identified from 2006-2010 at 3 U.S. sites. All events were evaluated by CT or MRI, and assigned a discharge modified Rankin score (mRS). AF was confirmed by ECG. Baseline medications and clinical characteristics were abstracted from the medical record. Race was determined by self-report.

Findings: We identified 1,030 AF-related IS; 96% (n=985) had race reported as White (n=764, 74%) or Black (n=221, 21%). Compared to Whites, Blacks were younger, had a higher burden of risk factors, had higher prevalence of paroxysmal or new onset AF, and more often presented outside the t-PA window. Among patients with known AF, 40% Whites and 39% Blacks were taking warfarin on admission. INR on admission was not different by race (mean 1.4, SD =0.7; p=0.64). These strokes resulted in severe neurological deficit (mRS >3) in a majority of Blacks and Whites (70% vs. 64%; p=0.09).

Conclusion: Blacks with AF who suffer IS are younger, have a higher burden of risk factors, and more often present with paroxysmal or new onset AF. IS in the setting of AF was associated with significant mortality and morbidity in both Blacks and Whites.

HIV status and the risk of ischemic stroke among men

OBJECTIVE

Given conflicting data regarding the association of HIV infection and ischemic stroke risk, we sought to determine whether HIV infection conferred an increased ischemic stroke risk among male veterans.

METHODS

The Veterans Aging Cohort Study-Virtual Cohort consists of HIV-infected and uninfected veterans in care matched (1:2) for age, sex, race/ethnicity, and clinical site. We analyzed data on 76,835 male participants in the Veterans Aging Cohort Study-Virtual Cohort who were free of baseline cardiovascular disease. We assessed demographics, ischemic stroke risk factors, comorbid diseases, substance use, HIV biomarkers, and incidence of ischemic stroke from October 1, 2003, to December 31, 2009.

RESULTS

During a median follow-up period of 5.9 (interquartile range 3.5-6.6) years, there were 910 stroke events (37.4% HIV-infected). Ischemic stroke rates per 1,000 person-years were higher for HIV-infected (2.79, 95% confidence interval 2.51-3.10) than for uninfected veterans (2.24 [2.06-2.43]) (incidence rate ratio 1.25 [1.09-1.43]; p < 0.01). After adjusting for demographics, ischemic stroke risk factors, comorbid diseases, and substance use, the risk of ischemic stroke was higher among male veterans with HIV infection compared with uninfected veterans (hazard ratio 1.17 [1.01-1.36]; p = 0.04).

CONCLUSIONS

HIV infection is associated with an increased ischemic stroke risk among HIV-infected compared with demographically and behaviorally similar uninfected male veterans.