Mahaffey, Kenneth W.

Background— Patients with atrial fibrillation (AF) at the highest stroke risk derive the largest benefit from oral anticoagulation (OAC). Those with the highest stroke risk have been paradoxically less likely to receive OAC. This study assessed the association between stroke and bleeding risk on rates of OAC. Methods and Results— We analyzed OAC use among 10 098 patients with AF from 174 community-based outpatient practices enrolled in 2010–2011 in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF). OAC was defined as warfarin or dabigatran use at study enrollment. Stroke and bleeding risk were calculated using congestive heart failure, hypertension, age, diabetes mellitus, prior stroke (CHADS 2 ), and anticoagulation and risk factors in AF (ATRIA) scores, respectively. The mean subject age was 73 years; 58% were men. Overall, 76% of patients received OAC (71% warfarin and 5% dabigatran). The use of OAC increased among those with higher CHADS 2 scores, from 53% for CHADS 2 =0 to 80% for CHADS 2 ≥2 ( P <0.001). OAC use fell slightly with increasing ATRIA bleeding risk score, from 81% for ATRIA=3 to 73% for ATRIA≥5 ( P <0.001). A significant interaction existed between ATRIA and CHADS 2 scores ( P =0.021). Among those with low bleeding risk, use of OAC increased significantly with increasing stroke risk. Among those with high bleeding risk, CHADS 2 stroke risk had a smaller impact on use of OAC. Conclusions— In community-based outpatients with AF, use of OAC was high and driven by not only predominantly stroke but also bleeding risk. Stroke risk significantly affects OAC use among those with low bleeding risk, whereas those with high bleeding risk demonstrate consistently lower use of OAC regardless of stroke risk.

Background— Prior studies demonstrate a direct relationship between treatment delays to primary percutaneous intervention and mortality in patients with ST-segment elevation myocardial infarction (STEMI). This analysis compared the relationship of symptom onset-to-balloon time and door-to-balloon time on mortality in patients with STEMI. Methods and Results— We analyzed different treatment delays (symptom onset-to-balloon time, door-to-balloon time) and mortality in 5745 STEMI patients. Baseline characteristics, flow grade, 90-day mortality, and clinical outcomes were compared in patients stratified by treatment delay. Multivariable logistic regression modeling was performed to assess the independent and relative effect of each treatment delay on 90-day mortality. Female sex, increased age, and worse thrombolysis in myocardial infarction flow grade were significantly associated with longer symptom onset-to-balloon times and door-to-balloon times. Longer symptom onset-to-balloon time was significantly associated with worse 90-day mortality (3.7%, 4.2%, and 6.5% for time delays <3 hours, 3 to 5 hours, and >5 hours, respectively, P <0.0001). Similarly, longer door-to-balloon times were significantly associated with worse 90-day mortality (3.2%, 4.0%, 4.6%, and 5.3% for delays <60 minutes, 60 to 90 minutes, 90 to 120 minutes, and ≥120 minutes respectively, P <0.0001). In a multivariate model of 90-day mortality, door-to-balloon time (χ 2 6.0, P <0.014), and symptom onset-to-hospital arrival (χ 2 9.8, P <0.007) remained independent determinants. Conclusions— Both symptom onset-to-balloon time and hospital door-to-balloon time are strongly associated with 90-day mortality following STEMI. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00091637.