Prospective surveillance pilot of rivaroxaban safety within the US Food and Drug Administration Sentinel System.

PURPOSE: The US Food and Drug Administration's Sentinel system developed tools for sequential surveillance. METHODS: In patients with non-valvular atrial fibrillation, we sequentially compared outcomes for new users of rivaroxaban versus warfarin, employing propensity score matching and Cox regression. A total of 36 173 rivaroxaban and 79 520 warfarin initiators were variable-ratio matched within 2 monitoring periods. RESULTS: Statistically significant signals were observed for ischemic stroke (IS) (first period) and intracranial hemorrhage (ICH) (second period) favoring rivaroxaban, and gastrointestinal bleeding (GIB) (second period) favoring warfarin. In follow-up analyses using primary position diagnoses from inpatient encounters for increased definition specificity, the hazard ratios (HR) for rivaroxaban vs warfarin new users were 0.61 (0.47, 0.79) for IS, 1.47 (1.29, 1.67) for GIB, and 0.71 (0.50, 1.01) for ICH. For GIB, the HR varied by age: <66 HR = 0.88 (0.60, 1.30) and 66+ HR = 1.49 (1.30, 1.71). CONCLUSIONS: This study demonstrates the capability of Sentinel to conduct prospective safety monitoring and raises no new concerns about rivaroxaban safety.

Outcomes of Dabigatran and Warfarin for Atrial Fibrillation in Contemporary Practice: A Retrospective Cohort Study.

BACKGROUND: Dabigatran (150 mg twice daily) has been associated with lower rates of stroke than warfarin in trials of atrial fibrillation, but large-scale evaluations in clinical practice are limited. OBJECTIVE: To compare incidence of stroke, bleeding, and myocardial infarction in patients receiving dabigatran versus warfarin in practice. DESIGN: Retrospective cohort. SETTING: National U.S. Food and Drug Administration Sentinel network. PATIENTS: Adults with atrial fibrillation initiating dabigatran or warfarin therapy between November 2010 and May 2014. MEASUREMENTS: Ischemic stroke, intracranial hemorrhage, extracranial bleeding, and myocardial infarction identified from hospital claims among propensity score-matched patients starting treatment with dabigatran or warfarin. RESULTS: Among 25 289 patients starting dabigatran therapy and 25 289 propensity score-matched patients starting warfarin therapy, those receiving dabigatran did not have significantly different rates of ischemic stroke (0.80 vs. 0.94 events per 100 person-years; hazard ratio [HR], 0.92 [95% CI, 0.65 to 1.28]) or extracranial hemorrhage (2.12 vs. 2.63 events per 100 person-years; HR, 0.89 [CI, 0.72 to 1.09]) but were less likely to have intracranial bleeding (0.39 vs. 0.77 events per 100 person-years; HR, 0.51 [CI, 0.33 to 0.79]) and more likely to have myocardial infarction (0.77 vs. 0.43 events per 100 person-years; HR, 1.88 [CI, 1.22 to 2.90]). However, the strength and significance of the association between dabigatran use and myocardial infarction varied in sensitivity analyses and by exposure definition (HR range, 1.13 [CI, 0.78 to 1.64] to 1.43 [CI, 0.99 to 2.08]). Older patients and those with kidney disease had higher gastrointestinal bleeding rates with dabigatran. LIMITATION: Inability to examine outcomes by dabigatran dose (unacceptable covariate balance between matched patients) or quality of warfarin anticoagulation (few patients receiving warfarin had available international normalized ratio values). CONCLUSION: In matched adults with atrial fibrillation treated in practice, the incidences of stroke and bleeding with dabigatran versus warfarin were consistent with those seen in trials. The possible relationship between dabigatran and myocardial infarction warrants further investigation. PRIMARY FUNDING SOURCE: U.S. Food and Drug Administration.

Antihypertensive drug associated angioedema: effect modification by race/ethnicity.

PURPOSE: Assess angioedema risk with exposure to angiotensin converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) compared with beta-blockers, by race/ethnicity. METHODS: New-user cohorts of Medicare beneficiaries 65 years or older initiating ACEI, ARB, or beta-blocker treatment from March 2007 to March 2014 were constructed. Angioedema incidence rates by drug and race/ethnicity were computed for 1-30 and 31-365 days of treatment. Cox proportional hazards regression was used to examine angioedema risk between cohorts. RESULTS: Angioedema incidence rates (per 1000 person years) in beta-blocker users were 1.80 (whites), 4.11 (blacks), 1.89 (Asians), and 2.10 (Hispanics); in ACEI users, 4.03, 23.77, 2.94, and 4.27; and in ARB users, 1.73, 3.11, 1.10, and 1.90, respectively. Incidence rates were significantly higher in the first 30 days of exposure for all drug × race/ethnic groups. Overall, angioedema risk increased among ACEI users (hazard ratio, 2.91; 95% confidence interval, 2.75-3.07) but not ARB users (0.93, 0.85-1.02) versus beta-blocker users. Angioedema risk with ACEIs versus beta-blockers increased more in blacks (6.28, 5.44-7.24) than whites (2.33, 2.19-2.48), Hispanics (2.04, 1.36-3.07), and Asians (1.48, 0.94-2.35). Compared with white beta-blocker users, angioedema risk was increased 2.9-fold in whites, 20.2-fold in blacks, and 2.3-fold in other race/ethnic groups combined during the first 30 days of ACEI exposure. CONCLUSIONS: There was significant effect modification of angioedema risk by race and ACEI use for blacks, but not for other race/ethnicity groups. Angioedema risk was significantly greater in the first 30 days of exposure for all, and highest among blacks.

Cardiovascular, bleeding, and mortality risks in elderly Medicare patients treated with dabigatran or warfarin for nonvalvular atrial fibrillation.

BACKGROUND: The comparative safety of dabigatran versus warfarin for treatment of nonvalvular atrial fibrillation in general practice settings has not been established. METHODS AND RESULTS: We formed new-user cohorts of propensity score-matched elderly patients enrolled in Medicare who initiated dabigatran or warfarin for treatment of nonvalvular atrial fibrillation between October 2010 and December 2012. Among 134 414 patients with 37 587 person-years of follow-up, there were 2715 primary outcome events. The hazard ratios (95% confidence intervals) comparing dabigatran with warfarin (reference) were as follows: ischemic stroke, 0.80 (0.67-0.96); intracranial hemorrhage, 0.34 (0.26-0.46); major gastrointestinal bleeding, 1.28 (1.14-1.44); acute myocardial infarction, 0.92 (0.78-1.08); and death, 0.86 (0.77-0.96). In the subgroup treated with dabigatran 75 mg twice daily, there was no difference in risk compared with warfarin for any outcome except intracranial hemorrhage, in which case dabigatran risk was reduced. Most patients treated with dabigatran 75 mg twice daily appeared not to have severe renal impairment, the intended population for this dose. In the dabigatran 150-mg twice daily subgroup, the magnitude of effect for each outcome was greater than in the combined-dose analysis. CONCLUSIONS: In general practice settings, dabigatran was associated with reduced risk of ischemic stroke, intracranial hemorrhage, and death and increased risk of major gastrointestinal hemorrhage compared with warfarin in elderly patients with nonvalvular atrial fibrillation. These associations were most pronounced in patients treated with dabigatran 150 mg twice daily, whereas the association of 75 mg twice daily with study outcomes was indistinguishable from warfarin except for a lower risk of intracranial hemorrhage with dabigatran.

Correction to: FDA Approval of Angiotensin II for the Treatment of Hypotension in Adults with Distributive Shock.

The author name that previously read.

FDA Approval of Angiotensin II for the Treatment of Hypotension in Adults with Distributive Shock.

Distributive shock is a subset of shock marked by decreased systemic vascular resistance, organ hypoperfusion and altered oxygen extraction. Despite the use of intravenous fluids and either higher dose of catecholamines or other additional exogenous vasopressors to maintain blood pressure in the target range, the rate of mortality remains higher in patients with septic shock. Therefore, there is clearly an unmet need for additional safe and effective treatments. The use of angiotensin II to raise the mean arterial pressure (MAP) could provide additional therapy and the opportunity to evaluate a catecholamine-sparing effect by decreasing the dose of concomitant catecholamines while maintaining a target MAP. ATHOS-3 (Angiotensin II for the Treatment of High-Output Shock phase 3; ClinicalTrials.gov number, NCT02338843) was an adequate and well-controlled trial. The primary endpoint was the rate of MAP response at hour 3 of treatment with study drug, defined as either a 10-mmHg increase from baseline in MAP or a MAP of at least 75 mmHg. The secondary endpoints were changes from baseline in Sequential Organ Failure Assessment (SOFA) scores (total and cardiovascular). Mortality was an exploratory endpoint. The trial provided substantial evidence of the effectiveness of angiotensin II in raising blood pressure over placebo in patients with distributive shock, while keeping catecholamine levels constant. There was no change in the secondary endpoint of total SOFA scores relative to placebo when catecholamine use was reduced in lieu of angiotensin II treatment. There was a slight decrease in the secondary endpoint of cardiovascular SOFA score relative to placebo during the catecholamine-sparing phase, reflecting the catecholamine-sparing effect. There was a consistent trend in decreased mortality relative to placebo over the 28-day study period. Based on the agreements emanating from the special protocol assessment to assess blood pressure effects, the data from this single study supported approval of angiotensin II by the Food and Drug Administration for marketing in the USA.

Comparative Stroke, Bleeding, and Mortality Risks in Older Medicare Patients Treated with Oral Anticoagulants for Nonvalvular Atrial Fibrillation.

BACKGROUND: Nonvitamin K antagonist oral anticoagulants (NOACs) are alternatives to warfarin in patients with nonvalvular atrial fibrillation. Randomized trials compared NOACs with warfarin, but none have compared individual NOACs against each other for safety and effectiveness. METHODS: We performed a retrospective new-user cohort study of patients with nonvalvular atrial fibrillation enrolled in US Medicare who initiated warfarin (n = 183,318), or a standard dose of dabigatran (150 mg twice daily; n = 86,198), rivaroxaban (20 mg once daily; n = 106,389), or apixaban (5 mg twice daily; n = 73,039) between October 2010 and September 2015. Propensity score-adjusted Cox proportional hazards regression was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the outcomes of thromboembolic stroke, intracranial hemorrhage, major extracranial bleeding, and all-cause mortality, comparing each NOAC with warfarin, and with each other NOAC. RESULTS: Compared with warfarin, each NOAC was associated with reduced risks of thromboembolic stroke (20%-29% reduction; P = .002 [dabigatran], P < 0.001 [rivaroxaban, apixaban]), intracranial hemorrhage (35%-62% reduction; P < 0.001 [each NOAC]), and mortality (19%-34% reduction; P < .001 [each NOAC]). The NOACs were similar for thromboembolic stroke but rivaroxaban was associated with increased risks of intracranial hemorrhage (vs dabigatran: HR = 1.71; 95% CI, 1.35-2.17), major extracranial bleeding (vs dabigatran: HR = 1.32; 95% CI, 1.21-1.45; vs apixaban: HR = 2.70; 95% CI, 2.38-3.05), and death (vs dabigatran: HR = 1.12; 95% CI, 1.01-1.24; vs apixaban: HR = 1.23; 95% CI, 1.09-1.38). Dabigatran was associated with reduced risk of intracranial hemorrhage (HR = 0.70; 95% CI ,0.53-0.94) and increased risk of major extracranial bleeding (HR = 2.04; 95% CI, 1.78-2.32) compared with apixaban. CONCLUSIONS: Among patients treated with standard-dose NOAC for nonvalvular atrial fibrillation and warfarin users with similar baseline characteristics, dabigatran, rivaroxaban, and apixaban were associated with a more favorable benefit-harm profile than warfarin. Among NOAC users, dabigatran and apixaban were associated with a more favorable benefit-harm profile than rivaroxaban.

Relationship between International Normalized Ratio and Outcomes in Modern Trials with Warfarin Controls.

INTRODUCTION: A target international normalized ratio (INR) of 2-3 has been recommended for patients with atrial fibrillation (AF) and risk factors for thromboembolism. This recommendation is largely based on evidence from observational studies a decade ago. This study utilized collective data from modern trials with warfarin controls to examine the relationship of warfarin anticoagulation, as assessed by INR, on the clinical outcome events of interest. METHODS: Data on warfarin-treated patients from three clinical studies supporting the approval of dabigatran (Pradaxa), apixaban (Eliquis), and edoxaban (Savaysa) were pooled. Ischemic stroke, intracranial hemorrhage (ICH), and all-cause death were selected as the outcome events of interest. Multivariate Cox regression modeling was performed to examine the association between time-dependent INR and each outcome event. Benefit-risk assessment was evaluated by summing the estimated annual event rate for ischemic stroke and ICH. RESULTS: A total of 21,883 patients representing 322 ischemic strokes, 288 ICHs, and 657 all-cause deaths were included in the analysis. The models used suggest that the risk of ischemic stroke is greatly reduced when INR exceeds 2; in contrast, the risk of ICH increases monotonically as INR increases. When combining ischemic stroke and ICH events, the lowest estimated annual event rate was observed between INR of 2 and 2.5; the risk only slightly increased between INR of 1.8 and 3.0. Similarly, a U-shaped relationship between INR and the risk of all-cause death was found. CONCLUSIONS: This study using collective warfarin data from recent large prospective trials indicates that INR between 2 and 2.5 provides the best balance between ischemic stroke and ICH, as well as optimal protection against death in patients with AF.