Efficacy and safety of rivaroxaban vs. warfarin in patients with non-valvular atrial fibrillation and a history of cancer: observations from ROCKET AF.

AIMS: The management of anticoagulation therapy in patients with atrial fibrillation (AF) and cancer is challenging due to increased thrombotic and bleeding risks. We sought to determine the safety and efficacy of rivaroxaban in patients with AF and a history of cancer. METHODS AND RESULTS: ROCKET AF randomized 14 264 patients with AF to rivaroxaban or warfarin with a median follow-up of 1.9 years. Cox regression models were used to assess the association between cancer history and clinical outcomes, and the relative treatment effect of rivaroxaban vs. warfarin in these patients. A total of 640 patients enrolled in ROCKET AF had a history of cancer, with the most common types being prostate (28.6%), colorectal (16.1%), and breast (14.7%) cancer. Patients with a history of cancer were older, more frequently male, more likely to have prior vitamin K antagonist (VKA) use and had higher rates of overall bleeding [hazard ratio (HR) 1.30, 95% confidence interval (CI) 1.16-1.47; P < 0.0001] and non-cardiovascular death (HR 1.47, 95% CI 1.04-2.07; P = 0.031) compared with those with no cancer history. There were no significant associations between cancer history and stroke, venous thromboembolism, or myocardial infarction. The relative efficacy of rivaroxaban vs. warfarin for prevention of stroke/systemic embolism was similar in those with and without a history of cancer (interaction P-value = 0.21). CONCLUSION: In ROCKET AF, a history of cancer was associated with a higher risk of bleeding and non-cardiovascular death, but not ischaemic events. The relative efficacy and safety of rivaroxaban compared with warfarin were not significantly different in patients with and without a history of cancer. The results of this study are exploratory and should be taken in context of the study population, which may not be generalizable to those with advanced malignancy. Further investigation is needed to understand optimal anticoagulation strategies in patients with AF and cancer.Clinical trial registration: ClinicalTrials.gov: NCT00403767.

Polypharmacy and the Efficacy and Safety of Rivaroxaban Versus Warfarin in the Prevention of Stroke in Patients With Nonvalvular Atrial Fibrillation.

BACKGROUND: Patients with atrial fibrillation (AF) often take multiple medications. METHODS AND RESULTS: We examined characteristics and compared adjusted outcomes between rivaroxaban and warfarin according to number of concomitant baseline medications and the presence of combined cytochrome P450 3A4 and P-glycoprotein inhibitors in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study. At baseline, 5101 patients (36%) were on 0 to 4 medications, 7298 (51%) were on 5 to 9, and 1865 (13%) were on ≥ 10. Although polypharmacy was not associated with higher risk of stroke or non-central nervous system embolism (adjusted hazard ratio, 1.02 for ≥ 10 versus 0-4 medications; 95% confidence interval, 0.76-1.38), it was associated with higher risks of the combined end point of stroke, non-central nervous system embolism, vascular death, or myocardial infarction (adjusted hazard ratio, 1.41 for ≥ 10 versus 0-4 medications; 95% confidence interval, 1.18-1.68) and nonmajor clinically relevant or major bleeding (adjusted hazard ratio, 1.47 for ≥ 10 versus 0-4 medications; 95% confidence interval, 1.31-1.65). There was no significant difference in primary efficacy (adjusted interaction P=0.99) or safety outcomes (adjusted interaction P=0.87) between treatment groups by number of medications. Patients treated with 0 to 4 medications had lower rates of major bleeding with rivaroxaban (adjusted hazard ratio, 0.71; 95% confidence interval, 0.52-0.95; interaction P=0.0074). There was no evidence of differential outcomes in those treated with ≥ 1 combined cytochrome P450 3A4 and P-glycoprotein inhibitors. CONCLUSIONS: In a population of patients with atrial fibrillation, two thirds were on ≥ 5 medications. Increasing medication use was associated with higher risk of bleeding but not stroke. Rivaroxaban was tolerated across complex patients on multiple medications. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00403767.

Enoxaparin vs unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndromes managed with an intended early invasive strategy: primary results of the SYNERGY randomized trial.

CONTEXT: Enoxaparin has demonstrated advantages over unfractionated heparin in low- to moderate-risk patients with non-ST-segment elevation acute coronary syndromes (ACS) treated with a conservative strategy. OBJECTIVES: To compare the outcomes of patients treated with enoxaparin vs unfractionated heparin and to define the role of enoxaparin in patients with non-ST-segment elevation ACS at high risk for ischemic cardiac complications managed with an early invasive approach. DESIGN, SETTING, AND PARTICIPANTS: The Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial was a prospective, randomized, open-label, multicenter, international trial conducted between August 2001 and December 2003. A total of 10 027 high-risk patients with non-ST-segment elevation ACS to be treated with an intended early invasive strategy were recruited. INTERVENTIONS: Subcutaneous enoxaparin (n = 4993) or intravenous unfractionated heparin (n = 4985) was to be administered immediately after enrollment and continued until the patient required no further anticoagulation, as judged by the treating physician. MAIN OUTCOME MEASURES: The primary efficacy outcome was the composite clinical end point of all-cause death or nonfatal myocardial infarction during the first 30 days after randomization. The primary safety outcome was major bleeding or stroke. RESULTS: The primary end point occurred in 14.0% (696/4993) of patients assigned to enoxaparin and 14.5% (722/4985) of patients assigned to unfractionated heparin (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.86-1.06). No differences in ischemic events during percutaneous coronary intervention (PCI) were observed between enoxaparin and unfractionated heparin groups, respectively, including similar rates of abrupt closure (31/2321 [1.3%] vs 40/2364 [1.7%]), threatened abrupt closure (25/2321 [1.1%] vs 24/2363 [1.0%]), unsuccessful PCI (81/2281 [3.6%] vs 79/2328 [3.4%]), or emergency coronary artery bypass graft surgery (6/2323 [0.3%] vs 8/2363 [0.3%]). More bleeding was observed with enoxaparin, with a statistically significant increase in TIMI (Thrombolysis in Myocardial Infarction) major bleeding (9.1% vs 7.6%, P =.008) but nonsignificant excess in GUSTO (Global Utilization of Streptokinase and t-PA for Occluded Arteries) severe bleeding (2.7% vs 2.2%, P =.08) and transfusions (17.0% vs 16.0%, P =.16). CONCLUSIONS: Enoxaparin was not superior to unfractionated heparin but was noninferior for the treatment of high-risk patients with non-ST-segment elevation ACS. Enoxaparin is a safe and effective alternative to unfractionated heparin and the advantages of convenience should be balanced with the modest excess of major bleeding.