Effectiveness and safety of anticoagulants for the treatment of venous thromboembolism in patients with cancer.

Anticoagulation is used to treat venous thromboembolism (VTE) in cancer patients, but may be associated with an increased risk of bleeding. VTE recurrence and major bleeding were assessed in cancer patients treated for VTE with the most currently prescribed anticoagulants in clinical practice. Newly diagnosed cancer patients (first VTE 1/1/2013-05/31/2015) who initiated rivaroxaban, low-molecular-weight heparin (LMWH), or warfarin were identified from Humana claims data and observed until end of eligibility or end of data availability. VTE recurrence was a hospitalization with a primary diagnosis of VTE ≥7 days after first VTE. Major bleeding events on treatment were identified using validated criteria. Cohorts were compared using Kaplan-Meier rates at 6 and 12 months and Cox proportional hazards models. Cohorts were adjusted for their differences at baseline. A total of 2428 patients (rivaroxaban: 707; LMWH: 660; warfarin: 1061) met inclusion criteria. Patient characteristics were well balanced after weighting. There was a trend for lower VTE recurrence rates in rivaroxaban users compared to LMWH users at 6 months (13.2% vs. 17.1%; P = .060) and significantly lower at 12 months (16.5% vs. 22.2%; P = .030) [HR: 0.72, 95% CI: (0.52-0.95); P = .024]. VTE recurrence rates were also lower for rivaroxaban than warfarin users at 6 months (13.2% vs. 17.5%; P = .014) and 12 months (15.7% vs. 19.9%; P = .017) [HR: 0.74, 95% CI: (0.56-0.96); P = .028]. Major bleeding rates were similar across cohorts. This real-world analysis suggests cancer patients with VTE treated with rivaroxaban had significantly lower risk of recurrent VTE and similar risk of bleeding compared to those treated with LMWH or warfarin.

Risk Prediction for Ischemic Stroke and Transient Ischemic Attack in Patients Without Atrial Fibrillation: A Retrospective Cohort Study.

BACKGROUND: Stroke mainly occurs in patients without atrial fibrillation (AF). This study explored risk prediction models for ischemic stroke and transient ischemic attack (TIA) in patients without AF. METHODS: Three US-based healthcare databases (Truven MarketScan Commercial Claims and Encounters [CCAE], Medicare Supplemental [MDCR], and Optum Clinformatics [Optum]) were used to establish patient cohorts without AF during the index period of 2008-2012. The performance of 2 existing models (CHADS2 and CHA2DS2-VASc) for predicting stroke and TIA was examined by fitting a logistic regression to a training dataset and evaluating predictive accuracy in a validation dataset (area under the curve, AUC) using patients with complete follow-up of 1 or 3 years, separately. RESULTS: The commercial populations were younger and had fewer comorbidities than Medicare-eligible population. The incidence proportions of ischemic stroke and TIA during 1 and 3 years of follow-up were .5% and 1.9% (CCAE), .6% and 2.2% (Optum), and 4.6% and 13.1% (MDCR), respectively. The models performed consistently across all 3 databases, with the AUC ranging from .69 to .77 and from .68 to .73 for 1- and 3-year prediction, respectively. Predictive accuracy was lower than the initial work of CHADS2 evaluation in patients with AF (AUC: .82), but consistent with a subsequent meta-analysis of CHADS2 (.60-.80) and CHA2DS2-VASc performance (.64-.79). CONCLUSION: Although the existing schemes for predicting ischemic stroke and TIA in patients with AF can be applied to patients without AF with comparable predictive accuracy, the evidence suggests that there is room for improvement in these models' performance.

Current practice patterns and patient persistence with anticoagulant treatments for cancer-associated thrombosis.

BACKGROUND: Recommended therapeutic options for the management of venous thromboembolism (VTE) in patients with cancer are burdensome, and compliance with guidelines is unknown. OBJECTIVES: To describe current treatment patterns and to evaluate patient persistence on various anticoagulants. PATIENTS/METHODS: Medical and pharmacy claims from the Humana Database were analyzed (01/2007-12/2014). Newly diagnosed cancer patients treated with anticoagulants were categorized into one of the following cohorts: low-molecular-weight heparin (LMWH), warfarin, and rivaroxaban. Discontinuation, switching, and persistence with the index therapy were analyzed. RESULTS: A total of 2941 newly diagnosed patients with cancer who developed VTE and received anticoagulation in outpatient settings were identified. Of these, 97% initiated anticoagulation with LMWH (n=735; 25%), warfarin (n=1403; 47.7%), or rivaroxaban (n=709; 24.1%). Median treatment durations for the LMWH, warfarin, and rivaroxaban cohorts were 3.3, 7.9, and 7.9 months, respectively; Kaplan-Meier rates of persistence to the initial therapy were 37%, 61%, and 61% at 6 months. Warfarin and rivaroxaban users were significantly more likely to remain on initial therapy compared to LMWH (adjusted hazard ratios [HRs; 95% CI]: warfarin, 0.33 [0.28-0.38]; rivaroxaban, 0.38 [0.32-0.46]). The proportion of patients that switched from their initial treatment to another anticoagulation treatment was 22.9%, 7.9%, and 4.7% in the LMWH, warfarin, and rivaroxaban cohorts, respectively. CONCLUSIONS: This real-world analysis showed that, despite guideline recommendations, warfarin and rivaroxaban are at least as equally utilized as LMWH for the treatment of cancer-associated thrombosis. LMWH was associated with significantly lower persistence, shorter duration of treatment, and more switching than warfarin and rivaroxaban.

Evaluation of US prescription patterns: Are treatment guidelines for cancer-associated venous thromboembolism being followed?

INTRODUCTION: Venous thromboembolism (VTE) is a common complication of cancer. Clinical practice guidelines recommend low-molecular-weight heparin (LMWH) for treatment of cancer-associated VTE, but it is unclear how frequently these are followed. This study assessed anticoagulation treatment patterns for VTE in newly diagnosed cancer patients in the United States. MATERIALS AND METHODS: MarketScan® claims records of more than 80 million insured members between January 1, 2009 and July 31, 2014 were retrospectively analyzed. Subjects were included if they were 18years of age or older, and had a diagnosis of cancer (9 solid tumor types) and VTE. Data were included for LMWH, warfarin, and other anticoagulants (fondaparinux and direct oral anticoagulants [DOACs]). Patients with anticoagulant treatment prior to cancer diagnosis were excluded. RESULTS: VTE developed in 6.2% of cancer patients (median, 181days after cancer diagnosis). VTE rates were highest for pancreatic (17.5%) and lung (12.6%) cancer and lowest for breast (4.2%) and prostate (4.1%) cancer. For patients for whom outpatient prescription data were available, warfarin was most commonly used (50.0%), followed by LMWH (40.0%) and other anticoagulants (10.0%). Over 6months, 13% of patients who initiated injectable anticoagulants remained on them compared with 30% of those who initiated oral anticoagulants. More patients switched from LMWH to warfarin and other anticoagulants (44%) versus those who switched from warfarin (28%). CONCLUSIONS: Warfarin was the most utilized anticoagulant for cancer-associated VTE despite guideline recommendations for LMWH. More patients remained on oral versus injectable agents, which may be related to self-injection burden and costs.

Incidence of ischemic stroke or transient ischemic attack in patients with multiple risk factors with or without atrial fibrillation: a retrospective cohort study.

BACKGROUND: The risk of stroke in atrial fibrillation (AF) increases with number of risk factors (RFs). However, the combined effect from multiple RFs on the incidence of ischemic stroke and transient ischemic attack (TIA) among US patients without AF has not been fully examined. METHODS AND RESULTS: Truven MarketScan Medicare Supplemental database was used to establish cohorts of patients ≥65 years old with and without AF. Index date was first occurrence of AF diagnosis (AF patients) or first medical encounter (non-AF patients) during the inception period from 2010 through 2011. Incidences of ischemic stroke/TIA in relation to number of baseline RFs (congestive heart failure, hypertension, advanced age, diabetes, and prior stroke/TIA, myocardial infarction) were determined during the follow-up period from the index date through March 2013. A total of 158,199 patients were included in the AF cohort and 1,181,273 patients in the non-AF cohort. Approximately 51% of AF patients had ≥3 RFs versus 18% in non-AF patients. Ischemic stroke/TIA were observed in 24,680 and 104,154 patients in the AF and non-AF cohorts, yielding incidence rate (SD) of 7.3 (0.05) and 3.2 (0.01) per 100 person-years, respectively. In the AF cohort, incidence rate of ischemic stroke/TIA was 2.3, 4.9, 9.4, and 16.9 per 100-person years for 0, 1-2, 3-4, and 5-6 RFs, respectively, compared with the corresponding rate of 1.3, 2.8, 6.4, and 12.3 per 100 person-years for the non-AF cohort. This positive association between the number of risk factors and incidence rates within each cohort was consistently observed in sensitivity analyses. CONCLUSION: In a large cohort of elderly patients without AF, the risk of ischemic stroke/TIA increased substantially in the presence of multiple RFs, highlighting potentially unmet medical needs. This observation implies that future studies may be warranted to investigate the effect of prophylactic anticoagulation in high risk non-AF patients.

Characterizing major bleeding in patients with nonvalvular atrial fibrillation: a pharmacovigilance study of 27 467 patients taking rivaroxaban.

BACKGROUND: In nonvalvular atrial fibrillation (NVAF), rivaroxaban is used to prevent stroke and systemic embolism. OBJECTIVE: To evaluate major bleeding (MB) in NVAF patients treated with rivaroxaban in a real-world clinical setting. METHODS: From January 1, 2013, to March 31, 2014, US Department of Defense electronic health care records were queried to describe MB rates and demographics. Major bleeding was identified using a validated algorithm. RESULTS: Of 27 467 patients receiving rivaroxaban, 496 MB events occurred in 478 patients, an incidence of 2.86 per 100 person-years (95% confidence interval: 2.61-3.13). The MB patients were older, mean (SD) age of 78.4 (7.7) vs 75.7 (9.7) years, compared with non-MB patients. Patients with MB had higher rates of hypertension (95.6% vs 75.8%), coronary artery disease (64.2% vs 36.7%), heart failure (48.5% vs 23.7%), and renal disease (38.7% vs 16.7%). Of MB patients, 63.2% were taking 20 mg, 32.2% 15 mg, and 4.6% 10 mg of rivaroxaban. Four percent of MB patients took warfarin within the prior 30 days. Major bleeding was most commonly gastrointestinal (88.5%) or intracranial (7.5%). Although 46.7% of MB patients received a transfusion, none had sufficient evidence of receiving any type of clotting factor. Fourteen died during their MB hospitalization, yielding a fatal bleeding incidence rate of 0.08 per 100 person-years (95% confidence interval: 0.05-0.14). Mean age at death was 82.4 years. CONCLUSIONS: In this large observational study, the MB rate was generally consistent with the registration trial results, and fatal bleeds were rare.

Effectiveness of oral propafenone for the prevention of atrial fibrillation after coronary artery bypass grafting.

The efficacy and safety of oral propafenone for the prevention of atrial fibrillation (AF) were tested in a group of 293 patients who underwent coronary artery bypass grafting. Patients were randomized to placebo or 1 of 2 doses of propafenone. Patients treated with propafenone 675 mg/day compared with placebo had a nonsignificantly reduced incidence of AF and did not have a reduction in length of stay. Adverse events and discontinuations for untoward events were equal among the 3 groups.