PCV4 REAL WORLD EVIDENCE OF RECURRENT VENUS THROMBOEMBOLISM (RVTE) IN ELDERLY PATIENTS: DIFFERENCES BY PHARMACOLOGIC PROPHYLAXIS TREATMENT

Abstract

To examine rVTE in patients receiving direct oral anticoagulants (DOACs), as compared to patients receiving heparin, in a representative sample of US adults. In a US-based, linked claims/EMR network, prophylactic DOAC and heparin treatment were compared for rVTE. Patients were 60+ years old, treated with heparin or DOACs in the month prior to their first VTE event, with no other anticoagulant treatment. Patients had at least one EMR fact/claim in the 12-months before the first medication code. A 1:1 matched propensity score analysis was employed using nearest-neighbor-greedy matching. rVTE was stratified by deep vein thrombosis (DVT) and pulmonary embolism (PE) events. Risk differences and Kaplan-Meier (KM) analyses measured recurrence 1 and 6 months after the index event. All patient characteristics were measured using ICD9/10 and RxNorm codes. Over 6,000 matched DOAC and heparin patients were identified. In the month following the first VTE event, patients treated with DOACs, compared to heparin patients, experienced 2.5% fewer rVTE events. This increased to 4.3% fewer events when only examining PE. When measuring recurrence over 6 months, patients treated with DOACs, compared to heparin patients, experienced 1.6% fewer rVTE events. However, heparin-treated patients experienced fewer DVT events and VTE events, overall. KM curves showed DOAC patients experience fewer rVTE events overall until about 3-4 months after the first VTE event, at which point patients who receive heparin respond more positively. No differences were overserved between heparin and specific DOACs. Results suggest that DOACs perform better than heparin in the first few months following the initial event, but this does not remain constant over time. Studies showing DOACs to be superior to heparin should closely consider length of observation. Further analysis is required to examine change in baseline confounders over time.