Abstract P33: The Impact of Stroke Risk on Warfarin and Aspirin Use in Patients With Non-Valvular Atrial Fibrillation Followed in Community-Based Primary Care Practices

• DOI: 10.1161/circoutcomes.4.suppl_1.ap33
• Publication Date: 2022-03-20T00:28:28Z
• Authors: Edward Ewen; Teresa A Simon; Claudine Jurkovitz; Joseph Jackson; William S Weintraub
• Keywords: 03 medical and health sciences; 0302 clinical medicine; 3. Good health

Background: The application of treatment guidelines for stroke prevention in patients with non-valvular atrial fibrillation (NVAF) in primary care practice is not well understood. This study examined the risk of stroke at diagnosis of NVAF and the decision to initiate oral anticoagulant (OAC) therapy or aspirin (ASA) in a community-based primary care population.

Methods: A retrospective cohort of patients with NVAF followed from 1998-2008 in a health system with a shared electronic medical record was evaluated. The presence of NVAF, OAC use, ASA use, and CHADS2 stroke risk score were collected through a review of the problem list, office and hospital records, laboratory values, and medication use. Stroke events following diagnosis were identified using office and hospital records. CHADS2 risk scores were categorized as 0, 1, and ≥ 2. We used t-test and the Chi-square to assess the association between continuous and categorical variables.

Results: A total of 840 NVAF patients were followed for a mean of 3.1 years. Those at high stroke risk (CHADS2 ≥ 2) were older (77 vs. 67 years, p < .001), more likely to be female (56% vs. 43%, p < .001), and followed for a shorter period of time (2.4 years vs. 3.6, p <.001). A total of 400 patients (47.6%) were classified as high risk, 289 (34.4%) with CHADS2 score of 1, and 151 (18%) with CHADS2 score of 0. Overall, there were no significant differences (p = 0.2) in the choice of treatment strategy by level of stroke risk (see Table ).

Conclusion: In this community setting, CHADS2 stroke risk in NVAF patients at the time of presentation appears to have little impact on the choice of treatment strategy. 35.8% of NVAF patients fail to receive warfarin anticoagulation despite CHADS2 treatment recommendations for stroke prevention. Additional research is needed to determine the reasons for failing to initiate stroke prevention therapy in real practice.

Table:

Treatment Strategy by CHADS2 Stroke Risk in NVAF Patients

Treatment Strategy

CHADS2 Score, n (%) No Treatment ASA Only Warfarin

0 19 (12.6) 51 (33.8) 81 (53.6)

1 37 (12.8) 81 (28.0) 171 (59.2)

≥ 2 43 (10.8) 100 (27.6) 257 (64.3)