Table 2.
Clinical characteristics of the POAT study participants at enrollment.
| Characteristic | African American (n=273) | European American (n=302) | p-value |
|---|---|---|---|
| Indication for warfarin therapy* | |||
| Deep Vein Thrombosis | 97 (35.5%) | 62 (20.5%) | <0.0001 |
| Pulmonary Thromboembolism | 49 (17.9%) | 27 (8.9%) | 0.0014 |
| Recurrent Venous Thromboembolism | 22 (8.1%) | 14 (4.6%) | 0.091 |
| Atrial Fibrillation | 87 (31.9%) | 174 (57.6%) | <0.0001 |
| Valvular Heart Disease | 32 (11.7%) | 54 (17.9%) | 0.04 |
| Low Left Ventricular Ejection Fraction | 42 (15.4%) | 29 (9.6%) | 0.03 |
| Cardiac Thrombus | 12 (4.4%) | 15 (5.0%) | 0.74 |
| Myocardial Infarction | 67 (24.5%) | 95 (31.5%) | 0.066 |
| Transient Ischemic Attack | 16 (5.9%) | 20 (6.6%) | 0.71 |
| Stroke | 57 (20.9%) | 38 (12.6%) | 0.007 |
| Peripheral Vascular Disease | 30 (11.0%) | 39 (12.9%) | 0.48 |
| Site of thromboembolism** | |||
| Arterial | 109 (39.9%) | 131 (43.4%) | 0.4 |
| Venous | 138 (50.5%) | 90 (29.8%) | <0.0001 |
| Both | 30 (11.0%) | 21 (6.9%) | 0.09 |
| None | 34 (12.4%) | 44 (14.6%) | 0.46 |
| Comorbidity | |||
| History of Myocardial Infarction | 9 (3.3%) | 30 (9.9%) | 0.0016 |
| History of CABG/ PTCA | 30 (11.0%) | 68 (22.5%) | 0.0002 |
| Cardiomyopathy | 32 (11.7%) | 43 (14.2%) | 0.37 |
| Coronary Artery Disease | 82 (30.0%) | 108 (35.8%) | 0.14 |
| Congestive Heart Failure | 69 (25.3%) | 59 (19.5%) | 0.10 |
| Hypertension | 134 (49.1%) | 132 (43.7%) | 0.20 |
| Hyperlipidemia | 63 (23.1%) | 118 (39.1%) | < 0.0001 |
| Diabetes Mellitus | 94 (34.4%) | 87 (28.8%) | 0.15 |
| Malignancy | 28 (10.3%) | 56 (18.5%) | 0.005 |
| Prior Hemorrhage | 24 (8.8%) | 16 (5.3%) | 0.1 |
| Renal insufficiency | 51 (18.7%) | 36 (11.9%) | 0.024 |
| End Stage Renal Disease | 36 (13.2%) | 10 (3.3%) | <0.0001 |
| Number of Comorbid Conditions | |||
| Low (0 or 1) | 88 (32.2%) | 74 (24.5%) | 0.03 |
| Medium (2 to 4) | 129 (47.2%) | 141 (46.7%) | |
| High (5 or more) | 56 (20.5%) | 87 (28.8%) | |
| Concurrent Medications | |||
| Antiplatelet agents | 133 (49.3%) | 189 (65.6%) | 0.001 |
| NSAIDS | 37 (13.7%) | 39 (12.9%) | 0.78 |
| CYP2C9 substrates | 91 (33.7%) | 96 (31.8%) | 0.62 |
| CYP2C9 inhibitors | 50 (18.3%) | 74 (24.4%) | 0.072 |
| VScoreΨ | 0.52 [0.27, 1.24] | 0.50 [0.25, 1.13] | 0.026 |
3 Hispanic patients excluded, significant p-values bolded
All patients had a prescribed target INR range of 2–3. Patients with orthopedic surgery excluded due to short (3–6 month) treatment duration, patients with mechanical heart valve and hypercoagulable state excluded due to higher intensity of anticoagulation required
Arterial thromboembolism includes patients with MI, Stroke & TIA. Venous thromboembolism includes patients with DVT & PE. Both include patients with venous and arterial events. None includes patients with no thromboembolic events (e.g. Atrial Fibrillation).
Patients can have more than one indication for therapy and comorbid conditions
CYp2C9 inhibitors included amiodarone, metronidazole, tamoxifen, propxyphene, co-trimoxazole, etc.. (Miners)
Variability Score captures the INR variation after accounting for the influence of the number of visits and the interval between visits on INR variation for each individual patient (presented as Median and Intraqaurtile range, with Wilcoxon p-value)