Risk factors for recurrent VTE after stopping anticoagulants
| Risk factors . | Risk ratio* . |
|---|---|
| Major transient risk factor vs unprovoked† | 0.24,12,14 |
| Minor transient risk factor vs unprovoked† | 0.54,12,14 |
| Cancer vs unprovoked† | 1.5-3‡15 |
| Noncancer persistent risk factor† | 1.5-216 |
| Isolated distal DVT vs proximal DVT | 0.2-0.5‡4,12 |
| Proximal DVT vs PE without proximal DVT | 1.412 |
| Previous VTE: yes vs no | 1.59 |
| Male vs female (after unprovoked VTE) | 1.7512,17,18 |
| Elevated d-dimer (after unprovoked VTE): yes vs no | 1.5-2.5‡19 |
| Antiphospholipid antibody: yes vs no | 1.5-3‡20,21 |
| Hereditary thrombophilia: yes vs no | 1.2-2.0‡19,22,23 |
| Asian vs white or black | 0.824 |
| Residual DVT on ultrasound¶ | 1.425 |
| Risk factors . | Risk ratio* . |
|---|---|
| Major transient risk factor vs unprovoked† | 0.24,12,14 |
| Minor transient risk factor vs unprovoked† | 0.54,12,14 |
| Cancer vs unprovoked† | 1.5-3‡15 |
| Noncancer persistent risk factor† | 1.5-216 |
| Isolated distal DVT vs proximal DVT | 0.2-0.5‡4,12 |
| Proximal DVT vs PE without proximal DVT | 1.412 |
| Previous VTE: yes vs no | 1.59 |
| Male vs female (after unprovoked VTE) | 1.7512,17,18 |
| Elevated d-dimer (after unprovoked VTE): yes vs no | 1.5-2.5‡19 |
| Antiphospholipid antibody: yes vs no | 1.5-3‡20,21 |
| Hereditary thrombophilia: yes vs no | 1.2-2.0‡19,22,23 |
| Asian vs white or black | 0.824 |
| Residual DVT on ultrasound¶ | 1.425 |
As the influence of risk factors on the risk for recurrence may not be independent, the overall risk ratio associated with a combination of factor may not be the product of the individual risk ratios.
Major transient risk factor: within 3 months of general anesthesia for ≥30 minutes or bedbound in hospital for ≥3 days. Minor transient risk factor: within 2 months of general anesthesia for <30 minutes, estrogen therapy, pregnancy/puerperium, hospitalized <3 days, leg injury with reduced mobility for ≥3 days. Cancer: active (not considered cured). Noncancer persistent risk factor: a chronic disease that is associated with an increase in VTE risk (eg, active inflammatory bowel disease). Unprovoked: does not meet criteria for transient or persistent provoking factor.26
The risk ratio with these risk factors is expected to vary with the severity of the risk factor (eg, extent, number, nature, persistence [APA], aggressiveness, and level).
We do not routinely assess for residual thrombosis when we are considering stopping anticoagulants. We are most likely to assess for residual thrombosis, primarily as a baseline for future comparison if recurrence is suspected, if the initial DVT was large and anticoagulants are being stopped.