Hematology and Oncology

LMWH vs UFH for VTE prophylaxis

In this large retrospective cohort of >32,000 patients with 4 common diagnoses with moderate to high risk of VTE, about half received LMWH and half UFH. There were no differences between the groups in rates of VTE, bleeding or cost, but UFH was associated 2.8 times the odds of a complication requiring discontinuation compared to LMWH. This large systematic review found LMWH was associated with lower odds of complications compared to UFH (abstract)

New transfusion guidelines

The AABB has issued updated guidelines on transfusion thresholds, which include a Hb<7 for most ICU patients, and a Hb<8 for most post-surgical patients, with higher thresholds for those with symptoms (such as chest pain or decompensated CHF). The full guidelines are available at (guidelines)

Rivaroxaban for PE

In this large trial of 4832 patients with PE, they were randomized to rivaroxaban (15mg bid for 3 weeks, then 20mg qday) or enoxaparin-warfarin. Recurrent VTE occurred at about the same rate in both groups (2.1% of rivaroxaban group and 1.8% of enoxaparin-warfarin group), but major bleeding was less common with rivaroxaban (1.1% vs 2.2%). Pending FDA approval, rivaroxaban may become the new standard for VTE treatment (abstract)

Add OSA to list of VTE risk factors

In this large cohort of >10,000 patients, although the overall risk of VTE in those with sleep apnea was low (0.5% at 3.5 year follow up), it was significantly higher compared to matched controls (0.2%, hazard ratio ~3) which is even higher in those with sleep apnea on CPAP (hazard ratio ~9). Sleep apnea should be factored into risk prediction of VTE (abstract)

Oral Xa inhibitors better than enoxaparin for VTE prophylaxis after hips/knees

This systematic review compared the efficacy and safety of the oral Xa inhibitors vs enoxaparin in patients post hip or knee arthroplasty; the Xa agents slightly reduced the risk of symptomatic DVT (by 3 events for every 1000 patients treated) compared to enoxaparin, at the risk of an increase in major bleeding events (by 2 events for every 1000 patients treated) for all doses, but no increased risk for low doses. Low dose Xa inhibitors may be as safe and more effective than enoxaparin for VTE prophylaxis post hip and knee arthroplasty (abstract)