Hematology and Oncology

Predicting bleeding risk in NSTEMI

In this large derivation and validation cohort (from the CRUSADE quality improvement initiative), researchers developed a risk score to predict the risk of major in-hospital bleeding in patients with NSTEMI. This can be easily calculated at the following url (link), and can be used to make decisions on risk / benefit ratios of various anticoagulant medications for NSTEMI patients.

Duration of warfarin for new DVT

Duration of warfarin for first DVT is hotly debated. In this multi-center trial of patients with new first DVT, patients were randomized to fixed-duration or flexible-duration (based on consecutive USG findings at 3 months). The fixed-group received 3 months of warfarin for secondary DVT, and 6 months for unprovoked DVT. The flexible-group received 3 months (if their 3 month USG showed vein re-canalization). For those not re-canalized at 3 months, they received additional USG at 3 and 9 months (for secondary DVT) and at 3, 9, 15, and 21 months (for unprovoked DVT). The 33 month f/u recurrent DVT risk was 12% in the flexible-group, which was significantly lower than the 17% in the fixed group. This indicates an advantage of continuing warfarin in patients without re-canalization. However, an editorialist points out that patients with idiopathic DVT need indefinite warfarin, and those with provoked DVT need "time-limited" warfarin. The latter…

Plavix + ASA reduces afib-related stroke risk

In this randomized trials of 7554 patients with atrial fibrillation, who were not candidates for warfarin, and had at least 1 risk factor for stroke, were randomized to ASA or ASA + plavix. After 3.6 years follow, those in the combined group had lower risk of stroke (2.4% versus 3.3% per year) and lower risk of vascular events (stroke, MI, non-CNS emboli, or death) (6.8% versus 7.6% per year). Major bleeding (primarily GI bleeding) was more common in the combination group (2% versus 1.3% per year). In patients at low risk for GI bleeding, high risk for stroke, and no candidacy for warfarin, ASA + plavix is a reasonable alternative (abstract).

Statins and primary prevention of VTE

In a follow-up study from the JUPITER trial (which randomized >17,000 older adults with LDL<130 and CRP >2 to rosuvastatin or placebo), after a median of 2 years, the rosuvastatin group had a lower risk of incident VTE (HR 0.57, CI 0.37-0.86). Although it would be premature to use statins for primary prevention of VTE, it is intriguing, and will likely results in studies evaluating the role of statins in preventing recurrent VTE (abstract).

Unfractionated heparin dosing; hard to get it right

This analysis is from a large prospective trial of over 20,000 patients with STEMI who were randomized to unfractionated (UFH) or low molecular weight heparin (LMWH). UFH was dosed bythe ACC/AHA weight based nomogram, with centrally monitored aPTTs (60 U/kg bolus and 12 U/kg/hour gtt). Despite 99% adherence to the nomogram, only 34% of initial aPTT's were therapeutic. Markedly low aPTT's (13%) were associated with increased risk reinfarction (OR 2.2), and markedly high aPTT's (16%) were associated with minor or major bleeding (OR 2.1). Markedly high aPTT's were more likely in patients that were older, female, lower weight, or with renal dysfunction. Unfortunately, even in the best of circumstances, we achieve therapeutic initial levels only 1/3 of the time, reminding us to remain vigilent despite protocols, especially in patients with the above risk factors (abstract).