Evaluation of Time to Therapeutic Anticoagulation and Associated Outcomes in Critically Ill, Obese Patients With Pulmonary Embolism Receiving Unfractionated Heparin

Background: Delays in time to therapeutic activated partial thromboplastin time (aPTT) have been associated with poor outcomes in patients with acute pulmonary embolism (PE). Objective: To investigate the relationship between time to therapeutic anticoagulation and in-hospital mortality in critically ill, obese patients with acute PE. Methods: This study examined 204 critically ill patients with a body mass index (BMI) ≥30 kg/m² receiving unfractionated heparin (UFH) for PE treatment. Patients achieving therapeutic anticoagulation within 24 hours of UFH initiation (early) were compared to those in >24 hours (delayed). Additional end points included 30-day mortality, median time to therapeutic aPTT, proportion of therapeutic and supratherapeutic aPTT values, hemodynamic deterioration, thrombolytic therapy after UFH initiation, length of stay, and bleeding. Results: No difference in in-hospital or 30-day all-cause mortality was seen (odds ratio [OR]: 1.33, confidence interval [CI]: 0.647-2.72; OR: 1.003, CI: 0.514-1.96). Patients in the early group had a greater proportion of therapeutic aPTT values (66.7% vs 50%, P <.001) and higher percentage of supratherapeutic aPTT values (20.9% vs 11.3%, P <.001); however, no increase in clinically significant bleeding was evident (15.2% vs 10.9%, P =.366). Conclusion: In this population, a shorter time to therapeutic aPTT was not associated with improved survival.