Apixaban better than enoxaparin for extended-duration VTE prophylaxis after surgery

Apixaban is not inferior to enoxaparin for extended-duration venous thromboembolic event (VTE) prophylaxis (EP) following urologic oncology surgery, reveals a study. In addition, apixaban is associated with fewer major complications and compliance-related adverse events.

“Apixaban may have a more favourable safety profile than enoxaparin, although this should be tested in a randomized controlled trial,” said the researchers led by Mary E Westerman, Department of Urology, The University of Texas, M.D. Anderson Cancer Center, Houston, Texas, US.

Westerman and her team conducted a single-centre prospective quality improvement study between 10 August 2020 and 21 September 2021 to measure patient compliance and safety with EP. They collected baseline data for 6 months, followed by a uniform departmental change from enoxaparin to apixaban. Data collection duration was set a priori via noninferiority sample size estimation (145 per group).

Compliance events (real or potential barriers to EP use) were the primary outcome, while 30-day postdischarge safety events (symptomatic VTE or major bleed) were secondary.

Enoxaparin was given to 161 discharged patients (baseline period) and apixaban to 154 (intervention period). [J Urol 2022;208:886-895]

More patients in the enoxaparin group experienced safety events compared to those receiving apixaban (3.1 percent vs 0 percent). The 3.1-percent (95 percent confidence interval, 0.043‒5.8) absolute risk difference reached the prespecified noninferiority threshold (p=0.028 for apixaban superiority).

Furthermore, compliance events occurred in more patients prescribed enoxaparin than in those treated with apixaban (33.5 percent vs 14.3 percent; p=0.0001).

“Patients had fewer compliance-related adverse events with apixaban than enoxaparin, and apixaban should be offered to patients needing EP,” the researchers said. “Based on these results, apixaban is now our departmental standard.”

Meds to beds program

Of note, the lower rate of compliance events with apixaban was because “nearly all apixaban prescription were filled at our hospital,” according to the researchers, who intentionally applied a broad definition of compliance events in designing this study.

“The need to resend a prescription to an external pharmacy because of cost may not have the same impact as a patient skipping doses due to side effects,” they said. “However, resending prescriptions can result in discharge delays, patient inconvenience, or patient noncompliance if the cost remains high.”

Such claim was consistent with a study in the paediatric literature, reporting improved compliance metrics among patients taking medications in the hospital prior to discharge, which was termed “meds to beds” program. [Pediatrics 2021;147:e20192413]

This intervention also worked in adults, with a study showing reduced rates of 30-day hospital readmissions and emergency department visits. [Am J Health Syst Pharm 2014;71:739]

“Notably, our pharmacy had a manufacturer coupon they could apply if the patient’s copay for apixaban was too high, which likely improved the percentage filled internally,” the researchers said.

“Other real-world limitations of our design include reliance on patient self-report for missed doses (no syringe counts or outside pharmacy verification) and adverse medication effects,” they added.