Impact of postdischarge low-molecular-weight heparin after gastrointestinal cancer surgery

The real-world effectiveness of low-molecular-weight heparin (LMWH) to prevent venous thromboembolism (VTE) among patients undergoing cancer surgery remains uncertain. We sought to examine postdischarge prescription patterns and outcomes associated with LMWH use among patients who underwent surgery for gastrointestinal (GI) cancer.

Individuals who underwent GI cancer resection between 2013 and 2020 were identified from the IBM MarketScan database. Entropy balancing (EB) and logistic regression were used to examine the association between postdischarge LMWH use and the incidence of thrombotic and bleeding events.

Among 17,541 patients who underwent GI cancer surgery (esophagus: n = 429 [2.4%]; gastric: n = 819 [4.7%]; liver: n = 544 [3.1%]; biliary: n = 252 [1.4%]; pancreas: n = 1237 [7.1%]; colon: n = 10,670 [60.8%]; rectum: n = 3590 [20.5%]), 9184 (52.4%) were male, with a median age of 54 years (IQR, 48-59), and 1606 (9.2%) received postdischarge LMWH. The 90-day incidence of thrombotic and bleeding events was similar between patients who received LMWH after discharge and those who did not receive LMWH ( thrombotic event: 3.0% vs 2.9%, respectively; bleeding event: 1.2% vs 0.8%, respectively; both P >.05). This association remained consistent after EB weighting, with comparable odds of VTE (odds ratio [OR], 0.93 [95% CI, 0.62-1.39]) and bleeding events (OR, 1.10 [95% CI, 0.56-2.09]) between patients who received LMWH and those who did not.

Of note, 1 in 10 commercially insured patients who underwent GI cancer surgery received VTE prophylaxis with LMWH after discharge. Nonetheless, the incidence of thrombotic complications was comparable among patients, regardless of postdischarge LMWH use.