The occurrence of thromboembolism among patients with coronavirus disease 2019: A systematic review and meta-analysis.

The results of reported thrombosis occurrences in patients with COVID-19 are inconsistent. Objectives To elucidate the occurrence of thromboembolism in COVID-19 patients with different types. The search was conducted up to May 10, 2024. The observational studies reporting the occurrence of venous thromboembolism (VTE) and/or arterial thromboembolism (ATE) in COVID-19 patients were included, which were independently evaluated by two researchers. The outcomes were VTE and ATE, including deep vein thrombosis, pulmonary embolism, myocardial infarction, and stroke. The effect sizes were combined using a random-effects model with inverse variance weighting, and a 95% confidence interval was calculated through arcsine transformation. A total of 224 studies was included. The occurrence of VTE was 5.8% (95% CI, 5.0%-6.7%, I2 = 99.912%; 91 studies; 4,545,285 patients). The occurrence of VTE was higher in the intensive care unit compared to the ward (13.2%, 95% CI, 11.7%-14.7%; I2 = 96.840%; 47 studies; 172,571 patients, vs. 3.2%, 95% CI, 2.9%-3.5%; I2 = 95.714%; 40 studies; 1,046,738 patients; P < 0.001), and was even lower among outpatient and discharged cohorts (0.0%, 95% CI, 0.0%-0.0%; I2 = 99.410%; 10 studies; 2,566,194 patients, vs. 0.7%, 95% CI, 0.4%-1.1%; I2 = 98.924%; 16 studies; 828,884 patients; P < 0.001). In contrast, the occurrence of ATE was lower, which was 2.6% (95% CI, 1.8%-3.5%, I2 = 99.924%; 44 studies; 2,884,839 patients). This study found that COVID-19 patients had a relatively high risk of VTE and ATE, but with significant variations among different types. Consequently, the selection of anticoagulant measures for them should be careful.