Background Venous thromboembolism (VTE) is a well-documented complication of both solid and hematologic malignancies, but there are fewer data on allogeneic hematopoietic cell transplant (HCT) recipients. Therefore, we studied the incidence, risk factors, and impact of VTE on post-HCT outcomes in a contemporary cohort.

Methods We retrospectively reviewed patients who underwent allogeneic HCT between January 2014 and August 2019 to identify patients with post-HCT VTE. Patient, disease, and transplant-related risk factors for VTE were investigated using competing risk analysis.

Results A total of 431 patients were included in this study. Median (interquartile range [IQR]) age in years was 59 (46–65) at transplant. The most common indication for transplant was acute myelogenous leukemia (49.4%). Within our cohort, 64 patients (14.8%) developed post-HCT VTE with a median (IQR) follow-up time of 24.6 (8.4–47.1) months. The cumulative incidence of VTE was 4.2% at 6 months, 9.0% at 12 months, 12.6% at 24 months, and 13.8% at 36 months. In multivariable analysis, older age (hazard ratio [HR] per 10-year increase: 1.36, 95% confidence interval [CI]: 1.09–1.70), history of VTE (HR: 1.95, 95% CI: 1.09–3.49), and grade 2–4 acute graft versus host disease (GVHD; HR: 1.75, 95% CI: 1.05–2.94) were independently associated with VTE. VTE was significantly associated with an increased risk of nonrelapse mortality (NRM; HR: 4.09, 95% CI: 2.47–6.74) and decreased overall survival (OS; HR: 2.19, 95% CI: 1.48–3.24).

Conclusion VTE is an important complication after allogeneic HCT and is significantly associated with increased NRM and decreased OS. Older patients, those with prior VTE, and patients with acute GVHD are at increased risk for development of VTE after HCT.

背景静脉血栓栓塞（VTE）是实体瘤和血液恶性肿瘤的一种有据可查的并发症，但有关同种异体造血细胞移植（HCT）受者的数据较少。因此，我们在当代队列中研究了 VTE 的发生率、危险因素以及对 HCT 后结局的影响。

方法我们回顾性分析了 2014 年 1 月至 2019 年 8 月期间接受同种异体 HCT 的患者，以确定 HCT 后发生 VTE 的患者。使用竞争风险分析来调查 VTE 的患者、疾病和移植相关风险因素。

结果本研究共纳入431例患者。移植时的中位年龄（四分位距 [IQR]）为 59 岁（46-65 岁）。最常见的移植适应症是急性髓性白血病（49.4%）。在我们的队列中，64 名患者 (14.8%) 发生 HCT 后 VTE，中位 (IQR) 随访时间为 24.6 (8.4–47.1) 个月。 VTE 的累积发生率为 6 个月时 4.2%、12 个月时 9.0%、24 个月时 12.6% 和 36 个月时 13.8%。在多变量分析中，年龄较大（每 10 年增加的风险比 [HR]：1.36，95% 置信区间 [CI]：1.09–1.70）、VTE 病史（HR：1.95，95% CI：1.09–3.49）、 2-4 级急性移植物抗宿主病（GVHD；HR：1.75，95% CI：1.05-2.94）与 VTE 独立相关。 VTE 与非复发死亡率风险增加（NRM；HR：4.09，95% CI：2.47-6.74）和总生存率降低（OS；HR：2.19，95% CI：1.48-3.24）显着相关。

结论VTE 是同种异体 HCT 后的重要并发症，与 NRM 增加和 OS 降低显着相关。老年患者、既往患有 VTE 的患者以及患有急性 GVHD 的患者在 HCT 后发生 VTE 的风险增加。