Venous Thromboembolic Disease and Bone Marrow Transplant: A Remarkable Cause of Mortality and Morbidity — Potentially Preventable

Thrombotic events are frequent in patients undergoing HSCT, being an important cause of morbidity and mortality. The highest incidence occurs three months after the transplant. There are several risk factors, which add to those already known for VTE: neoplasia, central venous catheters, immobilization, chemotherapy, infections, GVHD. In the series described, the frequencies are variable, between 0.5 and 23.5%, with an overall incidence of 5%. In patients with GVHD, this incidence increases, with up to 35% of events.

METHODS

A retrospective observational study that includes patients transplanted in our Unit between 2014 and 2017 has been conducted, with the objective of analyzing the incidence of VTE peri-TPH. Likewise, we have analyzed if it is associated to catheter, presence of CVRF, if there was a known medical history of thrombophilia, number of platelets at time of thrombosis, the heparin used and whether anticoagulation was maintained indefinitely or not.

RESULTS

Out of the 235 patients included in our series, 130 underwent an autologous transplant and 105 an allogeneic transplant. 18 thrombotic events occurred (9 men and 9 women, aged between 18 and 65 years), which means 7.5% (14 occurred between days 0-100, 12 in patients undergoing autologous hematopoietic stem cell transplantation). Three of them had thromboembolism and the rest deep vein thrombosis, 4 of which with catheter. The platelet count at the time of the event ranges from 21 to 409,000 / mm3. Regarding the heparin used, 2 were treated with Tinzaparin and the rest with Bemiparin. Only 1 of the patients presented prior VTE. Among the patients, there were some with CVRF and others without relevant medical history. Just in one patient, a family thrombophilia study had been performed prior to his hematological diagnosis, resulting in a deficit of protein S. In 8 of the patients, anticoagulation was maintained indefinitely with LMWH in the post-transplant period.

CONCLUSIONS

Our incidence approaches the literature, albeit the series of published cases are heterogeneous and with variable differences. Although the incidence of thrombosis in these patients is a cause of marked morbidity and mortality, the risk of bleeding also increases, therefore routine prophylaxis is not recommended in all patients. We must undergo an exhaustive analysis of the data to identify individually which patients may be candidates for prophylaxis, with the aim of reducing the incidence without raising the hemorrhagic risk of our patients.