Clinical Thrombosis Rate was not Increased in a Cohort of Cancer Patients with COVID-19

Zavras, Phaedon D.; Kabarriti, Rafi; Mehta, Vikas; Goel, Sanjay; Billett, Henny H.

Increased rates of thromboembolic events (TE) have been reported in patients with coronavirus disease (COVID-19), even without prior predisposition to thrombosis. D-dimer levels have been shown to positively correlate with disease severity and mortality, leading to adoption of new empiric anticoagulation protocols by many centers. We aimed to assess whether COVID-19 further increased the risk of TE events in a cancer population who tested positive for COVID-19 at Montefiore Medical Center, Bronx, NY. The electronic medical records of 218 cancer patients were retrospectively reviewed up to April 10th, 2020. Work-up of thrombosis was done by the primary team upon clinical or laboratory suspicion. All imaging studies' reports, within 20 days of COVID-19 positive test, were reviewed for presence of new arterial or venous thrombosis. Mortality was assessed up to one month since positive COVID-19 test result. Twelve patients (5.5%) were found to have new arterial (N=6, 50%) or venous (N=6, 50%) thrombosis. Five patients (41.7%) had history of prior TE events. Incidence of deep venous thrombosis and pulmonary embolism was 1.8% and 0.5%, respectively. Arterial events occurred in the brain (66.7%), aorta (16.7%) and coronary arteries (16.7%). Median time from COVID test was 8 days (IQR, 1.5 - 11.3). Five patients (41.7%) had received either prophylactic or therapeutic anticoagulation for a median 2 days (IQR, 1 - 5). Median peak D-dimer within 36 hours of the TE event was 9.8 mcg/mL (N=4 patients, IQR, 1.7 - 18.3). Mortality did not differ significantly between the patients with new TE events vs those without; mortality 41.7% vs 37.4%, respectively, p=0.77. Empiric anticoagulation did not improve mortality. Fifty percent of all TE events were arterial. The overall TE rate of 5.5% in the cancer population was not higher than the risk of general population. Our findings support the need for larger studies in the COVID-19+ cancer population.