D dimer dynamics in hospitalized COVID 19 patients: potential utility for diagnosis of pulmonary embolism.

Background A higher incidence of thrombotic events, mainly pulmonary embolism (PE), has been reported in hospitalized patients with COVID-19. The main objective was to assess clinical and weekly laboratory differences in hospitalized COVID-19 patients according to occurrence of PE. Methods This retrospective study included all consecutive patients hospitalized with COVID-19 who underwent a computed tomography (CT) angiography for PE clinical suspicion. Clinical data and median blood test results distributed into weekly periods from COVID-19 symptoms onset were compared between PE and non-PE patients. Results Ninety-two patients were included, 29 (32%) had PE. PE patients were younger (63.9 (SD13.7) vs 69.9 (SD12.5) years). Clinical symptoms and COVID-19 CT features were similar in both groups. PE was diagnosed after a mean of 20.0 (SD8.6) days from the onset of COVID-19 symptoms. Corticosteroid boluses were more frequently used in PE patients (62% vs. 43%). Median values [IQR] of D-dimer in PE vs non-PE patients were: week 2 (2010.7 [770.1-11208.9] vs 626.0 [374.0-2382.2]; p =0.04); 3 (3893.1 [1388.2-6694.0] vs 1184.4 [461.8-2447.8]; p =0.03); and 4 (2736.3 [1202.1-8514.1] vs 1129.1 [542.5-2834.6]; p =0.01). Median fold-increase of D-dimer between week 1 and 2 differed between groups (6.64 [3.02-23.05] vs 1.57 [0.64-2.71], p =0.003); ROC curve AUC was 0.879 ( p =0.003) with a sensitivity and specificity for PE of 86% and 80%, respectively. Conclusions Among hospitalized COVID-19 patients, D-dimer levels are higher at weeks 2, 3 and 4 after COVID-19 symptom onset in patients who develop PE. This difference is more pronounced when the fold increase between weeks 1 and 2 is compared. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement No funding was provided for this study. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The protocol was approved by the Ethics Committee of the Hospital Universitari de Bellvitge (Barcelona, Spain; approval number PR178/20). All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The datasets used and/or analysed for the current study are available from the corresponding author on reasonable request.