Readmission After COVID-19 for Late Acute Venous Thrombosis; CASE SERIES and Systematic Review of the Literature.

Objective: Assess heterogeneity within patients with resolved COVID-19 to broaden the vision about post-discharge thrombotic cases and postulate possible related mechanisms in search of better anticoagulation guidelines. This study details patients' characteristics, medical history, treatment, and outcomes of readmitted patients with late acute thrombosis through a systematic review of the literature and patients from our academic center database.

Methods: We extracted the records of patients readmitted for venous thrombosis complications after discharge from the database of the first 2000 patients admitted with COVID-19 in our academic center; we also performed a systematic review of the literature using the Medical Subject Headings terms "late thrombosis," "COVID-19," + "venous thrombosis" in PubMed and Google Scholar according to PRISMA guideline.

Results: The literature review found 20 patients suitable for review matching the inclusion criteria. These patients were added to those in our database, summing up a total of 26 patients. The median age was 50 years old, 76.9% were male, and most were overweight or had grade 1 obesity (n = 11, 42.3%). None had a previous thrombotic history, but 50% had an underlying comorbidity. Thrombotic events presented on a median of 20 days (range: 4-150 days) from discharge. Pulmonary embolisms occurred in 23 patients (88.46%), deep vein thrombosis in 4, mesenteric thrombosis, and cerebral venous thrombosis in 1, respectively.

Conclusion: This study found that most patients readmitted for thrombotic events after COVID-19 discharge were middle-aged men with Venous Thrombo Embolism events.