High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19.

Background: This study's primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods: This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray's method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results: Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8-11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7-21.0) and 9.3 (95% CI, 7.9-11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018-3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions: In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections.

Incidence of deep venous thrombosis in COVID-19 hospitalized patients during the first peak of the Italian outbreak.

OBJECTIVES: A high rate of thrombotic events has been reported in COVID-19 population. The study aims to assess the incidence of deep vein thrombosis (DVT) in COVID-19 patients admitted to a single tertiary hospital. METHODS: From April 2nd to April 18th, 2020, hospitalized patients with SARS-CoV-2 infection were screened by lower limb duplex ultrasound (DUS). Patients were on (low molecular weight heparin) LMWH prophylaxis in medical wards, and on therapeutic anticoagulation in intensive care unit (ICU). DVT risk factors, reported by the Padua prediction score and blood tests, were retrieved from institutional electronic charts. The study primary endpoint was the incidence of DVT in the in-hospital COVID-19 population and its association with clinical and laboratory risk factors. The secondary endpoint was the association of DVT with mortality. RESULTS: Two hundred patients (median age 62 years, 72% male, 40 in ICU) received DUS screening. DVT was observed in 29 patients (14.5%), with proximal extension in 16 patients, and in association with symptoms in four patients. The DVT rate was similar in ICU (12.5%) and non-ICU patients (15%). Eighty-seven patients underwent a computed tomography angiography (CTA) that showed pulmonary embolism in 35 patients (40.2%) not associated with DVT in 25/35 cases (71.4%). DVT in the ten patients with pulmonary embolism were symptomatic in four and with a proximal localization in eight cases. A D-dimer level ≥5 mg/l at admission was predictive of DVT (OR 1.02; IC95% 1.03-1.16; p = .003). At the multivariate analysis in-hospital mortality was predicted by age (OR 1.06; 95% CI 0.02-1.15; p = .004) and by being an ICU patient (OR 1.23; 95% CI 0.30-2.25; p = .01). CONCLUSIONS: Despite LMWH prophylaxis or full anticoagulant therapy, the incidence of DVT, mainly asymptomatic, in hospitalized COVID-19 patients was 14.5%. Further research should focus on the appropriate antithrombotic therapy for COVID-19 patients.

A Case of Covid-19 Patient with Acute Limb Ischemia and Heparin Resistance.

Heparin resistance is an uncommon phenomenon defined as the need for high-dose unfractionated heparin (UFH) of more than 35,000 IU/day to achieve the target activated partial-thromboplastin time ratio or the failure to achieve the desired activated clotting time after a full UFH dose. This rare phenomenon is being more commonly observed in Covid-19 patients in a hypercoagulable state. We describe a Covid-19 patient confirmed by reverse-transcriptase polymerase chain reaction assay, with acute limb ischemia, who developed heparin resistance. The patient was managed by the departments of vascular surgery, anesthesia and intensive care, and the Coagulation Service and Thrombosis Research from San Raffaele Scientific Institute, Milan, Italy.