High Incidence and Unique Features of Cerebral Venous Sinus Thrombosis in Hospitalized Patients With COVID-19 Infection.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) secondary to vaccine-induced thrombotic thrombocytopenia is an extremely rare side effect of adenovirus-based COVID-19 vaccines. CVST incidence associated with COVID-19 itself has not been widely reported. We report the incidence of CVST in patients hospitalized with COVID-19 during the first year of the pandemic. METHODS: We analyzed de-identified electronic medical records of a retrospective cohort of patients admitted with COVID-19 to >200 hospitals between March 2020 and March 2021. We used International Classification of Diseases, Tenth Revision codes and natural language processing extracts to identify patients with a new CVST diagnosis during COVID-19 hospitalization. The primary outcome was CVST incidence in hospitalized, COVID-19-positive patients. Secondary outcomes included CVST incidence and mortality. Incidence rates were calculated using the DerSimonian-Laird estimator method. RESULTS: Ninety-one thousand seven hundred twenty-seven patients were evaluated; 22 had new CVST diagnoses by electronic medical record review. CVST incidence in the hospitalized COVID-19 cohort was 231 per 1 000 000 person-years (95% CI, 152.1-350.8). Females<50 had the highest incidence overall (males <50: 378.4 [142-1008.2]; females<50: 796.5 [428.6-1480.4]). In patients ≥50 years old, males had a higher estimated CVST incidence (males≥50: 130.5 [54.3-313.6]; females≥50: 88.8 [28.6-275.2]). Older patients (45.5% of patients ≥50 versus 0% of <50 years of age, P=0.012) and males (44.4% of males versus 7.7% of females, P=0.023) were more likely to die in hospital. CONCLUSIONS: CVST incidence in COVID-19-positive hospitalized patients is high. Advanced age and male gender were associated with likelihood of death in hospital; further studies are required to confirm these findings.

Cerebral Venous Thrombosis in Patients With Heparin-Induced Thrombocytopenia a Systematic Review.

BACKGROUND: Cerebral venous thrombosis (CVT) has recently been reported as a common thrombotic manifestation in association with vaccine-induced thrombotic thrombocytopenia, a syndrome that mimics heparin-induced thrombocytopenia (HIT) and occurs after vaccination with adenovirus-based SARS-CoV-2 vaccines. We aimed to systematically review the incidence, clinical features, and prognosis of CVT occurring in patients with HIT. METHODS: The study protocol was registered with PROSPERO (CRD42021249652). MEDLINE, EMBASE and Cochrane CENTRAL were searched up to June 1, 2021 for HIT case series including >20 patients, or any report of HIT-related CVT. Demographic, neuroradiological, clinical, and mortality data were retrieved. Meta-analysis of proportions with random-effect modeling was used to derive rate of CVT in HIT and in-hospital mortality. Pooled estimates were compared with those for CVT without HIT and HIT without CVT, to determine differences in mortality. RESULTS: From 19073 results, we selected 23 case series of HIT (n=1220) and 27 cases of HIT-related CVT (n=27, 71% female). CVT developed in 1.6% of 1220 patients with HIT (95% CI,1.0%-2.5%, I2=0%). Hemorrhagic brain lesions occurred in 81.8% of cases of HIT-related CVT and other concomitant thrombosis affecting other vascular territory was reported in 47.8% of cases. In-hospital mortality was 33.3%. HIT-related CVT carried a 29% absolute increase in mortality rate compared with historical CVT controls (33.3% versus 4.3%, P<0.001) and a 17.4% excess mortality compared with HIT without CVT (33.3% versus 15.9%, P=0.046). CONCLUSIONS: CVT is a rare thrombotic manifestation in patients with HIT. HIT-related CVT has higher rates of intracerebral hemorrhage and a higher mortality risk, when compared with CVT in historical controls. The recently reported high frequency of CVT in patients with vaccine-induced thrombotic thrombocytopenia was not observed in HIT, suggesting that additional pathophysiological mechanisms besides anti-platelet factor-4 antibodies might be involved in vaccine-induced thrombotic thrombocytopenia-related CVT.

Declining mortality of cerebral venous sinus thrombosis with thrombocytopenia after SARS-CoV-2 vaccination.

BACKGROUND AND PURPOSE: High mortality rates have been reported in patients with cerebral venous sinus thrombosis (CVST) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) after vaccination with adenoviral vector SARS-CoV-2 vaccines. The aim of this study was to evaluate whether the mortality of patients with CVST-VITT has decreased over time. METHODS: The EudraVigilance database of the European Medicines Agency was used to identify cases of CVST with concomitant thrombocytopenia occurring within 28 days of SARS-CoV-2 vaccination. Vaccines were grouped based on vaccine type (adenoviral or mRNA). Cases with CVST onset until 28 March were compared to cases after 28 March 2021, which was the day when the first scientific paper on VITT was published. RESULTS: In total, 270 cases of CVST with thrombocytopenia were identified, of which 266 (99%) occurred after adenoviral vector SARS-CoV-2 vaccination (ChAdOx1 nCoV-19, n = 243; Ad26.COV2.S, n = 23). The reported mortality amongst adenoviral cases with onset up to 28 March 2021 was 47/99 (47%, 95% confidence interval 37%-58%) compared to 36/167 (22%, 95% confidence interval 16%-29%) in cases with onset after 28 March (p < 0.001). None of the four cases of CVST with thrombocytopenia occurring after mRNA vaccination died. CONCLUSION: The reported mortality of CVST with thrombocytopenia after vaccination with adenoviral vector-based SARS-CoV-2 vaccines has significantly decreased over time, which may indicate a beneficial effect of earlier recognition and/or improved treatment on outcome after VITT.