Pavord S, Scully M, Hunt BJ, et al. - Among patients with a low platelet count and intracranial hemorrhage, the high mortality correlated with vaccine-induced immune thrombocytopenia and thrombosis (VITT) was highest. The results illustrated that the treatment remains uncertain, but identification of prognostic markers may help guide effective management.

• Researchers distinguished 170 definite and 50 probable cases of VITT among 294 patients who were assessed. After vaccination, all the patients had received the first dose of ChAdOx1 nCoV-19 vaccine and presented 5 to 48 days (median, 14).

• In this study, 18 to 79 years was the age range (median, 48), with no sex preponderance and no identifiable medical risk factors.

• Overall mortality was 22%.

• It was shown that the odds of death elevated by a factor of 2.7 (95% confidence interval [CI], 1.4 to 5.2) among patients with cerebral venous sinus thrombosis, by a factor of 1.7 (95% CI, 1.3 to 2.3) for every 50% decrease in the baseline platelet count, by a factor of 1.2 (95% CI, 1.0 to 1.3) for every increase of 10,000 fibrinogen-equivalent units in the baseline d-dimer level, and by a factor of 1.7 (95% CI, 1.1 to 2.5) for every 50% decrease in the baseline fibrinogen level.

• Multivariate analysis distinguished the baseline platelet count and the presence of intracranial hemorrhage as being independently correlated with death; 73% was the observed mortality among patients with platelet counts below 30,000 per cubic millimeter and intracranial hemorrhage.