Prevalence and clinical implication of thrombocytopenia and heparin-induced thrombocytopenia in patients who are critically ill with COVID-19.

As the COVID-19 pandemic continues to evolve, different clinical manifestations are better understood and studied. These include various haematologic disorders that have been shown to be associated with increased morbidity and mortality. We studied the prevalence of one unusual manifestation, heparin-induced thrombocytopenia (HIT) and its clinical implications in patients who are severely ill with COVID-19 in a single tertiary centre in Israel. The presence of thrombocytopenia, disseminated intravascular coagulation (DIC) and HIT, and their association with clinical course and outcomes were studied. One-hundred and seven patients with COVID-19 were included. Fifty-seven (53.2%) patients developed thrombocytopenia, which was associated with the worst outcomes (ventilation, DIC and increased mortality). Sixteen (28.0%) patients with thrombocytopenia were positive for HIT, all of which were supported by extracorporeal devices. HIT was independently associated with ventilation days, blood product transfusions, longer hospitalisation and mortality.Platelet abnormalities and HIT are common in patients who are critically ill with COVID-19 and are associated with the worst clinical outcomes. The mechanisms underlying HIT in COVID-19 are yet to be studied; HIT may contribute to the dysregulated immunologic response associated with COVID-19 critical illness and may play a significant part in the coagulopathy seen in these patients. As many patients with COVID-19 require aggressive thromboprophylaxis, further understanding of HIT and the implementation of appropriate protocols are important.

The clinical course of patients with previous acute and recurrent pericarditis receiving the BNT162b2 vaccine.

Background: Vaccines against SARS-COV2 have been crucial in efforts against COVID19, yet there have been reports of pericarditis following vaccination with mRNA-based vaccines. Methods: We questioned consecutive patients with a history of acute pericarditis (AP) evaluated in the pericardial disease clinic during 3-11/2020 in a single tertiary center. Patients with significant myocardial involvement or pericarditis secondary to another systemic disease were excluded. Results: We included 64 patients in the final analysis. Mean age was 53.1 (±18), and 26 (41%) were female. At least 1 recurrence of AP was documented in 47 (73%) cases, 32 (50%) had ≥ 3 recurrences prior to vaccination. AP was considered to be idiopathic\viral in 45 (70%) cases, 20 (31%) cases were post-injury. All patients received at least 2 doses of the vaccine, and 48 patients (75%) received a 3rd dose. Two cases of breakthrough COVID19 infections were documented. Overall, 12 patients (19%) reported any adverse events. Of which, 2 had recurrent pericarditis. There was a trend for a younger age in those patients who had adverse events (median age 45 [IQR 36-61] vs. 60 [38-71], p = 0.08). no other significant difference was seen. Conclusion: In patients with a history of acute\recurrent pericarditis, the use of BNT162b2 was mostly uneventful, but some mild disease recurrences did occur.