The role of neutralizing antibodies by sVNT after two doses of BNT162b2 mRNA vaccine in a cohort of Italian healthcare workers.

OBJECTIVES: Evaluating anti-SARS-CoV-2 antibody levels is a current priority to drive immunization, as well as to predict when a vaccine booster dose may be required and for which priority groups. The aim of our study was to investigate the kinetics of anti-SARS-CoV-2 Spike S1 protein IgG (anti-S1 IgG) antibodies and neutralizing antibodies (NAbs) in an Italian cohort of healthcare workers (HCWs), following the Pfizer/BNT162b2 mRNA vaccine, over a period of up to six months after the second dose. METHODS: We enrolled 57 HCWs, without clinical history of COVID-19 infection. Fluoroenzyme-immunoassay was used for the quantitative anti-S1 IgG antibodies at different time points T1 (one month), T3 (three months) and T6 (six months) following the second vaccine shot. Simultaneously, a commercial surrogate virus neutralization test (sVNT) was used for the determination of NAbs, expressed as inhibition percentage (% IH). RESULTS: Median values of anti-S1 IgG antibodies decreased from T1 (1,452 BAU/mL) to T6 (104 BAU/mL) with a percent variation of 92.8% while the sVNT showed a percent variation of 34.3% for the same time frame. The decline in anti-S1 IgG antibodies from T1 to T6 was not accompanied by a loss of the neutralizing capacity of antibodies. In fact at T6 a neutralization percentage <20% IH was observed only in 3.51% of HCWs. CONCLUSIONS: Our findings reveal that the decrease of anti-S1 IgG levels do not correspond in parallel to a decrease of NAbs over time, which highlights the necessity of using both assays to assess vaccination effectiveness.

Impact of SARS-CoV-2 positivity on clinical outcome among STEMI patients undergoing mechanical reperfusion: Insights from the ISACS STEMI COVID 19 registry.

BACKGROUND AND AIMS: SARS-Cov-2 predisposes patients to thrombotic complications, due to excessive inflammation, endothelial dysfunction, platelet activation, and coagulation/fibrinolysis disturbances. The aim of the present study was to evaluate clinical characteristics and prognostic impact of SARS-CoV-2 positivity among STEMI patients undergoing primary percutaneous coronary intervention (PPCI). METHODS: We selected SARS-CoV-2 positive patients included in the ISACS-STEMI COVID-19, a retrospective multicenter European registry including 6609 STEMI patients treated with PPCI from March 1st until April 30th, in 2019 and 2020. As a reference group, we randomly sampled 5 SARS-Cov-2 negative patients per each SARS-CoV-2 positive patient, individually matched for age, sex, and hospital/geographic area. Study endpoints were in-hospital mortality, definite stent thrombosis, heart failure. RESULTS: Our population is represented by 62 positive SARS-CoV-2 positive patients who were compared with a matched population of 310 STEMI patients. No significant difference was observed in baseline characteristics or the modality of access to the PCI center. In the SARS-CoV-2 positive patients, the culprit lesion was more often located in the RCA (p < 0.001). Despite similar pre and postprocedural TIMI flow, we observed a trend in higher use of GP IIb-IIIa inhibitors and a significantly higher use of thrombectomy in the SARS-CoV-2 positive patients. SARS-CoV-2 positivity was associated with a remarkably higher in hospital mortality (29% vs 5.5%, p < 0.001), definite in-stent thrombosis (8.1% vs 1.6%, p = 0.004) and heart failure (22.6% vs 10.6%, p = 0.001) that was confirmed after adjustment for confounding factors. CONCLUSIONS: Our study showed that among STEMI patients, SARS-CoV-2 positivity is associated with larger thrombus burden, a remarkably higher mortality but also higher rates of in-stent thrombosis and heart failure.

Impact of COVID-19 Pandemic on Mechanical Reperfusion for Patients With STEMI.

BACKGROUND: The fear of contagion during the coronavirus disease-2019 (COVID-19) pandemic may have potentially refrained patients with ST-segment elevation myocardial infarction (STEMI) from accessing the emergency system, with subsequent impact on mortality. OBJECTIVES: The ISACS-STEMI COVID-19 registry aims to estimate the true impact of the COVID-19 pandemic on the treatment and outcome of patients with STEMI treated by primary percutaneous coronary intervention (PPCI), with identification of "at-risk" patient cohorts for failure to present or delays to treatment. METHODS: This retrospective registry was performed in European high-volume PPCI centers and assessed patients with STEMI treated with PPPCI in March/April 2019 and 2020. Main outcomes are the incidences of PPCI, delayed treatment, and in-hospital mortality. RESULTS: A total of 6,609 patients underwent PPCI in 77 centers, located in 18 countries. In 2020, during the pandemic, there was a significant reduction in PPCI as compared with 2019 (incidence rate ratio: 0.811; 95% confidence interval: 0.78 to 0.84; p < 0.0001). The heterogeneity among centers was not related to the incidence of death due to COVID-19. A significant interaction was observed for patients with arterial hypertension, who were less frequently admitted in 2020 than in 2019. Furthermore, the pandemic was associated with a significant increase in door-to-balloon and total ischemia times, which may have contributed to the higher mortality during the pandemic. CONCLUSIONS: The COVID-19 pandemic had significant impact on the treatment of patients with STEMI, with a 19% reduction in PPCI procedures, especially among patients suffering from hypertension, and a longer delay to treatment, which may have contributed to the increased mortality during the pandemic. (Primary Angioplasty for STEMI During COVID-19 Pandemic [ISACS-STEMI COVID-19] Registry; NCT04412655).