The effect of an mRNA vaccine against COVID-19 on endothelial function and arterial stiffness.

To fight the COVID-19 pandemic, messenger RNA (mRNA) vaccines were the first to be adopted by vaccination programs worldwide. We sought to investigate the short-term effect of mRNA vaccine administration on endothelial function and arterial stiffness. Thirty-two participants (mean age 37 ± 8 years, 20 men) who received the BNT162b2 mRNA COVID-19 vaccine were studied in three sessions in a sequence-randomized, sham-controlled, assessor-blinded, crossover design. The primary outcome was endothelial function (assessed by brachial artery flow-mediated dilatation (FMD)), and the secondary outcomes were aortic stiffness (evaluated with carotid-femoral pulse wave velocity (PWV)) and inflammation (measured by high-sensitivity C-reactive protein (hsCRP) in blood samples). The outcomes were assessed prior to and at 8 h and 24 h after the 1st dose of vaccine and at 8 h, 24 h, and 48 h after the 2nd dose. There was an increase in hsCRP that was apparent at 24 h after both the 1st dose (-0.60 [95% confidence intervals [CI]: -1.60 to -0.20], p = 0.013) and the 2nd dose (maximum median difference at 48 h -6.60 [95% CI: -9.80 to -3.40], p < 0.001) compared to placebo. The vaccine did not change PWV. FMD remained unchanged during the 1st dose but decreased significantly by 1.5% (95% CI: 0.1% to 2.9%, p = 0.037) at 24 h after the 2nd dose. FMD values returned to baseline at 48 h. Our study shows that the mRNA vaccine causes a prominent increase in inflammatory markers, especially after the 2nd dose, and a transient deterioration of endothelial function at 24 h that returns to baseline at 48 h. These results confirm the short-term cardiovascular safety of the vaccine.

Time-related aortic inflammatory response, as assessed with 18F-FDG PET/CT, in patients hospitalized with severely or critical COVID-19: the COVAIR study.

AIM: Arterial involvement has been implicated in the coronavirus disease of 2019 (COVID-19). Fluorine 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging is a valuable tool for the assessment of aortic inflammation and is a predictor of outcome. We sought to prospectively assess the presence of aortic inflammation and its time-dependent trend in patients with COVID-19. METHODS: Between November 2020 and May 2021, in this pilot, case-control study, we recruited 20 patients with severe or critical COVID-19 (mean age of 59 ± 12 years), while 10 age and sex-matched individuals served as the control group. Aortic inflammation was assessed by measuring 18F-FDG uptake in PET/CT performed 20-120 days post-admission. Global aortic target to background ratio (GLA-TBR) was calculated as the sum of TBRs of ascending and descending aorta, aortic arch, and abdominal aorta divided by 4. Index aortic segment TBR (IAS-TBR) was designated as the aortic segment with the highest TBR. RESULTS: There was no significant difference in aortic 18F-FDG PET/CT uptake between patients and controls (GLA-TBR: 1.46 [1.40-1.57] vs. 1.43 [1.32-1.70], respectively, P = 0.422 and IAS-TBR: 1.60 [1.50-1.67] vs. 1.50 [1.42-1.61], respectively, P = 0.155). There was a moderate correlation between aortic TBR values (both GLA and IAS) and time distance from admission to 18F-FDG PET-CT scan (Spearman's rho = - 0.528, P = 0.017 and Spearman's rho = - 0.480, p = 0.032, respectively). Patients who were scanned less than or equal to 60 days from admission (n = 11) had significantly higher GLA-TBR values compared to patients that were examined more than 60 days post-admission (GLA-TBR: 1.53 [1.42-1.60] vs. 1.40 [1.33-1.45], respectively, P = 0.016 and IAS-TBR: 1.64 [1.51-1.74] vs. 1.52 [1.46-1.60], respectively, P = 0.038). There was a significant difference in IAS- TBR between patients scanned ≤ 60 days and controls (1.64 [1.51-1.74] vs. 1.50 [1.41-1.61], P = 0.036). CONCLUSION: This is the first study suggesting that aortic inflammation, as assessed by 18F-FDG PET/CT imaging, is increased in the early post COVID phase in patients with severe or critical COVID-19 and largely resolves over time. Our findings may have important implications for the understanding of the course of the disease and for improving our preventive and therapeutic strategies.