Background Adverse reactions are more common after the second injection of messenger RNA vaccines such as Pfizer/BioNTech’s BNT162b2. We hypothesized that the degree and severity of reactogenicity after the second injection reflects the magnitude of antibody production against the SARS CoV-2 virus spike protein (spike IgG). Methods and results Blood samples were obtained from 67 Japanese healthcare workers three weeks after the first injection and two weeks after the second injection of the BNT162b2 vaccine to measure spike IgG levels. Using questionnaires, we calculated an adverse event (AE) score (0–11) for each participant. The geometric mean of spike IgG titers increased from 1,047 antibody units (AU/mL) (95% confidence interval (95% CI): 855–1282 AU/mL) after the first injection to 17,378 AU/mL (95% CI: 14,622–20,663 AU/mL) after the second injection. The median AE score increased from 2 to 5. Spike IgG levels after the second injection were negatively correlated with age and positively correlated with spike IgG after the first injection. AE scores after the second injection were not significantly associated with log-transformed spike IgG after the second injection, when adjusted for age, sex, AE score after the first injection, and log-transformed spike IgG after the first injection. Conclusions Although the sample size was relatively small, reactogenicity after the second injection may not accurately reflect antibody production.

Adverse reactions are more common after the second injection of messenger RNA vaccines such as Pfizer/BioNTech's BNT162b2. We hypothesized that the degree and severity of reactogenicity after the second injection reflects the magnitude of antibody production against the SARS CoV-2 virus spike protein (spike IgG). Blood samples were obtained from 67 healthy Japanese healthcare workers three weeks after the first injection and two weeks after the second injection of the BNT162b2 vaccine to measure spike IgG levels. Using questionnaires, we calculated an adverse event (AE) score (0-11) for each participant. The geometric mean of spike IgG titers increased from 1,047 antibody units (AU/mL) (95% CI: 855±1282 AU/mL) after the first injection to 17,378 AU/mL (14,622±20,663 AU/mL) after the second injection. The median AE score increased from 2 to 5. Spike IgG levels after the second injection were negatively correlated with age and positively correlated with spike IgG after the first injection. AE scores after the second injection were not significantly associated with log-transformed spike IgG after the second injection, when adjusted for age, sex, and log-transformed spike IgG after the first injection. Although the sample size was relatively small, reactogenicity after the second injection may not accurately reflect antibody production.

Background Although global longitudinal strain (GLS) measurements provide useful predictive information, measurement variability is still a major concern. We sought to determine whether fully automated GLS measurements could predict future cardiac events in patients with known or suspected heart failure (HF). Methods GLS was measured using fully automated 2D speckle tracking analysis software (Auto-Strain, TomTec) in 3,150 subjects who had undergone clinically indicated brain natriuretic peptide (BNP) assays and echocardiographic examinations. Among 1,514 patients in the derivation cohort, optimal cutoff values of BNP and GLS for cardiac death (CD) and major adverse cardiovascular events (MACEs) were determined using survival classification and regression tree (CART) analysis. The remaining 1,636 patients, comprising the validation cohort, were stratified into subgroups according to predefined cutoff values, and survival curves were compared. Results Survival CART analysis selected GLS with cutoff values of 6.2% and 14.0% for predicting CD. GLS of 6.9% and 13.9% and BNP of 83.2 pg/mL and 206.3 pg/mL were selected for predicting MACEs. For simplicity, we defined GLS of 7% and 14% and BNP of 100 pg/mL and 200 pg/mL as cutoff values. These cutoff values stratify high-risk patients in the validation cohort with known or suspected HF for both CD and MACEs. Conclusions In addition to BNP, fully automated GLS measurements provide prognostic information for patients with known or suspected HF, and this approach facilitates clinical work flow.

Both brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are established biomarkers that are necessary in the diagnosis and management of heart failure (HF). However, it is difficult to infer BNP concentration from NT-proBNP concentration for a clinician who is familiar with BNP. We investigated whether estimated BNP concentration from NT-proBNP has an equivalent prognostic strength compared with the actual BNP concentration in the prediction of future outcomes. We created a formula for estimating BNP concentration using multivariate analysis in a derivation cohort with known or suspected HF (n = 374). We determined whether the estimated BNP level had a similar prognostic power compared with the actual BNP and NT-proBNP levels in a validation cohort (n = 375). There was a strong correlation between log-transformed BNP and log-transformed NT-proBNP (r = 0.90) in the derivation cohort. We created two types of equation from the derivation cohort. During a median of 1 year of follow up, 49 major adverse cardiac events developed in the validation cohort. Cox proportional analysis revealed that the actual and estimated BNP levels represented equivalent and significant predictors of the future cardiovascular outcome. The estimated BNP levels calculated by our new formula showed a prognostic power similar to the actual BNP levels. This equation will be useful, especially for a physician who is not familiar with NT-proBNP testing.

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