Natriuretic peptides, body mass index and heart failure risk: Pooled analyses of SAVOR-TIMI 53, DECLARE-TIMI 58 and CAMELLIA-TIMI 61.

AIM: N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations are lower in patients with obesity. The interaction between body mass index (BMI) and NT-proBNP with respect to heart failure risk remains incompletely defined. METHODS AND RESULTS: Data were pooled across three randomized clinical trials enrolling predominantly patients who were overweight or obese with established cardiometabolic disease: SAVOR-TIMI 53, DECLARE-TIMI 58 and CAMELLIA-TIMI 61. Hospitalization for heart failure (HHF) was examined across strata of baseline BMI and NT-proBNP. The effect of dapagliflozin versus placebo was assessed for a treatment interaction across BMI categories in patients with or without an elevated baseline NT-proBNP (≥125 pg/ml). Among 24 455 patients, the median NT-proBNP was 96 (interquartile range [IQR]: 43-225) pg/ml and the median BMI was 33 (IQR 29-37) kg/m2, with 68% of patients having a BMI ≥30 kg/m2. There was a significant inverse association between NT-proBNP and BMI which persisted after adjustment for all clinical variables (p < 0.001). Within any range of NT-proBNP, those at higher BMI had higher risk of HHF at 2 years (comparing BMI <30 vs. ≥40 kg/m2 for NT-proBNP ranges of <125, 125-<450 and ≥450 pg/ml: 0.0% vs. 0.6%, 1.3% vs. 4.0%, and 8.1% vs. 13.8%, respectively), which persisted after multivariable adjustment (adjusted hazard ratio [HRadj] 7.47, 95% confidence interval [CI] 3.16-17.66, HRadj 3.22 [95% CI 2.13-4.86], and HRadj 1.87 [95% CI 1.35-2.60], respectively). In DECLARE-TIMI 58, dapagliflozin versus placebo consistently reduced HHF across BMI categories in those with an elevated NT-proBNP (p-trend for HR across BMI = 0.60), with a pattern of greater absolute risk reduction (ARR) at higher BMI (ARR for BMI <30 to ≥40 kg/m2: 2.2% to 4.7%; p-trend = 0.059). CONCLUSIONS: The risk of HHF varies across BMI categories for any given range of circulating NT-proBNP. These findings showcase the importance of considering BMI when applying NT-proBNP for heart failure risk stratification, particularly for patients with low-level elevations in NT-proBNP (125-<450 pg/ml) where there appears to be a clinically meaningful absolute and relative risk gradient.

Using Regional Sero-Epidemiology SARS-CoV-2 Anti-S Antibodies in the Dominican Republic to Inform Targeted Public Health Response.

Incidence of COVID-19 has been associated with sociodemographic factors. We investigated variations in SARS-CoV-2 seroprevalence at sub-national levels in the Dominican Republic and assessed potential factors influencing variation in regional-level seroprevalence. Data were collected in a three-stage cross-sectional national serosurvey from June to October 2021. Seroprevalence of antibodies against the SARS-CoV-2 spike protein (anti-S) was estimated and adjusted for selection probability, age, and sex. Multilevel logistic regression was used to estimate the effect of covariates on seropositivity for anti-S and correlates of 80% protection (PT80) against symptomatic infection for the ancestral and Delta strains. A total of 6683 participants from 134 clusters in all 10 regions were enrolled. Anti-S, PT80 for the ancestral and Delta strains odds ratio varied across regions, Enriquillo presented significant higher odds for all outcomes compared with Yuma. Compared to being unvaccinated, receiving ≥2 doses of COVID-19 vaccine was associated with a significantly higher odds of anti-S positivity (OR 85.94, [10.95-674.33]) and PT80 for the ancestral (OR 4.78, [2.15-10.62]) and Delta strains (OR 3.08, [1.57-9.65]) nationally and also for each region. Our results can help inform regional-level public health response, such as strategies to increase vaccination coverage in areas with low population immunity against currently circulating strains.

FGF-23 is a biomarker of RV dysfunction and congestion in patients with HFrEF.

There is no biomarker reflecting right ventricular dysfunction in HFrEF patients used in clinical practice. We have aimed to look for a circulating marker of RV dysfunction employing a quantitative proteomic strategy. The Olink Proteomics Multiplex panels (Cardiovascular Disease II, III, Cardiometabolic, and Inflammation Target Panels) identified FGF-23 to be the most differentially abundant (more than 2.5-fold) in blood plasma of HF patients with severe RV dysfunction (n = 30) compared to those with preserved RV function (n = 31). A subsequent ELISA-based confirmatory analysis of circulating FGF-23 in a large cohort of patients (n = 344, 72.7% NYHA III/IV, LVEF 22.5%, 54.1% with moderate/severe RV dysfunction), followed by multivariable regression analysis, revealed that the plasma FGF-23 level was most significantly associated with RV dysfunction grade (p = 0.0004) and congestion in the systemic circulation (p = 0.03), but not with LV-ejection fraction (p = 0.69) or estimated glomerular filtration rate (eGFR, p = 0.08). FGF-23 was associated with the degree of RV dysfunction in both sub-cohorts (i.e. in patients with and without congestion, p < 0.0001). The association between FGF-23 and RV-dysfunction remained significant after the adjustment for BNP (p = 0.01). In contrast, when adjusted for BNP, FGF-23 was no longer associated with LV dysfunction (p = 0.59). The Cox proportional hazard model revealed that circulating FGF-23 was significantly associated with adverse outcomes even after adjusting for BNP, LVEF, RV dysfunction grade and eGFR. Circulating FGF-23 is thus a biomarker of right ventricular dysfunction in HFrEF patients regardless of congestion status.

Association of Carbohydrate Antigen 125 on the Response to Dapagliflozin in Patients With Heart Failure.

BACKGROUND: Elevated circulating carbohydrate antigen 125 (CA125) is a marker of congestion and a predictor of outcomes in acute heart failure (HF). Less is known about CA125 in chronic ambulatory HF with reduced ejection fraction. OBJECTIVES: This study examined the association between baseline CA125 (and changes in CA125) and outcomes in patients with HF with reduced ejection fraction in the DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure; NCT03036124) trial and its relationship with the effect of dapagliflozin. METHODS: The primary outcome was a composite of a first episode of worsening HF or cardiovascular death. CA125 was measured at baseline and 12 months following randomization. RESULTS: Median baseline CA125 was 13.04 U/mL (IQR: 8.78-21.13 U/mL) in 3,123 of 4,774 patients with available data. Compared with CA125 ≤35 U/mL (upper limit of normal), patients with CA125 >35 U/mL were at a higher risk of the primary outcome (adjusted HR: 1.59; 95% CI: 1.29-1.96). The adjusted risks of the primary outcome relative to quartile 1 (Q1) (≤8.78 U/mL) were as follow: Q2, 8.79-13.04 U/mL (HR: 0.94; 95% CI: 0.71-1.24); Q3, 13.05-21.13 U/mL (HR: 1.22; 95% CI: 0.94-1.59); Q4, ≥21.14 U/mL (HR: 1.63; 95% CI: 1.28-2.09). The beneficial effect of dapagliflozin compared with placebo on the primary outcome was consistent whether CA125 was analyzed in quartiles (interaction P = 0.13) or as a continuous variable (interaction P = 0.75). The placebo-corrected relative change in CA125 at 12 months was -5.2% (95% CI: -10.6% to 0.5%; P = 0.07). CONCLUSIONS: In DAPA-HF, elevated CA125 levels were an independent predictor of the risk of worsening HF or cardiovascular death. Dapagliflozin reduced the risk of worsening HF or cardiovascular death regardless of baseline CA125.

Neutrophil-lymphocyte ratio and clinical outcomes in 19,697 patients with atrial fibrillation: Analyses from ENGAGE AF- TIMI 48 trial.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is the ratio between neutrophil and lymphocyte counts measured in peripheral blood. NLR is easily calculable based on a routine blood test available worldwide and may reflect systemic inflammation. However, the relationship between NLR and clinical outcomes in atrial fibrillation (AF) patients is not well-described. METHODS: We calculated NLR at baseline in ENGAGE AF-TIMI 48, a randomized trial comparing edoxaban versus warfarin in patients with AF followed for 2.8 years (median). The association of baseline NLR with major bleeding events, major adverse cardiac events (MACE), cardiovascular death, stroke/systemic embolism, and all-cause mortality were calculated. RESULTS: The median baseline NLR in 19,697 patients was 2.53 (interquartile range 1.89-3.41). NLR was associated with major bleeding events (HR 1.60; 95% CI 1.41-1.80), stroke/systemic embolism (HR 1.25; 95% CI, 1.09-1.44), MI (HR 1.73; 95% CI 1.41-2.12), MACE (HR 1.70; 95% CI 1.56-1.84), CV (HR 1.93; 95% CI 1.74-2.13) and all-cause mortality (HR 2.00; 95% CI 1.83-2.18). The relationships between NLR and outcomes remained significant after adjustment for risk factors. Edoxaban consistently reduced major bleeding. MACE, and CV death across NLR groups vs. warfarin. CONCLUSIONS: NLR represents a widely available, simple, arithmetic calculation that could be immediately and automatically reported during a white blood cell differential measurement to identify patients with AF at increased risk of bleeding, CV events, and mortality.

Endothelin-1, Outcomes in Patients With Heart Failure and Reduced Ejection Fraction, and Effects of Dapagliflozin: Findings From DAPA-HF.

BACKGROUND: ET-1 (endothelin-1) is implicated in the pathophysiology of heart failure and renal disease. Its prognostic importance and relationship with kidney function in patients with heart failure with reduced ejection fraction receiving contemporary treatment are uncertain. We investigated these and the efficacy of dapagliflozin according to ET-1 level in the DAPA-HF trial (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure). METHODS: We investigated the incidence of the primary outcome (cardiovascular death or worsening heart failure), change in kidney function, and the effect of dapagliflozin according to baseline ET-1 concentration, adjusting in Cox models for other recognized prognostic variables in heart failure including NT-proBNP (N-terminal pro-B-type natriuretic peptide). We also examined the effect of dapagliflozin on ET-1 level. RESULTS: Overall, 3048 participants had baseline ET-1 measurements: tertile 1 (T1; ≤3.28 pg/mL; n=1016); T2 (>3.28-4.41 pg/mL; n=1022); and T3 (>4.41 pg/mL; n=1010). Patients with higher ET-1 were more likely male, more likely obese, and had lower left ventricular ejection fraction, lower estimated glomerular filtration rate, worse functional status, and higher NT-proBNP and hs-TnT (high-sensitivity troponin-T). In the adjusted Cox models, higher baseline ET-1 was independently associated with worse outcomes and steeper decline in kidney function (adjusted hazard ratio for primary outcome of 1.95 [95% CI, 1.53-2.50] for T3 and 1.36 [95% CI, 1.06-1.75] for T2; both versus T1; estimated glomerular filtration rate slope: T3, -3.19 [95% CI, -3.66 to -2.72] mL/min per 1.73 m2 per y, T2, -2.08 [95% CI, -2.52 to -1.63] and T1 -2.35 [95% CI, -2.79 to -1.91]; P=0.002). The benefit of dapagliflozin was consistent regardless of baseline ET-1, and the placebo-corrected decrease in ET-1 with dapagliflozin was 0.13 pg/mL (95% CI, 0.25-0.01; P=0.029). CONCLUSIONS: Higher baseline ET-1 concentration was independently associated with worse clinical outcomes and more rapid decline in kidney function. The benefit of dapagliflozin was consistent across the range of ET-1 concentrations measured, and treatment with dapagliflozin led to a small decrease in serum ET-1 concentration. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03036124.

Serial assessment of biomarkers and heart failure outcomes in patients with atrial fibrillation.

AIMS: Cardiac functional and structural remodelling in patients with atrial fibrillation (AF) contributes to development of heart failure (HF) as their major cardiovascular comorbidity. Circulating biomarkers may reflect these cardiac alterations. METHODS AND RESULTS: ENGAGE AF-TIMI 48 was a randomized trial of edoxaban versus warfarin in 21 105 patients with AF. We performed a nested biomarker study, analysing high-sensitivity troponin T (hsTnT, n = 8705), N-terminal pro-B-type natriuretic peptide (NT-proBNP, n = 8765), and growth differentiation factor-15 (GDF-15, n = 8705) at baseline and 12 months. Of the biomarker cohort, 5207 had a history of HF, among whom 3996 had known ejection fraction (EF): 926 with reduced EF (HFrEF; ≤40%), 1043 with mildly reduced EF (HFmrEF; 40-49%), and 2027 with preserved EF (HFpEF; ≥50%). Elevated baseline hsTnT, NT-proBNP, and GDF-15 were associated with higher risk of hospitalization for HF (HHF) or HF death overall and in subpopulations defined by HF history and EF (p < 0.001 for each). These associations of outcome with each biomarker were consistent regardless of a history of HF or EF (p-interaction >0.05 for each). Patients who had an increase in or had persistently elevated values in any of the three biomarkers over 12 months were at higher risk for HHF or HF death in the overall population (p < 0.001 for each biomarker and category). CONCLUSION: Serial measurement of hsTnT, NT-proBNP, and GDF-15 revealed that higher baseline values, and increasing or persistently elevated values over 1 year are associated with higher risk of HF outcomes in patients with AF regardless of HF history or HF phenotype based on EF. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov unique identifier NCT00781391.

Association of Cardiac Biomarkers With Major Adverse Cardiovascular Events in High-risk Patients With Diabetes: A Secondary Analysis of the DECLARE-TIMI 58 Trial.

Importance: Dapagliflozin reduces the risk of hospitalizations for heart failure and the progression of chronic kidney disease in patients with and without type 2 diabetes (T2D), whereas the effects on reducing atherosclerotic events appear less clear. Objective: To explore whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hsTnT) levels can identify a subset of patients with T2D at higher risk and who might benefit more from dapagliflozin with regard to atherosclerotic events. Design, Setting, and Participants: This was a secondary analysis of the DECLARE-TIMI 58 trial, a randomized clinical trial of dapagliflozin in patients with T2D and either multiple risk factors for atherosclerotic cardiovascular disease (ASCVD; approximately 60%) or established ASCVD (approximately 40%). All patients with available blood samples at randomization were included in these analyses. Data were collected from May 2013 to September 2018, and data were analyzed from May 2019 to June 2022. Interventions: Dapagliflozin vs placebo. Main Outcomes and Measures: Major adverse cardiovascular events (MACE), the composite of myocardial infarction, ischemic stroke, or cardiovascular death, which was one of dual primary outcomes of the main trial. Results: Of 14 565 included patients, 9143 (62.8%) were male, and the mean (SD) age was 63.9 (6.8) years. When tested individually in a multivariable model for MACE risk, NT-proBNP and hsTnT were each significantly associated with the risk of MACE (adjusted hazard ratio [aHR] per 1 SD in log-transformed biomarker: NT-proBNP, 1.62; 95% CI, 1.49-1.76; hsTnT: 1.59; 95% CI, 1.46-1.74). The magnitude of the association was similar in patients with ASCVD (NT-proBNP: aHR, 1.60; 95% CI, 1.45-1.77; hsTnT: aHR, 1.62; 95% CI, 1.45-1.81) and multiple risk factors for ASCVD (NT-proBNP: aHR, 1.62; 95% CI, 1.40-1.88; hsTnT: aHR, 1.51; 95% CI, 1.29-1.77). Moreover, both biomarkers remained independently associated with MACE when both were included in the multivariable model (NT-proBNP: aHR, 1.46; 95% CI, 1.34-1.60; hsTnT: aHR, 1.39; 95% CI, 1.26-1.53). Modeled as a continuous variable, baseline biomarker levels did not modify the relative treatment effect of dapagliflozin vs placebo with MACE. However, the relative risk reduction numerically grew with higher biomarker levels, as did the baseline risk. Thus, MACE event rates were nominally lower in dapagliflozin-treated vs placebo-treated patients with biomarker concentrations in the top quartile (NT-proBNP: HR, 0.83; 95% CI, 0.71-0.97; absolute risk reduction [ARR], 2.4%; hsTnT: HR, 0.85; 95% CI, 0.72-0.99; ARR, 2.7%), whereas there was no significant treatment effect in patients with biomarkers levels in quartiles 1 to 3 (NT-proBNP: HR, 1.02; 95% CI, 0.88-1.18; ARR, 0%; hsTnT: HR, 0.97; 95% CI, 0.84-1.13; ARR, 0.2%). Conclusions and Relevance: In this study, NT-proBNP and hsTnT levels were associated with the risk for future cardiovascular events in both primary and secondary prevention patients with T2D. Both cardiac biomarkers were helpful to identify patients at very high risk for atherosclerotic events that may derive reduction in risk of MACE with dapagliflozin. Trial Registration: ClinicalTrials.gov Identifier: NCT01730534.

Attenuation of Hypocretin/Orexin Signaling Is Associated With Increased Mortality After Myocardial Infarction.

Background The hypocretin/orexin system has been shown to play a role in heart failure. Whether it also influences myocardial infarction (MI) outcomes is unknown. We evaluated the effect of the rs7767652 minor allele T associated with decreased transcription of the hypocretin/orexin receptor-2 and circulating orexin A concentrations on mortality risk after MI. Methods and Results Data from a single-center, prospectively designed registry of consecutive patients hospitalized for MI at a large tertiary cardiology center were analyzed. Patients without previous history of MI or heart failure were included. A random population sample was used to compare allele frequencies in the general population. Out of 1009 patients (aged 64±12 years, 74.6% men) after MI, 6.1% were homozygotes (TT) and 39.4% heterozygotes (CT) for minor allele. Allele frequencies in the MI group did not differ from 1953 subjects from general population (χ2 P=0.62). At index hospitalization, MI size was the same, but ventricular fibrillation and the need for cardiopulmonary resuscitation were more prevalent in the TT allele variant. Among patients with ejection fraction ≤40% at discharge, the TT variant was associated with a lower increase in left ventricular ejection fraction during follow-up (P=0.03). During the 27-month follow-up, there was a statistically significant association of the TT variant with increased mortality risk (hazard ratio [HR], 2.83; P=0.001). Higher circulating orexin A was associated with a lower mortality risk (HR, 0.41; P<0.05). Conclusions Attenuation of hypocretin/orexin signaling is associated with increased mortality risk after MI. This effect may be partially explained by the increased arrhythmic risk and the effect on the left ventricular systolic function recovery.

Monitoring Temporal Changes in SARS-CoV-2 Spike Antibody Levels and Variant-Specific Risk for Infection, Dominican Republic, March 2021-August 2022.

To assess changes in SARS-CoV-2 spike binding antibody prevalence in the Dominican Republic and implications for immunologic protection against variants of concern, we prospectively enrolled 2,300 patients with undifferentiated febrile illnesses in a study during March 2021-August 2022. We tested serum samples for spike antibodies and tested nasopharyngeal samples for acute SARS-CoV-2 infection using a reverse transcription PCR nucleic acid amplification test. Geometric mean spike antibody titers increased from 6.6 (95% CI 5.1-8.7) binding antibody units (BAU)/mL during March-June 2021 to 1,332 (95% CI 1,055-1,682) BAU/mL during May-August 2022. Multivariable binomial odds ratios for acute infection were 0.55 (95% CI 0.40-0.74), 0.38 (95% CI 0.27-0.55), and 0.27 (95% CI 0.18-0.40) for the second, third, and fourth versus the first anti-spike quartile; findings were similar by viral strain. Combining serologic and virologic screening might enable monitoring of discrete population immunologic markers and their implications for emergent variant transmission.

Growth differentiation factor 15 and cardiovascular risk: individual patient meta-analysis.

AIMS: Levels of growth differentiation factor 15 (GDF-15), a cytokine secreted in response to cellular stress and inflammation, have been associated with multiple types of cardiovascular (CV) events. However, its comparative prognostic performance across different presentations of atherosclerotic cardiovascular disease (ASCVD) remains unknown. METHODS AND RESULTS: An individual patient meta-analysis was performed using data pooled from eight trials including 53 486 patients. Baseline GDF-15 concentration was analyzed as a continuous variable and using established cutpoints (<1200 ng/L, 1200-1800 ng/L, > 1800 ng/L) to evaluate its prognostic performance for CV death/hospitalization for heart failure (HHF), major adverse cardiovascular events (MACE), and their components using Cox models adjusted for clinical variables and established CV biomarkers. Analyses were further stratified on ASCVD status: acute coronary syndrome (ACS), stabilized after recent ACS, and stable ASCVD. Overall, higher GDF-15 concentration was significantly and independently associated with an increased rate of CV death/HHF and MACE (P < 0.001 for each). However, while GDF-15 showed a robust and consistent independent association with CV death and HHF across all presentations of ASCVD, its prognostic association with future myocardial infarction (MI) and stroke only remained significant in patients stabilized after recent ACS or with stable ASCVD [hazard ratio (HR): 1.24, 95% confidence interval (CI): 1.17-1.31 and HR: 1.16, 95% CI: 1.05-1.28 for MI and stroke, respectively] and not in ACS (HR: 0.98, 95% CI: 0.90-1.06 and HR: 0.87, 95% CI: 0.39-1.92, respectively). CONCLUSION: Growth differentiation factor 15 consistently adds prognostic information for CV death and HHF across the spectrum of ASCVD. GDF-15 also adds prognostic information for MI and stroke beyond clinical risk factors and cardiac biomarkers but not in the setting of ACS.

A polygenic risk score predicts atrial fibrillation in cardiovascular disease.

AIMS: Interest in targeted screening programmes for atrial fibrillation (AF) has increased, yet the role of genetics in identifying patients at highest risk of developing AF is unclear. METHODS AND RESULTS: A total of 36,662 subjects without prior AF were analyzed from four TIMI trials. Subjects were divided into quintiles using a validated polygenic risk score (PRS) for AF. Clinical risk for AF was calculated using the CHARGE-AF model. Kaplan-Meier event rates, adjusted hazard ratios (HRs), C-indices, and net reclassification improvement were used to determine if the addition of the PRS improved prediction compared with clinical risk and N-terminal pro-B-type natriuretic peptide (NT-proBNP). Over 2.3 years, 1018 new AF cases developed. AF PRS predicted a significant risk gradient for AF with a 40% increased risk per 1-SD increase in PRS [HR: 1.40 (1.32-1.49); P < 0.001]. Those with high AF PRS (top 20%) were more than two-fold more likely to develop AF [HR 2.45 (1.99-3.03), P < 0.001] compared with low PRS (bottom 20%). Furthermore, PRS provided an additional gradient of risk stratification on top of the CHARGE-AF clinical risk score, ranging from a 3-year incidence of 1.3% in patients with low clinical and genetic risk to 8.7% in patients with high clinical and genetic risk. The subgroup of patients with high clinical risk, high PRS, and elevated NT-proBNP had an AF risk of 16.7% over 3 years. The C-index with the CHARGE-AF clinical risk score alone was 0.65, which improved to 0.67 (P < 0.001) with the addition of NT-proBNP, and increased further to 0.70 (P < 0.001) with the addition of the PRS. CONCLUSION: In patients with cardiovascular conditions, AF PRS is a strong independent predictor of incident AF that provides complementary predictive value when added to a validated clinical risk score and NT-proBNP.

SARS-CoV-2 seroprevalence, cumulative infections, and immunity to symptomatic infection - A multistage national household survey and modelling study, Dominican Republic, June-October 2021.

Background: Population-level SARS-CoV-2 immunological protection is poorly understood but can guide vaccination and non-pharmaceutical intervention priorities. Our objective was to characterise cumulative infections and immunological protection in the Dominican Republic. Methods: Household members ≥5 years were enrolled in a three-stage national household cluster serosurvey in the Dominican Republic. We measured pan-immunoglobulin antibodies against the SARS-CoV-2 spike (anti-S) and nucleocapsid glycoproteins, and pseudovirus neutralising activity against the ancestral and B.1.617.2 (Delta) strains. Seroprevalence and cumulative prior infections were weighted and adjusted for assay performance and seroreversion. Binary classification machine learning methods and pseudovirus neutralising correlates of protection were used to estimate 50% and 80% protection against symptomatic infection. Findings: Between 30 Jun and 12 Oct 2021 we enrolled 6683 individuals from 3832 households. We estimate that 85.0% (CI 82.1-88.0) of the ≥5 years population had been immunologically exposed and 77.5% (CI 71.3-83) had been previously infected. Protective immunity sufficient to provide at least 50% protection against symptomatic SARS-CoV-2 infection was estimated in 78.1% (CI 74.3-82) and 66.3% (CI 62.8-70) of the population for the ancestral and Delta strains respectively. Younger (5-14 years, OR 0.47 [CI 0.36-0.61]) and older (≥75-years, 0.40 [CI 0.28-0.56]) age, working outdoors (0.53 [0.39-0.73]), smoking (0.66 [0.52-0.84]), urban setting (1.30 [1.14-1.49]), and three vs no vaccine doses (18.41 [10.69-35.04]) were associated with 50% protection against the ancestral strain. Interpretation: Cumulative infections substantially exceeded prior estimates and overall immunological exposure was high. After controlling for confounders, markedly lower immunological protection was observed to the ancestral and Delta strains across certain subgroups, findings that can guide public health interventions and may be generalisable to other settings and viral strains. Funding: This study was funded by the US CDC.

Association of Serial High-Sensitivity Cardiac Troponin T With Subsequent Cardiovascular Events in Patients Stabilized After Acute Coronary Syndrome: A Secondary Analysis From IMPROVE-IT.

Importance: Studies have demonstrated an association between single measures of high-sensitivity troponin (hsTn) and future cardiovascular events in patients with chronic coronary syndromes. However, limited data exist regarding the association between changes in serial values of hsTn and subsequent cardiovascular events in this patient population. Objective: To evaluate the association between changes in high-sensitivity troponin T (hsTnT) and subsequent cardiovascular events in patients stabilized after acute coronary syndrome (ACS). Design, Setting, and Participants: This is a secondary analysis from the Improved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT), a randomized clinical trial of ezetimibe vs placebo on a background of simvastatin in 18 144 patients hospitalized for an ACS across 1147 sites in 39 countries. The current biomarker substudy includes the 6035 participants consenting to the biomarker substudy with available hsTnT at months 1 and 4. Data were collected from October 26, 2005, through July 8, 2010, with the database locked October 21, 2014. Data were analyzed from February 28, 2021, through August 14, 2022. Main Outcomes and Measures: The outcomes of interest were cardiovascular death, myocardial infarction (MI), stroke, or hospitalization for heart failure (HHF). Associations of absolute and relative changes in hsTnT between month 1 and month 4 as a function of the starting month 1 hsTnT and the composite outcome were examined using landmark analyses. Results: Of 6035 patients in this analysis (median [IQR] age, 64 [57-71]), 1486 (24.6%) were female; 361 (6.0%) were Asian; 121 were (2.0%) Black; 252 (4.2%) were Spanish descent; 4959 were (82.2%) White; and 342 (5.7%) reported another race (consolidated owing to small numbers), declined to respond, or were not asked to report race owing to regulatory prohibitions. Most patients (4114 [68.2%]) had stable hsTnT values (change <3 ng/L), with 1158 (19.2%) and 763 (12.6%) having changes of 3 to less than 7 ng/L and 7 ng/L or more, respectively. After adjustment for clinical risk factors and stratification by the starting month 1 hsTnT level, an absolute increase in hsTnT of 7 ng/L or more was associated with a more than 3-fold greater risk of the composite outcome (adjusted hazard ratio [aHR], 3.33; 95% CI, 1.99-5.57; P < .001), whereas decreases of 7 ng/L or more were associated with similar to lower risk (aHR, 0.51; 95% CI, 0.26-1.03; P = .06) compared with stable values. There was a stepwise association moving from larger absolute decreases (aHR, 0.51; 95% CI, 0.26-1.03) to larger absolute increases (aHR, 3.33; 95% CI, 1.99-5.57) in hsTnT with future risk of the composite outcome (P trend <.001). A similar association was observed when analyzed on the basis of relative percent and continuous change. Conclusions and Relevance: Among stable patients post-ACS, changes in hsTnT were associated with a gradient of risk of subsequent cardiovascular events across the range of starting hsTnT values. Serial assessment of hsTnT may refine risk stratification with the potential to guide therapy decisions in this patient population. Trial Registration: ClinicalTrials.gov Identifier: NCT00202878.

Longitudinal SARS-CoV-2 Nucleocapsid Antibody Kinetics, Seroreversion, and Implications for Seroepidemiologic Studies.

Given widespread use of spike antibody in generating coronavirus disease vaccines, SARS-CoV-2 nucleocapsid antibodies are increasingly used to indicate previous infection in serologic surveys. However, longitudinal kinetics and seroreversion are poorly defined. We found substantial seroreversion of nucleocapsid total immunoglobulin, underscoring the need to account for seroreversion in seroepidemiologic studies.

Metformin treatment is associated with improved outcome in patients with diabetes and advanced heart failure (HFrEF).

The role of metformin (MET) in the treatment of patients with advanced HFrEF and type 2 diabetes mellitus (DM) is not firmly established. We studied the impact of MET on metabolic profile, quality of life (QoL) and survival in these patients. A total of 847 stable patients with advanced HFrEF (57.4 ± 11.3 years, 67.7% NYHA III/IV, LVEF 23.6 ± 5.8%) underwent clinical and laboratory evaluation and were prospectively followed for a median of 1126 (IQRs 410; 1781) days for occurrence of death, urgent heart transplantation or mechanical circulatory support implantation. A subgroup of 380 patients (44.9%) had DM, 87 of DM patients (22.9%) were treated with MET. Despite worse insulin sensitivity and more severe DM (higher BMI, HbA1c, worse insulin resistance), MET-treated patients exhibited more stable HF marked by lower BNP level (400 vs. 642 ng/l), better LV and RV function, lower mitral and tricuspid regurgitation severity, were using smaller doses of diuretics (all p < 0.05). Further, they had higher eGFR (69.23 vs. 63.34 ml/min/1.73 m2) and better QoL (MLHFQ: 36 vs. 48 points, p = 0.002). Compared to diabetics treated with other glucose-lowering agents, MET-treated patients had better event-free survival even after adjustment for BNP, BMI and eGFR (p = 0.035). Propensity score-matched analysis with 17 covariates yielded 81 pairs of patients and showed a significantly better survival for MET-treated subgroup (p = 0.01). MET treatment in patients with advanced HFrEF and DM is associated with improved outcome by mechanisms beyond the improvement of blood glucose control.

Hemolysis Index and Potassium Reporting.

OBJECTIVES: In vitro hemolysis generates a spurious increase in potassium. Roche Diagnostics recently revised its recommended guidelines for potassium reporting on cobas analyzers. By dramatically reducing the allowable degree of hemolysis, these guidelines would increase specimen rejection rates. We attempted to balance the desire to avoid inaccurate results with the clinical implications of increased specimen rejection rates. METHODS: We downloaded hemolytic indices (HI) for 80,795 specimens tested at our institution on cobas chemistry analyzers in 1 month and evaluated potential specimen rejection rates based on the new criteria. We also spiked nonhemolyzed samples with hemolyzed blood to assess the influence of HI values on potassium measurements. RESULTS: The new recommendations would lead to specimen rejection rates of 76% in the neonatal intensive care unit (NICU), 41% in the emergency department (ED), 16% in inpatient specimens, and 9% in outpatient samples. Our current criteria of reporting potassium concentrations in inpatient and outpatient specimens with HI ≤100 and in NICU and ED specimens with HI ≤300 and additional interpretive guidance for HI values between 100 and 300 reduce unnecessary specimen rejections to 3% in NICU, 2% in ED and inpatients, and less than 1% in outpatients without significantly increasing the number of clinically consequential incorrect results. CONCLUSIONS: The new recommendations would lead to unacceptably high specimen rejection rates. Laboratories should develop context-specific, evidence-based reporting criteria that minimize reporting of inaccurate results without disrupting delivery of care.

A Potassium-Based Quality-of-Service Metric Reduces Phlebotomy Errors, Resulting in Improved Patient Safety and Decreased Cost.

OBJECTIVES: Poor phlebotomy technique can introduce pseudohyperkalemia without hemolysis, requiring additional workup and placing a significant burden on patients, clinical teams, and laboratories. Such preanalytical biases can be detected through systematic evaluation of potassium concentrations on a per-phlebotomist basis. We report our long-term experience with a potassium-based quality-of-service phlebotomy metric and its effects on resource utilization. METHODS: Potassium monitoring and retraining of 26 full-time phlebotomists were piloted as a quality-of-service intervention. Changes in potassium concentrations and impact on resource utilization were assessed. An algorithm for data monitoring and phlebotomist feedback was developed, followed by institution-wide implementation. RESULTS: Systematic intervention and retraining normalized K+ concentrations and lowered the percentage of venipunctures with K+ above 5.2 mmol/L, leading to a marked increase in phlebotomist compliance. This change resulted in resources savings of 13% to 100% for individual phlebotomists, reducing the total extra laboratory time required for repeat phlebotomies to determine hyperkalemia, mostly in the high-volume phlebotomist group. CONCLUSIONS: A quality-of-service algorithm that involved monitoring potassium concentrations on a per-phlebotomist basis with feedback and retraining contributed to a concrete, data-based quality improvement plan. The institution-wide implementation of this metric allowed for significant cost savings and a reduction in critical value alerts, directly affecting the quality of patient care.