Trans-cardiac gradient of secretoneurin in patients with Takotsubo syndrome.

INTRODUCTION: Secretoneurin (SN) is a novel biomarker that provides prognostic information in patients with cardiovascular disease. In experimental models, SN production is increased in the failing myocardium. Currently, no information is available on SN production in human myocardium. Accordingly, we wanted to determine the trans-cardiac gradient of SN in patients with Takotsubo syndrome (TTS), and to correlate circulating SN concentrations with indices of cardiac structure and function. METHODS: We included 15 women diagnosed with TTS according to established criteria. Plasma SN concentrations were measured in blood samples obtained simultaneously from the aortic root and the coronary sinus. Coronary physiology was assessed by invasive measurements, and we used cardiac magnetic resonance imaging (cMRI) to determine left ventricular ejection fraction (LVEF) and cardiac mass. RESULTS: Median age was 65 years and median LVEF was 45%. Median SN concentration was 39 (25th-75th percentile 31-44) pmol/L in the coronary sinus and 37 (30-41) pmol/L in the aortic root (p=0.02 for difference). SN concentrations in the aortic root showed the highest correlations with N-terminal B-type natriuretic peptide (rho=0.47) and estimated glomerular filtration rate (rho=-0.41). In contrast, we found weak correlations between SN concentrations and index of myocardial resistance (rho=0.12), LVEF (rho=0.08), and cardiac mass (rho= -0.09). CONCLUSION: We demonstrate a positive trans-cardiac gradient of SN in patients with TTS, which supports the hypothesis that SN is produced and released in the human myocardium in situations of myocardial dysfunction and stress.

Systolic Blood Pressure, Diastolic Blood Pressure and Pulse Pressure and the Risk of Subclinical Myocardial Injury: The HUNT Study.

BACKGROUND: Subclinical myocardial injury expressed as higher cardiac troponin concentrations may represent an important intermediary between hypertension and the risk of cardiovascular disease. The study aimed to assess the relative strength of associations between systolic blood pressure (BP), diastolic BP, and pulse pressure, and subclinical myocardial injury, and how change in BP variables over time associates with subclinical myocardial injury. METHODS AND RESULTS: cTnl (cardiac troponin I) was measured in 32 968 participants of the fourth wave of the population-based cohort HUNT4 (Trøndelag Health Study) without a history of cardiovascular disease. An additional longitudinal analysis included participants from HUNT4 with BP measurements from HUNT3 (n=18 681). Associations between BP variables and cTnI concentrations were assessed by linear and logistic regression analyses. The median cTnI concentration was 1.6 ng/L (25th-75th percentiles, 0.6-3.1 ng/L), median age was 52 years (39.1-65.6 years), and 57% were female subjects. Cross-sectionally, only systolic BP categories ≥130 mm Hg associated with higher cTnI concentrations, compared with a reference systolic BP of <110 mm Hg. All categories of diastolic BP and pulse pressure were positively associated with higher cTnI concentrations when diastolic BP 70 to 79 mm Hg and pulse pressure <40 mm Hg were used as references, respectively. When comparing systolic BP, diastolic BP, and pulse pressure as continuous variables, cross-sectionally, pulse pressure most strongly associated with cTnI concentrations (P for all comparisons <0.001), whereas longitudinally, change in diastolic BP was most strongly associated with cTnI concentrations (P for all comparisons <0.05). CONCLUSIONS: Subjects with high pulse pressure and longitudinal increase in diastolic BP are at higher risk for subclinical myocardial injury.

Reference intervals of circulating secretoneurin concentrations determined in a large cohort of community dwellers: the HUNT study.

OBJECTIVES: Secretoneurin (SN) is a novel cardiac biomarker that associates with the risk of mortality and dysfunctional cardiomyocyte Ca2+ handling in heart failure patients. Reference intervals for SN are unknown. METHODS: SN was measured with a CE-marked ELISA in healthy community dwellers from the fourth wave of the Trøndelag Health Study (HUNT4) conducted in 2017-2019. The common, sex and age specific 90th, 95th, 97.5th and 99th percentiles were calculated using the non-parametric method and outlier exclusion according to the Reed test. The applicability of sex and age specific reference intervals were investigated using Harris and Boyd test. We also estimated the percentiles in a subset with normal findings on echocardiographic screening. RESULTS: The total cohort included 887 persons (56.4 % women). After echocardiographic screening 122 persons were excluded, leaving a total of 765 persons (57.8 % women). The 97.5th percentile (95 % CI in brackets) of SN was 59.7 (57.5-62.1) pmol/L in the total population and 58.6 (57.1-62.1) pmol/L after echocardiography screening. In general, slightly higher percentiles were found in women and elderly participants, but less than 4 % in these subgroups had concentrations deviating from the common 97.5th percentile. Low BMI or eGFR was also associated with higher concentrations of SN. CONCLUSIONS: Upper reference limits for SN were similar amongst healthy adult community dwellers regardless of prescreening including cardiac echocardiography or not. Women and elderly showed higher concentrations of SN, but the differences were not sufficiently large to justify age and sex stratified upper reference limits.

Trajectory of cardiac troponin T following moderate-to-severe COVID-19 and the association with cardiac abnormalities.

BACKGROUND: COVID-19 has been associated with cardiac troponin T (cTnT) elevations and changes in cardiac structure and function, but the link between cardiac dysfunction and high-sensitive cardiac troponin T (hs-cTnT) in the acute and convalescent phase is unclear. OBJECTIVE: To assess whether hs-cTnT concentrations are associated with cardiac dysfunction and structural abnormalities after hospitalization for COVID-19, and to evaluate the performance of hs-cTnT to rule out cardiac pathology. METHODS: Patients hospitalized with COVID-19 had hs-cTnT measured during the index hospitalization and after 3-and 12 months, when they also underwent an echocardiographic study. A subset also underwent cardiovascular magnetic resonance imaging (CMR) after 6 months. Cardiac abnormalities were defined as left ventricular hypertrophy or dysfunction, right ventricular dysfunction, or CMR late gadolinium. RESULTS: We included 189 patients with hs-cTnT concentrations measured during hospitalization for COVID-19, and after 3-and 12 months: Geometric mean (95%CI) 13 (11-15) ng/L, 7 (6-8) ng/L and 7 (6-8) ng/L, respectively. Cardiac abnormalities after 3 months were present in 45 (30%) and 3 (8%) of patients with hs-cTnT ≥ and < 5 ng/L at 3 months, respectively (negative predictive value 92.3% [95%CI 88.5-96.1%]). The performance was similar in patients with and without dyspnea. Hs-cTnT decreased from hospitalization to 3 months (more pronounced in intensive care unit-treated patients) and remained unchanged from 3 to 12 months, regardless of the presence of cardiac abnormalities. CONCLUSION: Higher hs-cTnT concentrations in the convalescent phase of COVID-19 are associated with the presence of cardiac pathology and low concentrations (< 5 ng/L) may support in ruling out cardiac pathology following the infection.

Impact of the ESC Cardio-Oncology Guidelines Biomarker Criteria on Incidence of Cancer Therapy-Related Cardiac Dysfunction.

Background: The impact of recent consensus definitions of cancer therapy-related cardiac dysfunction (CTRCD) from the European Society of Cardiology cardio-oncology guidelines on the reported incidence of CTRCD has not yet been assessed. Objectives: The aim of this study was to assess the: 1) cumulative incidence; 2) point prevalence during and after adjuvant therapy; and 3) prognostic value of CTRCD as defined by different asymptomatic CTRCD guideline criteria. Methods: The cumulative incidence and point prevalence of CTRCD were retrospectively assessed in 118 patients participating in the PRADA (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy) trial. Asymptomatic CTRCD was assessed using alternative cardiac troponin (cTn) 99th percentile upper reference limits (URLs) to define cTnT and cTnI elevation. Results: The cumulative incidence of moderate or severe CTRCD was low (1.7%), whereas the cumulative incidence of mild asymptomatic CTRCD was higher and differed markedly according to the biomarker criteria applied, ranging from 49.2% of patients when cTnT greater than the sex-specific 99th percentile URL was used to define cTn elevation to 9.3% when sex-neutral cTnI was used. The point prevalence of CTRCD was highest at the end of anthracycline therapy (47.8%) and was driven primarily by asymptomatic cTn elevation. CTRCD during adjuvant therapy was not prognostic for CTRCD at extended follow-up of 24 months (Q1-Q3: 21-29 months) after randomization. Conclusions: Mild asymptomatic CTRCD during adjuvant breast cancer therapy was frequent and driven mainly by cTn elevation and was not prognostic of subsequent CTRCD. The incidence of mild, asymptomatic CTRCD differed markedly depending on the cTn assay and whether sex-neutral or sex-dependent URLs were applied. (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy [PRADA]; NCT01434134).

Large scale plasma proteomics identifies novel proteins and protein networks associated with heart failure development.

Heart failure (HF) causes substantial morbidity and mortality but its pathobiology is incompletely understood. The proteome is a promising intermediate phenotype for discovery of novel mechanisms. We measured 4877 plasma proteins in 13,900 HF-free individuals across three analysis sets with diverse age, geography, and HF ascertainment to identify circulating proteins and protein networks associated with HF development. Parallel analyses in Atherosclerosis Risk in Communities study participants in mid-life and late-life and in Trøndelag Health Study participants identified 37 proteins consistently associated with incident HF independent of traditional risk factors. Mendelian randomization supported causal effects of 10 on HF, HF risk factors, or left ventricular size and function, including matricellular (e.g. SPON1, MFAP4), senescence-associated (FSTL3, IGFBP7), and inflammatory (SVEP1, CCL15, ITIH3) proteins. Protein co-regulation network analyses identified 5 modules associated with HF risk, two of which were influenced by genetic variants that implicated trans hotspots within the VTN and CFH genes.

Exercise training and high-sensitivity cardiac troponin-I in patients with heart failure with reduced ejection fraction.

AIMS: The aims of this sub-study of the SMARTEX trial were (1) to evaluate the effects of a 12-week exercise training programme on serum levels of high sensitivity cardiac troponin I (hs-cTnI) in patients with moderate chronic heart failure (CHF), in New York Heart Association class II-III with reduced ejection fraction (HFrEF) and (2) to explore the associations with left ventricular remodelling, functional capacity and filling pressures measured with N-terminal pro brain natriuretic peptide (NT-proBNP). METHODS AND RESULTS: In this sub-study, 196 patients were randomly assigned to high intensity interval training (HIIT, n = 70), moderate continuous training (MCT, n = 59) or recommendation of regular exercise (RRE), (n = 67) for 12 weeks. To reveal potential difference between structured intervention and control, HIIT and MCT groups were merged and named supervised exercise training (SET) group. The RRE group constituted the control group (CG). To avoid contributing factors to myocardial injury, we also evaluated changes in patients without additional co-morbidities (atrial fibrillation, hypertension, diabetes mellitus, and chronic obstructive pulmonary disease). The relationship between hs-cTnI and left ventricular end-diastolic diameter (LVEDD), VO2peak, and NT-proBNP was analysed by linear mixed models. At 12 weeks, Hs-cTnI levels were modestly but significantly reduced in the SET group from median 11.9 ng/L (interquartile ratio, IQR 7.1-21.8) to 11.5 ng/L (IQR 7.0-20.7), P = 0.030. There was no between-group difference (SET vs. CG, P = 0.116). There was a numerical but not significant reduction in hs-cTnI for the whole population (P = 0.067) after 12 weeks. For the sub-group of patients without additional co-morbidities, there was a significant between-group difference: SET group (delta -1.2 ng/L, IQR -2.7 to 0.1) versus CG (delta -0.1 ng/L, IQR -0.4 to 0.7), P = 0.007. In the SET group, hs-cTnI changed from 10.9 ng/L (IQR 6.0-22.7) to 9.2 ng/L (IQR 5.2-20.5) (P = 0.002), whereas there was no change in the CG (6.4 to 5.8 ng/L, P = 0.64). Changes in hs-cTnI (all patients) were significantly associated with changes in; LVEDD, VO2peak, and NT-proBNP, respectively. CONCLUSIONS: In patients with stable HFrEF, 12 weeks of structured exercise intervention was associated with a modest, but significant reduction of hs-cTnI. There was no significant difference between intervention group and control group. In the sub-group of patients without additional co-morbidities, this difference was highly significant. The alterations in hs-cTnI were associated with reduction of LVEDD and natriuretic peptide concentrations as well as improved functional capacity.

Prognostic significance of chronic myocardial injury diagnosed by three different cardiac troponin assays in patients admitted with suspected acute coronary syndrome.

OBJECTIVES: Chronic myocardial injury (CMI) is defined as stable concentrations of cardiac troponin T or I (cTnT or cTnI) above the assay-specific 99th percentile upper reference limit (URL) and signals poor outcome. The clinical implications of diagnosing CMI are unclear. We aimed to assess prevalence and association of CMI with long-term prognosis using three different high-sensitivity cTn (hs-cTn) assays. METHODS: A total of 1,292 hospitalized patients without acute myocardial injury had cTn concentrations quantified by hs-cTn assays by Roche Diagnostics, Abbott Diagnostics and Siemens Healthineers. The median follow-up time was 4.1 years. The prevalence of CMI and hazard ratios for mortality and cardiovascular (CV) events were calculated based on the URL provided by the manufacturers and compared to the prognostic accuracy when lower percentiles of cTn (97.5, 95 or 90), limit of detection or the estimated bioequivalent concentrations between assays were used as cutoff values. RESULTS: There was no major difference in prognostic accuracy between cTnT and cTnI analyzed as continuous variables. The correlation between cTnT and cTnI was high (r=0.724-0.785), but the cTnT assay diagnosed 3.9-4.5 times more patients with having CMI based on the sex-specific URLs (TnT, n=207; TnI Abbott, n=46, TnI Siemens, n=53) and had higher clinical sensitivity and AUC at the URL. CONCLUSIONS: The prevalence of CMI is highly assay-dependent. cTnT and cTnI have similar prognostic accuracy for mortality or CV events when measured as continuous variables. However, a CMI diagnosis according to cTnT has higher prognostic accuracy compared to a CMI diagnosis according to cTnI.

Prognostic value of growth differentiation factor-15 3 months after an acute chest pain admission.

OBJECTIVE: Growth differentiation factor-15 (GDF-15) is a predictor of death and cardiovascular events when measured during index hospitalisation in patients with acute chest pain. This study investigated the prognostic utility of measuring GDF-15 3 months after an admission with suspected non-ST-elevation acute coronary syndrome (NSTE-ACS). METHODS: GDF-15 was measured at baseline and 3 months after admission in 758 patients admitted with suspected NSTE-ACS. Patients were followed for a median of 1540 (IQR: 1087-1776) days after the 3-month visit. The primary endpoint was all-cause mortality, while the secondary composite endpoint included all-cause mortality, incident myocardial infarction and heart failure hospitalisation during follow-up. RESULTS: In patients with GDF-15 ≥1200 pg/mL (n=248), 18% died and 25% met the composite endpoint. In patients with GDF-15 <1200 pg/mL (n=510), 1.7% died and 4% met the composite endpoint. The GDF-15 concentration (log2 transformed) at 3 months was significantly associated with all-cause mortality (adjusted HR: 2.2, 95% CI: 1.4 to 3.3, p<0.001) and the composite endpoint (adjusted HR: 1.9, 95% CI: 1.4 to 2.7, p<0.001), independently of traditional risk factors and baseline troponin T. A 10% change in GDF-15 concentration from baseline to the 3-month visit was associated with increased risk of all-cause mortality (HR: 1.06, 95% CI: 1.01 to 1.13, p=0.031), adjusting for baseline GDF-15 concentrations. CONCLUSIONS: High GDF-15 concentrations 3 months after admission for suspected NSTE-ACS are associated with long-term mortality and cardiovascular events, independent of traditional risk factors and troponin T. A change in GDF-15 concentration can provide prognostic information.

Aiming toWards Evidence baSed inTerpretation of Cardiac biOmarkers in patients pResenting with chest pain using Point of Care Testing (WESTCOR-POC): study design.

OBJECTIVES: Patients presenting with symptoms suggestive of acute coronary syndrome (ACS) contribute to a high workload and overcrowding in the Emergency Department (ED). Accelerated diagnostic protocols for non-ST-elevation myocardial infarction have proved challenging to implement. One obstacle is the turnaround time for analyzing high-sensitivity cardiac troponin (hs-cTn). In the WESTCOR-POC study (Clinical Trials number NCT05354804) we aim to evaluate safety and efficiency of a 0/1 h hs-cTn algorithm utilizing a hs-cTnI point of care (POC) instrument in comparison to central laboratory hs-cTnT measurements. DESIGN: This is a prospective single-center randomized clinical trial aiming to include 1500 patients admitted to the ED with symptoms suggestive of ACS. Patients will receive standard investigations following the European Society of Cardiology 0/1h protocols for centralized hs-cTnT measurements or the intervention using a 0/1h POC hs-cTnI algorithm. Primary end-points are 1) Safety; death, myocardial infarction or acute revascularization within 30 days 2) Efficiency; length of stay in the ED, 3) Cost- effectiveness; total episode cost, 4) Patient satisfaction, 5) Patient symptom burden and 6) Patients quality of life. Secondary outcomes are 12-months death, myocardial infarction or acute revascularization, percentage discharged after 3 and 6 h, total length of hospital stay and all costs related to hospital contact within 12 months. CONCLUSION: Results from this study may facilitate implementation of POC hs-cTn testing assays and accelerated diagnostic protocols in EDs, and may serve as a valuable resource for guiding future investigations for the use of POC high sensitivity troponin assays in outpatient clinics and prehospital settings.

Recent successes in heart failure treatment.

Remarkable recent advances have revolutionized the field of heart failure. Survival has improved among individuals with heart failure and a reduced ejection fraction and for the first time, new therapies have been shown to improve outcomes across the entire ejection fraction spectrum of heart failure. Great strides have been taken in the treatment of specific cardiomyopathies such as cardiac amyloidosis and hypertrophic cardiomyopathy, whereby conditions once considered incurable can now be effectively managed with novel genetic and molecular approaches. Yet there remain substantial residual unmet needs in heart failure. The translation of successful clinical trials to improved patient outcomes is limited by large gaps in implementation of care, widespread lack of disease awareness and poor understanding of the socioeconomic determinants of outcomes and how to address disparities. Ongoing clinical trials, advances in phenotype segmentation for precision medicine and the rise in technology solutions all offer hope for the future.

Cardiac Troponin T and NT-proBNP for Prediction of 30-Day Readmission or Death in Patients with Acute Dyspnea: Data from the Akershus Cardiac Examination 2 Study.

INTRODUCTION: N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) measurements are recommended in patients with acute dyspnea. We aimed to assess the prognostic merit of cTnT compared to NT-proBNP for 30-day readmission or death in patients hospitalized with acute dyspnea. METHODS: We measured cTnT and NT-proBNP within 24 h in 314 patients hospitalized with acute dyspnea and adjudicated the cause of the index admission. Time to first event of readmission or death ≤30 days after hospital discharge was recorded, and cTnT and NT-proBNP measurements were compared head-to-head. RESULTS: Patients who died (12/314) or were readmitted (71/314) within 30 days had higher cTnT concentrations (median: 32.6, Q1-Q3: 18.4-74.2 ng/L vs. median: 19.4, Q1-Q3: 8.4-36.1 ng/L; p for comparison <0.001) and NT-proBNP concentrations (median: 1,753.6, Q1-Q3: 464.2-6,862.0 ng/L vs. median 984, Q1-Q3 201-3,600 ng/L; for comparison p = 0.027) compared to patients who survived and were not readmitted. cTnT concentrations were associated with readmission or death within 30 days after discharge both in the total cohort (adjusted hazard ratio [aHR]: 1.64, 95% confidence interval [CI]: 1.30-2.05) and in patients with heart failure (HF) (aHR: 1.58, 95% CI: 1.14-2.18). In contrast, NT-proBNP concentrations were not associated with short-term events, neither in the total cohort (aHR: 1.10, 95% CI: 0.94-1.30) nor in patients with adjudicated HF (aHR: 1.06, 95% CI: 0.80-1.40). CONCLUSION: cTnT concentrations are associated with 30-day readmission or death in patients hospitalized with acute dyspnea, as well as in patients adjudicated HF.

Prognostic value of secretoneurin in chronic heart failure. Data from the GISSI-Heart Failure trial.

BACKGROUND: Circulating secretoneurin (SN) concentrations have been found to provide prognostic information in patients with acute heart failure. We wanted to assess whether SN would improve prognostication also in patients with chronic heart failure (HF) in a large multicenter trial. METHODS: We measured plasma SN concentrations at randomization (n = 1224) and after 3 months (n = 1103) in patients with chronic, stable HF from the GISSI-HF study. The co-primary endpoints were (1) time to death or (2) admission to hospital for cardiovascular reasons. RESULTS: Mean age was 67 years and 80% were male. Median (quartile 1-3) SN concentrations were 42.6 (35.0-62.8) pmol/L on randomization and 42.0 (34.5-53.1) pmol/L after 3 months, which are higher than SN concentrations in healthy subjects. Higher SN concentrations at randomization were associated with lower body-mass index (BMI), lower systolic blood pressure, lower estimated glomerular filtration rate (eGFR), higher B-type natriuretic peptide (BNP) concentrations, and diagnosis of chronic obstructive pulmonary disease. During median follow-up of 3.9 years, 344 patients (27.0%) died. After adjusting for age, sex, left ventricular ejection fraction, BMI, functional class, ischemic etiology, heart rate, blood pressure, eGFR, bilirubin, comorbidities, and BNP concentrations, logarithmically transformed SN concentrations on randomization were associated with mortality (HR 2.60 (95% CI 1.01-6.70), p = 0.047). SN concentrations were also associated with admission to hospital for cardiovascular reasons, but the association was attenuated and no longer significant in multivariable analysis. CONCLUSION: Plasma SN concentrations provided incremental prognostic information to established risk indices and biomarkers in a large cohort of chronic HF patients.

Single Troponin Measurement to Rule Out Myocardial Infarction: JACC Review Topic of the Week.

The term "single-sample rule-out" refers to the ability of very low concentrations of high-sensitivity cardiac troponin (hs-cTn) on presentation to exclude acute myocardial infarction with high clinical sensitivity and negative predictive value. Observational and randomized studies have confirmed this ability. Some guidelines endorse use of a concentration of hs-cTn at the assay's limit of detection, while other studies have validated the use of higher concentrations, allowing this approach to identify a greater proportion of patients at low risk. In most studies, at least 30% of patients can be triaged with this approach. The concentration of hs-cTn varies according to the assay used and sometimes how regulations permit reporting. It is clear that patients need to be at least 2 hours from the onset of symptoms being evaluated. Caution is warranted, particularly with older patients, women, and patients with underlying cardiac comorbidities.

Trajectories of cardiac troponin in the decades before cardiovascular death: a longitudinal cohort study.

BACKGROUND: High-sensitivity cardiac troponin testing is a promising tool for cardiovascular risk prediction, but whether serial testing can dynamically predict risk is uncertain. We evaluated the trajectory of cardiac troponin I in the years prior to a cardiovascular event in the general population, and determine whether serial measurements could track risk within individuals. METHODS: In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on three occasions over a 15-year period. Time trajectories of troponin were constructed in those who died from cardiovascular disease compared to those who survived or died from other causes during follow up and these were externally validated in the HUNT Study. A joint model that adjusts for cardiovascular risk factors was used to estimate risk of cardiovascular death using serial troponin measurements. RESULTS: In 7,293 individuals (mean 58 ± 7 years, 29.4% women) cardiovascular and non-cardiovascular death occurred in 281 (3.9%) and 914 (12.5%) individuals (median follow-up 21.4 years), respectively. Troponin concentrations increased in those dying from cardiovascular disease with a steeper trajectory compared to those surviving or dying from other causes in Whitehall and HUNT (Pinteraction < 0.05 for both). The joint model demonstrated an independent association between temporal evolution of troponin and risk of cardiovascular death (HR per doubling, 1.45, 95% CI,1.33-1.75). CONCLUSIONS: Cardiac troponin I concentrations increased in those dying from cardiovascular disease compared to those surviving or dying from other causes over the preceding decades. Serial cardiac troponin testing in the general population has potential to track future cardiovascular risk.

Longitudinal whole blood transcriptomic analysis characterizes neutrophil activation and interferon signaling in moderate and severe COVID-19.

A maladaptive inflammatory response has been implicated in the pathogenesis of severe COVID-19. This study aimed to characterize the temporal dynamics of this response and investigate whether severe disease is associated with distinct gene expression patterns. We performed microarray analysis of serial whole blood RNA samples from 17 patients with severe COVID-19, 15 patients with moderate disease and 11 healthy controls. All study subjects were unvaccinated. We assessed whole blood gene expression patterns by differential gene expression analysis, gene set enrichment, two clustering methods and estimated relative leukocyte abundance using CIBERSORT. Neutrophils, platelets, cytokine signaling, and the coagulation system were activated in COVID-19, and this broad immune activation was more pronounced in severe vs. moderate disease. We observed two different trajectories of neutrophil-associated genes, indicating the emergence of a more immature neutrophil phenotype over time. Interferon-associated genes were strongly enriched in early COVID-19 before falling markedly, with modest severity-associated differences in trajectory. In conclusion, COVID-19 necessitating hospitalization is associated with a broad inflammatory response, which is more pronounced in severe disease. Our data suggest a progressively more immature circulating neutrophil phenotype over time. Interferon signaling is enriched in COVID-19 but does not seem to drive severe disease.