Proenkephalin Improves Cardio-Renal Risk Prediction in Acute Coronary Syndromes: The KID-ACS Score.

BACKGROUND AND AIMS: Circulating proenkephalin (PENK) is a stable endogenous polypeptide with fast response to glomerular dysfunction and tubular damage. This study examined the predictive value of PENK for renal outcomes and mortality in patients with acute coronary syndromes (ACS). METHODS: Proenkephalin was measured in plasma in a prospective multicentre ACS cohort from Switzerland (n=4787) and in validation cohorts from the UK (n=1141), Czechia (n=927), and Germany (n=220). A biomarker-enhanced risk score (KID-ACS score) for simultaneous prediction of in-hospital acute kidney injury (AKI) and 30-day mortality was derived and externally validated. RESULTS: On multivariable adjustment for established risk factors, circulating PENK remained associated with in-hospital AKI (per log2 increase: adjusted odds ratio [OR] 1.53, 95% confidence interval [CI] 1.13-2.09, P=0.007) and 30-day mortality (adjusted hazard ratio [HR] 2.73, 95% CI 1.85-4.02, P<0.001). The KID-ACS score integrates PENK and showed an area under the receiver operating characteristic curve (AUC) of 0.72 (95% CI 0.68-0.76) for in-hospital AKI, and of 0.91 (95% CI 0.87-0.95) for 30-day mortality in the derivation cohort. Upon external validation, KID-ACS achieved similarly high performance for in-hospital AKI (Zurich: AUC 0.73, 95% CI 0.70-0.77; Czechia: AUC 0.75, 95% CI 0.68-0.81; Germany: AUC 0.71, 95% CI 0.55-0.87) and 30-day mortality (UK: AUC 0.87, 95% CI 0.83-0.91; Czechia: AUC 0.91, 95% CI 0.87-0.94; Germany: AUC 0.96, 95% CI 0.92-1.00) outperforming the CA-AKI score and the GRACE 2.0 score, respectively. CONCLUSIONS: Circulating PENK offers incremental value for predicting in-hospital AKI and mortality in ACS. The simple 6-item KID-ACS risk score integrates PENK and provides a novel tool for simultaneous assessment of renal and mortality risk in patients with ACS.

Bioactive adrenomedullin and interleukin-6 in COVID-19: potential biomarkers of acute kidney injury and critical illness.

BACKGROUND: The aim of this study was to investigate whether bioactive adrenomedullin (bio-ADM) and interleukin-6 (IL-6) are related to acute kidney injury (AKI) and severe illness in COVID-19 patients. METHODS: 153 patients with COVID-19 admitted to the emergency department (ED) were included. Blood samples were collected from each patient at admission. Bio-ADM and IL-6, as well as DPP3 and routinely measured markers were evaluated regarding the endpoints AKI (22/128 hospitalized patients) and a composite endpoint of admission to intensive care unit and/or in-hospital death (n = 26/153 patients). RESULTS: Bio-ADM and IL-6 were significantly elevated in COVID-19 patients with AKI compared to COVID-19 patients without AKI (each p < 0.001). According to ROC analyses IL-6 and bio-ADM had the largest AUC (0.84 and 0.81) regarding the detection of AKI. Furthermore, bio-ADM and IL-6 were significantly elevated in COVID-19 patients reaching the composite endpoint (each p < 0.001). Regarding the composite endpoint ROC analysis showed an AUC of 0.89 for IL-6 and 0.83 for bio-ADM in COVID-19 patients. In the multivariable logistic model bio-ADM and IL-6 presented as independent significant predictors regarding both endpoints AKI and the composite endpoint in COVID-19 patients (as well as creatinine regarding the composite endpoint; each p < 0.05), opposite to leukocytes, C-reactive protein (CRP) and dipeptidyl peptidase 3 (DPP3; each p = n.s.). CONCLUSION: Elevated levels of bio-ADM and IL-6 are associated with AKI and critical illness in patients with COVID-19. Therefore, both biomarkers may be potential tools in risk stratification in COVID-19 patients at presentation in the ED.

Dipeptidyl-peptidase 3 and IL-6: potential biomarkers for diagnostics in COVID-19 and association with pulmonary infiltrates.

Coronavirus SARS-CoV-2 spread worldwide, causing a respiratory disease known as COVID-19. The aim of the present study was to examine whether Dipeptidyl-peptidase 3 (DPP3) and the inflammatory biomarkers IL-6, CRP, and leucocytes are associated with COVID-19 and able to predict the severity of pulmonary infiltrates in COVID-19 patients versus non-COVID-19 patients. 114 COVID-19 patients and 35 patients with respiratory infections other than SARS-CoV-2 were included in our prospective observational study. Blood samples were collected at presentation to the emergency department. 102 COVID-19 patients and 28 non-COVID-19 patients received CT imaging (19 outpatients did not receive CT imaging). If CT imaging was available, artificial intelligence software (CT Pneumonia Analysis) was used to quantify pulmonary infiltrates. According to the median of infiltrate (14.45%), patients who obtained quantitative CT analysis were divided into two groups (> median: 55 COVID-19 and nine non-COVID-19, ≤ median: 47 COVID-19 and 19 non-COVID-19). DPP3 was significantly elevated in COVID-19 patients (median 20.85 ng/ml, 95% CI 18.34-24.40 ng/ml), as opposed to those without SARS-CoV-2 (median 13.80 ng/ml, 95% CI 11.30-17.65 ng/ml; p < 0.001, AUC = 0.72), opposite to IL-6, CRP (each p = n.s.) and leucocytes (p < 0.05, but lower levels in COVID-19 patients). Regarding binary logistic regression analysis, higher DPP3 concentrations (OR = 1.12, p < 0.001) and lower leucocytes counts (OR = 0.76, p < 0.001) were identified as significant and independent predictors of SARS-CoV-2 infection, as opposed to IL-6 and CRP (each p = n.s.). IL-6 was significantly increased in patients with infiltrate above the median compared to infiltrate below the median both in COVID-19 (p < 0.001, AUC = 0.78) and in non-COVID-19 (p < 0.05, AUC = 0.81). CRP, DPP3, and leucocytes were increased in COVID-19 patients with infiltrate above median (each p < 0.05, AUC: CRP 0.82, DPP3 0.70, leucocytes 0.67) compared to infiltrate below median, opposite to non-COVID-19 (each p = n.s.). Regarding multiple linear regression analysis in COVID-19, CRP, IL-6, and leucocytes (each p < 0.05) were associated with the degree of pulmonary infiltrates, as opposed to DPP3 (p = n.s.). DPP3 showed the potential to be a COVID-19-specific biomarker. IL-6 might serve as a prognostic marker to assess the extent of pulmonary infiltrates in respiratory patients.

Urinary N-Terminal Pro-Brain Natriuretic Peptide Predicts Acute Kidney Injury and Severe Disease in COVID-19.

INTRODUCTION: The ongoing COVID-19 pandemic is placing an extraordinary burden on our health care system with its limited resources. Accurate triage of patients is necessary to ensure medical care for those most severely affected. In this regard, biomarkers could contribute to risk evaluation. The aim of this prospective observational clinical study was to assess the relationship between urinary N-terminal pro-brain natriuretic peptide (NT-proBNP) and acute kidney injury (AKI) as well as severe disease in patients with COVID-19. METHODS: 125 patients treated with an acute respiratory infection in the emergency department of the University Hospital Regensburg were analyzed. These patients were divided into a COVID-19 cohort (n = 91) and a cohort with infections not caused by severe acute respiratory syndrome-coronavirus-2 (n = 34). NT-proBNP was determined from serum and fresh urine samples collected in the emergency department. Clinical endpoints were the development of AKI and a composite one consisting of AKI, intensive care unit admission, and in-hospital death. RESULTS: 11 (12.1%) COVID-19 patients developed AKI during hospitalization, whereas 15 (16.5%) reached the composite endpoint. Urinary NT-proBNP was significantly elevated in COVID-19 patients who suffered AKI or reached the composite endpoint (each p < 0.005). In a multivariate regression analysis adjusted for age, chronic kidney disease, chronic heart failure, and arterial hypertension, urinary NT-proBNP was identified as independent predictor of AKI (p = 0.017, OR = 3.91 [CI: 1.28-11.97] per standard deviation [SD]), as well as of the composite endpoint (p = 0.026, OR 2.66 [CI: 1.13-6.28] per SD). CONCLUSION: Urinary NT-proBNP might help identify patients at risk for AKI and severe disease progression in COVID-19.

A Pilot Trial to Compare the Long-Term Efficacy of Pulmonary Vein Isolation with High-Power Short-Duration Radiofrequency Versus Laser Energy with Rapid Ablation Mode.

BACKGROUND: Pulmonary vein (PV) reconnection is the major cause of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). The probability of reconnection is higher if the primary lesion is not sufficiently effective, which can be unmasked with an adenosine provocation test (APT). High-power short-duration radiofrequency energy (HPSD) guided with ablation index (AI) and the third generation of the visually guided laser balloon (VGLB) are new methods for PVI. METHODS: A total of 70 participants (35 in each group) who underwent a PVI with either AI-guided HPSD (50 W; AI 500 for the anterior and 400 for the posterior wall, respectively) or VGLB ablation were included in this observational pilot trial. Twenty minutes after each PVI, an APT was performed. The primary endpoint was the event-free survival from AF after three years. RESULTS: A total of 137 (100%) PVs in the HPSD arm and 131 PVs (98.5%) in the VGLB arm were initially successfully isolated (p = 0.24). The overall procedure duration was similar in both arms (155 ± 39 in HPSD vs. 175 ± 58 min in VGLB, p = 0.191). Fluoroscopy time, left atrial dwelling time and duration from the first to the last ablation were longer in the VGLB arm (23 ± 8 vs. 12 ± 3 min, p < 0.001; 157 (111-185) vs. 134 (104-154) min, p = 0.049; 92(59-108) vs. 72 (43-85) min, p = 0.010). A total of 127 (93%) in the HPSD arm and 126 (95%) PVs in the VGLB arm remained isolated after APT (p = 0.34). The primary endpoint was met 1107 ± 68 days after ablation in 71% vs. 66% in the VGLB and HPSD arms, respectively (p = 0.65). CONCLUSIONS: HPSD and VGLB did not differ with respect to long-term outcome of PVI. A large, randomized study should be conducted to compare clinical outcomes with respect to these new ablation techniques.

Kidney injury molecule-1: potential biomarker of acute kidney injury and disease severity in patients with COVID-19.

AIMS: The aim of the current study was to evaluate whether tubular markers kidney injury molecule-1 (KIM-1) and N-acetyl-ß-glucosaminidase (NAG) are related to acute kidney injury (AKI) and severe disease in patients with COVID-19. METHODS AND RESULTS: In this prospective observational clinical trial we examined a cohort of 80 patients with proof of acute respiratory infection and divided them into a COVID-19 cohort (n = 54) and a control cohort (n = 26). KIM-1 and NAG were measured from urine samples collected in the emergency department. We assessed the development of AKI, admission to the intensive care unit (ICU) and intrahospital death as clinical endpoints. Urinary KIM-1 and NAG were not significantly different between patients with SARS-CoV-2 and those with other respiratory infections (each p = n.s.). Eight patients from the COVID-19 cohort and five of the non-COVID-19-patients suffered from acute kidney injury during their stay. Nine COVID-19 patients and two non-COVID-19 patients were admitted to the ICU. KIM-1 was significantly elevated in COVID-19 patients with, compared to those without AKI (p = 0.005), as opposed to NAG and creatinine (each p = n.s.). Furthermore, KIM-1 was significantly elevated in the patients with COVID-19 that had to be transferred to the ICU (p = 0.015), in contrast to NAG and creatinine (each p = n.s.). CONCLUSION: Assessing KIM-1 in patients with COVID-19 might provide additional value in recognizing AKI at an early stage of disease. Further, KIM-1 might indicate higher risk for clinical deterioration as displayed by admission to the ICU.

Urinary N-terminal pro-brain natriuretic peptide: prognostic value in patients with acute chest pain.

AIMS: The objective of this study was to investigate the prognostic value of urinary N-terminal pro-brain natriuretic peptide (NT-proBNP) compared with plasma NT-proBNP in patients presenting with acute chest pain in the emergency department. METHODS AND RESULTS: We measured simultaneously plasma and urinary NT-proBNP at admission in 301 patients with acute chest pain. In our cohort, 174 patients suffered from acute coronary syndrome (ACS). A follow-up (median of 55 months) was performed regarding the endpoints all-cause mortality and major adverse cardiac events (mortality, congestive heart failure, ACS with the necessity of a coronary intervention, and stroke). Fifty-four patients died during follow-up; 98 suffered from the combined endpoint. A significant and positive correlation of urinary and plasma NT-proBNP was found (r = 0.87, P < 0.05). Patients with troponin positive ACS had significantly elevated levels of plasma and urinary NT-proBNP compared with those with unstable angina pectoris or chest wall syndrome (each P < 0.05). The highest levels of both biomarkers were found in patients with congestive heart failure (each P < 0.05). According to Kaplan-Meier analysis, plasma and urinary NT-proBNP were significant predictors for mortality and the combined endpoint in the whole study cohort and in the subgroup of patients with ACS (each P < 0.05). Regarding Cox regression analysis, plasma and urinary NT-proBNP were independent predictors for mortality and the combined endpoint (each P < 0.05). CONCLUSIONS: Urinary NT-proBNP seems to provide a significant predictive value regarding the endpoints all-cause mortality and major adverse cardiac events in patients with acute chest pain and those with ACS.

Protected risk stratification with the wearable cardioverter-defibrillator: results from the WEARIT-II-EUROPE registry.

BACKGROUND: The prospective WEARIT-II-EUROPE registry aimed to assess the value of the wearable cardioverter-defibrillator (WCD) prior to potential ICD implantation in patients with heart failure and reduced ejection fraction considered at risk of sudden arrhythmic death. METHODS AND RESULTS: 781 patients (77% men; mean age 59.3 ± 13.4 years) with heart failure and reduced left ventricular ejection fraction (LVEF) were consecutively enrolled. All patients received a WCD. Follow-up time for all patients was 12 months. Mean baseline LVEF was 26.9%. Mean WCD wearing time was 75 ± 47.7 days, mean daily WCD use 20.3 ± 4.6 h. WCD shocks terminated 13 VT/VF events in ten patients (1.3%). Two patients died during WCD prescription of non-arrhythmic cause. Mean LVEF increased from 26.9 to 36.3% at the end of WCD prescription (p < 0.01). After WCD use, ICDs were implanted in only 289 patients (37%). Forty patients (5.1%) died during follow-up. Five patients (1.7%) died with ICDs implanted, 33 patients (7%) had no ICD (no information on ICD in two patients). The majority of patients (75%) with the follow-up of 12 months after WCD prescription died from heart failure (15 patients) and non-cardiac death (15 patients). Only three patients (7%) died suddenly. In seven patients, the cause of death remained unknown. CONCLUSIONS: Mortality after WCD prescription was mainly driven by heart failure and non-cardiovascular death. In patients with HFrEF and a potential risk of sudden arrhythmic death, WCD protected observation of LVEF progression and appraisal of competing risks of potential non-arrhythmic death may enable improved selection for beneficial ICD implantation.

The role of the tubular biomarkers NAG, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in patients with chest pain before contrast media exposition.

Aim: We evaluated the role of the tubular biomarkers N-acetyl-ß-D-glucosaminidase (NAG), kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in patients with chest pain. Methods: Serum and urine samples were collected of 223 patients and 47 healthy controls. None of them was exposed to contrast media. Results: NAG showed among others significant correlation with N-terminal pro brain natriuretic peptide (NTproBNP), troponin I and creatinine. KIM-1 and NGAL showed weaker correlations. NAG was significantly elevated in all subgroups of acute coronary syndrome (ACS) compared with chest wall syndrome and controls. NAG was an independent predictor for the diagnosis of myocardial infarction. Conclusion: NAG may demonstrate the presence of acute tubular injury due to cardiac impairment already in the emergency department. NAG should be evaluated as marker of acute cardiorenal syndrome in patients with chest pain.

Achieving Guideline-Directed Heart Rate ControlEarly Posthospitalization.

Guidelines for the treatment of heart failure (HF) recommend the titration of ß blockers (BB) to a target dosage shown to be effective in clinical trials. The benefit of BBs is associated with heart rate (HR) control, with a target resting HR <70 bpm which in clinical trials have been associated with improved clinical outcomes. The primary purpose of this study was to gauge the ability to achieve guideline-directed medical therapy HR control in the early posthospitalization period for HF patients with the wearable cardioverter defibrillator (WCD), assessing whether the WCD could be used to evaluate HR both at rest and during activity to determine if targets were being met and to adequately direct clinical decision making. The WCD platform allows continuous recording of HR. To assess the guideline-directed therapy goals for reduction of resting HR, HR was evaluated both at rest (nighttime: midnight-7 a.m.; daytime: 7 a.m. midnight), and during activity of daily living. HR data during activity of daily living (ADL) and rest were collected from patients with HF that wore the WCD for ≥5 weeks (n = 1,353) between 2015 and 2017. First, 643,891 activity episodes from 1,353 patients were analyzed. Daytime and nighttime resting HRs significantly dropped from beginning to end of WCD use (day: 72.5 bpm vs 69.0 bpm, p <0.0001; night: 68.1 vs 64.3, p <0.0001). However, 43% of patients still had an average daytime resting HR ≥70 bpm during the last week of WCD use. When comparing a patient's peak activity HR during the first week of WCD use to the last week, there was no difference (93.6 bpm vs 94.1 bpm, p = 0.23). During ADL, 31% of patients had a HR ≥100 bpm, 14% of patients had a HR ≥110 bpm, and 6% had a HR ≥120 bpm. In conclusion, months after hospital discharge, 43% of patients did not meet guideline-directed resting target HR control, indicating they may not have been effectively managed with BB. HR during ADL may have also been higher than preferred. Remote HR monitoring may help physicians to adequately titrate guideline-directed medical therapy, thus improving clinical outcomes in HF patients.

N-acteyl-ß-D-glucosaminidase and kidney injury molecule-1: New predictors for long-term progression of chronic kidney disease in patients with heart failure.

AIM: Patients with chronic heart failure (CHF) are often characterized by the cardiorenal syndrome (CRS). The aim of the present study was to assess whether novel markers of kidney injury are able to predict progression of chronic kidney disease (CKD) in patients with CHF. METHODS: New renal biomarkers, N-acteyl-ß-D-glucosaminidase (NAG), kidney injury molecule-1 (KIM-1) and Neutrophil Gelatinase-Associated Lipocalin (NGAL), were assessed from urine samples of 149 patients with chronic heart failure. During a 5-year-follow-up, renal function was assessed by creatinine and estimated glomerular filtration rate (eGFR CKD EPI) and was available for 138 patients. Further, data regarding all-cause mortality was obtained. RESULTS: Twenty-six patients (18.8%) developed a progression of CKD during the follow-up period, as defined by decline in eGFR category accompanied by a ≥25% drop in eGFR form baseline. No difference regarding age, sex, body mass index, hypertension, diabetes or EF was present between patients with and without CKD progression (each P = n.s.). At baseline, creatinine concentrations and eGFR were significantly different between both groups (sCr: 1.50 ± 0.67 vs 1.04 ± 0.37, P = < 0.001; eGFR: 47.8 ± 12.3 vs. 77.3 ± 23.5 mL/min per 1.73m(2) , each P < 0.001). In a Kaplan-Meier-analysis, KIM-1 and NAG were significant predictors for CKD progression (both P < 0.05). In Cox regression analysis, NAG > median (OR 3.25,P = 0.013), initial eGFR (OR 0.94, P < 0.001) and diuretic use (OR 3.92, P = 0.001) were independent predictors of CKD progression. Further, KIM-1 and NAG were also independent predictors of a combined endpoint of CKD progression and all-cause mortality by Cox regression analysis (each P < 0.05). The combination of both markers showed additive value regarding both endpoints. NGAL showed no association with CKD progression. CONCLUSIONS: During long-term follow-up chronic heart failure patients with CKD show a relevant disease progression. The current study emphasizes a strong association of the tubular biomarkers NAG and KIM-1 with CKD progression in chronic heart failure and suggests their usefulness as cardiorenal markers.

Panel of emerging cardiac biomarkers contributes for prognosis rather than diagnosis in chronic heart failure.

BACKGROUND: As complex disease, heart failure is associated with various pathophysiological and biochemical disorders. No single biomarker is able to display all these characteristics. Therefore, we evaluated a multimarker panel together with the biochemical gold-standard NT-proBNP. Part of the panel are markers for angiogenesis (Endostatin, IBP-4, IBP-7, sFlt-1 as antiangiogenetic factors and PLGF as angiogenectic factor), myocyte stress (GDF-15), extracellular matrix remodelling (galectin-3, mimecan and TIMP-1), inflammation (galectin-3) and myocyte injury (hs-TnT). METHODS: All markers (Roche Diagnostics, Penzberg, Germany) were assessed in a cohort of 149 patients with chronic heart failure and 84 healthy controls. RESULTS: All markers were positively correlated with ln NT-proBNP (each p < 0.05). Furthermore, they were significantly elevated in patients with chronic heart failure (each p < 0.05). All markers increased significantly with severity of LV dysfunction and severity of New York Heart Association class (each p < 0.05), except for PLGF and Mimecan (each p = NS). With the exception of endostatin, mimecan and PLGF, all other markers were further significant predictors for all-cause mortality in a 3-year follow-up. In a multimarker approach of the five biomarkers with the best performance (NT-proBNP, hs-TnT, TIMP-1, GDF-15 and IBP-4), the event rate was superior to NT-proBNP alone and increased significantly and progressively with the number of elevated biomarkers. CONCLUSION: All emerging markers increased stepwise with the severity of symptoms and LV dysfunction and offer important prognostic information in chronic heart failure, except for PLGF and mimecan. Five biomarkers with different pathophysiological background incorporated additive prognostic value in heart failure. Prognostication in heart failure may be further improved through a multimarker approach.

Equal performance of novel N-terminal proBNP (Cardiac proBNP®) and established BNP (Triage BNP®) point-of-care tests.

BACKGROUND: Recently, a novel point-of-care test (POCT) for N-terminal proBNP (NTproBNP) has been introduced (Cardiac proBNP®, Roche). AIM: The aim was to compare the novel POCT for NTproBNP with the established POCT for BNP. METHODS: NTproBNP and BNP were assessed in 222 individuals with chronic heart failure (n = 151) or controls (n = 71) with both POCTs. RESULTS: NTproBNP and BNP were closely correlated upon regression analysis (r = 0.93; p < 0.01). NTproBNP and BNP were both correlated with ejection fraction and New York Heart Association stage. Receiver operating characteristic analysis yielded satisfying and equivalent predictive values for the detection of left ventricular dysfunction (ejection fraction <40%; NTproBNP: area under the curve 0.97; BNP: area under the curve 0.96; p > 0.05) and presence of New York Heart Association stage >2 (area under the curve 0.92 vs 0.91 for NT-proBNP and BNP, respectively; p > 0.05). CONCLUSION: The NTproBNP POCT allows biochemical detection of heart failure with satisfactory predictive values, is equivalent to the BNP POCT and will improve near-patient testing.

Cyclosporine A impairs norepinephrine-induced vascular contractility.

Usage of cyclosporine A (CsA) after kidney transplantation may be associated with development of nephrotoxicity and vasculopathy, but the mechanisms by which CsA causes vascular dysfunction are still under scrutiny. We established a transplantation model and investigated the effect of CsA on vascular contractility with the aid of a pressurized myograph in comparison with control and unilaterally nephrectomized rats. Results were correlated with mRNA expression studies of α- and ß-adrenoreceptors, in mesenteric resistance arteries versus the thoracic aorta. Consequences of everolimus on functional properties as well as adrenoreceptor expression were also studied. CsA significantly downregulated expression of mesenteric adrenoreceptors, whereas no effect on aortic adrenoreceptors was seen. Administration of everolimus had no influence on mRNA adrenoreceptor expression in mesenteric resistance arteries. Furthermore, contractile responses of mesenteric resistance arteries to norepinephrine were markedly reduced after treatment with CsA, while there was no difference in contraction by endothelin. Everolimus did not alter the contractility response at all. In summary, norepinephrine-induced, but not endothelin-induced, contractile responses of mesenteric resistance arteries are blunted in CsA-treated rats. This finding was accompanied by a marked downregulation of adrenoreceptors in mesenteric resistance arteries and was limited to the usage of CsA.

High-sensitive Troponin I in acute cardiac conditions: implications of baseline and sequential measurements for diagnosis of myocardial infarction.

BACKGROUND: High-sensitive Troponin I (hsTnI) facilitates the early diagnosis of myocardial infarction (MI). However, since hsTnI has not been well characterized in non-ischemic cardiac conditions, the predictive value of hsTnI for MI remains unclear. METHODS: hsTnI (ADVIA Centaur, Siemens) on admission was analyzed in 929 patients with acute cardiac condition and invasive ascertainment of coronary status by catheterization. RESULTS: Hs-TnI upon presentation was higher in patients with STEMI (median 1.27 ng/mL, IQR 0.13-14.5 ng/mL) as compared to patients with Non-STEMI (0.66 ng/mL, IQR 0.10-4.0 ng/mL, p<0.001) whereas it did not differ from STEMI in Tako-Tsubo cardiomyopathy (2.57 ng/mL, IQR 0.17-8.4 ng/mL) and myocarditis (9.76 ng/mL, IQR 2.0-27.0 ng/mL). In patients with resuscitation of non-ischemic cause (0.31 ng/mL, IQR 0.06-1.3 ng/mL), acute heart failure (0.088 ng/mL, IQR 0.035-0.30 ng/mL) and hypertensive emergency (0.066 ng/mL, IQR 0.032-0.34 ng/mL), hs-TnI was elevated above the recommended threshold of 0.04 ng/mL. At this cutpoint of 0.04 ng/mL, hsTnI indicated acute MI (STEMI or Non-STEMI) with a sensitivity of 88% and a specificity of 45% (ROC-AUC 0.748). When patients with STEMI were excluded, hsTnI indicated Non-STEMI with a sensitivity of 87% and a specificity of 45% (ROC-AUC 0.725). When sequential measurements were taken into account in a restricted cohort, a maximum hsTnI of ≥0.40 ng/mL provided a sensitivity of 89% and a specificity of 85% (ROC-AUC 0.909) for Non-STEMI. CONCLUSIONS: HsTnI is a sensitive, albeit unspecific marker of MI. In patients with mildly elevated hsTnI and without evidence for STEMI, we suggest serial assessment of hsTnI and a 10-fold higher cutpoint of 0.40 ng/mL before Non-STEMI is assumed.

High-sensitive troponin T in chronic heart failure correlates with severity of symptoms, left ventricular dysfunction and prognosis independently from N-terminal pro-b-type natriuretic peptide.

BACKGROUND: Troponin T is an established marker of myocardial ischemia. We speculated that the role of the new high-sensitive troponin T (hs-cTnT) might expand towards non-ischemic myocardial disease, indicate disease severity and allow for prognostication in chronic heart failure. METHODS: Hs-cTnT (Roche Diagnostics, Mannheim, Germany) was assessed in 233 individuals with chronic heart failure (n=149) or healthy controls (n=84). RESULTS: Hs-cTnT was significantly elevated in patients with chronic heart failure [0.018 ng/mL, interquartile range (IQR) 0.009-0.036 ng/mL, vs. controls 0.003 ng/mL, 0.003-0.003 ng/mL, p<0.001] and positively correlated with N-terminal pro-b-type natriuretic peptide (NT-proBNP) (r=0.79, p<0.001). Hs-cTnT increased stepwise and signitificantly according to clinical (NYHA stage) as well as functional (LV ejection fraction, fluid retention) severity (each p<0.001). At a binary cutpoint of 0.014 ng/mL, hs-TropT was a significant predictor of all-cause mortality and all-cause mortality or rehospitalization for congestive heart failure (each p≤0.01). Of note, the prognostic value of hs-TropT was independent and additive to that of NT-proBNP. CONCLUSIONS: Hs-cTnT increases stepwise with the severity of symptoms and LV dysfunction and offers important prognostic information in chronic heart failure, independently from and additive to NT-proBNP. The utility of hs-cTnT expands beyond acute myocardial ischemia and towards chronic heart failure.

Kidney injury molecule-1 and N-acetyl-ß-D-glucosaminidase in chronic heart failure: possible biomarkers of cardiorenal syndrome.

AIMS: Patients with chronic heart failure are often characterized by impaired renal function, also referred to as cardiorenal syndrome (CRS). The aim of this study was to assess whether novel markers of kidney injury are elevated in chronic heart failure and CRS. METHODS AND RESULTS: The new renal biomarkers kidney injury molecule-1 (KIM-1), N-acetyl-ß-d-glucosaminidase (NAG) and neutrophil gelatinase-associated lipocalin (NGAL) were assessed from urine samples of 173 individuals. Patients with chronic heart failure (n= 150) were characterized by decreased ejection fraction (32 ± 9% vs. controls 62 ± 4%, P < 0.001) and increased plasma N-terminal pro-brain natriuretic peptide (median 1460 pg/mL, interquartile range (IQR) 630-3000 pg/mL vs. controls 56, IQR 25-64l pg/mL, P < 0.001). Urinary analysis showed that KIM-1 was significantly elevated in heart failure patients compared with healthy controls (1100, IQR 620-1920 vs. 550, IQR 320-740 ng/g urinary creatinine, P < 0.001). Further, KIM-1 increased significantly with decreasing left ventricular function (r = -0.37, P < 0.001) and severity of New York Heart Association (NYHA)-class (r = 0.5, P < 0.001). N-acetyl-ß-d-glucosaminidase showed a weaker response but correlated significantly with left ventricular dysfunction (r = -0.18, P= 0.015) and more severe clinical condition (r = 0.22, P= 0.04). In contrast, NGAL showed no significant correlation. Kidney injury molecule-1 and NAG were also predictors of all-cause mortality and the composite of all-cause mortality and rehospitalization for heart failure (all P < 0.05). CONCLUSIONS: Kidney injury molecule-1 and NAG are elevated in symptomatic heart failure. This finding may be present in patients with apparently normal kidney function and indicates tubular injury in chronic heart failure. Kidney injury molecule-1 and NAG are potential markers of CRS with additional prognostic value.

N-terminal pro-brain natriuretic peptide from fresh urine for the biochemical detection of heart failure and left ventricular dysfunction.

AIMS: Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) is a strong biochemical marker of heart failure and left ventricular dysfunction (LVD). Due to renal arterio-venous clearance of NT-proBNP and the correlation of plasma concentrations with renal function, we hypothesized that NT-proBNP may have potential as a urinary marker. The objective of this study was to assess urinary concentrations of NT-proBNP and to identify the predictive value of urinary NT-proBNP for detecting LVD and heart failure. METHODS AND RESULTS: N-terminal pro-brain natriuretic peptide (Elecsys proBNP((R)), Roche) was assessed simultaneously in fresh spot urine and plasma from 191 individuals. In patients with heart failure (n = 149), urinary and plasma NT-proBNP concentrations were positively correlated (r = 0.79, P < 0.001), but urinary NT-proBNP was significantly lower than plasma NT-proBNP (42 +/- 25 vs. 1389 +/- 325 pg/mL, P < 0.001). Upon receiver operating curve analysis, urinary NT-proBNP detected LV dysfunction (ejection fraction <40%) with a sensitivity of 91% and a specificity of 98% at a cutpoint of 22 pg/mL [area under the curves (AUC) 0.98]. At the same cutpoint, symptomatic heart failure (NYHA-class > 2) was detected with a sensitivity of 97% and specificity of 98% (AUC 0.99) and clinical signs of fluid retention were detected with a sensitivity and specificity of 98% each (AUC 0.99). CONCLUSION: N-terminal pro-brain natriuretic peptide concentrations were markedly lower in the urine than in the plasma. However, urinary NT-proBNP levels increased stepwise with the severity of heart failure and LVD, and therefore yielded satisfactory predictive values for the detection of significant LVD and symptomatic heart failure. Measurement of urinary NT-proBNP is a novel, promising, and simple method for the biochemical detection of heart failure.