Christian Mueller

Early Diagnosis of Myocardial Infarction with Sensitive Cardiac Troponin Assays

BACKGROUND The rapid and reliable diagnosis of acute myocardial infarction is a major unmet clinical need. METHODS We conducted a multicenter study to examine the diagnostic accuracy of new, sensitive cardiac troponin assays performed on blood samples obtained in the emergency department from 718 consecutive patients who presented with symptoms suggestive of acute myocardial infarction. Cardiac troponin levels were determined in a blinded fashion with the use of four sensitive assays (Abbott-Architect Troponin I, Roche High-Sensitive Troponin T, Roche Troponin I, and Siemens Troponin I Ultra) and a standard assay (Roche Troponin T). The final diagnosis was adjudicated by two independent cardiologists. RESULTS Acute myocardial infarction was the adjudicated final diagnosis in 123 patients (17%). The diagnostic accuracy of measurements obtained at presentation, as quantified by the area under the receiver-operating-characteristic curve (AUC), was significantly higher with the four sensitive cardiac troponin assays than with the standard assay (AUC for Abbott-Architect Troponin I, 0.96; 95% confidence interval [CI], 0.94 to 0.98; for Roche High-Sensitive Troponin T, 0.96; 95% CI, 0.94 to 0.98; for Roche Troponin I, 0.95; 95% CI, 0.92 to 0.97; and for Siemens Troponin I Ultra, 0.96; 95% CI, 0.94 to 0.98; vs. AUC for the standard assay, 0.90; 95% CI, 0.86 to 0.94). Among patients who presented within 3 hours after the onset of chest pain, the AUCs were 0.93 (95% CI, 0.88 to 0.99), 0.92 (95% CI, 0.87 to 0.97), 0.92 (95% CI, 0.86 to 0.99), and 0.94 (95% CI, 0.90 to 0.98) for the sensitive assays, respectively, and 0.76 (95% CI, 0.64 to 0.88) for the standard assay. We did not assess the effect of the sensitive troponin assays on clinical management. CONCLUSIONS The diagnostic performance of sensitive cardiac troponin assays is excellent, and these assays can substantially improve the early diagnosis of acute myocardial infarction, particularly in patients with a recent onset of chest pain. (ClinicalTrials.gov number, NCT00470587.)

State of the art: using natriuretic peptide levels in clinical practice

Natriuretic peptide (NP) levels (B‐type natriuretic peptide (BNP) and N‐terminal proBNP) are now widely used in clinical practice and cardiovascular research throughout the world and have been incorporated into most national and international cardiovascular guidelines for heart failure. The role of NP levels in state‐of‐the‐art clinical practice is evolving rapidly. This paper reviews and highlights ten key messages to clinicians:

Mid-Region Pro-Hormone Markers for Diagnosis and Prognosis in Acute Dyspnea: Results From the BACH (Biomarkers in Acute Heart Failure) Trial

OBJECTIVES Our purpose was to assess the diagnostic utility of mid-regional pro-atrial natriuretic peptide (MR-proANP) for the diagnosis of acute heart failure (AHF) and the prognostic value of mid-regional pro-adrenomedullin (MR-proADM) in patients with AHF. BACKGROUND There are some caveats and limitations to natriuretic peptide testing in the acute dyspneic patient. METHODS The BACH (Biomarkers in Acute Heart Failure) trial was a prospective, 15-center, international study of 1,641 patients presenting to the emergency department with dyspnea. A noninferiority test of MR-proANP versus B-type natriuretic peptide (BNP) for diagnosis of AHF and a superiority test of MR-proADM versus BNP for 90-day survival were conducted. Other end points were exploratory. RESULTS MR-proANP (> or =120 pmol/l) proved noninferior to BNP (> or =100 pg/ml) for the diagnosis of AHF (accuracy difference 0.9%). In tests of secondary diagnostic objectives, MR-proANP levels added to the utility of BNP levels in patients with intermediate BNP values and with obesity but not in renal insufficiency, the elderly, or patients with edema. Using cut-off values from receiver-operating characteristic analysis, the accuracy to predict 90-day survival of heart failure patients was 73% (95% confidence interval: 70% to 77%) for MR-proADM and 62% (95% confidence interval: 58% to 66%) for BNP (difference p < 0.001). In adjusted multivariable Cox regression, MR-proADM, but not BNP, carried independent prognostic value (p < 0.001). Results were consistent using NT-proBNP instead of BNP (p < 0.001). None of the biomarkers was able to predict rehospitalization or visits to the emergency department with clinical relevance. CONCLUSIONS MR-proANP is as useful as BNP for AHF diagnosis in dyspneic patients and may provide additional clinical utility when BNP is difficult to interpret. MR-proADM identifies patients with high 90-day mortality risk and adds prognostic value to BNP. (Biomarkers in Acute Heart Failure [BACH]; NCT00537628).

Early diagnosis of acute myocardial infarction in the elderly using more sensitive cardiac troponin assays.

AIMS To examine the diagnostic accuracy of sensitive cardiac troponin (cTn) assays in elderly patients, since elevated levels with sensitive cTn assays were reported in 20% of elderly patients without acute myocardial infarction (AMI). METHODS AND RESULTS In this multi-centre study, we included 1098 consecutive patients presenting with symptoms suggestive of AMI, 406 (37%) were >70 years old. Measurement of three investigational sensitive cTn assays [Roche high-sensitive cTnT (hs-cTnT), Siemens cTnI-Ultra, and Abbott-Architect cTnI) and the standard assay (Roche cTnT) was performed in a blinded fashion. The final diagnosis was adjudicated by two independent cardiologists. Acute myocardial infarction was the adjudicated final diagnosis in 24% of elderly patients. Among elderly patients without AMI, baseline cTn levels were elevated above the 99th percentile in 51% with Roche hs-cTnT, in 17% with Siemens TnI-Ultra, and 13% with Abbott-Architect cTnI. The diagnostic accuracy as quantified by the area under the receiver operating characteristic (ROC) curve (AUC) was significantly greater for the sensitive cTn assays compared with the standard assay (AUC for Roche hs-cTnT, 0.94; Siemens cTnI-Ultra, 0.95; and Abbott-Architect cTnI, 0.95 vs. AUC for the standard assay, 0.90; P < 0.05 for comparisons). The best cut-offs for the sensitive cTn-assays determined by the ROC-curve in elderly patients differed clearly from those in younger patients. Furthermore, the prognostic value regarding 90-day mortality varied among the sensitive cTn assays. CONCLUSION Sensitive cTn assays have high diagnostic accuracy also in the elderly. Mild elevations are common in elderly non-AMI patients, therefore the optimal cut-off levels are substantially higher in elderly as compared with younger patients. Furthermore, sensitive cTn assays yielded different prognostic value.

Prognostic utility of plasma neutrophil gelatinase-associated lipocalin in patients with acute heart failure: The NGAL EvaLuation Along with B-type NaTriuretic Peptide in acutely decompensated heart failure (GALLANT) trial

Neutrophil gelatinase‐associated lipocalin (NGAL) is a measure of acute kidney injury. Renal dysfunction portends significant risk after discharge from acute heart failure (AHF). Thus, a sensitive marker of renal injury might also help to risk stratify HF patients.

CD11b+ Monocytes Abrogate Th17 CD4+ T Cell-Mediated Experimental Autoimmune Myocarditis

Experimental autoimmune myocarditis (EAM) represents a Th17 T cell-mediated mouse model of postinflammatory heart disease. In BALB/c wild-type mice, EAM is a self-limiting disease, peaking 21 days after α-myosin H chain peptide (MyHC-α)/CFA immunization and largely resolving thereafter. In IFN-γR−/− mice, however, EAM is exacerbated and shows a chronic progressive disease course. We found that this progressive disease course paralleled persistently elevated IL-17 release from T cells infiltrating the hearts of IFN-γR−/− mice 30 days after immunization. In fact, IL-17 promoted the recruitment of CD11b+ monocytes, the major heart-infiltrating cells in EAM. In turn, CD11b+ monocytes suppressed MyHC-α-specific Th17 T cell responses IFN-γ-dependently in vitro. In vivo, injection of IFN-γR+/+CD11b+, but not IFN-γR−/−CD11b+, monocytes, suppressed MyHC-α-specific T cells, and abrogated the progressive disease course in IFN-γR−/− mice. Finally, coinjection of MyHC-α-specific, but not OVA-transgenic, IFN-γ-releasing CD4+ Th1 T cell lines, together with MyHC-α-specific Th17 T cells protected RAG2−/− mice from EAM. In conclusion, CD11b+ monocytes play a dual role in EAM: as a major cellular substrate of IL-17-induced inflammation and as mediators of an IFN-γ-dependent negative feedback loop confining disease progression.

Copeptin Helps in the Early Detection of Patients With Acute Myocardial Infarction Primary Results of the CHOPIN Trial (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction)

OBJECTIVES The goal of this study was to demonstrate that copeptin levels <14 pmol/L allow ruling out acute myocardial infarction (AMI) when used in combination with cardiac troponin I (cTnI) <99 th percentile and a nondiagnostic electrocardiogram at the time of presentation to the emergency department (ED). BACKGROUND Copeptin is secreted from the pituitary early in the course of AMI. METHODS This was a 16-site study in 1,967 patients with chest pain presenting to an ED within 6 hours of pain onset. Baseline demographic characteristics and clinical data were collected prospectively. Copeptin levels and a contemporary sensitive cTnI (99 th percentile 40 ng/l; 10% coefficient of variation 0.03 μg/l) were measured in a core laboratory. Patients were followed up for 180 days. The primary outcome was diagnosis of AMI. Final diagnoses were adjudicated by 2 independent cardiologists blinded to copeptin results. RESULTS AMI was the final diagnosis in 156 patients (7.9%). A negative copeptin and cTnI at baseline ruled out AMI for 58% of patients, with a negative predictive value of 99.2% (95% confidence interval: 98.5 to 99.6). AMIs not detected by the initial cTnI alone were picked up with copeptin >14 pmol/l in 23 (72%) of 32 patients. Non-ST-segment elevation myocardial infarctions undetected by cTnI at 0 h were detected with copeptin >14 pmol/l in 10 (53%) of 19 patients. Projected average time-to-decision could be reduced by 43% (from 3.0 h to 1.8 h) by the early rule out of 58% of patients. Both abnormal copeptin and cTnI were predictors of death at 180 days (p < 0.0001 for both; c index 0.784 and 0.800, respectively). Both were independent of age and each other and provided additional predictive value (all p < 0.0001). CONCLUSIONS Adding copeptin to cTnI allowed safe rule out of AMI with a negative predictive value >99% in patients presenting with suspected acute coronary syndromes. This combination has the potential to rule out AMI in 58% of patients without serial blood draws.

Increased 90-Day Mortality in Patients With Acute Heart Failure With Elevated Copeptin Secondary Results From the Biomarkers in Acute Heart Failure (BACH) Study

Background— In patients with heart failure (HF), increased arginine vasopressin concentrations are associated with more severe disease, making arginine vasopressin an attractive target for therapy. However, AVP is difficult to measure due to its in vitro instability and rapid clearance. Copeptin, the C-terminal segment of preprovasopressin, is a stable and reliable surrogate biomarker for serum arginine vasopressin concentrations. Methods and Results— The Biomarkers in Acute Heart Failure (BACH) trial was a 15-center, diagnostic and prognostic study of 1641 patients with acute dyspnea; 557 patients with acute HF were included in this analysis. Copeptin and other biomarker measurements were performed by a core laboratory at the University of Maryland. Patients were followed for up to 90 days after initial evaluation for the primary end point of all-cause mortality, HF-related readmissions, and HF-related emergency department visits. Patients with copeptin concentrations in the highest quartile had increased 90-day mortality ( P <0.001; hazard ratio, 3.85). Mortality was significantly increased in patients with elevated copeptin and hyponatremia ( P <0.001; hazard ratio, 7.36). Combined end points of mortality, readmissions, and emergency department visits were significantly increased in patients with elevated copeptin. There was no correlation between copeptin and sodium ( r =0.047). Conclusions— This study showed significantly increased 90-day mortality, readmissions, and emergency department visits in patients with elevated copeptin, especially in those with hyponatremia. Copeptin was highly prognostic for 90-day adverse events in patients with acute HF, adding prognostic value to clinical predictors, ser um sodium, and natriuretic peptides. Clinical Trial Registration— URL: . Unique identifier: [NCT00537628][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00537628&atom=%2Fcirchf%2F4%2F5%2F613.atomBackground— In patients with heart failure (HF), increased arginine vasopressin concentrations are associated with more severe disease, making arginine vasopressin an attractive target for therapy. However, AVP is difficult to measure due to its in vitro instability and rapid clearance. Copeptin, the C-terminal segment of preprovasopressin, is a stable and reliable surrogate biomarker for serum arginine vasopressin concentrations. Methods and Results— The Biomarkers in Acute Heart Failure (BACH) trial was a 15-center, diagnostic and prognostic study of 1641 patients with acute dyspnea; 557 patients with acute HF were included in this analysis. Copeptin and other biomarker measurements were performed by a core laboratory at the University of Maryland. Patients were followed for up to 90 days after initial evaluation for the primary end point of all-cause mortality, HF-related readmissions, and HF-related emergency department visits. Patients with copeptin concentrations in the highest quartile had increased 90-day mortality (P<0.001; hazard ratio, 3.85). Mortality was significantly increased in patients with elevated copeptin and hyponatremia (P<0.001; hazard ratio, 7.36). Combined end points of mortality, readmissions, and emergency department visits were significantly increased in patients with elevated copeptin. There was no correlation between copeptin and sodium (r=0.047). Conclusions— This study showed significantly increased 90-day mortality, readmissions, and emergency department visits in patients with elevated copeptin, especially in those with hyponatremia. Copeptin was highly prognostic for 90-day adverse events in patients with acute HF, adding prognostic value to clinical predictors, ser um sodium, and natriuretic peptides. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00537628.

Use of B-Type Natriuretic Peptide in the Risk Stratification of Acute Exacerbations of COPD

BACKGROUND In patients with COPD, prognosis might be determined at least in part by the extent of cardiac stress induced by hypoxia and pulmonary arterial hypertension. METHODS B-type natriuretic peptide (BNP), a quantitative marker of cardiac stress, was determined in 208 consecutive patients presenting to the emergency department with an acute exacerbation of COPD (AECOPD). The accuracy of BNP to predict death at a 2-year follow-up was evaluated as the primary end point. The need for intensive care and in-hospital mortality were determined as secondary end points. RESULTS BNP levels were significantly elevated during the acute exacerbation compared to recovery (65 pg/mL; interquartile range [IQR], 34 to 189 pg/mL; vs 45 pg/mL; IQR, 25 to 85 pg/mL; p < 0.001), particularly in those patients requiring ICU treatment (105 pg/mL; IQR, 66 to 553 pg/mL; vs 60 pg/mL; IQR, 31 to 169 pg/mL; p = 0.007). In multivariate Cox regression analysis, BNP accurately predicted the need for ICU care (hazard ratio, 1.13; 95% confidence interval [CI], 1.03 to 1.24 for an increase in BNP of 100 pg/mL; p = 0.008). In a receiver operating characteristic analysis to evaluate the potential of BNP levels to predict short-term and long-term mortality rates, areas under the curve were 0.55 (SD, 0.71; 95% CI, 0.41 to 0.68) and 0.56 (SD, 0.53; 95% CI, 0.45 to 0.66, respectively). CONCLUSIONS In patients with AECOPD, BNP levels independently predict the need for intensive care. However, BNP levels failed to adequately predict short-term and long-term mortality rates in AECOPD patients.

Midregion Prohormone Adrenomedullin and Prognosis in Patients Presenting With Acute Dyspnea : Results From the BACH (Biomarkers in Acute Heart Failure) Trial

OBJECTIVES The aim of this study was to determine the prognostic utility of midregion proadrenomedullin (MR-proADM) in all patients, cardiac and noncardiac, presenting with acute shortness of breath. BACKGROUND The recently published BACH (Biomarkers in Acute Heart Failure) study demonstrated that MR-proADM had superior accuracy for predicting 90-day mortality compared with B-type natriuretic peptide (area under the curve: 0.674 vs. 0.606, respectively, p < 0.001) in acute heart failure. METHODS The BACH trial was a prospective, 15-center, international study of 1,641 patients presenting to the emergency department with dyspnea. Using this dataset, the prognostic accuracy of MR-proADM was evaluated in all patients enrolled for predicting 90-day mortality with respect to other biomarkers, the added value in addition to clinical variables, as well as the added value of additional measurements during hospital admission. RESULTS Compared with B-type natriuretic peptide or troponin, MR-proADM was superior for predicting 90-day all-cause mortality in patients presenting with acute dyspnea (c index = 0.755, p < 0.0001). Furthermore, MR-proADM added significantly to all clinical variables (all adjusted hazard ratios: >3.28), and it was also superior to all other biomarkers. MR-proADM added significantly to the best clinical model (bootstrap-corrected c index increase: 0.775 to 0.807; adjusted standardized hazard ratio: 2.59; 95% confidence interval: 1.91 to 3.50; p < 0.0001). Within the model, MR-proADM was the biggest contributor to the predictive performance, with a net reclassification improvement of 8.9%. Serial evaluation of MR-proADM performed in patients admitted provided a significant added value compared with a model with admission values only (p = 0.0005). More than one-third of patients originally at high risk could be identified by the biomarker evaluation at discharge as low-risk patients. CONCLUSIONS MR-proADM identifies patients with high 90-day mortality and adds prognostic value to natriuretic peptides in patients presenting with acute shortness of breath. Serial measurement of this biomarker may also prove useful for monitoring, although further studies will be required. (Biomarkers in Acute Heart Failure [BACH]; NCT00537628).