Tobias Breidthardt

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.)

Incremental value of copeptin for rapid rule out of acute myocardial infarction.

OBJECTIVES The purpose of this study was to examine the incremental value of copeptin for rapid rule out of acute myocardial infarction (AMI). BACKGROUND The rapid and reliable exclusion of AMI is a major unmet clinical need. Copeptin, the C-terminal part of the vasopressin prohormone, as a marker of acute endogenous stress may be useful in this setting. METHODS In 487 consecutive patients presenting to the emergency department with symptoms suggestive of AMI, we measured levels of copeptin at presentation, using a novel sandwich immunoluminometric assay in a blinded fashion. The final diagnosis was adjudicated by 2 independent cardiologists using all available data. RESULTS The adjudicated final diagnosis was AMI in 81 patients (17%). Copeptin levels were significantly higher in AMI patients compared with those in patients having other diagnoses (median 20.8 pmol/l vs. 6.0 pmol/l, p < 0.001). The combination of troponin T and copeptin at initial presentation resulted in an area under the receiver-operating characteristic curve of 0.97 (95% confidence interval: 0.95 to 0.98), which was significantly higher than the 0.86 (95% confidence interval: 0.80 to 0.92) for troponin T alone (p < 0.001). A copeptin level <14 pmol/l in combination with a troponin T < or =0.01 microg/l correctly ruled out AMI with a sensitivity of 98.8% and a negative predictive value of 99.7%. CONCLUSIONS The additional use of copeptin seems to allow a rapid and reliable rule out of AMI already at presentation and may thereby obviate the need for prolonged monitoring and serial blood sampling in the majority of patients. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE]; NCT00470587).

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.

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.

Use of Myeloperoxidase for Risk Stratification in Acute Heart Failure

BACKGROUND Myeloperoxidase (MPO) is a biomarker of inflammation and oxidative stress produced by neutrophils, monocytes, and endothelial cells. Concentrations of MPO predict mortality in patients with chronic heart failure. This study sought to investigate the diagnostic accuracy and prognostic value of MPO in patients with acute heart failure (AHF). METHODS We prospectively enrolled 667 patients presenting to the emergency department with dyspnea and observed them for 1 year. MPO and B-type natriuretic peptide (BNP) were measured at presentation. Two independent cardiologists adjudicated final discharge diagnoses. RESULTS MPO concentrations were similar in patients with AHF (n = 377, median 139 pmol/L) and patients with noncardiac causes of dyspnea (n = 290, median 150 pmol/L, P = 0.26). The diagnostic accuracy of MPO for AHF was limited [area under the ROC curve (AUC) 0.53] and inferior to that of BNP (AUC 0.95, P < 0.001). In patients with AHF, MPO concentrations above the lowest tertile (MPO >99 pmol/L) were associated with significantly increased 1-year mortality (hazard ratio 1.58, P = 0.02). The combination of MPO (< or = 99 vs >99 pmol/L) and BNP (median of < or = 847 vs >847 ng/L) improved the prediction of 1-year mortality (hazard ratio 2.80 for both variables increased vs both low, P < 0.001). After adjustment for cardiovascular risk factors in multivariable Cox proportional hazard analysis, increases in MPO contributed significantly toward the prediction of 1-year mortality (hazard ratio 1.51, P = 0.045). CONCLUSIONS MPO is an independent predictor of 1-year mortality in AHF, is additive to BNP, and could be helpful in identifying patients with a favorable prognosis despite increased BNP concentrations.

Use of B‐type natriuretic peptide in the risk stratification of community‐acquired pneumonia

Background.  Community‐acquired pneumonia (CAP) is the leading infectious cause of death in developed countries. Risk stratification has previously been difficult.

Central venous pressure and impaired renal function in patients with acute heart failure

To determine the relationship between central venous pressure (CVP) and renal function in patients with acute heart failure (AHF) presenting to the emergency department.

Sodium chloride vs. sodium bicarbonate for the prevention of contrast medium-induced nephropathy: A randomized controlled trial

AIMS The most effective regimen for the prevention of contrast-induced nephropathy (CIN) remains uncertain. Our purpose was to compare two regimens of sodium bicarbonate with 24 h sodium chloride 0.9% infusion in the prevention of CIN. METHODS AND RESULTS We performed a prospective, randomized trial between March 2005 and December 2009, including 258 consecutive patients with renal insufficiency undergoing intravascular contrast procedures. Patients were randomized to receive intravenous volume supplementation with either (A) sodium chloride 0.9% 1 mL/kg/h for at least 12h prior and after the procedure or (B) sodium bicarbonate (166 mEq/L) 3 mL/kg for 1 h before and 1 mL/kg/h for 6 h after the procedure or (C) sodium bicarbonate (166 mEq/L) 3 mL/kg over 20 min before the procedure plus sodium bicarbonate orally (500 mg per 10 kg). The primary endpoint was the change in estimated glomerular filtration rate (eGFR) within 48 h after contrast. Secondary endpoints included the development of CIN. The maximum change in eGFR was significantly greater in Group B compared with Group A {mean difference -3.9 [95% confidence interval (CI), -6.8 to -1] mL/min/1.73 m2, P = 0.009} and similar between groups C and B [mean difference 1.3 (95% CI, -1.7-4.3) mL/min/1.73 m(2), P = 0.39]. The incidence of CIN was significantly lower in Group A (1%) vs. Group B (9%, P = 0.02) and similar between Groups B and C (10%, P = 0.9). CONCLUSION Volume supplementation with 24 h sodium chloride 0.9% is superior to sodium bicarbonate for the prevention of CIN. A short-term regimen with sodium bicarbonate is non-inferior to a 7 h regimen. ClinicalTrials.gov Identifier: NCT00130598.

S3 Detection as a Diagnostic and Prognostic Aid in Emergency Department Patients With Acute Dyspnea

STUDY OBJECTIVE Dyspneic emergency department (ED) patients present a diagnostic dilemma. Recent technologic advances have made it possible to capture information about pathologic heart sounds at ECG recording. This study evaluates the effect of an S3 captured by acoustic cardiography on emergency physician diagnostic accuracy and confidence in their diagnosis of acute decompensated heart failure, as well as the patients prognosis. METHODS Dyspneic ED patients older than 40 years who were not dialysis dependent were prospectively enrolled in this multinational study. Treating emergency physicians, initially blinded to all laboratory and acoustic cardiography results, estimated acute decompensated heart failure probability from 0% to 100% on a visual analog scale. The emergency physician repeated the visual analog scale after acoustic cardiography results were provided. Physician diagnostic accuracy for and confidence in acute decompensated heart failure were evaluated against a reference standard diagnosis, as determined by 2 independent cardiologists blinded to acoustic cardiography. Patients were followed through 90 days to determine the relationship of the S3 to adverse events. RESULTS Nine hundred ninety-five patients with acoustic cardiography results were enrolled from March to October 2006 at 7 US and 2 international sites. Median age was 63 years, 55% were men, and 44% were white. The reference diagnosis was acute decompensated heart failure in 41.5%. After initial history and physical examination, the treating physicians initial sensitivity, specificity, and accuracy for acute decompensated heart failure as a possible diagnosis were 89.0% (95% confidence interval [CI] 85.5% to 91.8%), 58.2% (95% CI 54.0% to 62.2%), and 71.0% (95% CI 68.4% to 73.8%), respectively. Acoustic cardiography had an accuracy of 68% (95% CI 65.4% to 71.3%), sensitivity of 40.2% (95% CI 35.5% to 45.1%), and specificity of 88.5% (95% CI 85.5% to 90.9%). Emergency physician confidence and diagnostic accuracy were influenced by adding information about the presence or absence of S3. In a multivariable model, the S3 added no independent prognostic information for 30-day (odds ratio 1.20; 95% CI 0.67 to 2.14) or 90-day events (odds ratio 1.22; 95% CI 0.78 to 1.90). CONCLUSION In patients presenting with acute dyspnea, the acoustic cardiography S3 was specific for acute decompensated heart failure and affected physician confidence but did not improve diagnostic accuracy for acute decompensated heart failure, largely because of its low sensitivity. Further, the acoustic cardiography S3 provided no significant independent prognostic information.

Midregional pro-Adrenomedullin in addition to b-type natriuretic peptides in the risk stratification of patients with acute dyspnea: an observational study

IntroductionThe identification of patients at highest risk for adverse outcome who are presenting with acute dyspnea to the emergency department remains a challenge. This study investigates the prognostic value of the newly described midregional fragment of the pro-Adrenomedullin molecule (MR-proADM) alone and combined to B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP) in patients with acute dyspnea.MethodsWe conducted a prospective, observational cohort study in the emergency department of a University Hospital and enrolled 287 unselected, consecutive patients (48% women, median age 77 (range 68 to 83) years) with acute dyspnea.ResultsMR-proADM levels were elevated in non-survivors (n = 77) compared to survivors (median 1.9 (1.2 to 3.2) nmol/L vs. 1.1 (0.8 to 1.6) nmol/L; P < 0.001). The areas under the receiver operating characteristic curve (AUC) to predict 30-day mortality were 0.81 (95% CI 0.73 to 0.90), 0.76 (95% CI 0.67 to 0.84) and 0.63 (95% CI 0.53 to 0.74) for MR-proADM, NT-proBNP and BNP, respectively (MRproADM vs. NTproBNP P = 0.38; MRproADM vs. BNP P = 0.009). For one-year mortality the AUC were 0.75 (95% CI 0.69 to 0.81), 0.75 (95% CI 0.68 to 0.81), 0.69 (95% CI 0.62 to 0.76) for MR-proADM, NT-proBNP and BNP, respectively without any significant difference. Using multivariate linear regression analysis, MR-proADM strongly predicted one-year all-cause mortality independently of NT-proBNP and BNP levels (OR = 10.46 (1.36 to 80.50), P = 0.02 and OR = 24.86 (3.87 to 159.80) P = 0.001, respectively). Using quartile approaches, Kaplan-Meier curve analyses demonstrated a stepwise increase in one-year all-cause mortality with increasing plasma levels (P < 0.0001). Combined levels of MR-proADM and NT-proBNP did risk stratify acute dyspneic patients into a low (90% one-year survival rate), intermediate (72 to 82% one-year survival rate) or high risk group (52% one-year survival rate).ConclusionsMR-proADM alone or combined to NT-proBNP has a potential to assist clinicians in risk stratifying patients presenting with acute dyspnea regardless of the underlying disease.