Clinical Utility of Procalcitonin in the Diagnosis of Pneumonia.

BACKGROUND: The clinical utility of procalcitonin in the diagnosis and management of pneumonia remains controversial. METHODS: We assessed the clinical utility of procalcitonin in 2 prospective studies: first, a multicenter diagnostic study in patients presenting to the emergency department with acute dyspnea to directly compare the diagnostic accuracy of procalcitonin with that of interleukin 6 and C-reactive protein (CRP) in the diagnosis of pneumonia; second, a randomized management study of procalcitonin guidance in patients with acute heart failure and suspected pneumonia. Diagnostic accuracy for pneumonia as centrally adjudicated by 2 independent experts was quantified with the area under the ROC curve (AUC). RESULTS: Among 690 patients in the diagnostic study, 178 (25.8%) had an adjudicated final diagnosis of pneumonia. Procalcitonin, interleukin 6, and CRP were significantly higher in patients with pneumonia than in those without. When compared to procalcitonin (AUC = 0.75; 95% CI, 0.71-0.78), interleukin 6 (AUC = 0.80; 95% CI, 0.77-0.83) and CRP (AUC = 0.82; 95% CI, 0.79-0.85) had significantly higher diagnostic accuracy (P = 0.010 and P < 0.001, respectively). The management study was stopped early owing to the unexpectedly low AUC of procalcitonin in the diagnostic study. Among 45 randomized patients, the number of days on antibiotic therapy and the length of hospital stay were similar (both P = 0.39) in patients randomized to the procalcitonin-guided group (n = 25) and usual-care group (n = 20). CONCLUSIONS: In patients presenting with dyspnea, diagnostic accuracy of procalcitonin for pneumonia is only moderate and lower than that of interleukin 6 and CRP. The clinical utility of procalcitonin was lower than expected. SUMMARY: Pneumonia has diverse and often unspecific symptoms. As the role of biomarkers in the diagnosis of pneumonia remains controversial, it is often difficult to distinguish pneumonia from other illnesses causing shortness of breath. The current study prospectively enrolled unselected patients presenting with acute dyspnea and directly compared the diagnostic accuracy of procalcitonin, interleukin 6, and CRP for the diagnosis of pneumonia. In this setting, diagnostic accuracy of procalcitonin for pneumonia was lower as compared to interleukin 6 and CRP. The clinical utility of procalcitonin was lower than expected. CLINICALTRIALSGOV IDENTIFIER: NCT01831115.

[Hyperuricemia, gout and cardiovascular diseases]. / Hyperurikämie, Gicht und kardiovaskuläre Erkrankungen.

Hyperuricemia, gout as well as arterial hypertension and metabolic syndrom are highly prevalent and clinicians are frequently confronted with both conditions in the same patient. Hyperuricemia and gout are associated with cardiovascular comorbidities and a high cardiovascular risk. Despite coherent pathophysiological concepts, it remains to be determined, if this association is independent and causal. In daily clinical practice, cardiovascular risk factors should be thoroughly identified and consequently treated in all patients with hyperuricemia and gout. If preventive treatment of asymptomatic hyperuricemia with urate-lowering agents may improve cardiovascular risk and outcomes remains to be determined and is recommended only in special situations like young patients with severe hyperuricemia.

Risk stratification in patients with acute chest pain using three high-sensitivity cardiac troponin assays.

AIMS: Several high-sensitivity cardiac troponin (hs-cTn) assays have recently been developed. It is unknown which hs-cTn provides the most accurate prognostic information and to what extent early changes in hs-cTn predict mortality. METHODS AND RESULTS: In a prospective, international multicentre study, cTn was simultaneously measured with three novel [high-sensitivity cardiac Troponin T (hs-cTnT), Roche Diagnostics; hs-cTnI, Beckman-Coulter; hs-cTnI, Siemens] and a conventional assay (cTnT, Roche Diagnostics) in a blinded fashion in 1117 unselected patients with acute chest pain. Patients were followed up 2 years regarding mortality. Eighty-two (7.3%) patients died during the follow-up. The 2-year prognostic accuracy of hs-cTn was most accurate for hs-cTnT [area under the receivers operating characteristic curve (AUC) 0.78 (95% CI: 0.73-0.83) and outperformed both hs-cTnI (Beckman-Coulter, 0.71 (95% CI: 0.65-0.77; P = 0.001 for comparison), hs-cTnI (Siemens) 0.70 (95% CI: 0.64-0.76; P < 0.001 for comparison)] and cTnT 0.67 (95% CI: 0.61-0.74; P < 0.001 for comparison). Absolute changes of hs-cTnT were more accurate than relative changes in predicting mortality, but inferior to presentation values of hs-cTnT. Combining changes of hs-cTnT within the first 6 h with their presentation values did not further improve prognostic accuracy. Similar results were obtained for both hs-cTnI assays regarding the incremental value of changes. Hs-cTn concentrations remained predictors of death in clinically challenging subgroups such as patients with pre-existing coronary artery disease, impaired renal function, and patients older than 75 years. CONCLUSION: High-sensitivity cardiac Troponin T is more accurate than hs-cTnI in the prediction of long-term mortality. Changes of hs-cTn do not seem to further improve risk stratification beyond initial presentation values.

Heart failure therapy-induced early ST2 changes may offer long-term therapy guidance.

BACKGROUND: Biomarkers may help to monitor and tailor treatment in patients with acute heart failure (AHF). METHODS AND RESULTS: Levels of ST2, a novel biomarker integrating hypervolemic cardiac strain and proinflammatory signals, were measured at presentation to the emergency department (ED) and after 48 hours in 207 patients with AHF. Patients were stratified according to their early ST2 response (responders: ST2 decrease ≥25%; nonresponders: ST2 decrease <25%) and beta-blocker, renin-angiotensin-aldosterone system (RAAS) blockade, or diuretic treatment status at hospital discharge. We assessed the utility of ST2 levels and its changes to predict long-term mortality and the interaction between ST2 levels, treatment at discharge, and 1-year mortality. ST2 levels were higher in nonsurvivors than in survivors (median 108 vs 69 ng/mL; P < .01) and decreased significantly during the 1st 48 hours (median decrease 33%). ST2 decrease was less in nonsurvivors compared with survivors (median -25% vs -42%; P < .01). In Cox regression, early ST2 changes independently predicted 1-year mortality (hazard ratio 1.07 for every increase of 10%; P = .02). RAAS blockers at discharge were associated with survival independently from ST2 response, whereas the association of beta-blockers with survival differed markedly according to ST2 response, with beneficial effects restricted to ST2 nonresponders (P interaction = .04). A similar, albeit nonsignificant, trend was observed for diuretics (P interaction = .11). CONCLUSIONS: ED and serial ST2 measurements are independent predictors of 1-year mortality in AHF.

Serial changes in high-sensitivity cardiac troponin I in the early diagnosis of acute myocardial infarction.

BACKGROUND: Current guidelines require a change (rise and/or fall) in levels of cardiac troponin (cTn) for the diagnosis of acute myocardial infarction (AMI). It is unknown whether absolute or relative changes provide higher accuracy when using high-sensitivity cTnI assays. METHODS: In a prospective international multicentre study, we assessed the diagnostic accuracy of early absolute and relative changes in cTnI measured with two novel pre-commercial high-sensitivity assays (Siemens and Beckman Coulter) in 943 unselected patients presenting to the ED with suspected AMI. The final diagnosis of AMI was adjudicated using all available data including serial hs-cTnT levels by two independent cardiologists. RESULTS: The diagnostic accuracy of absolute changes in the diagnosis of AMI as quantified by the area under the receiver operating characteristics curve (AUC) was very high (e.g. at 2 h, Siemens high-sensitivity cTnI AUC 0.93, 95%Cl 0.90-0.96; Beckman Coulter high-sensitivity cTnI AUC 0.93, 95%Cl 0.90-0.96) and superior to relative changes at all time points (p < 0.001). The results were consistent in clinically important subgroups. Direct comparison of the absolute changes in the two high-sensitivity cTnI assays showed similar accuracy. When combined with the baseline cTnI levels, the difference between absolute and relative changes became much smaller and remained statistically significant only for the Siemens assay. CONCLUSIONS: As single variables early absolute changes in high-sensitivity cTnI levels have significantly higher diagnostic accuracy than relative changes. When combined with the baseline cTn level, reflecting clinical practice, both absolute and relative changes provided very high accuracy with much smaller differences between both approaches.

Early diagnosis of myocardial infarction using absolute and relative changes in cardiac troponin concentrations.

BACKGROUND: Absolute changes in high-sensitivity cardiac troponin T (hs-cTnT) seem to have higher diagnostic accuracy in the early diagnosis of acute myocardial infarction compared with relative changes. It is unknown whether the same applies to high-sensitivity cardiac troponin I (hs-cTnI) assays and whether the combination of absolute and relative change might further increase accuracy. METHODS: In a prospective, international multicenter study, high-sensitivity cardiac troponin (hs-cTn) was measured with 3 novel assays (hs-cTnT, Roche Diagnostics Corp, Indianapolis, Ind; hs-cTnI, Beckman Coulter Inc, Brea, Calif; hs-cTnI, Siemens, Munich, Germany) in a blinded fashion at presentation and after 1 and 2 hours in a blinded fashion in 830 unselected patients with suspected acute myocardial infarction. The final diagnosis was adjudicated by 2 independent cardiologists. RESULTS: The area under the receiver operating characteristic curve for diagnosing acute myocardial infarction was significantly higher for 1- and 2-hour absolute versus relative hs-cTn changes for all 3 assays (P < .001). The area under the receiver operating characteristic curve of the combination of 2-hour absolute and relative change (hs-cTnT 0.98 [95% confidence interval {CI}, 0.97-0.99]; hs-cTnI, Beckman Coulter Inc, 0.97 [95% CI, 0.96-0.99]; hs-cTnI, Siemens, 0.96 [95% CI, 0.93-0.99]) were high and provided some benefit compared with the use of absolute change alone for hs-cTnT, but not for the hs-cTnI assays. Reclassification analysis confirmed the superiority of absolute changes versus relative changes. CONCLUSIONS: Absolute changes seem to be the preferred metrics for both hs-cTnT and hs-cTnI in the early diagnosis of acute myocardial infarction. The combination of absolute and relative changes provides a small added value for hs-cTnT, but not for hs-cTnI.

Rapid rule out of acute myocardial infarction using undetectable levels of high-sensitivity cardiac troponin.

BACKGROUND: We examined whether undetectable levels of high-sensitivity cardiac Troponin (hs-cTn) can be used to rule out acute myocardial infarction (AMI) with a single blood draw at presentation to the emergency department (ED). METHODS AND RESULTS: In a prospective multicenter study we used 4 different hs-cTn assays (hs-cTnT Roche, and hs-cTnI Siemens, hs-cTnI Beckman Coulter and hs-cTnI Abbott) in consecutive patients presenting with acute chest pain. The final diagnosis of AMI was adjudicated by two independent cardiologists using all available data including serial hs-cTnT levels. Mean follow up was 24 months. Among 2072 consecutive patients with available hs-cTnT levels, 21% had an adjudicated diagnosis of AMI. Among AMI patients, 98.2% had initially detectable levels of hs-cTnT (sensitivity 98.2%, 95%CI 96.3%-99.2%, negative predictive value (NPV) 98.6%, 95%CI 97.0%-99.3%). Undetectable levels of hs-cTnT ruled out AMI in 26.5% of patients at presentation. The NPV was similar with the three hs-cTnI assays: among 1180 consecutive patients with available hs-cTnI (Siemens), the NPV was 98.8%; among 1151 consecutive patients with available hs-cTnI (Beckman Coulter), the NPV was 99.2%; among 1567 consecutive patients with available hs-cTnI (Abbott), the NPV was 100.0%. The percentage of patients with undetectable levels of hs-cTnI was similar among the three hs-cTnI assays and ranged from 11.4% to 13.9%. CONCLUSIONS: Undetectable levels of hs-cTn at presentation have a very high NPV and seem to allow the simple and rapid rule out of AMI. This criteria applies to much more patients with hs-TnT as compared to the investigated hs-cTnI assays.

Normal presenting levels of high-sensitivity troponin and myocardial infarction.

OBJECTIVE: To analyse whether levels of high-sensitivity cardiac troponin (hs-cTn) below their respective 99th percentile can be used as a single parameter to rule out acute myocardial infarction (AMI) at presentation. DESIGN: Prospective, multicentre study. MAIN OUTCOME MEASURES: We measured hs-cTn using four different methods (hs-cTnT Roche, hs-cTnI Siemens, hs-cTnI Beckman Coulter and hs-cTnI Abbott) in consecutive patients presenting to the emergency department with acute chest pain. Two independent cardiologists adjudicated the final diagnosis. Patients were followed for death or AMI during a mean period of 24 months. RESULTS: Among 2072 consecutive patients with hs-cTnT measurements available, 21.4% had an adjudicated diagnosis of AMI (sensitivity 89.6%, 95% CI 86.4% to 92.3%, negative predictive value (NPV): 96.5%, 95% CI 95.4% to 97.4%). Among 1180 consecutive patients with hs-cTnI Siemens measurements available, 20.0% had AMI (sensitivity 94.1%, 95% CI 90.3% to 96.7%, NPV: 98.0%, 95% CI: 96.6% to 98.9%). Among 1151 consecutive patients with hs-cTnI Beckman Coulter measurements available, 19.7% had AMI (sensitivity 92.1%, 95% CI 87.8% to 95.2%, NPV: 97.5%, 95% CI 96.0% to 98.5%). Among 1567 consecutive patients with hs-cTnI Abbott measurements available, 20.0% had AMI (sensitivity 77.2%, 95% CI 72.1% to 81.7%, NPV: 94.3%, 95% CI 92.8% to 95.5%). CONCLUSIONS: Normal hs-cTn levels at presentation should not be used as a single parameter to rule out AMI as 6%-23% of adjudicated AMI cases had normal levels of hs-cTn levels at presentation. Our data highlight the lack of standardisation among hs-cTnI assays resulting in substantial differences in sensitivity and NPV at the 99th percentile.

Validation of high-sensitivity troponin I in a 2-hour diagnostic strategy to assess 30-day outcomes in emergency department patients with possible acute coronary syndrome.

OBJECTIVES: The study objective was to validate a new high-sensitivity troponin I (hs-TnI) assay in a clinical protocol for assessing patients who present to the emergency department with chest pain. BACKGROUND: Protocols using sensitive troponin assays can accelerate the rule out of acute myocardial infarction in patients with low-risk (suspected) acute coronary syndrome (ACS). METHODS: This study evaluated 2 prospective cohorts of patients in the emergency department with ACS in an accelerated diagnostic pathway integrating 0- and 2-h hs-TnI results, Thrombolysis In Myocardial Infarction (TIMI) risk scores, and electrocardiography. Strategies to identify low-risk patients incorporated TIMI risk scores= 0 or ≤ 1. The primary endpoint was a major adverse cardiac event (MACE) within 30 days. RESULTS: In the primary cohort, 1,635 patients were recruited and had 30-day follow-up. A total of 247 patients (15.1%) had a MACE. The finding of no ischemic electrocardiogram and hs-TnI ≤ 26.2 ng/l with the TIMI = 0 and TIMI ≤ 1 pathways, respectively, classified 19.6% (n = 320) and 41.5% (n = 678) of these patients as low risk; 0% (n = 0) and 0.8% (n = 2) had a MACE, respectively. In the secondary cohort, 909 patients were recruited. A total of 156 patients (17.2%) had a MACE. The TIMI = 0 and TIMI ≤ 1 pathways classified 25.3% (n = 230) and 38.6% (n = 351), respectively, of these patients as low risk; 0% (n = 0) and 0.8% (n = 1) had a MACE, respectively. Sensitivity, specificity, and negative predictive value for TIMI = 0 in the primary cohort were 100% (95% confidence interval [CI]: 98.5% to 100%), 23.1% (95% CI: 20.9% to 25.3%), and 100% (95% CI: 98.8% to 100%), respectively. Sensitivity, specificity, and negative predictive value for TIMI ≤ 1 in the primary cohort were 99.2 (95% CI: 97.1 to 99.8), 48.7 (95% CI: 46.1 to 51.3), and 99.7 (95% CI: 98.9 to 99.9), respectively. Sensitivity, specificity, and negative value for TIMI ≤ 1 in the secondary cohort were 99.4% (95% CI: 96.5 to 100), 46.5% (95% CI: 42.9 to 50.1), and 99.7% (95% CI: 98.4 to 100), respectively. CONCLUSIONS: An early-discharge strategy using an hs-TnI assay and TIMI score ≤ 1 had similar safety as previously reported, with the potential to decrease the observation periods and admissions for approximately 40% of patients with suspected ACS. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] Study, NCT00470587; A 2 hr Accelerated Diagnostic Protocol to Assess patients with chest Pain symptoms using contemporary Troponins as the only biomarker [ADAPT]: a prospective observational validation study, ACTRN12611001069943).

Direct comparison of mid-regional pro-atrial natriuretic peptide with N-terminal pro B-type natriuretic peptide in the diagnosis of patients with atrial fibrillation and dyspnoea.

OBJECTIVES: Due to different release mechanisms, mid-regional pro-atrial natriuretic peptide (MR proANP) may be superior to N-terminal pro-B-type natriuretic peptide (NT proBNP) in the diagnosis of acute heart failure (AHF) in patients with atrial fibrillation (AF). We compared MR proANP and NT proBNP for their diagnostic value in patients with AF and sinus rhythm (SR). DESIGN: Prospective cohort study. SETTING: University hospital, emergency department. PATIENTS: 632 consecutive patients presenting with acute dyspnoea. MAIN OUTCOME MEASURES: MR proANP and NT proBNP plasma levels were determined. The diagnosis of AHF was adjudicated by two independent cardiologists using all available data. Patients received long-term follow-up. RESULTS: AF was present in 151 patients (24%). MR proANP and NT proBNP levels were significantly higher in the AF group compared with the SR group (385 (258-598) versus 201 (89-375) pmol/l for MR proANP, p<0.001 and 4916 (2169-10285) versus 1177 (258-5166) pg/ml, p<0.001 for NT proBNP). Diagnostic accuracy in AF patients was similar for MR proANP (0.90, 95% CI 0.84 to 0.95) and NT proBNP (0.89, 95% CI 0.81 to 0.96). Optimal cut-off levels in AF patients were significantly higher compared with the optimal cut-off levels for patients in SR (MR proANP 240 vs 200 pmol/l; NT proBNP 2670 vs 1500 pg/ml respectively). After adjustment in multivariable Cox proportional hazard analysis, MR proANP strongly predicted one-year all-cause mortality (HR=1.13 (1.09-1.17), per 100 pmol/l increase, p<0.001). CONCLUSION: In AF patients, NT proBNP and MR proANP have similar diagnostic value for the diagnosis of AHF. The rhythm at presentation has to be taken into account because plasma levels of both peptides are significantly higher in patients with AF compared with SR.