Skeletal Muscle Disorders: A Noncardiac Source of Cardiac Troponin T.

BACKGROUND: Cardiac troponin (cTn) T and cTnI are considered cardiac specific and equivalent in the diagnosis of acute myocardial infarction. Previous studies suggested rare skeletal myopathies as a noncardiac source of cTnT. We aimed to confirm the reliability/cardiac specificity of cTnT in patients with various skeletal muscle disorders (SMDs). METHODS: We prospectively enrolled patients presenting with muscular complaints (≥2 weeks) for elective evaluation in 4 hospitals in 2 countries. After a cardiac workup, patients were adjudicated into 3 predefined cardiac disease categories. Concentrations of cTnT/I and resulting cTnT/I mismatches were assessed with high-sensitivity (hs-) cTnT (hs-cTnT-Elecsys) and 3 hs-cTnI assays (hs-cTnI-Architect, hs-cTnI-Access, hs-cTnI-Vista) and compared with those of control subjects without SMD presenting with adjudicated noncardiac chest pain to the emergency department (n=3508; mean age, 55 years; 37% female). In patients with available skeletal muscle biopsies, TNNT/I1-3 mRNA differential gene expression was compared with biopsies obtained in control subjects without SMD. RESULTS: Among 211 patients (mean age, 57 years; 42% female), 108 (51%) were adjudicated to having no cardiac disease, 44 (21%) to having mild disease, and 59 (28%) to having severe cardiac disease. hs-cTnT/I concentrations significantly increased from patients with no to those with mild and severe cardiac disease for all assays (all P<0.001). hs-cTnT-Elecsys concentrations were significantly higher in patients with SMD versus control subjects (median, 16 ng/L [interquartile range (IQR), 7-32.5 ng/L] versus 5 ng/L [IQR, 3-9 ng/L]; P<0.001), whereas hs-cTnI concentrations were mostly similar (hs-cTnI-Architect, 2.5 ng/L [IQR, 1.2-6.2 ng/L] versus 2.9 ng/L [IQR, 1.8-5.0 ng/L]; hs-cTnI-Access, 3.3 ng/L [IQR, 2.4-6.1 ng/L] versus 2.7 ng/L [IQR, 1.6-5.0 ng/L]; and hs-cTnI-Vista, 7.4 ng/L [IQR, 5.2-13.4 ng/L] versus 7.5 ng/L [IQR, 6-10 ng/L]). hs-cTnT-Elecsys concentrations were above the upper limit of normal in 55% of patients with SMD versus 13% of control subjects (P<0.01). mRNA analyses in skeletal muscle biopsies (n=33), mostly (n=24) from individuals with noninflammatory myopathy and myositis, showed 8-fold upregulation of TNNT2, encoding cTnT (but none for TNNI3, encoding cTnI) versus control subjects (n=16, PWald<0.001); the expression correlated with pathological disease activity (R=0.59, Pt-statistic<0.001) and circulating hs-cTnT concentrations (R=0.26, Pt-statistic=0.031). CONCLUSIONS: In patients with active chronic SMD, elevations in cTnT concentrations are common and not attributable to cardiac disease in the majority. This was not observed for cTnI and may be explained in part by re-expression of cTnT in skeletal muscle. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03660969.

Hyperacute T Wave in the Early Diagnosis of Acute Myocardial Infarction.

STUDY OBJECTIVE: The diagnostic performance of T-wave amplitudes for the detection of myocardial infarction is largely unknown. We aimed to address this knowledge gap. METHODS: T-wave amplitudes were automatically measured in 12-lead ECGs of patients presenting with acute chest discomfort to the emergency department within a prospective diagnostic multicenter study. The final diagnosis was centrally adjudicated by 2 independent cardiologists. Patients with left ventricular hypertrophy, complete left bundle branch block, or paced ventricular depolarization were excluded. The performance for lead-specific 95th-percentile thresholds were reported as likelihood ratios (lr), specificity, and sensitivity. RESULTS: Myocardial infarction was the final diagnosis in 445 (18%) of 2457 patients. In most leads, T-wave amplitudes tended to be greater in patients without myocardial infarction than those with myocardial infarction, and T-wave amplitude exceeding the 95th percentile had positive and negative lr close to 1 or with confidence intervals (CIs) crossing 1. The exceptions were leads III, aVR, and V1, which had positive lrs of 3.8 (95% CI, 2.7 to 5.3), 4.3 (95% CI, 3.1 to 6.0) and 2.0 (95% CI, 1.4 to 2.9), respectively. These leads normally have inverted T waves, so T-wave amplitude exceeding the 95th percentile reflects upright rather than increased-amplitude hyperacute T waves. CONCLUSION: Hyperacute T waves, when defined as increased T-wave amplitude exceeding the 95th percentile, did not provide useful information in diagnosing myocardial infarction in this sample.

International Validation of the Canadian Syncope Risk Score : A Cohort Study.

BACKGROUND: The Canadian Syncope Risk Score (CSRS) was developed to predict 30-day serious outcomes not evident during emergency department (ED) evaluation. OBJECTIVE: To externally validate the CSRS and compare it with another validated score, the Osservatorio Epidemiologico della Sincope nel Lazio (OESIL) score. DESIGN: Prospective cohort study. SETTING: Large, international, multicenter study recruiting patients in EDs in 8 countries on 3 continents. PARTICIPANTS: Patients with syncope aged 40 years or older presenting to the ED within 12 hours of syncope. MEASUREMENTS: Composite outcome of serious clinical plus procedural events (primary outcome) and the primary composite outcome excluding procedural interventions (secondary outcome). RESULTS: Among 2283 patients with a mean age of 68 years, the primary composite outcome occurred in 7.2%, and the composite outcome excluding procedural interventions occurred in 3.1% at 30 days. Prognostic performance of the CSRS was good for both 30-day composite outcomes and better compared with the OESIL score (area under the receiver-operating characteristic curve [AUC], 0.85 [95% CI, 0.83 to 0.88] vs. 0.74 [CI, 0.71 to 0.78] and 0.80 [CI, 0.75 to 0.84] vs. 0.69 [CI, 0.64 to 0.75], respectively). Safety of triage, as measured by the frequency of the primary composite outcome in the low-risk group, was higher using the CSRS (19 of 1388 [0.6%]) versus the OESIL score (17 of 1104 [1.5%]). A simplified model including only the clinician classification of syncope (cardiac syncope, vasovagal syncope, or other) variable at ED discharge-a component of the CSRS-achieved similar discrimination as the CSRS (AUC, 0.83 [CI, 0.80 to 0.87] for the primary composite outcome). LIMITATION: Unable to disentangle the influence of other CSRS components on clinician classification of syncope at ED discharge. CONCLUSION: This international external validation of the CSRS showed good performance in identifying patients at low risk for serious outcomes outside of Canada and superior performance compared with the OESIL score. However, clinician classification of syncope at ED discharge seems to explain much of the performance of the CSRS in this study. The clinical utility of the CSRS remains uncertain. PRIMARY FUNDING SOURCE: Swiss National Science Foundation & Swiss Heart Foundation.

Performance of the ESC 0/2h-algorithm using high-sensitivity cardiac troponin I in the early diagnosis of myocardial infarction.

The 2020 guidelines of the European Society of Cardiology (ESC) recommend a novel ESC 0/2h-algorithm as the preferred alternative to the ESC 0/1h-algorithm in the early triage for rule-out and/or rule-in of Non-ST-segment-elevation myocardial infarction (NSTEMI). The aim was to prospectively validate the performance of the ESC 0/2h-algorithm using the high-sensitivity cardiac troponin I (hs-cTnI) assay (ARCHITECT) in an international, multicenter diagnostic study enrolling patients presenting with acute chest discomfort to the emergency department.

External Validation of the MEESSI Acute Heart Failure Risk Score: A Cohort Study.

Background: The MEESSI-AHF (Multiple Estimation of risk based on the Emergency department Spanish Score In patients with AHF) score was developed to predict 30-day mortality in patients presenting with acute heart failure (AHF) to emergency departments (EDs) in Spain. Whether it performs well in other countries is unknown. Objective: To externally validate the MEESSI-AHF score in another country. Design: Prospective cohort study. (ClinicalTrials.gov: NCT01831115). Setting: Multicenter recruitment of dyspneic patients presenting to the ED. Participants: The external validation cohort included 1572 patients with AHF. Measurements: Calculation of the MEESSI-AHF score using an established model containing 12 independent risk factors. Results: Among 1572 patients with adjudicated AHF, 1247 had complete data that allowed calculation of the MEESSI-AHF score. Of these, 102 (8.2%) died within 30 days. The score predicted 30-day mortality with excellent discrimination (c-statistic, 0.80). Assessment of cumulative mortality showed a steep gradient in 30-day mortality over 6 predefined risk groups (0 patients in the lowest-risk group vs. 35 [28.5%] in the highest-risk group). Risk was overestimated in the high-risk groups, resulting in a Hosmer-Lemeshow P value of 0.022. However, after adjustment of the intercept, the model showed good concordance between predicted risks and observed outcomes (P = 0.23). Findings were confirmed in sensitivity analyses that used multiple imputation for missing values in the overall cohort of 1572 patients. Limitations: External validation was done using a reduced model. Findings are specific to patients with AHF who present to the ED and are clinically stable enough to provide informed consent. Performance in patients with terminal kidney failure who are receiving long-term dialysis cannot be commented on. Conclusion: External validation of the MEESSI-AHF risk score showed excellent discrimination. Recalibration may be needed when the score is introduced to new populations. Primary Funding Source: The European Union, the Swiss National Science Foundation, the Swiss Heart Foundation, the Cardiovascular Research Foundation Basel, the University of Basel, and University Hospital Basel.

0/1-Hour Triage Algorithm for Myocardial Infarction in Patients With Renal Dysfunction.

BACKGROUND: The European Society of Cardiology recommends a 0/1-hour algorithm for rapid rule-out and rule-in of non-ST-segment elevation myocardial infarction using high-sensitivity cardiac troponin (hs-cTn) concentrations irrespective of renal function. Because patients with renal dysfunction (RD) frequently present with increased hs-cTn concentrations even in the absence of non-ST-segment elevation myocardial infarction, concern has been raised regarding the performance of the 0/1-hour algorithm in RD. METHODS: In a prospective multicenter diagnostic study enrolling unselected patients presenting with suspected non-ST-segment elevation myocardial infarction to the emergency department, we assessed the diagnostic performance of the European Society of Cardiology 0/1-hour algorithm using hs-cTnT and hs-cTnI in patients with RD, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2, and compared it to patients with normal renal function. The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including cardiac imaging. Safety was quantified as sensitivity in the rule-out zone, accuracy as the specificity in the rule-in zone, and efficacy as the proportion of the overall cohort assigned to either rule-out or rule-in based on the 0- and 1-hour sample. RESULTS: Among 3254 patients, RD was present in 487 patients (15%). The prevalence of non-ST-segment elevation myocardial infarction was substantially higher in patients with RD compared with patients with normal renal function (31% versus 13%, P<0.001). Using hs-cTnT, patients with RD had comparable sensitivity of rule-out (100.0% [95% confidence interval {CI}, 97.6-100.0] versus 99.2% [95% CI, 97.6-99.8]; P=0.559), lower specificity of rule-in (88.7% [95% CI, 84.8-91.9] versus 96.5% [95% CI, 95.7-97.2]; P<0.001), and lower overall efficacy (51% versus 81%, P<0.001), mainly driven by a much lower percentage of patients eligible for rule-out (18% versus 68%, P<0.001) compared with patients with normal renal function. Using hs-cTnI, patients with RD had comparable sensitivity of rule-out (98.6% [95% CI, 95.0-99.8] versus 98.5% [95% CI, 96.5-99.5]; P=1.0), lower specificity of rule-in (84.4% [95% CI, 79.9-88.3] versus 91.7% [95% CI, 90.5-92.9]; P<0.001), and lower overall efficacy (54% versus 76%, P<0.001; proportion ruled out, 18% versus 58%, P<0.001) compared with patients with normal renal function. CONCLUSIONS: In patients with RD, the safety of the European Society of Cardiology 0/1-hour algorithm is high, but specificity of rule-in and overall efficacy are decreased. Modifications of the rule-in and rule-out thresholds did not improve the safety or overall efficacy of the 0/1-hour algorithm. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Combining High-Sensitivity Cardiac Troponin I and Cardiac Troponin T in the Early Diagnosis of Acute Myocardial Infarction.

BACKGROUND: Combining 2 signals of cardiomyocyte injury, cardiac troponin I (cTnI) and T (cTnT), might overcome some individual pathophysiological and analytical limitations and thereby increase diagnostic accuracy for acute myocardial infarction with a single blood draw. We aimed to evaluate the diagnostic performance of combinations of high-sensitivity (hs) cTnI and hs-cTnT for the early diagnosis of acute myocardial infarction. METHODS: The diagnostic performance of combining hs-cTnI (Architect, Abbott) and hs-cTnT (Elecsys, Roche) concentrations (sum, product, ratio, and a combination algorithm) obtained at the time of presentation was evaluated in a large multicenter diagnostic study of patients with suspected acute myocardial infarction. The optimal rule-out and rule-in thresholds were externally validated in a second large multicenter diagnostic study. The proportion of patients eligible for early rule-out was compared with the European Society of Cardiology 0/1 and 0/3 hour algorithms. RESULTS: Combining hs-cTnI and hs-cTnT concentrations did not consistently increase overall diagnostic accuracy as compared with the individual isoforms. However, the combination improved the proportion of patients meeting criteria for very early rule-out. With the European Society of Cardiology 2015 guideline recommended algorithms and cut-offs, the proportion meeting rule-out criteria after the baseline blood sampling was limited (6% to 24%) and assay dependent. Application of optimized cut-off values using the sum (9 ng/L) and product (18 ng2/L2) of hs-cTnI and hs-cTnT concentrations led to an increase in the proportion ruled-out after a single blood draw to 34% to 41% in the original (sum: negative predictive value [NPV] 100% [95% confidence interval (CI), 99.5% to 100%]; product: NPV 100% [95% CI, 99.5% to 100%]) and in the validation cohort (sum: NPV 99.6% [95% CI, 99.0-99.9%]; product: NPV 99.4% [95% CI, 98.8-99.8%]). The use of a combination algorithm (hs-cTnI <4 ng/L and hs-cTnT <9 ng/L) showed comparable results for rule-out (40% to 43% ruled out; NPV original cohort 99.9% [95% CI, 99.2-100%]; NPV validation cohort 99.5% [95% CI, 98.9-99.8%]) and rule-in (positive predictive value [PPV] original cohort 74.4% [95% Cl, 69.6-78.8%]; PPV validation cohort 84.0% [95% Cl, 79.7-87.6%]). CONCLUSIONS: New strategies combining hs-cTnI and hs-cTnT concentrations may significantly increase the number of patients eligible for very early and safe rule-out, but do not seem helpful for the rule-in of acute myocardial infarction. CLINICAL TRIAL REGISTRATION: URL (APACE): https://www.clinicaltrial.gov . Unique identifier: NCT00470587. URL (ADAPT): www.anzctr.org.au . Unique identifier: ACTRN12611001069943.

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.

Effect of a Strategy of Comprehensive Vasodilation vs Usual Care on Mortality and Heart Failure Rehospitalization Among Patients With Acute Heart Failure: The GALACTIC Randomized Clinical Trial.

Importance: Short-term infusions of single vasodilators, usually given in a fixed dose, have not improved outcomes in patients with acute heart failure (AHF). Objective: To evaluate the effect of a strategy that emphasized early intensive and sustained vasodilation using individualized up-titrated doses of established vasodilators in patients with AHF. Design, Setting, and Participants: Randomized, open-label blinded-end-point trial enrolling 788 patients hospitalized for AHF with dyspnea, increased plasma concentrations of natriuretic peptides, systolic blood pressure of at least 100 mm Hg, and plan for treatment in a general ward in 10 tertiary and secondary hospitals in Switzerland, Bulgaria, Germany, Brazil, and Spain. Enrollment began in December 2007 and follow-up was completed in February 2019. Interventions: Patients were randomized 1:1 to a strategy of early intensive and sustained vasodilation throughout the hospitalization (n = 386) or usual care (n = 402). Early intensive and sustained vasodilation was a comprehensive pragmatic approach of maximal and sustained vasodilation combining individualized doses of sublingual and transdermal nitrates, low-dose oral hydralazine for 48 hours, and rapid up-titration of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or sacubitril-valsartan. Main Outcomes and Measures: The primary end point was a composite of all-cause mortality or rehospitalization for AHF at 180 days. Results: Among 788 patients randomized, 781 (99.1%; median age, 78 years; 36.9% women) completed the trial and were eligible for primary end point analysis. Follow-up at 180 days was completed for 779 patients (99.7%). The primary end point, a composite of all-cause mortality or rehospitalization for AHF at 180 days, occurred in 117 patients (30.6%) in the intervention group (including 55 deaths [14.4%]) and in 111 patients (27.8%) in the usual care group (including 61 deaths [15.3%]) (absolute difference for the primary end point, 2.8% [95% CI, -3.7% to 9.3%]; adjusted hazard ratio, 1.07 [95% CI, 0.83-1.39]; P = .59). The most common clinically significant adverse events with early intensive and sustained vasodilation vs usual care were hypokalemia (23% vs 25%), worsening renal function (21% vs 20%), headache (26% vs 10%), dizziness (15% vs 10%), and hypotension (8% vs 2%). Conclusions and Relevance: Among patients with AHF, a strategy of early intensive and sustained vasodilation, compared with usual care, did not significantly improve a composite outcome of all-cause mortality and AHF rehospitalization at 180 days. Trial Registration: ClinicalTrials.gov Identifier: NCT00512759.

Direct Comparison of Cardiac Myosin-Binding Protein C With Cardiac Troponins for the Early Diagnosis of Acute Myocardial Infarction.

BACKGROUND: Cardiac myosin-binding protein C (cMyC) is a cardiac-restricted protein that is more abundant than cardiac troponins (cTn) and is released more rapidly after acute myocardial infarction (AMI). We evaluated cMyC as an adjunct or alternative to cTn in the early diagnosis of AMI. METHODS: Unselected patients (N=1954) presenting to the emergency department with symptoms suggestive of AMI, concentrations of cMyC, and high-sensitivity (hs) and standard-sensitivity cTn were measured at presentation. The final diagnosis of AMI was independently adjudicated using all available clinical and biochemical information without knowledge of cMyC. The prognostic end point was long-term mortality. RESULTS: Final diagnosis was AMI in 340 patients (17%). Concentrations of cMyC at presentation were significantly higher in those with versus without AMI (median, 237 ng/L versus 13 ng/L, P<0.001). Discriminatory power for AMI, as quantified by the area under the receiver-operating characteristic curve (AUC), was comparable for cMyC (AUC, 0.924), hs-cTnT (AUC, 0.927), and hs-cTnI (AUC, 0.922) and superior to cTnI measured by a contemporary sensitivity assay (AUC, 0.909). The combination of cMyC with hs-cTnT or standard-sensitivity cTnI (but not hs-cTnI) led to an increase in AUC to 0.931 (P<0.0001) and 0.926 (P=0.003), respectively. Use of cMyC more accurately classified patients with a single blood test into rule-out or rule-in categories: Net Reclassification Improvement +0.149 versus hs-cTnT, +0.235 versus hs-cTnI (P<0.001). In early presenters (chest pain <3 h), the improvement in rule-in/rule-out classification with cMyC was larger compared with hs-cTnT (Net Reclassification Improvement +0.256) and hs-cTnI (Net Reclassification Improvement +0.308; both P<0.001). Comparing the C statistics, cMyC was superior to hs-cTnI and standard sensitivity cTnI (P<0.05 for both) and similar to hs-cTnT at predicting death at 3 years. CONCLUSIONS: cMyC at presentation provides discriminatory power comparable to hs-cTnT and hs-cTnI in the diagnosis of AMI and may perform favorably in patients presenting early after symptom onset. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Direct Comparison of 4 Very Early Rule-Out Strategies for Acute Myocardial Infarction Using High-Sensitivity Cardiac Troponin I.

BACKGROUND: Four strategies for very early rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I (hs-cTnI) have been identified. It remains unclear which strategy is most attractive for clinical application. METHODS: We prospectively enrolled unselected patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction. The final diagnosis was adjudicated by 2 independent cardiologists. Hs-cTnI levels were measured at presentation and after 1 hour in a blinded fashion. We directly compared all 4 hs-cTnI-based rule-out strategies: limit of detection (LOD, hs-cTnI<2 ng/L), single cutoff (hs-cTnI<5 ng/L), 1-hour algorithm (hs-cTnI<5 ng/L and 1-hour change<2 ng/L), and the 0/1-hour algorithm recommended in the European Society of Cardiology guideline combining LOD and 1-hour algorithm. RESULTS: Among 2828 enrolled patients, acute myocardial infarction was the final diagnosis in 451 (16%) patients. The LOD approach ruled out 453 patients (16%) with a sensitivity of 100% (95% confidence interval [CI], 99.2%-100%), the single cutoff 1516 patients (54%) with a sensitivity of 97.1% (95% CI, 95.1%-98.3%), the 1-hour algorithm 1459 patients (52%) with a sensitivity of 98.4% (95% CI, 96.8%-99.2%), and the 0/1-hour algorithm 1463 patients (52%) with a sensitivity of 98.4% (95% CI, 96.8%-99.2%). Predefined subgroup analysis in early presenters (≤2 hours) revealed significantly lower sensitivity (94.2%, interaction P=0.03) of the single cutoff, but not the other strategies. Two-year survival was 100% with LOD and 98.1% with the other strategies (P<0.01 for LOD versus each of the other strategies). CONCLUSIONS: All 4 rule-out strategies balance effectiveness and safety equally well. The single cutoff should not be applied in early presenters, whereas the 3 other strategies seem to perform well in this challenging subgroup. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Diagnostic and Prognostic Utility of Circulating Cytochrome c in Acute Myocardial Infarction.

RATIONALE: In contrast to cardiomyocyte necrosis, which can be quantified by cardiac troponin, functional cardiomyocyte impairment, including mitochondrial dysfunction, has escaped clinical recognition in acute myocardial infarction (AMI) patients. OBJECTIVE: To investigate the diagnostic accuracy for AMI and prognostic prediction of in-hospital mortality of cytochrome c. METHODS AND RESULTS: We prospectively assessed cytochrome c serum levels at hospital presentation in 2 cohorts: a diagnostic cohort of patients presenting with suspected AMI and a prognostic cohort of definite AMI patients. Diagnostic accuracy for AMI was the primary diagnostic end point, and prognostic prediction of in-hospital mortality was the primary prognostic end point. Serum cytochrome c had no diagnostic utility for AMI (area under the receiver-operating characteristics curve 0.51; 95% confidence intervals 0.44-0.58; P=0.76). Among 753 AMI patients in the prognostic cohort, cytochrome c was detectable in 280 (37%) patients. These patients had higher in-hospital mortality than patients with nondetectable cytochrome c (6% versus 1%; P<0.001). This result was mainly driven by the high mortality rate observed in ST-segment-elevation AMI patients with detectable cytochrome c, as compared with those with nondetectable cytochrome c (11% versus 1%; P<0.001). At multivariable analysis, cytochrome c remained a significant independent predictor of in-hospital mortality (odds ratio 3.0; 95% confidence interval 1.9-5.7; P<0.001), even after adjustment for major clinical confounders (odds ratio 4.01; 95% confidence interval 1.20-13.38; P=0.02). CONCLUSIONS: Cytochrome c serum concentrations do not have diagnostic but substantial prognostic utility in AMI.

Incremental value of C-reactive protein to the MEESSI acute heart failure risk score.

AIMS: We hypothesized that the current gold standard for risk stratification of patients with acute heart failure (AHF), the Multiple Estimation of risk based on the Emergency department Spanish Score In patients with AHF (MEESSI-AHF) risk score, can be further improved by adding systemic inflammation as quantified by C-reactive protein (CRP). METHODS AND RESULTS: In a prospective multicentre diagnostic study (BASEL V), AHF was centrally adjudicated by two independent cardiologists. The MEESSI-AHF risk score was calculated using an established reduced and recalibrated model containing 12 independent risk factors. Model extension was performed by refitting and adding CRP in the logistic regression model with 30-day mortality as binary outcome. Discrimination, calibration and clinical usefulness were used to assess the performance of the extended Multiple Estimation of risk based on the Emergency department Spanish Score In patients (MEESSI) model. Validation was performed in an independent, retrospective and single-centre AHF cohort. Among 1208 AHF patients with complete data allowing calculation of the recalibrated MEESSI and the extended MEESSI models, the prognostic accuracy for 30-day mortality of the extended MEESSI model (c-statistic 0.83, 95% confidence interval [CI] 0.79-0.87) was significantly higher compared to the recalibrated model (c-statistic 0.79, 95% CI 0.75-0.83, p = 0.013). The extended model allowed to stratify a higher percentage of patients into the lowest risk group compared to the recalibrated model (33.1% vs. 20.3%). Demonstrating a calibration plot's slope of 1.00 (95% CI 0.81-1.19) and an intercept of 0.0 (95% CI -0.22 to 0.22), the extended MEESSI model achieved excellent and improved calibration. Results were confirmed in the independent validation cohort (n = 575). CONCLUSIONS: Quantifying inflammation using CRP concentration provided incremental value in AHF risk stratification using the established MEESSI model.

Quantifying Hemodynamic Cardiac Stress and Cardiomyocyte Injury in Normotensive and Hypertensive Acute Heart Failure.

BACKGROUND: The characterization of the different pathophysiological mechanisms involved in normotensive versus hypertensive acute heart failure (AHF) might help to develop individualized treatments. METHODS: The extent of hemodynamic cardiac stress and cardiomyocyte injury was quantified by measuring the B-type natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP), and high-sensitivity cardiac troponin T (hs-cTnT) concentrations in 1152 patients presenting with centrally adjudicated AHF to the emergency department (ED) (derivation cohort). AHF was classified as normotensive with a systolic blood pressure (SBP) of 90-140 mmHg and hypertensive with SBP > 140 mmHg at presentation to the ED. Findings were externally validated in an independent AHF cohort (n = 324). RESULTS: In the derivation cohort, with a median age of 79 years, 43% being women, 667 (58%) patients had normotensive and 485 (42%) patients hypertensive AHF. Hemodynamic cardiac stress, as quantified by the BNP and NT-proBNP, was significantly higher in normotensive as compared to hypertensive AHF [1105 (611-1956) versus 827 (448-1419) pg/mL, and 5890 (2959-12,162) versus 4068 (1986-8118) pg/mL, both p < 0.001, respectively]. Similarly, the extent of cardiomyocyte injury, as quantified by hs-cTnT, was significantly higher in normotensive AHF as compared to hypertensive AHF [41 (24-71) versus 33 (19-59) ng/L, p < 0.001]. A total of 313 (28%) patients died during 360 days of follow-up. All-cause mortality was higher in patients with normotensive AHF vs. patients with hypertensive AHF (hazard ratio 1.66, 95%CI 1.31-2.10; p < 0.001). Normotensive patients with a high BNP, NT-proBNP, or hs-cTnT had the highest mortality. The findings were confirmed in the validation cohort. CONCLUSION: Biomarker profiling revealed a higher extent of hemodynamic stress and cardiomyocyte injury in patients with normotensive versus hypertensive AHF.

Quantifying inflammation using interleukin-6 for improved phenotyping and risk stratification in acute heart failure.

AIMS: Systemic inflammation may be central in the pathophysiology of acute heart failure (AHF). We aimed to assess the possible role of systemic inflammation in the pathophysiology, phenotyping, and risk stratification of patients with AHF. METHODS AND RESULTS: Using a novel Interleukin-6 immunoassay with unprecedented sensitivity (limit of detection 0.01 ng/L), we quantified systemic inflammation in unselected patients presenting with acute dyspnoea to the emergency department in a multicentre study. One-year mortality was the primary prognostic endpoint. Among 2042 patients, 1026 (50.2%) had an adjudicated diagnosis of AHF, 83.7% of whom had elevated interleukin-6 concentrations (>4.45 ng/L). Interleukin-6 was significantly higher in AHF patients compared to patients with other causes of dyspnoea (11.2 [6.1-26.5] ng/L vs. 9.0 [3.2-32.3] ng/L, p < 0.0005). Elevated interleukin-6 concentrations were independently predicted by increasing N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin T, as well as the clinical diagnosis of infection. Among the different AHF phenotypes, interleukin-6 concentrations were highest in patients with cardiogenic shock (25.7 [14.0-164.2] ng/L) and lowest in patients with hypertensive AHF (9.3 [4.8-21.6] ng/L, p = 0.001). Inflammation as quantified by interleukin-6 was a strong and independent predictor of 1-year mortality both in all AHF patients, as well as those without clinically overt infection at presentation (adjusted hazard ratio [95% confidence interval] 1.45 [1.15-1.83] vs. 1.48 [1.09-2.00]). The addition of interleukin-6 significantly improved the discrimination of the BIOSTAT-CHF risk score. CONCLUSION: An unexpectedly high percentage of patients with AHF have subclinical systemic inflammation as quantified by interleukin-6, which seems to contribute to AHF phenotype and to the risk of death.

Prognostic Value of Self-Reported Subjective Exercise Capacity in Patients With Acute Dyspnea.

Background: Self-reported exercise capacity is a well-established prognostic measure in stable ambulatory patients with cardiac and pulmonary disease. Objectives: The authors aimed to directly compare the prognostic accuracy of quantified self-reported exercise capacity using the Duke Activity Status Index (DASI) with the established objective disease-severity marker B-type natriuretic peptide (BNP) in patients presenting with acute dyspnea to the emergency department. Methods: The DASI was obtained in a prospective multicenter diagnostic study recruiting unselected patients presenting with acute dyspnea to the emergency department. The prognostic accuracy of DASI and BNP for 90-day and 720-day all-cause mortality was evaluated using C-index. Results: Among 1,019 patients eligible for this analysis, 75 (7%) and 297 (29%) patients died within 90 and 720 days after presentation, respectively. Unadjusted hazard ratios (HRs) and multivariable adjusted hazard ratios (aHRs) for 90- and 720-day mortality increased continuously from the fourth (best self-reported exercise capacity) to the first DASI quartile (worst self-reported exercise capacity). For 720-day mortality the HR of the first quartile vs the fourth was 9.1 (95% CI, 5.5-14.9) vs (aHR: 6.1, 95% CI: 3.7-10.1), of the second quartile 6.4 (95% CI: 3.9-10.6) vs (aHR: 4.4, 95% CI: 2.6-7.3), while of the third quartile the HR was 3.2 (95% CI: 1.9-5.5) vs (aHR: 2.4, 95% CI: 1.4-4.0). The prognostic accuracy of the DASI score was high, and higher than that of BNP concentrations (720-day mortality C-index: 0.67 vs 0.62; P = 0.024). Conclusions: Quantification of self-reported subjective exercise capacity using the DASI provides high prognostic accuracy and may aid physicians in risk stratification. (Basics in Acute Shortness of Breath EvaLuation [BASEL V] Study [BASEL V]; NCT01831115).

Acute heart failure after non-cardiac surgery: incidence, phenotypes, determinants and outcomes.

AIMS: Primary acute heart failure (AHF) is a common cause of hospitalization. AHF may also develop postoperatively (pAHF). The aim of this study was to assess the incidence, phenotypes, determinants and outcomes of pAHF following non-cardiac surgery. METHODS AND RESULTS: A total of 9164 consecutive high-risk patients undergoing 11 262 non-cardiac inpatient surgeries were prospectively included. The incidence, phenotypes, determinants and outcome of pAHF, centrally adjudicated by independent cardiologists, were determined. The incidence of pAHF was 2.5% (95% confidence interval [CI] 2.2-2.8%); 51% of pAHF occurred in patients without known heart failure (de novo pAHF), and 49% in patients with chronic heart failure. Among patients with chronic heart failure, 10% developed pAHF, and among patients without a history of heart failure, 1.5% developed pAHF. Chronic heart failure, diabetes, urgent/emergent surgery, atrial fibrillation, cardiac troponin elevations above the 99th percentile, chronic obstructive pulmonary disease, anaemia, peripheral artery disease, coronary artery disease, and age, were independent predictors of pAHF in the logistic regression model. Patients with pAHF had significantly higher all-cause mortality (44% vs. 11%, p < 0.001) and AHF readmission (15% vs. 2%, p < 0.001) within 1 year than patients without pAHF. After Cox regression analysis, pAHF was an independent predictor of all-cause mortality (adjusted hazard ratio [aHR] 1.7 [95% CI 1.3-2.2]; p < 0.001) and AHF readmission (aHR 2.3 [95% CI 1.5-3.7]; p < 0.001). Findings were confirmed in an external validation cohort using a prospective multicentre cohort of 1250 patients (incidence of pAHF 2.4% [95% CI 1.6-3.3%]). CONCLUSIONS: Postoperative AHF frequently developed following non-cardiac surgery, being de novo in half of cases, and associated with a very high mortality.

Comprehensive vasodilatation in women with acute heart failure: Novel insights from the GALACTIC randomized controlled trial.

AIMS: Sex-specific differences in acute heart failure (AHF) are both relevant and underappreciated. Therefore, it is crucial to evaluate the risk/benefit ratio and the implementation of novel AHF therapies in women and men separately. METHODS AND RESULTS: We performed a pre-defined sex-specific analysis in AHF patients randomized to a strategy of early intensive and sustained vasodilatation versus usual care in an international, multicentre, open-label, blinded endpoint trial. Inclusion criteria were AHF with increased plasma concentrations of natriuretic peptides, systolic blood pressure ≥100 mmHg, and plan for treatment in a general ward. Among 781 eligible patients, 288 (37%) were women. Women were older (median 83 vs. 76 years), had a lower body weight (median 64.5 vs. 77.6 kg) and lower estimated glomerular filtration rate (median 48 vs. 54 ml/min/1.73 m2 ). The primary endpoint, a composite of all-cause mortality or rehospitalization for AHF at 180 days, showed a significant interaction of treatment strategy and sex (p for interaction = 0.03; hazard ratio adjusted for female sex 1.62, 95% confidence interval 1.05-2.50; p = 0.03). The combined endpoint occurred in 53 women (38%) in the intervention group and in 35 (24%) in the usual care group. The implementation of rapid up-titration of renin-angiotensin-aldosterone system (RAAS) inhibitors was less successful in women versus men in the overall cohort and in patients with heart failure with reduced ejection fraction (median discharge % target dose in patients randomized to intervention: 50% in women vs. 75% in men). CONCLUSION: Rapid up-titration of RAAS inhibitors was less successfully implemented in women possibly explaining their higher rate of all-cause mortality and rehospitalization for AHF. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, unique identifier NCT00512759.