Detecting Hexafluoroisopropanol Using Soft Chemical Ionization Mass Spectrometry and Analytical Applications to Exhaled Breath.

Here we explore the potential use of proton transfer reaction/selective reagent ion-time-of-flight-mass spectrometry (PTR/SRI-ToF-MS) to monitor hexafluoroisopropanol (HFIP) in breath. Investigations of the reagent ions H3O+, NO+, and O2+• are reported using dry (relative humidity (rH) ≈ 0%) and humid (rH ≈ 100%)) nitrogen gas containing traces of HFIP, i.e., divorced from the complex chemical environment of exhaled breath. HFIP shows no observable reaction with H3O+ and NO+, but it does react efficiently with O2+• via dissociative charge transfer resulting in CHF2+, CF3+, C2HF2O+, and C2H2F3O+. A minor competing hydride abstraction channel results in C3HF6O+ + HO2• and, following an elimination of HF, C3F5O+. There are two issues associated with the use of the three dominant product ions of HFIP, CHF2+, CF3+, and C2H2F3O+, to monitor it in breath. One is that CHF2+ and CF3+ also result from the reaction of O2+• with the more abundant sevoflurane. The second is the facile reaction of these product ions with water, which reduces analytical sensitivity to detect HFIP in humid breath. To overcome the first issue, C2H2F3O+ is the ion marker for HFIP. The second issue is surmounted by using a Nafion tube to reduce the breath sample's humidity prior to its introduction into drift tube. The success of this approach is illustrated by comparing the product ion signals either in dry or humid nitrogen gas flows and with or without the use of the Nafion tube, and practically from the analysis of a postoperative exhaled breath sample from a patient volunteer.

The course of adrenomedullin and endothelin levels in patients with vasodilatory shock after cardiac surgery compared to patients after uncomplicated elective cardiac surgery.

PURPOSE: The aim of this study was to analyse the course of adrenomedullin (ADM) and endothelin-1 (ET-1) levels in patients with vasodilatory shock after cardiac surgery and to explore differences compared to patients after uncomplicated coronary artery bypass graft (CABG) surgery. ADM and ET-1 are involved in the vasomotor response during vasodilatory shock. MATERIALS AND METHODS: We included 32 patients with vasodilatory shock (study group) and 10 patients after uncomplicated CABG surgery (control group). Daily measurements of MR-proADM and CT-proET-1 (stable surrogate markers for ADM and ET-1) were collected during the first 7 postoperative days. RESULTS: MR-proADM and CT-proET-1 levels were significantly elevated in the study group when compared to the control group. In addition, the course of both biomarkers was significantly different in the study versus control group. Higher levels of both biomarkers were associated with organ dysfunction (higher maximum multiple organ dysfunction score, acute kidney injury). CONCLUSIONS: Significantly higher levels of MR-proADM and CT-proET-1 and a different course of both biomarkers were observed in patients with vasodilatory shock after cardiac surgery and seemed to be associated with organ dysfunction.

Diagnostic and prognostic value of ST-segment deviation scores in suspected acute myocardial infarction.

BACKGROUND: Recent advances in digital electrocardiography technology allow evaluating ST-segment deviations in all 12 leads as quantitative variables and calculating summed ST-segment deviation scores. The diagnostic and prognostic utility of summed ST-segment deviation scores is largely unknown. METHODS: We aimed to explore the diagnostic and prognostic utility of the conventional and the modified ST-segment deviation score (Better Analysis of ST-segment Elevations and Depressions in a 12- Lead-ECG-Score (BASEL-Score): sum of elevations in the augmented voltage right - lead (aVR) plus absolute, unsigned ST-segment depressions in the remaining leads) in patients presenting with suspected non-ST-segment elevation myocardial infarction. The diagnostic endpoint was non-ST-segment elevation myocardial infarction, adjudicated by two independent cardiologists. Prognostic endpoint was mortality during two-year follow up. RESULTS: Among 1330 patients, non-ST-segment elevation myocardial infarction was present in 200 (15%) patients. Diagnostic accuracy for non-ST-segment elevation myocardial infarction as quantified by the area under the receiver-operating-characteristics curve was significantly higher for the BASEL-Score (0.73; 95% confidence interval 0.69-0.77) as compared to the conventional ST-segment deviation score (0.53; 95% confidence interval 0.49-0.57, p<0.001). The BASEL-Score provided additional independent diagnostic value to dichotomous electrocardiogram variables (ST-segment depression, T-inversion, both p<0.001) and to high-sensitivity cardiac troponin (p<0.001) as well as clinical judgment at 90 min (p<0.001). Similarly, only the BASEL-Score proved to be an independent predictor of two year mortality. CONCLUSIONS: The modified ST-segment deviation score BASEL-Score focusing on ST-segment elevation in aVR and ST-segment depressions in the remaining leads provides incremental diagnostic and prognostic information.

Prospective validation of current quantitative electrocardiographic criteria for ST-elevation myocardial infarction.

BACKGROUND: Rapid and reliable diagnosis of ST-elevation myocardial infarction (STEMI) as a surrogate for acute coronary occlusion is critical for early reperfusion therapy. OBJECTIVES: We aimed to examine the diagnostic performance of current guideline-recommended Electrocardiogram (ECG) STEMI criteria. METHODS: In a prospective diagnostic multicenter study, we objectively quantified the extent of ST-segment elevation in all ECG leads using an automated software-based analysis of the digital 12-lead-ECG in adult patients presenting to the emergency department (ED) with suspected myocardial infarction (MI). Classification according to current guideline-recommended ECG criteria for STEMI at ED presentation was compared against a final diagnosis adjudicated by two independent cardiologists after reviewing all available medical records including serial ECGs, cardiac imaging and coronary angiograms. RESULTS: Among 2486 patients, 52 (2%) were found to have significant ST-segment elevation on ECG at ED presentation according to current guideline-recommended ECG criteria for STEMI. Eighty-one (3%) patients received a final adjudicated diagnosis of STEMI. Only 35% (28 of 81) of all patients with a final diagnosis of STEMI were correctly identified (PPV 54% (95% CI 41-66%), sensitivity 35% (95% Cl 24-46%), NPV 97.8% (95% CI 97.5-98.1%). Four reasons for missing STEMIs emerged: timing (significant STE at an earlier/later time point) in 25%, incorrect measurement points in 30%, non or borderline-significant STE in 36% and inferoposterior MI localisation in 9%. CONCLUSIONS: A computerized analysis of current guideline-recommended ECG criteria for STEMI showed suboptimal diagnostic performance when applied to a single 12­lead ECG performed at ED presentation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

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.

Diagnostic value of ST-segment deviations during cardiac exercise stress testing: Systematic comparison of different ECG leads and time-points.

BACKGROUND: Exercise ECG stress testing is the most widely available method for evaluation of patients with suspected myocardial ischemia. Its major limitation is the relatively poor accuracy of ST-segment changes regarding ischemia detection. Little is known about the optimal method to assess ST-deviations. METHODS: A total of 1558 consecutive patients undergoing bicycle exercise stress myocardial perfusion imaging (MPI) were enrolled. Presence of inducible myocardial ischemia was adjudicated using MPI results. The diagnostic value of ST-deviations for detection of exercise-induced myocardial ischemia was systematically analyzed 1) for each individual lead, 2) at three different intervals after the J-point (J+40ms, J+60ms, J+80ms), and 3) at different time points during the test (baseline, maximal workload, 2min into recovery). RESULTS: Exercise-induced ischemia was detected in 481 (31%) patients. The diagnostic accuracy of ST-deviations was highest at +80ms after the J-point, and at 2min into recovery. At this point, ST-amplitude showed an AUC of 0.63 (95% CI 0.59-0.66) for the best-performing lead I. The combination of ST-amplitude and ST-slope in lead I did not increase the AUC. Lead I reached a sensitivity of 37% and a specificity of 83%, with similar sensitivity to manual ECG analysis (34%, p=0.31) but lower specificity (90%, p<0.001). CONCLUSION: When using ECG stress testing for evaluation of patients with suspected myocardial ischemia, the diagnostic accuracy of ST-deviations is highest when evaluated at +80ms after the J-point, and at 2min into recovery.

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 values of the V-index, a novel ECG marker quantifying spatial heterogeneity of ventricular repolarization, in patients with symptoms suggestive of non-ST-elevation myocardial infarction.

BACKGROUND: The V-index is an ECG marker quantifying spatial heterogeneity of ventricular repolarization. We prospectively assessed the diagnostic and prognostic values of the V-index in patients with suspected non-ST-elevation myocardial infarction (NSTEMI). METHODS: We prospectively enrolled 497 patients presenting with suspected NSTEMI to the emergency department (ED). Digital 12-lead ECGs of five-minute duration were recorded at presentation. The V-index was automatically calculated in a blinded fashion. Patients with a QRS duration >120ms were ruled out from analysis. The final diagnosis was adjudicated by two independent cardiologists. The prognostic endpoint was all-cause mortality during 24months of follow-up. RESULTS: NSTEMI was the final diagnosis in 14% of patients. V-index levels were higher in patients with AMI compared to other causes of chest pain (median 23ms vs. 18ms, p<0.001). The use of the V-index in addition to conventional ECG-criteria improved the diagnostic accuracy for the diagnosis of NSTEMI as quantified by area under the ROC curve from 0.66 to 0.73 (p=0.001) and the sensitivity of the ECG for AMI from 41% to 86% (p<0.001). Cumulative 24-month mortality rates were 99.4%, 98.4% and 88.3% according to tertiles of the V-index (p<0.001). After adjustment for age and important ECG and clinical parameters, the V-index remained an independent predictor of death. CONCLUSIONS: The V-index, an ECG marker quantifying spatial heterogeneity of ventricular repolarization, significantly improves the accuracy and sensitivity of the ECG for the diagnosis of NSTEMI and independently predicts mortality during follow-up.

Early diagnosis of acute myocardial infarction in patients with mild elevations of cardiac troponin.

BACKGROUND: The early diagnosis of acute myocardial infarction (AMI) in patients with mild elevations of high-sensitivity cardiac troponin (hs-cTn) is a challenge. It is unclear whether copeptin, a marker of endogenous stress, or 1h-hs-cTn changes are better suited to address this important unmet clinical need. METHODS: We prospectively enrolled patients presenting with symptoms suggestive of AMI to the emergency department (ED). Two independent cardiologists adjudicated the final diagnosis. Mild hs-cTn elevations were defined as 26.2 ng/L (99th percentile) to 75 ng/L for hs-cTnI, and 14 ng/L (99th percentile) to 50 ng/L (biological-equivalent to 75 ng/L for hs-cTnI) for hs-cTnT. RESULTS: Among 1356 patients, 80 (6%) had mild hs-cTnI elevations at presentation. Within this group, AMI was the final diagnosis in 39 patients (49%). The diagnostic accuracy for the diagnosis of AMI as quantified by the area under the receiver operating characteristic curve (AUC) was 0.51 (95% CI 0.39-0.64) for hs-cTnI at presentation, 0.58 (95% CI 0.45-0.71) for copeptin at presentation, and 0.78 (95% CI 0.68-0.88) for 1h-hs-cTnI changes, which was significantly higher as compared to copeptin (p = 0.02) or hs-cTnI alone (p < 0.001). The additional use of 1h-hs-cTnI changes, but not of copeptin, improved diagnostic accuracy of hs-cTnI at presentation (AUC 0.80, 95% CI 0.70-0.90; p = 0.002 for comparison). Similar findings regarding copeptin and 1h-hs-cTnT/I changes were obtained for mild hs-cTnT elevations. CONCLUSIONS: About 6-22% of patients presenting with suggestive AMI to the ED have mild hs-cTnT/I elevations at presentation. In contrast to copeptin, the addition of 1h-hs-cTn changes substantially improves the early diagnosis of AMI.

Gender-specific uncertainties in the diagnosis of acute coronary syndrome.

BACKGROUND: It is unknown whether higher rates of delayed diagnosis and misdiagnosis of acute coronary syndrome (ACS) in women might have contributed to the poorer outcome of women. METHODS: In a prospective diagnostic multicenter study, we recruited patients presenting to the emergency department (ED) with any kind of chest discomfort/chest pain with onset or peak within the last 12 h. We quantified early diagnostic uncertainty for the presence of ACS among treating physicians at the ED after 90 min, possibly responsible for delayed diagnosis, using a visual analogue scale. Late diagnostic uncertainty, possibly responsible for misdiagnosis, was defined as disagreement among two independent cardiologists' adjudication of the final diagnosis after complete work-up. RESULTS: Among 2795 patients (897 women and 1898 men), ACS was the adjudicated final diagnosis in 24 % of women and 35 % of men. Early diagnostic accuracy of clinical judgment of the ED physician for ACS as quantified by the area under the receiver-operating characteristics curve was 0.89 (95 % CI 0.87-0.92) in women and 0.86 (95 % CI 0.85-0.88) in men (p = 0.046). Late diagnostic uncertainty regarding the diagnosis of ACS was 5 % in women and 7 % in men (p = 0.069). CONCLUSION: Diagnostic uncertainty for the presence of ACS in women is not more common as compared to men and does, therefore, not explain the poorer outcome observed in women with ACS. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00470587.

Impact of haemoconcentration during acute heart failure therapy on mortality and its relationship with worsening renal function.

AIMS: Treatment goals in acute heart failure (AHF) are poorly defined. We aimed to characterize further the impact of in-hospital haemoconcentration and worsening renal function (WRF) on short- and long-term mortality. METHODS AND RESULTS: Haematocrit, haemoglobin, total protein, serum creatinine, and albumin levels were measured serially in 1019 prospectively enrolled AHF patients. Haemoconcentration was defined as an increase in at least three of four of the haemoconcentration-defining parameters above admission values at any time during the hospitalization. Patients were divided into early (Day 1-4) and late haemoconcentration (>Day 4). Ninety-day mortality was the primary endpoint. Haemoconcentration occurred in 392 (38.5%) patients, with a similar incidence of the early (44.6%) and late (55.4%) phenotype. Signs of decongestion (reduction in BNP blood concentrations, P = 0.003; weight loss, P = 0.002) were significantly more pronounced in haemoconcentration patients. WRF was more common in haemoconcentration patients (P = 0.04). After adjustment for established risk factors for AHF mortality, including WRF and HF therapy at discharge, haemoconcentration was significantly associated with a reduction in 90-day mortality [hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.37-0.95, P = 0.01]. The beneficial effect of haemoconcentration seemed to be exclusive for late haemoconcentration (late vs. early: adjusted HR 0.41, 95% CI 0.19-0.90, P = 0.03) and persisted in patients with or without WRF. CONCLUSIONS: Haemoconcentration represents an inexpensive and easily assessable pathophysiological signal of adequate decongestion in AHF and is associated with lower mortality. WRF in the setting of haemoconcentration does not appear to offset the benefits of haemoconcentration.

Safety and efficacy of the 0 h/3 h protocol for rapid rule out of myocardial infarction.

BACKGROUND: The early and accurate diagnosis of acute myocardial infarction (AMI) is an important medical and economic challenge. We aimed to prospectively evaluate the performance of the new European Society of Cardiology rapid 0-hour/3-hour (0 h/3 h) rule out protocol for AMI. METHODS: We enrolled 2,727 consecutive patients presenting with suspected AMI without persistent ST-segment elevation to the emergency department in a prospective international multicenter study. The final diagnosis was adjudicated by 2 independent cardiologists. The performance of the 0 h/3 h rule out protocol was evaluated using 4 high-sensitivity (primary analysis) and 3 sensitive cardiac troponin (cTn) assays. RESULTS: Acute myocardial infarction was the final diagnosis in 473 patients (17.3%). Using the 4 high-sensitivity cTn assays, the 0-hour rule out protocol correctly ruled out 99.8% (95% [confidence interval] CI, 98.7%-100%), 99.6% (95% CI, 98.5%-99.9%), 100% (95% CI, 97.9%-100%), and 100% (95% CI, 98.0%-100%) of late presenters (>6 h from chest pain onset). The 3-hour rule out protocol correctly ruled out 99.9% (95% CI, 99.1%-100%), 99.5% (95% CI, 98.3%-99.9%), 100% (95% CI, 98.1%-100%), and 100% (95% CI, 98.2%-100%) of early presenters (<6 h from chest pain onset). Using the 3 sensitive cTn assays, the 0-hour rule out protocol correctly ruled out 99.6% (95% CI, 98.6%-99.9%), 99.0% (95% CI, 96.9%-99.7%), and 99.1% (95% CI, 97.2%-99.8%) of late presenters; and the 3-hour rule out protocol correctly ruled out 99.4% (95% CI, 98.3%-99.8%), 99.2% (95% CI, 97.3%-99.8%), and 99.0% (95% CI, 97.2%-99.7%) of early presenters. Overall, the 0 h/3 h rule out protocol assigned 40% to 60% of patients to rule out. None of the patients assigned rule out died during 3-months follow-up. CONCLUSIONS: The 0 h/3 h rule out protocol seems to allow the accurate rule out of AMI using both high-sensitivity and sensitive cTn measurements in conjunction with clinical assessment. Additional studies are warranted for external validation.

Diurnal Rhythm of Cardiac Troponin: Consequences for the Diagnosis of Acute Myocardial Infarction.

BACKGROUND: Interpretation of serial high-sensitivity cardiac troponin (hs-cTn) measurements for the diagnosis of acute myocardial infarction (AMI) assumes random fluctuation of hs-cTn around an individual's homeostatic set point. The aim of this study was to challenge this diagnostic concept. METHODS: Study 1 examined the presence of a diurnal hs-cTn rhythm by hourly blood sampling, day and night, in 24 individuals without a recent history of AMI. Study 2 assessed morning vs evening diagnostic accuracy of hs-cTnT and hs-cTnI in a prospective multicenter diagnostic study of 2782 unselected patients, presenting to the emergency department with acute chest pain. RESULTS: In study 1, hs-cTnT, but not hs-cTnI, exhibited a diurnal rhythm, characterized by gradually decreasing concentrations throughout daytime, rising concentrations during nighttime, to peak concentrations in the morning (mean 16.2 ng/L at 8:30 AM and 12.1 ng/L at 7:30 PM). In study 2, the hs-cTnT rhythm was confirmed by higher hs-cTnT concentrations in early-morning presenters compared to evening presenters with an adjudicated diagnosis of noncardiac disease. The diagnostic accuracy [area under the receiver-operation characteristics curve (AUC)] of hs-cTnT at presentation, 1 h, and for the combination of absolute changes with presenting concentration, were very high and comparable among patients presenting early morning as compared to evening (all AUC >0.93). hs-cTnI exhibited no diurnal rhythm with no differences in AUC among early-morning and evening presenters. CONCLUSIONS: Rhythmic diurnal variation of hs-cTnT is a general phenomenon that is not seen with hs-cTnI. While the diurnal hs-cTnT rhythm does not seem to affect the diagnostic accuracy of hs-cTnT for AMI, it should be considered when using hs-cTnT for screening purposes. CLINICAL TRIAL REGISTRATION: 1. Circadian Variation of Cardiac Troponin, NCT02091427, www.clinicaltrials.gov/ct2/show/NCT02091427. 2. Advantageous Predictors of Acute Coronary Syndrome Evaluation (APACE) Study, NCT00470587, www.clinicaltrials.gov/ct2/show/NCT00470587.

Clinical Effect of Sex-Specific Cutoff Values of High-Sensitivity Cardiac Troponin T in Suspected Myocardial Infarction.

Importance: It is currently unknown whether the uniform (universal clinical practice for more than 2 decades) or 2 sex-specific cutoff levels are preferable when using high-sensitivity cardiac troponin T (hs-cTnT) levels in the diagnosis of acute myocardial infarction (AMI). Objective: To improve the management of suspected AMI in women by exploring sex-specific vs uniform cutoff levels for hs-cTnT. Design, Setting, and Participants: In an ongoing prospective, diagnostic, multicenter study conducted at 9 emergency departments, the present study evaluated patients enrolled from April 21, 2006, through June 5, 2013. The participants included 2734 adults presenting with suspected AMI. Duration of follow-up was 2 years, and data analysis occurred from June 5 to December 21, 2015. Interventions: The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including measurements of serial hs-cTnT blood concentrations twice: once using the uniform 99th percentile cutoff value level of 14 ng/L and once using sex-specific 99th percentile levels of hs-cTnT (women, 9 ng/L; men, 15.5 ng/L). Main Outcomes and Measures: Diagnostic reclassification in women and men using sex-specific vs the uniform cutoff level in the diagnosis of AMI. Results: Of the 2734 participants, 876 women (32%) and 1858 men (68%) were included. Median (interquartile range) age was 68 (55-77) and 59 (48-71) years, respectively. With the use of the uniform cutoff value, 127 women (14.5%) and 345 men (18.6%) received a final diagnosis of AMI. Among these, at emergency department presentation, levels of hs-cTnT were already above the uniform cutoff value in 427 patients (sensitivity, 91.3% [95% CI, 85%-95.6%] in women vs 90.7% [95% CI, 87.1%-93.5% in men]; specificity, 79.2% [95% CI, 76.1%-82.1%] in women vs 78.5% [95% CI, 76.4%-80.6%] in men). After readjudication using sex-specific 99th percentile levels, diagnostic reclassification regarding AMI occurred in only 3 patients: 0.11% (95% CI, 0.02-0.32) of all patients and 0.6% (95% CI, 0.13-1.85) of patients with AMI. The diagnosis in 2 women was upgraded from unstable angina to AMI, and the diagnosis in 1 man was downgraded from AMI to unstable angina. These diagnostic results were confirmed when using 2 alternative pairs of uniform and sex-specific cutoff values. Conclusions and Relevance: The uniform 99th percentile should remain the standard of care when using hs-cTnT levels for the diagnosis of AMI.

Clinical impact of the 2010-2012 low-end shift of high-sensitivity cardiac troponin T.

BACKGROUND: The clinical implications of the 2010-2012 low-end shift of high-sensitivity cardiac troponin T (hs-cTnT) regarding possible misdiagnosis of acute myocardial infarction are largely unknown. METHODS: We aimed to quantify the impact of the 2010-2012 low-end shift and adjustment issue in 857 patients presenting to the emergency department with suspected acute myocardial infarction by comparing measurements performed with affected 2010-2012 lots with recalculated 2010-2012 values using a linear regression formula (provided by the manufacturer) and the corrected assay (re-measured in 2013). The final diagnosis was adjudicated by two independent cardiologists using all information including coronary angiography, echocardiography and serial hs-cTnT levels (with the corrected 2013 assay). RESULTS: Acute myocardial infarction was the adjudicated diagnosis in 195 patients (22.7%). Median hs-TnT values were 8.5 ng/l for affected lots, 11.1 ng/l with recalculated and 10 ng/l with the corrected assay (P<0.001 for all comparisons). Spearman correlation coefficient was 0.937 (<0.001) for correct and affected respective correct and recalculated values. The Cusum test indicated significant deviation from linearity (P<0.01) for both correlations. Deviations nearly exclusively affected hs-cTnT levels below the 99th percentile (14 ng/L). Among the 195 patients with an adjudicated diagnosis of acute myocardial infarction, no patient was misclassified using affected lots if using conventional serial sampling. In contrast, misdiagnosis of acute myocardial infarction was significantly increased by affected lots if applying the novel ESC 0 h/1 h algorithm for the early rule-out of acute myocardial infarction (negative predictive value with affected lots 97.7% versus 99.7% with corrected lots). CONCLUSION: The 2010-2012 hs-cTnT low-end shift affected nearly exclusively levels below the 99th percentile cut-off. While it did not affect the diagnosis of acute myocardial infarction when using conventional serial sampling as done in 2010-2012, it would impact on new early rule-out strategies using very low levels of hs-cTnT such as the ESC 0 h/1 h algorithm. CLINICAL TRIALS REGISTRATION: NCT0047058, NCT00470587.

Incremental value of copeptin in suspected acute myocardial infarction very early after symptom onset.

BACKGROUND: Patients presenting very early after chest pain onset may provide a diagnostic challenge even when using a high-sensitivity cardiac troponin (hs-cTnT). We hypothesized that in these patients the incremental value of copeptin in the early diagnosis of acute myocardial infarction (AMI) may be substantial. METHODS: We aimed to investigate the incremental value of copeptin in a pre-specified subgroup analysis of patients presenting with suspected AMI to the emergency department within 2 hours of symptom onset in a multicenter study. Copeptin was measured in a blinded fashion. Two independent cardiologists adjudicated the final diagnosis using all available clinical informations, including high-sensitivity cardiac troponin T (hs-cTnT). RESULTS: Overall, 2000 patients were enrolled, of whom 519 (26%) arrived within 2 hours of symptom onset. Of these, 102 patients (20%) had an AMI. The additional use of copeptin did not increase diagnostic accuracy as quantified by the area under the receiver-operating characteristic curve (AUC) of hs-cTnT (0.87 (95% confidence interval (CI): 0.83-0.90) for hs-cTnT alone to 0.86 (95% CI: 0.82-0.90) for the combination; p = NS). Copeptin (using 9 pmol/L as a cut-off) increased the negative predictive value (NPV) of hs-cTnT (using 14 ng/L as a cut-off) alone from 93% (95% CI: 90-95%) to 96% (95% CI: 93-98%). The NPV for the combination of hs-cTnT and copeptin was lower in patients arriving in the first 2 hours than in those arriving after 2 hours: 96% (95% CI: 93-98%) versus 99% (95% CI: 99-100%), respectively. CONCLUSIONS: The additional use of copeptin on top of hs-cTnT seems to lead to a small increase in NPV, but no increase in AUC. Routine use of copeptin in early presenters does not seem warranted.

Clinical benefit of high-sensitivity cardiac troponin I in the detection of exercise-induced myocardial ischemia.

BACKGROUND: A pilot study using a novel high-sensitivity cardiac troponin I (hs-cTnI) assay suggested that cTnI might be released into blood during exercise-induced myocardial ischemia. We investigated the potential clinical value of this signal. METHODS: We included 819 patients with suspected exercise-induced myocardial ischemia referred for rest/bicycle myocardial perfusion single-photon emission computed tomography. The treating cardiologist used all available clinical information to quantify clinical judgment regarding the presence of myocardial ischemia using a visual analog scale twice: prior and after stress testing. High-sensitivity cTnI measurements were obtained before, immediately after peak stress, and 2 hours after stress testing in a blinded manner. Myocardial ischemia was adjudicated using perfusion single-photon emission computed tomography and coronary angiography findings. RESULTS: Exercise-induced myocardial ischemia was detected in 278 (34%) patients. High-sensitivity cTnI levels were significantly higher at all time points in patients with myocardial ischemia as compared with those without (P < .001 for all). Combining clinical judgment prior exercise testing with baseline hs-cTnI levels increased diagnostic accuracy as quantified by the area under the receiver operating characteristics curve (AUC) from 0.672 to 0.757 (P < .001). Combining clinical judgment after exercise testing (AUC 0.704) with baseline or poststress hs-cTnI levels also increased the diagnostic accuracy (AUC 0.761-0.771, P < .001 for all). In contrast, exercise-induced changes in hs-cTnI during exercise did not seem useful, as they were small and similar in patients with or without myocardial ischemia. CONCLUSIONS: High-sensitivity cTnI concentrations at rest and after exercise, but not its exercise-induced changes, provide substantial incremental value to clinical judgment including exercise electrocardiography regarding the presence of myocardial ischemia.

Incidence and Predictors of Cardiomyocyte Injury in Elective Coronary Angiography.

OBJECTIVE: Coronary angiography is considered to be a safe tool for the evaluation of coronary artery disease and performed in approximately 12 million patients each year worldwide. The aim of our study was to investigate the frequency and predictors of cardiomyocyte injury in patients undergoing elective coronary angiography. METHODS: A total of 749 consecutive patients who were scheduled to undergo elective coronary angiography were prospectively analyzed. High-sensitivity cardiac troponin T concentrations were measured both before and after elective coronary angiography (without intervention). Acute cardiomyocyte injury was predefined as an absolute increase in high-sensitivity cardiac troponin T of at least 7 ng/L (if also fulfilling a relative change of >20%). RESULTS: Acute cardiomyocyte injury was observed in 101 patients (13.5%, 95% confidence interval [CI], 11.1-16.2). It was independently associated with aortic valve stenosis (odds ratio [OR], 5.4; 95% CI, 3.0-9.8; P <.001), age (OR, 1.05; 95% CI, 1.02-1.08; P <.001), female sex (OR, 3.5; 95% CI, 1.8-6.8; P <.001), contrast volume (OR, 1.006; 95% CI, 1.001-1.012; P = .019 per 10 mL of contrast volume), documented cardiomyopathy (OR, 2.5; 95% CI, 1.0-6.0; P = .045), and mitral regurgitation (OR, 2.3; CI, 1.0-4.9; P = .033). In contrast, operator experience and extent of coronary artery disease were not found to be associated with acute cardiomyocyte injury. CONCLUSIONS: Cardiomyocyte injury accompanies elective coronary angiography in 1 of 8 patients. Sex, age, contrast agent volume, and ventricular disease, rather than the extent of coronary artery disease, independently predict cardiomyocyte injury. Further research aiming to reduce the incidence of cardiomyocyte injury seems warranted.

Characterization of the observe zone of the ESC 2015 high-sensitivity cardiac troponin 0h/1h-algorithm for the early diagnosis of acute myocardial infarction.

OBJECTIVE: The novel high-sensitivity cardiac troponin (hs-cTn) 0h/1h-algorithm substantially improves the early triage of patient's assigned "rule-out" or "rule-in" of acute myocardial infarction (AMI), while diagnostic uncertainty remains in that 25-30% of patients assigned to "observe". We aimed to better characterize these patients. METHODS: In a prospective multicenter diagnostic study, we applied the hs-cTnT 0h/1h-algorithm in 2213 unselected patients presenting with symptoms suggestive of AMI to the emergency department. The final diagnosis was adjudicated by two independent cardiologists using all available information. Survival at 720-days was the prognostic endpoint. Findings were validated using a hs-cTnI 0h/1h-algorithm. RESULTS: Twenty-four percent (n=523) of patients were assigned to "observe" by the hs-cTnT 0h/1h-algorithm. These patients differed significantly in multiple characteristics from "rule-out" and "rule-in" patients: they were older, in 75% male, and very often (57%) had pre-existing coronary artery disease (CAD). Diagnostic uncertainty for the presence of an AMI/UA was high. Only 39% of patients were suitable for coronary computed tomography angiography (CCTA). The most common final adjudicated diagnoses were non-cardiac disease (38%), non-coronary cardiac disease (24%), unstable angina (UA, 21%), and AMI (15%). Absolute hs-cTnT-changes within 3h had the highest diagnostic accuracy for AMI (AUC 0.86). Cumulative 720-day survival rate was 86%, which was significantly lower as compared to "rule-out" (p<0.001) and comparable to "rule-in" (p=ns). Findings were similar for the hs-cTnI "observe" zone. CONCLUSION: "Observe" patients are typically elderly men with pre-existing CAD and high long-term mortality. Absolute hs-cTn-changes within 3h, functional stress imaging and coronary angiography are the key diagnostic modalities.