Clinical Evaluation Versus Undetectable High-Sensitivity Troponin for Assessment of Patients With Acute Chest Pain

Derivation and external validation of machine-learning models for risk stratification in chest pain with normal troponin

AIMS

Risk stratification of patients with chest pain and a high-sensitivity cardiac troponin T (hs-cTnT) concentration

METHODS AND RESULTS

Four machine-learning-based models and one logistic regression (LR) model were trained on 4075 patients (single-centre Spanish cohort) and externally validated on 3609 patients (international prospective Advantageous Predictors of Acute Coronary syndromes Evaluation cohort). Models were compared with GRACE and HEART scores and a single undetectable hs-cTnT-based strategy (u-cTn; hs-cTnT < 5 ng/L and time from symptoms onset >180 min). Probability thresholds for safe discharge were derived in the derivation cohort. The endpoint occurred in 105 (2.6%) patients in the training set and 98 (2.7%) in the external validation set. Gradient boosting full (GBf) showed the best discrimination (area under the curve = 0.808). Calibration was good for the reduced neural network and LR models. Gradient boosting full identified the highest proportion of patients for safe discharge (36.7 vs. 23.4 vs. 27.2%; GBf vs. LR vs. u-cTn, respectively) with similar safety (missed endpoint per 1000 patients: 2.2 vs. 3.5 vs. 3.1, respectively). All derived models were superior to the HEART and GRACE scores (P < 0.001).

CONCLUSION

Machine-learning and LR prediction models were superior to the HEART, GRACE, and u-cTn for risk stratification of patients with chest pain and a baseline hs-cTnT

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00470587, https://clinicaltrials.gov/ct2/show/NCT00470587.

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Key Words

• Machine learning
• Myocardial infarction
• Prediction
• Troponin

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MESH Headings

• Humans
• Troponin
• Prospective Studies
• Biomarkers
• Troponin T
• Chest Pain/diagnosis
• Chest Pain/etiology
• Risk Assessment

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Grants

• Swiss National Science Foundation

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Affiliation(s)

Agustín Fernández-Cisnal Cardiology Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), University of València, Centro de Investigación Biomédica en Red Enfermedades Cardiovaculares (CIBERCV), València, Spain
Pedro Lopez-Ayala Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Heart Center Basel, University Hospital Basel, University of Basel, Basel, Switzerland
Ernesto Valero Cardiology Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), University of València, Centro de Investigación Biomédica en Red Enfermedades Cardiovaculares (CIBERCV), València, Spain
Luca Koechlin Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Heart Center Basel, University Hospital Basel, University of Basel, Basel, Switzerland
Arturo Catarralá Clinical Biochemistry Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), València 46010, Spain
Jasper Boeddinghaus Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Heart Center Basel, University Hospital Basel, University of Basel, Basel, Switzerland
José Noceda Emergency Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), València 46010, Spain
Thomas Nestelberger Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Heart Center Basel, University Hospital Basel, University of Basel, Basel, Switzerland
Òscar Miró Emergency Department, Hospital Clinic, Barcelona, Catalonia, Spain
Núñez Julio Cardiology Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), University of València, Centro de Investigación Biomédica en Red Enfermedades Cardiovaculares (CIBERCV), València, Spain
Christian Mueller Cardiovascular Research Institute Basel (CRIB) and Department of Cardiology, University Heart Center Basel, University Hospital Basel, University of Basel, Basel, Switzerland
Juan Sanchis Cardiology Department, Hospital Clínico Universitario de València, Instituto de Investigación Sanitaria (INCLIVA), University of València, Centro de Investigación Biomédica en Red Enfermedades Cardiovaculares (CIBERCV), València, Spain

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Undetectable high-sensitivity troponin in combination with clinical assessment for risk stratification of patients with chest pain and normal troponin at hospital arrival

BACKGROUND

Undetectable high-sensitivity cardiac troponin (hs-cTn) in a single determination upon admission may rule out acute coronary syndrome. We investigated undetectable hs-cTnT (<detection limit; <5 ng/l) together with clinical risk scores (GRACE, TIMI, HEART and a previously published simple score), for one-year outcomes in patients with chest pain and normal hs-cTnT (<99th percentile; <14 ng/l) upon admission.

METHODS

This study was a retrospective design involving 2254 consecutive patients (July 2016-November 2017). The primary endpoint was one-year death or acute myocardial infarction; the secondary endpoint added unstable angina requiring revascularization. Early (<90 minutes since pain onset, n = 661) and late (n = 1593) presenters were separately considered.

RESULTS

A total of 56 (2.5%) patients reached the primary endpoint and 91 (4%) the secondary endpoint. Undetectable hs-cTnT had a poor C-statistic in early and late presenters (0.648 and 0.703, respectively). Adding hs-cTnT measurable concentrations above the detection limit (as continuous variable) significantly enhanced the C-statistics (0.754 and 0.847, respectively). Addition of the HEART (0.809, p = 0.005) or simple clinical scores (0.804, p = 0.02) further improved the model and significantly reclassified patient risk, in early presenters. The results were similar for the secondary endpoint. The TIMI risk score performed worse and the GRACE score did not give additional information. In late presenters, no clinical score provided significant additional information over hs-cTnT.

CONCLUSIONS

Diagnostic algorithms should consider not only whether hs-cTnT is above or below the detection limit but also its concentration if above, for risk stratification over one year in patients with initial normal hs-cTnT. The clinical scores provide valuable additional information in early presenters.

Rapid rule out for suspected myocardial infarction: is the algorithm appropriate for all?

Aims

Patients presenting to the emergency department (ED) with cardiac chest pain and high-sensitive troponin I (HsTnI) less than 5 ng/L have very good prognosis and low risk for major adverse cardiovascular events. The 2015 European Society of Cardiology (ESC) guidelines for non-ST-elevation myocardial infarction (MI)/acute coronary syndrome (ACS) suggests that patients with normal high-sensitive troponin, which are free of chest pain and have a global registry of acute coronary events (GRACE) score less than 140 are eligible for discharge from the hospital for outpatient workup. Our hypothesis suggests that not all patients with GRACE score under 140 should be discharged for ambulatory tests even with undetectable HsTnI as recommended in the guidelines.

Methods and results

Population-based retrospective cohort study in a large tertiary care centre. The study population included all patients discharged from the hospital between 1 February 2016 and 28 February 2019 following rule out of MI. During the study period, a total of 13 800 patients were discharged from the hospital after rule out of MI. Among them, 9236 (67%) had HsTnI below 5 ng/L. A total of 7705 patients (83%) met the criteria for low (n = 7162) or moderate (n = 543) GRACE risk score. Moderate-risk patients had significantly more adverse events than low-risk patients (4.6% vs. 2.1%, P &lt; 0.001). They are in higher risk of death (0.5% vs. 0.1%, P = 0.042), revascularization (3.9% vs. 1.8%, P = 0.0047), and readmission due to ACS (1.1% vs. 0.4%, P = 0.031).

Conclusion

Patients presenting to the ED with chest pain and HsTnI less than 5 ng/L and GRACE score under 140 have 2–4% adverse event in 60 days. The differences between the groups suggest using rapid rule out algorithms for only low-risk patients with GRACE score under 73.

Rapid rule-out of suspected acute coronary syndrome in the Emergency Department by high-sensitivity cardiac troponin T levels at presentation

The reliability of initial high-sensitivity cardiac troponin T (hs-cTnT) under limit-of-detection in ruling-out short- and long-term acute coronary events in subjects for suspected non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is not definitely settled. In a retrospective chart review analysis, 1001 subjects with hs-cTnT ≤ 14 ng/L out of 4053 subjects with hs-cTnT measured at Emergency Department (ED) presentation were recruited. The main outcome measure is fatal or non-fatal myocardial infarction (MI) within 30 days; secondary outcomes are MI or major acute coronary events (MACE) as a combination of MI or re-hospitalization for unstable angina within 1 year. In subjects with hs-cTnT < 5 ng/L [32.6% of cases, mean age 63 years (interquartile range 23)], no cases (0%, NPV 100%) had MI within 30 days, 2 cases (0.6%, NPV 99.4%) MI at 1-year, and 11 cases (3.4%, NPV 96.6%) MACE at 1-year. Patients with hs-cTnT < 5 ng/L would have benefited from a shortened decision (9.30 h and 53% overnight ED stay saved). Hs-cTnT < 5 ng/L is confirmed as safe for patients and comfortable for physicians in ruling out MI or MACE both at short and long term, suggesting that a sizable number of patients can be rapidly discharged without unnecessary diagnostic tests and ED observation.

Characteristics and Outcomes of Patients Hospitalized With Suspected Acute Coronary Syndrome in Whom the Diagnosis is not Confirmed

Patients admitted with suspected acute coronary syndrome (ACS) in whom the diagnosis is not confirmed are poorly characterized. In a contemporary registry of consecutive patients hospitalized with suspected ACS as the primary diagnosis, we assessed characteristics on admission and in-hospital and 6-month mortality of patients discharged with other diagnoses and compared this subgroup with true ACS patients. Of 2557 patients included, 9.0% were discharged with a non-ACS diagnosis such as nonspecific chest pain, myopericarditis, stress cardiomyopathy, hemodynamic disturbances, heart failure, myocardial, pulmonary or valvular disease, or others. Compared with true ACS patients, those with other diagnoses were younger, more often female, and had less cardiovascular risk factors. Both groups had comparable rates of nonchest pain presentation and similar hemodynamic characteristics on admission. Non-ACS patients presented less often with Q waves or with ST-segment or T-wave changes and had a lower Global Registry of Acute Coronary Events score than true ACS patients. In-hospital (4.3 vs 4.0%, respectively, p = 0.834) and 6-month (5.4 vs 8.0%, respectively, p = 0.163) mortality rates were comparable in both groups. However, if patients in the non-ACS group were divided into subgroups with nonspecific chest pain (6.2% of total) or other diagnoses (2.8% of total), major differences in in-hospital (0.0 vs 13.9%, respectively, p < 0.001) and 6-month (0.7 vs 15.7%, respectively, p < 0.001) mortality rates would become apparent and remain after multivariable adjustment. In conclusion, in a non-negligible proportion of patients hospitalized with suspected ACS, this diagnosis is not confirmed. Prognosis of these patients follows a bimodal pattern, being excellent in those with nonspecific chest pain but worse than that of true ACS patients in the rest. Efforts are necessary to ensure prompt identification and early risk stratification of these patients allowing appropriate management decisions.

N-Terminal Pro B-Type Natriuretic Peptide and High-Sensitivity Cardiac Troponin T Levels Are Related to the Extent of Hibernating Myocardium in Patients With Ischemic Heart Failure

BACKGROUND

Increased N-terminal pro b-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) can identify patients with heart failure (HF) who are at increased risk of cardiac events. The relationship of these biomarkers to the extent of hibernating myocardium and scar has not been previously characterized in patients with ischemic left ventricular dysfunction and HF.

METHODS

Patients with ischemic HF meeting recruitment criteria and undergoing perfusion and fluorodeoxyglucose-positron emission tomography to define myocardial hibernation and scar were included in the study. A total of 39 patients (mean age 67 ± 8 years) with New York Heart Association class II-IV HF and ischemic cardiomyopathy (ejection fraction [EF], 27.9% ± 8.5%) were enrolled in the study.

RESULTS

Serum NT-proBNP and hs-cTnT levels were elevated in patients with ≥ 10% hibernating myocardium compared with those with < 10% (NT-pro-BNP, 7419.10 ± 7169.5 pg/mL vs 2894.6 ± 2967.4 pg/mL; hs-cTnT, 789.3 ± 1835.3 pg/mL vs 44.8 ± 78.9 pg/mL; P < 0.05). The overall receiver operating characteristic under the curve value for NT-proBNP and hs-cTnT to predict hibernating myocardium was 0.76 and 0.78, respectively (P < 0.05). The NT-proBNP (P = 0.02) and hs-cTnT (P < 0.0001) levels also correlated with hibernation, particularly in patients with ≥ 10% scar, independent of EF, age, and estimated glomerular filtration rate. No differences were noted in biomarker levels for patients with vs those without ≥ 10% scar.

CONCLUSIONS

NT-proBNP and hs-cTnT levels are elevated in patients with ischemic HF hibernation and are correlated with the degree of hibernation but not with the presence or extent of scar. Taken together, these data support the novel concept that NT-proBNP and hs-cTnT release in patients with ischemic HF reflects the presence and extent of hibernating myocardium.