Direct Comparison of the European Society of Cardiology 0/1-Hour Vs. 0/2-Hour Algorithms in Patients with Acute Chest Pain.

BACKGROUND: The recent guidelines from the European Society of Cardiology recommends using high-sensitivity cardiac troponin (hs-cTn) in either 0/1-h or 0/2-h algorithms to identify or rule out acute myocardial infarction (AMI). Several studies have reported good diagnostic accuracy with both algorithms, but few have compared the algorithms directly. OBJECTIVE: We aimed to compare the diagnostic accuracy of the algorithms head-to-head, in the same patients. METHODS: This was a secondary analysis of data from a prospective observational study; 1167 consecutive patients presenting with chest pain to the emergency department at Skåne University Hospital (Lund, Sweden) were enrolled. Only patients with a hs-cTnT sample at presentation AND after 1 AND 2 h were included in the analysis. We compared sensitivity, specificity, and negative (NPV) and positive predictive value (PPV). The primary outcome was index visit AMI. RESULTS: A total of 710 patients were included, of whom 56 (7.9%) had AMI. Both algorithms had a sensitivity of 98.2% and an NPV of 99.8% for ruling out AMI, but the 0/2-h algorithm ruled out significantly more patients (69.3% vs. 66.2%, p < 0.001). For rule-in, the 0/2-h algorithm had higher PPV (73.4% vs. 65.2%) and slightly better specificity (97.4% vs. 96.3%, p = 0.016) than the 0/1-h algorithm. CONCLUSION: Both algorithms had good diagnostic accuracy, with a slight advantage for the 0/2-h algorithm. Which algorithm to implement may thus depend on practical issues such as the ability to exploit the theoretical time saved with the 0/1-h algorithm. Further studies comparing the algorithms in combination with electrocardiography, history, or risk scores are needed.

Cardiac Troponin Assays With Improved Analytical Quality: A Trade-Off Between Enhanced Diagnostic Performance and Reduced Long-Term Prognostic Value.

Background Cardiac troponin (cTn) permits early rule-out/rule-in of patients admitted with possible non-ST-segment-elevation myocardial infarction. In this study, we developed an admission and a 0/1 hour rule-out/rule-in algorithm for a troponin assay with measurable results in >99% of healthy individuals. We then compared its diagnostic and long-term prognostic properties with other protocols. Methods and Results Blood samples were collected at 0, 1, 3, and 8 to 12 hours from patients admitted with possible non-ST-segment-elevation myocardial infarction. cTnT (Roche Diagnostics), cTnI(Abbott) (Abbott Diagnostics), and cTnI(sgx) (Singulex Clarity System) were measured in 971 admission and 465 1-hour samples. An admission and a 0/1 hour rule-out/rule-in algorithm were developed for the cTnI(sgx) assay and its diagnostic properties were compared with cTnTESC (European Society of Cardiology), cTnI(Abbott)ESC, and 2 earlier cTnI(sgx) algorithms. The prognostic composite end point was all-cause mortality and future nonfatal myocardial infarction during a median follow-up of 723 days. non-ST-segment-elevation myocardial infarction prevalence was 13%. The novel cTnI(sgx) algorithms showed similar performance regardless of time from symptom onset, and area under the curve was significantly better than comparators. The cTnI(sgx)0/1 hour algorithm classified 92% of patients to rule-in or rule-out compared with ≤78% of comparators. Patients allocated to rule-out by the prior published 0/1 hour algorithms had significantly fewer long-term events compared with the rule-in and observation groups. The novel cTnI(sgx)0/1 hour algorithm used a higher troponin baseline concentration for rule-out and did not allow for prognostication. Conclusions Increasingly sensitive troponin assays may improve identification of non-ST-segment-elevation myocardial infarction but could rule-out patients with subclinical chronic myocardial injury. Separate protocols for diagnosis and risk prediction seem appropriate.

The HEART score in the era of the European Society of Cardiology 0/1-hour algorithm.

BACKGROUND: The European Society of Cardiology's 0/1-hour algorithm improves the early triage of patients towards "rule-out" or "rule-in" of non-ST-segment elevation myocardial infarction. The HEART score is a risk stratification tool for patients with undifferentiated chest pain. We sought to evaluate the performance of the European Society of Cardiology 0/1-hour algorithm and the HEART score to evaluate chest pain patients in the emergency department. METHODS: In this prospective study, we applied the European Society of Cardiology 0/1-hour algorithm and the HEART score in 1355 consecutive patients who presented to the emergency department with symptoms suggestive of acute coronary syndrome without ST-segment elevation. Patients were followed for non-ST-segment elevation myocardial infarctions and major adverse cardiac events at 30 days: death, non-ST-segment elevation myocardial infarction, or unplanned coronary revascularization. RESULTS: The European Society of Cardiology 0/1-hour algorithm classified 921 (68.0%) patients as "rule-out" and the HEART score classified 686 (50.6%) patients as "low-risk". The 30-day incidence of non-ST-segment elevation myocardial infarctions was 0.32% in the European Society of Cardiology 0/1-hour algorithm "rule-out" patients versus 0.29% in the HEART score "low-risk" patients (p=0.75). The rate of major adverse cardiac events was 7.7% in the European Society of Cardiology 0/1-hour algorithm "rule-out" patients versus 1.1% in the HEART score "low-risk" patients (p<0.001). CONCLUSION: The European Society of Cardiology 0/1-hour algorithm identified more patients with low risk of non-ST-segment elevation myocardial infarctions at 30 days whereas for major adverse cardiac events, the HEART score had a greater capacity to detect low-risk patients.

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.