Indroduction: As acute chest pain is one of the main reasons for presentation in emergency departments, early identification of patients with potential myocardial infarction (MI) is of crucial importance. Current guidelines recommend application of rapid 0/1h diagnostic algorithms using high-sensitivity cardiac Troponin (hs-cTn) for diagnosis of MI. Several hs-cTn assays have been evaluated and assay specific algorithms have been developed, achieving great diagnostic performance. Yet, for some of these assays, existing data is limited. We aimed to evaluate the diagnostic and prognostic performance of the ESC rapid 0/1h diagnostic algorithm for Beckman Access II hs-TnI in the Biomarkers in Acute Cardiac Care (BACC) study.

Methods: We measured concentrations of Beckman Access II hs-TnI (Beckman Coulter) at presentation and after 1 hour in 1879 patients presenting to the emergency department of the University Hospital Hamburg-Eppendorf with suspected MI. The standard diagnostic assay was Roche Elecsys hs-TnT. Final diagnosis was made independently by two cardiologists, considering all available clinical data. Diagnoses were adjudicated according to 4th Universal Definition of MI. Parameters for diagnostic performance were calculated, applying the ESC 0/1 h algorithm. Rule-out ws defined as baseline hs-TnI <4 pg/mL if chest pain onset was >3h ago or baseline hs-TnI <5 pg/mL and 1h delta <4 pg/mL. Patients were ruled-in if hs-TnI was ≥50 or 1h delta ≥15. Additionally, we performed survival analyses for the all-cause mortality and incident MI, computing Kaplan-Meier-curves and Cox-regression adjusted for common cardiovascular risk factors as well as pre-existing coronary artery disease and congestive heart failure.

Results:  Of all patients included, 257 patients were diagnosed as having NSTEMI. Median age was 63 years, 64.3 % of the population was male. Cardiovascular risk factors were highly prevalent. Beckman hs-TnI provided high sensitivity [97.7 % (95.0, 99.1)] with a corresponding negative predictive value (NPV) of 99.3 (98.4, 99.7) ruling out 44.5 % of patients. Application of the ESC 0/1h algorithm resulted in a specificity of 88.0 % (86.3 %, 89.6 %) and a corresponding positive predictive value (PPV) of 50.8 (45.7, 55.9) diagnosing 20.3 % of patients as having MI (Table 1). Regarding predictive value, patients not ruled-out showed a significantly higher all-cause mortality over three years (p < 0.001) (Figure 1). Adjusted hazard ratios also indicate a significantly worse prognosis for patients ruled-in [4.64 (2.41, 8.95), p <0.001]as well as in the observe group [2.31 (1.20, 4.47), p =0.013].

Conclusion: The ESC 0/1h algorithm for Beckman hs-TnI achieves great diagnostic performance with high sensitivity and specificity for diagnosis of MI as well as good predictive value for all-cause mortality and MI.

Table 1:  Diagnostic perfomance of Beckman hs-TnI applying ESC 0/1h algorithm