Combination Algorithm for Fast Rule-Out and Rule-In of MACE

Study Questions:

What is the diagnostic accuracy of the 1-hour algorithm based on high-sensitivity cardiac troponin T (hs-cTnT) testing at presentation and again 1 hour thereafter, supplemented with patient history and an electrocardiogram (ECG) for predicting 30-day major adverse cardiac events (MACE) compared with the algorithm using hs-cTnT alone?

Methods:

This prospective observational study enrolled consecutive patients presenting to the emergency department (ED) with chest pain, for whom hs-cTnT was ordered at presentation. Hs-cTnT at 1 hour and the ED physician’s assessments of patient history and ECG were collected. The primary outcome was an adjudicated diagnosis of 30-day MACE defined as acute myocardial infarction (AMI), unstable angina, cardiogenic shock, ventricular arrhythmia, atrioventricular block, cardiac arrest, or death of a cardiac or unknown cause. The investigators assessed the diagnostic accuracy of the 1-hour algorithm based on hs-cTnT testing at presentation and again 1 hour thereafter supplemented with patient history and an ECG (the extended algorithm) for predicting 30-day MACE compared with the algorithm using hs-cTnT alone (the troponin algorithm). Sensitivity, specificity, positive and negative predictive value (PPV and NPV), and likelihood ratios (LRs) were calculated for the algorithms.

Results:

In the final analysis, 1,038 patients were included. The extended algorithm identified 60% of all patients for rule-out and had a higher sensitivity than the troponin algorithm (97.5% vs. 87.6%; p < 0.001). The NPV was 99.5% and LR was 0.04 with the extended algorithm versus 97.8% and 0.17, respectively, with the troponin algorithm. The extended algorithm ruled in 14% of patients with a higher sensitivity (75.2% vs. 56.2%; p < 0.001), but a slightly lower specificity (94.0% vs. 96.4%; p < 0.001) than the troponin algorithm. The rule-in arms of both algorithms had an LR >10.

Conclusions:

The authors concluded that a 1-hour combination algorithm allowed fast rule-out and rule-in of 30-day MACE in a majority of ED chest pain patients, and performed better than the troponin-alone algorithm.

Perspective:

This study reports that a 1-hour combination algorithm incorporating patient history and an ECG allowed fast rule-out and rule-in of 30-day MACE in a majority of ED chest pain patients, and performed better than the 1-hour algorithm based on hs-cTnT alone. Additional prospective, larger, multicenter studies are indicated to assess the incremental performance of this extended algorithm as compared to the troponin-alone algorithm in a wide variety of care settings.

Keywords: Acute Coronary Syndrome, Algorithms, Angina, Unstable, Arrhythmias, Cardiac, Atrioventricular Block, Chest Pain, Electrocardiography, Emergency Service, Hospital, Heart Arrest, Heart Conduction System, Shock, Cardiogenic, Troponin, Troponin T


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