External validation of the 0/1h-algorithm and derivation of a 0/2h-algorithm using a new point-of-care Hs-cTnI assay.

BACKGROUND: The high-sensitivity cardiac troponin (hs-cTn) I point-of-care (POC) hs-cTnI-PATHFAST assay has recently become clinically available. METHODS: We aimed to externally validate the hs-cTnI-PATHFAST 0/1h-algorithm recently developed for the early diagnosis of non-ST-segment-elevation myocardial infarction (NSTEMI) and derive and validate a 0/2-algorithm in patients presenting to the emergency department with acute chest discomfort included in a multicenter diagnostic study. Two independent cardiologists centrally adjudicated the final diagnoses using all the clinical and study-specific information available including serial measurements of hs-cTnI-Architect. RESULTS: Among 1,532 patients (median age 60 years, 33% [n = 501] women), NSTEMI was the final diagnosis in 13%. External validation of the hs-cTnI-PATHFAST 0/1h-algorithm showed very high negative predictive value (NPV; 100% [95%CI, 99.5%-100%]) and sensitivity 100% (95%CI, 98.2%-100%) for rule-out of NSTEMI. Positive predictive value (PPV) and specificity for rule-in of NSTEMI were high (74.9% [95%CI, 68.3%-80.5%] and 96.4% [95%CI, 95.2%-97.3%], respectively). Among 1,207 patients (median age 61 years, 32% [n = 391] women) available for the derivation (n = 848) and validation (n = 359) of the hs-cTnI-PATHFAST 0/2h-algorithm, a 0h-concentration <3 ng/L or a 0h-concentration <4 ng/L with a 2h-delta <4ng/L ruled-out NSTEMI in 52% of patients with a NPV of 100% (95%CI, 98-100) and sensitivity of 100% (95%CI, 92.9%-100%) in the validation cohort. A 0h-concentration ≥90ng/L or a 2h-delta ≥ 55ng/L ruled-in 38 patients (11%): PPV 81.6% (95%CI, 66.6-90.8), specificity 97.7% (95%CI, 95.4-98.9%). CONCLUSIONS: The POC hs-cTnI-PATHFAST assay allows rapid and effective rule-out and rule-in of NSTEMI using both a 0/1h- and a 0/2h-algorithm with high NPV/sensitivity for rule-out and high PPV/specificity for rule-in. CLINICAL TRIAL REGISTRATION: NCT00470587.

Chest Pain in Cancer Patients: Prevalence of Myocardial Infarction and Performance of High-Sensitivity Cardiac Troponins.

Background: Little is known about patients with cancer presenting with acute chest discomfort to the emergency department (ED). Objectives: The aim of this study was to assess the prevalence of acute myocardial infarction (AMI), outcomes, and the diagnostic utility of recommended diagnostic tools in this population. Methods: Patients presenting with chest pain to the ED were prospectively enrolled in an international multicenter diagnostic study with central adjudication. Cancer status was assessed prospectively and additional cancer details retrospectively. Findings were externally validated in an independent multicenter cohort. Results: Among 8,267 patients, 711 (8.6%) had cancer. Patients with cancer had a higher burden of cardiovascular risk factors and pre-existing cardiac disease. Total length of stay in the ED (5.2 hours vs 4.3 hours) and hospitalization rate (49.8% vs 34.3%) were both increased in patients with cancer (P < 0.001 for both). Among 8,093 patients eligible for the AMI analyses, those with cancer more often had final diagnoses of AMI (184 of 686 with cancer [26.8%] vs 1,561 of 7,407 without cancer [21.1%]; P < 0.001). In patients with cancer, high-sensitivity cardiac troponin T (hs-cTnT) but not high sensitivity cardiac troponin I (hs-cTnI) concentration had lower diagnostic accuracy for non-ST-segment elevation myocardial infarction (for hs-cTnT, area under the curve: 0.89 [95% CI: 0.86-0.92] vs 0.94 [95% CI: 0.93-0.94] [P < 0.001]; for hs-cTnI, area under the curve: 0.93 [95% CI: 0.91-0.95] vs 0.95 [95% CI: 0.94-0.95] [P = 0.10]). In patients with cancer, the European Society of Cardiology 0/1-hour hs-cTnT and hs-cTnI algorithms maintained very high safety but had lower efficacy, with twice the number of patients remaining in the observe zone. Similar findings were obtained in the external validation cohort. Conclusions: Patients with cancer have a substantially higher prevalence of AMI as the cause of chest pain. Length of ED stay and hospitalization rates are increased. The diagnostic performance of hs-cTnT and the efficacy of both the European Society of Cardiology 0/1-hour hs-cTnT and hs-cTnI algorithms is reduced. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] Study; NCT00470587).