October 1, 2000Open Access

Clinical Evaluation of the First Medical Whole Blood, Point-of-Care Testing Device for Detection of Myocardial Infarction

Q: What is the clinical evidence from this study?

Study design: Observational. Population: myocardial infarction (n=369). Intervention: First Medical Cardiac Test device vs. modified WHO criteria. Primary outcome: sensitivity for detection of MI based on peak concentrations within 24 h.

Key Result

The First Medical point-of-care device detected myocardial infarction with peak sensitivities of 93% for cardiac troponin I and 90% for CKMB within 24 hours of presentation.

Study Design

Type

Observational (n=369)

PICO

Population

369 patients presenting to the emergency department with chest pain evaluated for myocardial infarction over a 6-month period.

Exposure / Comparator

First Medical Cardiac Test device vs modified WHO criteria

Primary Outcome

sensitivity for detection of MI based on peak concentrations within 24 h

Abstract

BACKGROUND: Validation of whole blood, point-of-care testing devices for monitoring cardiac markers to aid clinicians in ruling in and ruling out myocardial infarction (MI) is necessary for both laboratory and clinical acceptance. METHODS: This study evaluated the clinical diagnostic sensitivity and specificity of the First Medical Cardiac Test device operated by nursing and laboratory personnel that simultaneously measures cardiac troponin I (cTnI), creatine kinase (CK) MB, myoglobin, and total CK on the Alpha Dx analyzer in whole blood for detection of MI. Over a 6-month period, 369 patients initially presenting to the emergency department with chest pain were evaluated for MI using modified WHO criteria. Eighty-nine patients (24%) were diagnosed with MI. RESULTS: In whole blood samples collected at admission and at 3- to 6-h intervals over 24 h, ROC curve-determined MI decision limits were as follows: cTnI, 0.4 microgram/L; CKMB, 7.0 microgram/L; myoglobin, 180 microgram/L; total CK, 190 microgram/L. Based on peak concentrations within 24 h after presentation, the following sensitivities (+/- 95% confidence intervals) were found: cTnI, 93% +/- 5.5%; myoglobin, 81% +/- 9.7%; CKMB, 90% +/- 6.3%; total CK, 86% +/- 7.5%. Sensitivities were maximal at >90% for both cTnI and CKMB at >12 h in MI patients, without differences between ST-segment elevation and non-ST-segment elevation MI patients. CONCLUSIONS: The First Medical point-of-care device provides cardiac marker assays that can be used by laboratories and clinicians in a variety of hospital settings for ruling in and ruling out MI.