Sample comparison with Siemens® point-of-care device for cardiac troponin I assay by using a heparin coated transfer device vs. non-heparin coated transfer device at the emergency department (validation study 2.0).

Point-of-care (POC) troponin testing, defined as laboratory testing near a
patient location with rapid availability of results, has attracted much
interest in the emergency department setting (ED) and seems feasible. These
devices might enable earlier decisions, reduce stay at the ED and improve
patient flow. While an elevated troponin in patients with suspected acute
coronary syndrome (ACS) confirms diagnosis and initiates adequate treatment,
ruling out ACS aids in proper patient dismissal. A next step could be ruling
out myocardial infarction by the general practitioner (GP) or fast responder
using an on-site POC troponin test. However, drawing venous blood might not be
easily available to every GP, especially not during peak hours. The Minicare
cTnI is a bedside system which requires capillary blood, venous whole blood or
plasma. The results of the troponin will be given within 10 minutes. It is a
very sensitive troponin test, the most clinically sensitive available POC for
c-Troponin. Currently Minicare prepares for a high sensitive troponin analysis
targeting a reliable result within an hour after onset of chest pain.

In September 2019, the validation study 1.0 started, in which the cTnI result
of the Siemens POC device on three sample types are compared. Interim analysis
of the sample comparison was performed by regression analysis using Passing and
Bablock, and calculating the Pearson correlation coefficient.
The Li-hep Plasma vs Li-hep venous blood show a very good correlation. For the
capillary sample vs the Li-hep sample (both blood and plasma) the slope is
8-12% higher.
We hypothesize that the presence of the Li-heparin anti-coagulant in the venous
draw lead to a slight reduction of the apparent cTnI concentration. By using a
heparin coated transfer device for the capillary samples instead of an uncoated
transfer device, this hypothesis will be tested.

The objective of the study is to compare the analytical perfomance of POC Hs
cTnI testing in different sample types. This will be achieved by taking:
* Two capillary samples: one sample with a heparin coated transfer device
(drawn from a finger of the right hand) and the other one with a non-heparin
coated transfer device. (drawn from a finger of the left hand)
* One extra venous blood sample: for POC venous and POC plasma analysis.
We hypothesize that three different sample types of Siemens® POC high sensitive
troponin I (HS cTnI) show the same analytical performance when using a heparin
coated transfer device instead of a non-heparin coated transfer device. The use
of capillary blood as interchangeable sample type would enable on-site POC
troponin testing.

This study is a prospective, observational, cohort study aiming to compare
point-of-care high-sensitive troponin I testing from different sample types:
venous Li-hep blood, Li-hep plasma, capillary sample without anticoagulant and
capillary sample with Li-heparin.
All patients aged 18 years or older referred to the cardiac ED with chest pain
suspected of ACS and having standard troponin tests ordered by their treating
ED physician are eligible for the study, including patients with a STEMI who
already underwent rescue/emergency percutaneous coronary intervention (PCI).
Patients with (supra)ventricular tachycardia, cardiac arrest and patients in
which an acute non-cardiac diagnose is suspected, will be excluded. Written
informed consent will be obtained from each study participant.
Patients will receive standard medical care defined by their treating physician
and based upon complaints, physical examination and laboratory results
including standard HS cTnT analyses.
From every included patient two capillary blood samples (one with a heparin
coated transfer device and one with a non-heparin coated transfer device) and
an extra venous blood sample will be drawn to evaluate HS cTnI levels obtained
with the POC instrument. The capillary sample with the heparin coated transfer
device will be drawn from the right hand. The capillary sample with the
non-heparin coated transfer device will be drawn from the left hand. All
samples will be collected once, at one time point with a maximum of 10 minutes
in between. This will be done during regularly ordered blood work at the
cardiac ED/coronary care unit (CCU). Patients will not undergo extra
venipuncture for study purposes only.
A registry of all included patients and their POC troponin results will be made
to compare these testing methods.
Study nurses and clinical chemistry analysts will be trained on the study
workflow including usage of the POC analyzer and adequate fingerstick technique
with deep puncture of a suitable fingertip.

We expect no adverse events and there are no expected risks associated with
this protocol. The burden on the patient is low. The fingerstick is a
non-invasive procedure and for the collection of venous blood we use the
regular troponin protocol at our hospital. The patients do not undergo an extra
venipuncture. We monitor patients for one month after their visit / admission
by their medical file. There will be no additional visits.