| dc.description.abstract | Patients with chest pain complaints are suspected of an obstruction in the vessels of the heart, also known as atherosclerosis. However, many of these patients do not have an obstruction. We call these patients the ANOCA patients. Nowadays, we know that the cause of symptoms in ANOCA patients may be due to a dysfunction of the vessels, called coronary vasomotor dysfunction (CVDys). CVDys is either squeezing of the vessels (abbreviated as CVS) and/or the inability of the small vessels to function properly (abbreviated as CMD). CVDys is diagnosed with coronary function testing (CFT), a test that takes place at the heart catheterization lab. However, this test carries non-negligible risks and costs and has a large burden on patients. Therefore, there is a need for a low-risk diagnostic tool for CVDys. The rest electrocardiogram (ECG) may be such a low-risk tool, as the electrical activity of the heart is measured for only ten seconds with electrodes placed on the body. There are studies that suggest that some markers (e.g. QTc interval prolongation) on the rest ECG differ in ANOCA patients with CVDys compared to patients without CVDys. As it is interesting to further test whether there are markers that can be used in diagnosis, we set up a study as a first exploration to investigate the potential of a rest ECG as diagnostic tool for CVDys in ANOCA patients.
We collected clinical characteristics (e.g. risk factors) and a rest ECG obtained on the day of and prior to CFT of 128 ANOCA patients that underwent CFT and participated in the NL-CFT registry. We compared several ECG parameters, such as heart axis and conduction times, between patients without CVDys and patients with CVS, patients with CMD and patients with a combination of both. Furthermore, we used different models to investigate which ECG parameters are linked to CVDys. For the ECG parameters linked to CVDys, we evaluated their ability to separate patients with CVDys from those without CVDys.
In total, we analyzed 23 patients without CVDys, 35 patients with CVS, 24 with CMD and 26 with CVS/CMD, of whom 95% were women. Most ECG parameters were comparable between the groups, except for a small prolongation of the QT-interval corrected for heart rate in two different ways (i.e. QTcB and QTcF) in patients with CVDys compared to patients without CVDys. However, both QTcB and QTcF had very low ability to separate patients with CVDys from patients without CVDys. This study therefore shows that the rest ECG is not suitable for the diagnostic evaluation of CVDys. We recommend focusing on ECG monitoring tools other than the 10-seconds rest ECG to further explore the value of ECG for CVDys diagnosis in a low-risk manner. | |
