Development and validation of a machine learning model for diagnosis of ischemic heart disease using single-lead electrocardiogram parameters

Table 5 Features of the categorical variables of the participants

Index	Factor	Absolute value, relative value
Gender	F	39 (48.75)
	M	41 (51.25)
Obesity stage	Normal	30 (37.500)
	Overweight	29 (36.25)
	1 degree	20 (25.00)
	3 degree	1 (1.25)
Smoking	Yes	14 (17.50)
	No	66 (82.50)
Concomitant diseases	Yes	41 (51.25)
	No	35 (43.75)
	Missing data	4 (5.00)
Atherosclerosis of the coronary artery	Yes	31 (38.75)
	No	49 (61.25)
Hemodynamically significant coronary artery atherosclerosis on the CTP (> 60% stenosis)	Yes	9 (11.25)
	No	71 (88.75)
Stress-induced myocardial perfusion defect on the CTP	Yes	31 (38.75)
	No	49 (61.25)
Myocardial perfusion defect before stress ATP on the CTP	Yes	26 (32.50)
	No	54 (67.50)
Atherosclerosis in other arteries	Yes	41 (51.25)
	No	32 (40.00)
	Missing data	7 (8.75)
Atherosclerotic vascular (namely)	Carotid	1 (1.25)
	Carotid brachiocephalic bifurcation	41 (51.25)
	Missing data	38 (47.50)
Carotid artery atherosclerosis	Yes	39 (48.75)
	No	34 (42.50)
	Missing data	7 (8.750)
Brachiocephalic artery atherosclerosis	Yes	37 (46.25)
	No	36 (45.00)
	Missing data	7 (8.75)
Arterial hypertension	Yes	40 (50.00)
	No	40 (50.00)
Stage of the arterial hypertension	I	5 (6.25)
	II	20 (25.00)
	III	16 (20.00)
Degree of hypertension	Degree 1	19 (23.75)
	Degree 2	13 (16.25)
	Degree 3	9 (11.25)
Risk of cardiovascular disease	Low	27 (33.75)
	Moderate	27 (33.75)
	High	18 (22.50)
	Very high	8 (10.00)
SCAD from anamnesis	Yes	3 (3.75)
	No	29 (36.25)
	Missing data	48 (60.00)
Blood pressure reaction type on stress test	Asthenic	4 (5.00)
	Hypotonic	4 (5.00)
	Hypertonic	8 (10.00)
	Normotonic	64 (80.00)
Functional class by Watt	FC-I	8 (10.00)
	FC-II	9 (11.25)
	No SCAD	63 (78.75)
Functional class by METs	FC-I	6 (7.50)
	FC-II	10 (12.50)
	FC-III	1 (1.25)
	No SCAD	63 (78.75)
Reaction type to stress test (positive/negative)	Negative	42 (52.50)
	Suspected	21 (22.5)
	Positive	17 (21.25)
Reason for discontinuation of the stress test	Horizontal ST depression > 1 mm	8 (10)
	Reach goal HR	72 (90)
Tolerance to exertion on stress test	Low	2 (2.50)
	Moderate	43 (53.75)
	Close to high	8 (10.00)
	High	16 (20.00)
	Very high	11 (13.75)
CAVI degree	Normal (< 8)	36 (45.00)
	Borderline (8-9)	22 (27.50)
	Pathological (> 9)	22 (27.50)
ABI degree	Normal	76 (95.00)
	Borderline	2 (2.50)
	Abnormal	1 (1.25)
	Noncompressible	1 (1.25)
Biological estimated vascular age	Normal	45 (56.25)
	High	35 (43.75)
CKD stage	I	35 (43.75)
	II	41 (51.25)
	IIIa	4 (5.00)

Data were presented as n (%). F: Female; M: Male; CTP: Computed tomography myocardial perfusion; SCAD: Stable coronary artery disease; FC: Functional classification of angina; METs: Metabolic equivalent; CAVI: Cardio-ankle vascular index; ABI: Ankle-brachial index; HR: Heart rate; CKD: Chronic kidney disease.