Diagnostic accuracy and cost-effectiveness of the CAR-OLT score in predicting cardiac risk for liver transplantation

Table 1 CAR-OLT score components in our cohort, n (%)

Pretransplant risk factors	Entire cohort (n = 342)	Missing data
Age group		None
< 45	31 (9)
45-49	29 (8.5)
50-54	49 (14.3)
55-59	73 (21.3)
60-64	83 (24.3)
65+	77 (22.5)
Sex
Men	276 (80.7)
Women	66 (19.3)	None
Race
White	333 (97.4)
Black	5 (1.5)
Others	4 (1.1)
Working status
Working for income	149 (43.6)	None
Not working for income	193 (56.4)	None
Education
≤ High school	326 (95.3)
College+	16 (4.7)
Atrial fibrillation
Yes	16 (4.7)
No	326 (95.3)	None
Respiratory failure on ventilator at transplant
Yes	1 (0.3)
No	341 (99.7)	None
Pulmonary hypertension
Yes	11 (3.2)
No	331 (96.8)
Hepatocellular carcinoma
Yes	158 (46.2)
No	184 (53.8)
Hypertension
Yes	118 (34.5)
No	224 (65.5)	None
Diabetes
Yes	128 (37.4)
No	214 (62.6)	None
Heart failure
Yes	16 (4.7)
No	326 (95.3)	None

Table 2 Cardiac workup and pharmacoeconomic analysis¹, n (%)

Variable	Entire cohort (n = 342)	Patients with CAR-OLT scores ≤ 23 (n = 84)	Potential saving (€)	Potential saving (€) per patient
Exercise electrocardiogram
Tests performed	54/342 (15.8)	18/84 (21.4)	1004.40	11.95
Doubtful/positive result (on valid tests)	9/44 (20.4)	5/13 (38.5)
Stress myocardial perfusion imaging
Tests performed	206/342 (60.2)	58/84 (69)	17864	212.66
Doubtful/positive result	68/206 (33)	12/58 (20.7)
Stress echocardiogram
Test performed	14/342 (4.1)	2/84 (2.4)	140€	1.66€
Doubtful/positive result	1/14 (7.1)	0
Coronary computed tomography angiography
Tests performed	34/342 (9.9)	9/84 (10.7)	1422€	16.93€
Significant stenosis	4/34 (11.8)	1/9 (11.1)
Coronary angiography
Test performed	80/342 (23.4)	13/84 (15.5)	27846€	331.5€
Significant stenosis	25/80 (31.2)	3/13 (23.1)
1 vessel	10	1
2 vessels	9	0
3 vessels	6	2
Myocardial revascularization
Percutaneous coronary intervention	11	1
Coronary artery bypass	1	1
Right heart catheterization	11	1		-
Cardiac contraindications to listing	21/342 (6.1)	2/84 (2.4)
Coronary artery disease	10	1
Valvular heart disease	4	0
Severe pulmonary hypertension	3	1
Atrial fibrillation associated with left ventricular ejection fraction < 45%	4	0
Overall diagnostic work-up	388 diagnostic exams	100 diagnostic exams	48276.40€	574.70€

¹Pharmacoeconomic analysis based on the diagnostic algorithm which defines low-risk patients with CAR-OLT scores ≤ 23, in our cohort 84 patients (24.6%) out of 342.

The cost estimates for each diagnostic test are as follows: Exercise electrocardiogram 55.80 €, myocardial perfusion imaging 308€, stress echocardiogram 70€, coronary computed tomography angiography 158€, coronary angiography 2142€. For exercise electrocardiogram, the test was considered valid if it reached at least 85% of the age-predicted maximum exercise heart rate. CAR-OLT: Cardiovascular risk in orthotopic liver transplantation.