Table 2.

Procedural Characteristics and Outcomes of the Study Lesions, Classified According to Whether Retrograde Crossing was Attempted or Not

Variable	Overall	Retrograde	Antegrade-only	p
IVUS used (%)†	37.2	48.5	30.5	<0.001
Stent optimization (%)	46.2	42.6	49.6	0.283
To guide rCART (%)	11.4	23.5	-	-
To determine appropriate   stent size (%)	36.9	37.4	36.4	0.870
To assist wiring (%)	25.9	30.4	21.5	0.117
To guide antegrade cap   puncture (%)	13.1	14.8	11.6	0.465
Stenting (%)	88.6	84.2	91.6	<0.001
Number of stents*	2.5±1.1	2.9±1.2	2.3±1	<0.001
Stent length (mm)*	52.3±45.6	59.5±51.9	47.7±40.2	<0.001
Hemodynamic support (%)	4.0	6.7	2.1	<0.001
Fluoroscopy time (min)*	45.6 (27.2–75.1)	73.8 (53.1– 101.4)	31.8 (20.2–46.4)	<0.001
Patient air kerma radiation dose (Gray)*	3.5 (2.0–5.4)	4.8 (3.0–6.6)	2.6 (1.6–4.2)	<0.001
Procedure time (min)*	125 (85–185)	183 (128–234)	100 (68–135)	<0.001
Contrast volume (ml)*	260 (200 – 360)	300 (220 – 404)	245 (180 – 320)	<0.001
Technical success (%)	90.0	84.8	93.7	<0.001
Antegrade wire   escalation (%)	46.7	8.8	71.0	<0.001
Antegrade dissection/re-   entry (%)	24.6	17.7	29.0
Retrograde (%)	28.7	73.5	-
Procedural success (%)	88.6	81.9	93.3	<0.001
MACE (%)	2.4	4.3	1.1	<0.001
Death (%)	0.4	0.8	0.1	0.167
Myocardial infarction (%)	1.0	2.1	0.3	0.003
Stroke (%)	0.3	0.4	0.3	0.999
Emergency re-PCI (%)	0.3	0.6	0.1	0.314
Emergency CABG (%)	-	-	-	-
Emergency	0.7	1.3	0.3	0.039
Pericardiocentesis (%)
Coronary perforation (%)	3.4	5.5	1.9	<0.001

CABG, coronary artery bypass graft surgery; IVUS, intravascular ultrasound; MACE, major adverse cardiovascular events; PCI, percutaneous coronary intervention; rCART, reverse controlled antegrade and retrograde subintimal tracking

^*mean±standard deviation or median (interquartile range).

^†In some procedures IVUS was used for multiple indications.