Retrograde CTO-PCI of Native Coronary Arteries Via Left Internal Mammary Artery Grafts: Insights From a Multicenter U.S. Registry.

BACKGROUND

Retrograde percutaneous coronary intervention (PCI) of native coronary artery chronic total occlusion (CTO) via left internal mammary artery (LIMA) graft has received limited study.

METHODS AND RESULTS

We compared the clinical and procedural characteristics and outcomes of retrograde CTO-PCI through LIMA grafts vs other conduits in a contemporary multicenter CTO registry. The LIMA was used as the collateral channel in 20 of 990 retrograde CTO-PCIs (2.02%) performed at 18 United States centers. The mean age of the study patients was 69 ± 7 years and 95% were men. The most common CTO target vessel was the right coronary artery (55%). The mean J-CTO score in the LIMA group was high (3.45 ± 0.76). The technical success rates were 70% for retrograde PCI via LIMA graft vs 81.05% for retrograde via other conduits (P=.25), while procedural success rates were 70% for retrograde PCI via LIMA graft and 78.19% for retrograde via other conduits (P=.41). The incidence of major in-hospital complications was also similar between the LIMA and non-LIMA retrograde groups (5% vs 6%; P>.99). Use of guide-catheter extensions (40% vs 28%; P=.22), intravascular ultrasound (45% vs 31%; P=.20), and left ventricular assist devices (24% vs 10%; P=.08) was numerically higher in retrograde CTO-PCIs via LIMA grafts.

CONCLUSIONS

Retrograde CTO-PCI is infrequently performed via LIMA grafts and is associated with similar success and major in-hospital complication rates as retrograde CTO-PCI performed via other conduits.