The efficacy of coronary stenting of aorto-ostial atherosclerotic lesions is still unclear. We investigated the frequency and mechanism of stent restenosis
at this particular lesion.
Fifty-five consecutive patients with 64 native aorto-ostial lesions in the right coronary artery (RCA, n
=38) and the left main trunk (LM, n
=26) were treated by conventional stenting. Determinants of angiographic restenosis
were established. The mechanism of stent restenosis
was evaluated using post-stenting and follow-up intravascular ultrasound (IVUS) findings.
was more frequent in the RCA than in the LM (50% compared with 19%, P
<0.03) and determinants included diabetes mellitus (63% compared with 21%, P
<0.03), calcium deposition (58% compared with 5%, P
<0.003), smaller stent
cross-sectional area (SA) (as demonstrated by post-stenting IVUS studies, 8.1±1.4 mm2
compared with 10.2±2.2 mm2
<0.01), larger plaque burden (64±6% compared with 57±8%, P
<0.03) and less circular expansion at the aorto-coronary junction. Serial IVUS examination was performed in 11 patients with restenosis
of the right coronary ostium. The mean reduction in the SA was 21% at the aorto-coronary junction (6.4±1.9 mm2
<0.003), whereas the SA at the distal edge was unchanged. Thirty-three per cent of late luminal loss was due to chronic stent
These findings suggest that stenosis of the right coronary ostium is a high-risk lesion for stent restenosis
. In addition to excessive intimal growth, chronic stent
recoil might be an important etiologic factor at this particular location.