Angiographic patterns of in-stent restenosis and implications on subsequent revascularization

Stent implantation has become the mainstay of percutaneous revascularization for most coronary lesions; in-stent restenosis (ISR) can occur in 6%-40% of stent procedures and the subsequent response to repeat intervention can possibly be predicted by the angiographic patterns of ISR. This study evaluated the incidence and predictors of angiographic patterns of ISR and its impact on subsequent target lesion revascularization (TLR) in 100 consecutive patients having Palmaz-Schatz ISR undergoing intervention. Diffuse ISR (≥10 mm) was observed in 78% and focal ISR (>10 mm) in 22%. Diffuse vs. focal ISR occurred earlier after stent implantation and was more common in diabetics. Angiographic predictors of diffuse ISR were stent implantation for a restenotic lesion, long lesions, smaller vessel, stenting without debulking, and high-pressure balloon inflation (>16 atm). TLR after repeat intervention was 46% for diffuse and 14% for focal ISR (P < 0.02). Rotational atherectomy resulted in lower TLR (31%) vs. PTCA or restent (64%) in diffuse ISR (P < 0.004). Therefore, diffuse ISR is more common than focal ISR, usually occurs in the setting of aggressive intimal hyperplasia, and can be predicted by clinical and angiographic variables. Also, diffuse intimal hyperplasia within a stent responds poorly to PTCA and may benefit from a more aggressive debulking strategy such as rotational atherectomy.