Symptomatic failure after sirolimus-eluting stent implantation: a rare but challenging condition.

BACKGROUND: Limited information is available regarding restenosis after implantation of a sirolimus-eluting stent (SES).
OBJECTIVE: To report on angiographic characteristics, clinical presentation and treatment of this particularly complex type of coronary lesion. METHODS AND
RESULTS: A total of 1424 SES were implanted in 1159 patients (average 1.2 per patient) for chronic or acute coronary syndromes in the University Hospital of Siena (Siena, Italy), which is a tertiary centre. Symptomatic in-SES restenosis was observed in 26 patients (2.2%) at 10+/-5 months (median eight months, range four to 23 months) following the initial intervention. In-SES restenosis was associated with stable angina in 16 patients, acute myocardial infarction in three patients and unstable angina in seven patients. Two patients had restenosis in two separate SES. Conditions often associated with in-SES restenosis included treatment of chronic total occlusion, geographic miss or in-stent restenosis during the index procedure. Among the first 20 patients, those with focal, in-body SES (type Ic) restenosis received balloon-only angioplasty, and patients with other patterns received repeat SES implantation. Clinical and angiographic follow-up (average 16+/-7 months) recorded one death (noncardiac) in the balloon-only group and four cases of unstable angina (three due to relapsing in-SES restenosis in the balloon-only group and the fourth due to a de novo lesion). Follow-up quantitative angiography showed a higher incidence of binary restenosis after balloon-only treatment (57% versus 17%; P<0.05), as well as higher lumen loss and loss index (P<0.05).
CONCLUSIONS: Restenosis after SES implantation occurs more commonly in a focal pattern in-body or at the proximal edge of the stent. Repeat SES implantation appears to be a safer and more effective therapeutic choice than balloon-only angioplasty.