In an attempt to determine the early and late outcomes of small vessel stenting, we retrospectively evaluated our database on 51 consecutive patients (41 males, mean age, 57.1 ± 10.1 years) who underwent stenting of at least one significant lesion in a coronary artery with a reference vessel diameter (RVD) < 2.8 mm between March 1999 and March 2001.
Sixty balloon expandable tubular stents were implanted in 57 lesions (29 Type B2/C, mean RVD: 2.54 ± 0.16 mm) without intravascular ultrasound guidance under a heparin-aspirin-ticlopidine regimen. The mean diameter stenosis (DS) decreased from 75.8 ± 13.6% to 4.2 ± 1.9% (P < 0.0001) with stenting at a mean deployment pressure of 13.6 ± 1.7 atm and a final balloon to RVD ratio (FB/RVD) of 1.08 ± 0.03. All stents were deployed successfully. Acute stent thrombosis occurred in 3 patients (6%), one died, and 2 developed non-Q-wave myocardial infarction (procedural success 94%). Clinical follow-up, available in 48 patients, revealed a 29% target lesion revascularization rate, a 2% myocardial infarction rate, and a 71% event-free survival at a mean of 11.6 months. Angiographic follow-up, available in 40 patients, showed a DS of 48.8 ± 31.3% and a binary restenosis rate of 50% at a mean of 7.7 months. The FB/RVD ratio was significantly lower in the group with restenosis than in the group without (1.06 ± 0.02 vs 1.1 ± 0.05, P = 0.04). Subgroup analysis yielded a significantly greater rate of restenosis in diabetics with complex (Type B2/C) lesion morphology compared to nondiabetics with simple (Type A/B1) lesions (75% vs 21%, P < 0.05).
In conclusion, stenting in vessels < 2.8 mm was found to be associated with a high rate of acute stent thrombosis and in-stent restenosis. Further analysis detected a subgroup of patients without diabetes or complex lesions who could be stented with an acceptable in-stent restenosis rate.