[Intracoronary stents in small vessels: short- and long-term clinical results]

To assess the clinical outcome of coronary stenting in small vessels (< 3 mm), using high pressure balloon inflation and antithrombotic therapy.

Vessel size was evaluated as < or >= 3 mm at the time of procedure and measured at a level of maximum diameter. We studied 234 consecutive patients with placement of 300 stents in 279 lesions, comprising 84 stents implanted in 79 lesions located at small vessels (< 3 mm). The standard technique included high pressure balloon inflation (15.8 +/- 2.2 atm) and post-stenting therapy with ticlopidine and aspirin for one month. Mean clinical follow-up was 17.6 +/- 10 months.

Procedural success without in-hospital major events was similar between small and large vessels (93.7 in vessels of < 3 mm vs 93.5% in vessels of >= 3 mm; p = NS). Three small vessels presented subacute stent thrombosis, whereas no thrombotic occlusion occurred in large vessels (3.8 vs 0%; p = 0.006). At two years, small vessels had a lower target lesion revascularization free survival (73.6 vs 90.3%; p < 0.001). After adjustment for variables previously described as predictors of stent restenosis, in multivariate analysis, a small vessel of < 3 mm was an independent predictor of target lesion revascularization (p = 0.001). Although patients with stenting in small vessels did not differ significantly in terms of any cause death (4.6 vs 3.8%; p = 0.7) nor acute myocardial infarction (2.9 vs 1.1%; p = 0.3), event-free survival was significantly lower after two years (69.1 vs 86.6%; p < 0.001).

As compared to large vessels, coronary stenting in small vessels was performed with similar rates of initial success, however they had a significantly worse clinical long-term outcome in terms of subacute stent thrombosis and target lesion revascularization at follow-up.