Background: Treatment of lesions in small vessels was associated with worse clinical outcome, and various definitions of “small vessels” have been used. Data with novel drug-eluting stents are scarce.
Methods: To compare the outcome of patients with vs without small-vessel treatment, we assessed 2-year follow-up data of the DUTCH PEERS randomized trial (ClinicalTrials.gov: NCT01331707), in which 1,811 all-comers were treated with contemporary zotarolimus-eluting (Resolute Integrity) or everolimus-eluting (Promus Element) stents. Primary end point was target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization.
Results: The rates of TLF (9.5% vs 5.4%; P log rank = .001) and 2 individual components thereof—target vessel myocardial infarction (3.1% vs 1.3%; P log rank = .006) and target lesion revascularization (4.8% vs 2.8%; P log rank = .02)—were higher among 798 (44.1%) patients treated in at least one small vessel (<2.50 mm by quantitative coronary angiography). Multivariate analysis with propensity score adjustment demonstrated that treatment of small-vessel lesions independently predicted TLF at 2-year follow-up (hazard ratio 1.60, 95% CI 1.09-2.34). Patients with the smallest target vessel being <2.25 mm had TLF rates similar to patients with smallest target vessels of 2.25 to <2.50 mm; however, patients treated in vessels no smaller than 2.50 to <3.00 mm and patients treated in vessels ≥3.00 mm had lower TLF rates (9.3%, 9.8%, 5.0%, and 5.8%, respectively; P log rank = .009).
Conclusion: Patients treated with novel drug-eluting stents in small-vessel lesions had higher adverse event rates than did patients who had no small-vessel treatment. Our data suggest that with current stents, a vessel diameter <2.50 mm is a suitable threshold to identify small target vessels.