ABSTRACT
Since the introduction of coronary angioplasty by Andrea Gruntzig in 1977, the long-term durability of this procedure has been limited by recurrent narrowing within the stent: restenosis. The emergence of coronary stents proved superior to balloon angioplasty alone for long-term vessel patency.1,2
The invention of drug-eluting stents (DES) was another leap forward in further reducing the restenosis rate. First-in-man studies demonstrated striking reductions in clinical restenosis.3 The first major clinical trial examining the durable patency of DES was the Randomized Study with the SirolimusEluting Bx Velocity Balloon-ExpandabLe stent (RAVEL).4 This trial was followed by the pivotal US Food and Drug Administration (FDA) approval trial SIRolImUS (SIRIUS)-coated stent in the treatment of patients with de-novo coronary artery lesions, that resulted in approval of DES by the FDA in October 2002.5
The pivotal FDA approval trials for DES were conducted on single lesions in native coronary arteries. Patient selection was carefully restricted by lesion characteristics and clinical presentation. The RAVEL trial selection criteria included a clinical diagnosis of stable angina, unstable angina, or silent ischemia in native vessels with single lesions, with a diameter of 2.5-3.5 mm; stenoses of 51% to 99% were included. Subjects with evolving myocardial infarction (MI), left main coronary artery disease, ostial lesions, heavily calcified lesions, and thrombus-containing lesions were excluded. The results of the RAVEL trial were unprecedented with a reduction in restenosis to zero compared to 26.6% (P < 0.001) in the bare metal stent (BMS) group.4
