The effectiveness of drug-eluting stents (DES) in reducing rates of restenosis has led many clinicians to extend their use to patients with clinical and anatomical features that are beyond those that are approved by the United States Food and Drug Administration (FDA). However, the FDA has questioned the safety and effectiveness of this off-label use, citing a potentially increased risk of stent thrombosis and death or myocardial infarction (MI). Mohamad Ahmad Mosaad, MD, Al-Azhar University, Cairo, Egypt, presented data from a nonrandomized study that compared intermediate- and mid-term clinical outcomes between bare-metal stents (BMS) and DES that were used for either on- or off-label indications. The investigators concluded that DES, whether applied in on- or off-label situations, were safe and effective with a low incidence of stent thrombosis when compared with BMS.

The study comprised 102 patients who were admitted to two hospitals in Egypt between April 2008 and August 2010 with on- and off-label coronary artery lesions but without acute ST elevation myocardial infarction (STEMI). On-label use included treatment of lesions in native coronary arteries that were 30 mm or less in length with a reference vessel diameter of 2.5 to 3.5 mm for the Cypher stent and 28 mm or less in length with a reference vessel diameter of 2.5 to 3.75 mm for the Taxus stent. Patients who were included in the off-label group had restenotic lesions; lesions in a bypass graft; left main coronary artery disease; ostial, bifurcated, or totally occluded lesions; or a reference vessel <2.5 mm or >3.75 mm or a lesion length of >30 mm. Subjects were stratified into four groups (DES on-label, DES off-label, BMS on-label, BMS off-label), each with an approximately equal number of patients. The choice of balloon type and stent was left to the discretion of the operator. Angiograms of the coronary artery were obtained before percutaneous coronary intervention (PCI), after PCI, and at angiographic follow-up 1 year later. Major adverse cardiac events (death, MI, target lesion revascularization, and target vessel revascularization) were assessed at 12 months. Dual antiplatelet therapy with aspirin and an ADP receptor blocker were recommended for 12 months in all patients. Patients were also assessed clinically and for medication compliance at 12 months.

The incidence of in-stent restenosis (ISR) at 12 months with DES was 4% in the on-label group and 8% in the off-label group (p>0.05; compared with 29.2% and 31%, respectively, with BMS (p>0.05). In-stent thrombosis occurred in only 1 patient in each off-label group. Predictors of ISR in the BMS group were more complex lesions (p=0.046), longer mean lesion length (p=0.044), and hypertension (p=0.044). Left ventricular ejection fraction was significantly higher in the DES group (62.4%) versus the BMS group (57.7%; p<0.04). Stent diameter and length, inflation pressure, and lesion characteristics in the off-label and on-label BMS and DES groups were not significantly different.

The authors conclude that although they are not approved by the United States FDA or recommended by current guidelines, DES may be safe for some off-label indications in carefully selected patients. As these preliminary data are nonrandomized and modestly powered, the investigators recommended that this question be studied in a larger, randomized, multicenter trial of longer duration.