Treatment with drug-eluting stents (DES) has revolutionized percutaneous coronary intervention (PCI) due to their substantial efficacy in reducing restenosis and the need for repeat revascularization procedures. Despite this benefit, the delivery of DES remains challenging in complex coronary anatomy, including lesions with extensive calcification and eccentricity. In addition, stent placement with DES still does not exclude the potential mechanical complications associated with plaque shift associated with percutaneous revascularization of bifurcation and ostial lesions. While these persistent challenges underscore the ongoing limitations of PCI, they also support the occasional but longstanding use of adjunctive technologies to facilitate balloon angioplasty and stent placement.

Randomized clinical trials evaluating coronary stents versus balloon angioplasty have demonstrated marked improvements in the short- and long-term safety and efficacy of percutaneous coronary intervention (PCI) by reducing restenosis and the need for repeat revascularization.^1–5 However, since the introduction of coronary stents, whether advances in stent design, balloon delivery catheter and adjunctive pharmacologic therapies have improved clinical outcomes among patients undergoing percutaneous revascularization remains uncertain.

Urgent coronary reperfusion unequivocally saves lives in the setting of acute coronary syndromes, however for most patients, the goal of percutaneous coronary intervention remains the control of anginal symptoms.^1,2 As a standalone procedure, balloon angioplasty is associated with relatively high rates of acute vessel closure and late restenosis.³ These complications are reduced with the use of bare metal stents deployed at high pressure and adjuvant dual antiplatelet therapy.^4–6 While bare metal stents effectively reduce the need for repeat revascularization compared to balloon angioplasty, they have not been shown to decrease the incidence of death or myocardial infarction.⁶

Several randomized trials have demonstrated the efficacy of drug-eluting stents (DES) in reducing restenosis and the need for target vessel revascularization (TVR) in comparison to bare metal stents (BMS).^1-3 Patient and lesion subsets examined in most trials were highly selected and thus not representative of the “real-world” patients undergoing coronary artery stent placement. However, several published series and registries have shown that the benefits of DES in reducing restenosis could be extended to several higher-risk patient subsets.^4-7

Cardiovascular disease is the main cause of death at all stages of chronic renal failure and end-stage renal disease on hemodialysis (ESRD) in adults; it accounts for almost 50% of the mortality of these patients, with an annual mortality rate of 18–20%.^1–6 Although atherosclerosis seems to be accelerated in these patients, it does not seem to be secondary to the dialysis itself. Half of all dialysis patients have evidence of coronary artery disease before the initiation of hemodialysis.^10–12 The high prevalence of coronary artery disease in these patients has not been completely elucidated, but seems to be related to multiple concomitant risk factors, such as hypertension and diabetes, high levels of triglycerides and homocysteine and low levels of high-density lipoproteins.

The percutaneous radial artery approach for coronary angiography (CAG) was first reported in 1989–1999¹ and subsequently transradial coronary angioplasty was reported in 1995 by Kiemeneij et al.² The advantages of the radial artery approach are numerous and include, a lower incidence of access site complications, earlier ambulation, decreased hospital stay and expenses.³ A larger number of patients prefer this approach.⁴ In patients with peripheral vascular disease it offers an excellent alternative to the femoral approach.

Coronary stent placement is the most commonly employed technique for percutaneous treatment of atherosclerotic heart disease. It accounts for about 75% of the procedures performed worldwide.¹ In comparison to conventional balloon angioplasty, stents have improved the efficacy of percutaneous coronary interventions (PCI) by reducing abrupt or threatened vessel closure^2,3 and by reducing restenosis.^4,5 Notwithstanding, coronary stent thrombosis has remained an uncommon, but serious complication of PCI.⁶ The newer drug-eluting stent (DES) inhibits restenosis by inhibiting SMC proliferation, but there are concerns that the drug eluted from the stents may delay the endothelialization process⁷ around the stent struts and thus increase the risk of prolonged thrombogenicity of the stent leading to late stent thrombosis.⁸ Therefore, stent thrombosis may be more common after DES use, with consequent danger to the patients.

Attempts to reduce neointimal proliferation following coronary artery stent implantation have focused on stent coatings with or without local drug delivery.

Ideally, cardiologists would like a stent that is easy to deliver, causes no acute thrombosis, provides insignificant late loss due to intimal hyperplasia and offers no risk of late thrombosis should antiplatelet therapy have to be withdrawn.

Drug-eluting stent (DES) implantation has been shown to considerably reduce the occurrence of restenosis compared to other modalities of percutaneous coronary intervention (PCI) such as plain old balloon angioplasty (POBA), bare metal stent (BMS) implantation, directional coronary atherectomy (DCA), rotational atherectomy and others.
However, restenosis still occurs in about 4% to 10% of cases according to the lesion complexity.^1–4 The predictors of post-sirolimus-eluting stent (SES) restenosis are similar to those following POBA or BMS implantation, and include treatment of small vessel size, ostial lesions, diffuse lesions or diabetes.⁵ These characteristics may prevent adequate expansion or apposition of the stent, impeding the antiproliferative action of the drug. In these lesions, some modification of the plaque prior to stenting may be required.