Systemic Immunosuppressive Therapy with Oral Sirolimus after Bare Metal Stent Implantation: The Missing Alternative in the Prevention of Coronary Restenosis after Percutaneous Coronary Interventions

Abstract

In recent years, percutaneous coronary intervention (PCI) with drug eluting stents (DES) to treat de novo coronary lesions has been associated with a significant reduction of neointimal hyperplasia and in-stent restenosis. However, several publications raise concerns about long-term safety of DES, especially with the emerging anxiety with the problem of late stent thrombosis. Different registries with DES reported a growing incidence of stent thrombosis up to three years after stent implantation. In parallel with DES introduction in clinical practice in the last seven years, we identified six reported observational and randomized clinical experiences assessing the potential role of oral Sirolimus therapy in the prevention of coronary restenosis after bare metal stent implantation. Three observational and three randomized studies were performed during these years. Several implications were drawn: First, systemic therapy was given for only 14 days after PCI; minor transient side effects were observed in 25% of patients and were completely relieved after discontinuation of the drug. Secondly, angiographic restenosis and late loss are strongly related with Sirolimus blood concentration during the first week of treatment and were significantly reduced compared to non therapy. Finally, in the last randomized study, oral Sirolimus plus bare metal stent were cost saving compared to drug eluting stents with a trend to better clinical late outcome with the oral immunosuppressive therapy. The manuscript also reviews recent patents with new drugs, combination of drugs and DES designs which would improve safety and efficacy in the restenosis prevention after angioplasty.