RESUMO
Myocardial bridging is the most common congenital coronary abnormality, and is frequently found on post-mortem cardiac examination. Although often asymptomatic, clinical presentation can vary from unstable angina to sudden cardiac death. Only isolated cases of using drug eluting stents (DES) for bridging segments have been described. Our objective was to retrospectively analyze a series of patients undergoing percutaneous coronary intervention (PCI) with DES for symptomatic myocardial bridging and follow post-procedure outcomes. Results revealed favorable peri-procedural angiographic and short-term clinical results with DES implantation. Although initial data regarding DES implantation for symptomatic myocardial bridging are promising, long-term follow up, particularly related to in-stent restenosis will be important.
Assuntos
Angioplastia Coronária com Balão/métodos , Estenose Coronária/terapia , Anomalias dos Vasos Coronários/terapia , Stents , Estudos de Coortes , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Anomalias dos Vasos Coronários/diagnóstico por imagem , Anomalias dos Vasos Coronários/mortalidade , Sistemas de Liberação de Medicamentos , Feminino , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/mortalidade , Cardiopatias Congênitas/terapia , Humanos , Masculino , Infarto do Miocárdio/prevenção & controle , Paclitaxel/uso terapêutico , Prognóstico , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Sirolimo/uso terapêutico , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução VascularRESUMO
Percutaneous transluminal coronary angioplasty (PTCA) has greatly benefited patients with occluded coronary arteries, but its benefits have been undermined by a high incidence of restenosis. The introduction of coronary stents has significantly improved the short and long term outcome but restenosis still occurs in approximately 15 to 30% of patients within 6 months. Research efforts are now being directed toward combination stenting and drug delivery. Among the therapeutic targets being pursued are agents that can impede smooth muscle cell migration and proliferation, as these processes are critical components of restenosis injury. We propose that inhibiting the conversion of ribonucleotides to deoxyribonucleotides will impede cell proliferation and, as such, limit the degree of restenosis. Therefore, we tested whether the potent ribonucleotide reductase inhibitors Didox (3,4-dihydroxybenzohydraxamic acid) and Imidate (ethyl-3,4,5-hydroxybenzimidate) can limit the neointimal proliferation associated with restenosis using a rat carotid model of balloon dilatation injury. Results demonstrated that both Didox and Imidate significantly reduced intimal thickening, resulting in a 71 and 62% decrease in the intima/media ratio, respectively. Similar efficacy was seen with the commercially available ribonucleotide reductase inhibitor hydroxyurea, demonstrating the importance of this enzyme in vascular remodeling. Results from cell proliferation studies suggest that the mechanism of protection is inhibition of smooth muscle cell (SMC) proliferation. In addition, Didox and Imidate (100 microM) are potent inhibitors of SMC migration, which may also contribute to their vascular protective effects. These results suggest that inhibition of ribonucleotide reductase may provide a potent strategy to prevent post-PTCA restenosis.