Radiotherapy for stenotic coronary vessels

During the last 25 years there has been considerable scientific progress in interventional cardiology. The introduction of balloon dilatation (PTCA=Percutaneous transluminal coronary angioplasty), a catheter-based interventional technique, into clinical cardiology by the native Dresdener Andreas Gruentzig in 1977 has revolutionized the treatment of coronary heart disease. Meanwhile, worldwide more than 1 million patients per year (more than 150 000 patients per year in Germany), who otherwise would have been candidates for bypass surgery, are treated by the less invasive technique PTCA. The second interventional milestone was the introduction of coronary stents in 1986, which minimized the risk of PTCA and made surgical stand-by and emergency bypass surgery after PTCA an extremely rare event. Despite these remarkable new catheterbased techniques, renarrowing of coronary arteries after PTCA (restenosis) occurring in about 30-40% of all cases has remained the Achilles' heel of interventional cardiology for more than two decades. Restenosis after PTCA is not only a disappointing experience for patients, referring physicians and cardiologists, but also an important socioeconomic problem. In Germany with more than 150 000 procedures per year more than 315 million Deutschmarks are only spent for the treatment of restenosis after PTCA. Since the days of Andreas Gruentzig numerous systemic and local pharmacological approaches for the prevention of restenosis have been tested in more than 50 randomized studies and more than 12 000 patients, yielding only negative results. Catheter-based intravascular radiation therapy using Gamma or Beta sources promises to be the first interventional therapy capable of reducing the restenosis rate after PTCA significantly. Our first experiences with a Strontium-90/Yttrium-90 Beta source (Beta-CathTM system of the Novoste Company, Norcross, Ga., U.S.A.) are reported. (orig.)