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21st Congress of the European Society of Cardiology, August 1999, Barcelona, Spain
First report on safety and practicability of intracoronary radiation using a new monorail delivery system (Beta-Rail).
S. Silber, N. Seidel, P. von Rottkay, A. Schneider, A. Bauer
Dr. Müller Hospital, Munich, Germany
Eur Heart J 20: (Suppl), 409 (1999)
Beta or gamma radiation subsequent to coronary interventions is currently being applied as prophylaxis and/or therapy for (in-stent) restenosis. Possible safety risks during and shortly after administration may be a dissection, created by the 5F intracoronary catheter, longer periods of ischemia as well as inadvertent overdose. Further, delayed endothelialization can comprise an increased risk of acute/subacute stent thrombosis, which may possibly be avoided by extending administration of ticlopidine or clopidogrel. In a double-blind, placebo-controlled study, we are investigating the influence of a beta-emitting source train (ca. 42 mCi, Stron-ti-um/Yttrium-90, Novoste) on restenosis following PTCA of de-novo lesions and restenoses. 40 patients have been thus far included with a single lesion and stable angina pectoris. Mean age was 60,5±9 years, LV-EF was 61±10%, reference diameter was 3,0±0,6 mm; MLD before and directly after radiation was 0,6±0,36 respectively 2,8±0,4 mm. The dose for coronary vessels with a diameter of 2,7-3,35 mm is 14 Gy; for 3,36-4,0 mm is 18 Gy. Mean duration of radiation with 14 Gy was 173±8 s (165-187 s) and 222 ± 12 s (212-240 s) with 18 Gy. The relatively bulky radiation catheter led neither to dissections nor to clinically relevant myocardial ischemia. Coronary overdose or a "getting stuck" of the radioactive pellets during passage of the inguinal region did not occur thanks to modifications required by the German authorities. In the 4-week period following radiation, coronary thromboses did not occur even after stent implantation. The added time needed for radiation after PTCA was ca. 18±6 min.
Conclusions: Intracoronary brachytherapy with the new Beta-Rail is safe. However, Ticlopidine may have to be routinely administered for 2 months after stent implantation and brachytherapy. Long-term results will be reported.