Aims: Restenosis after PCI and/or stent implantation is still one of the challenging problems in the field of interventional cardiology. Different approaches to prevent and to treat restenosis include the use of drug-eluting stents, which have shown to reduce restenosis. Another approach is the treatment with drug-coated balloons. This approach has been proven for different indications, e.g., in-stent restenosis and treatment of peripheral artery disease.
Methods and results: Patients from the PEPCAD III multicentre randomised trial in two study centres (Homburg and Hannover, Germany) were asked to participate in this intravascular ultrasound (IVUS) study at nine-month follow-up. At baseline (nine months before), patients were randomly assigned to receive either a paclitaxel-coated balloon (drug-coated balloon [DCB]) plus a premounted bare metal stent (DCB/BMS) or a sirolimus-eluting stent (drug-eluting stent [DES]) to treat de novo lesions. IVUS at follow-up was performed in order to analyse the restenosis for potential understanding of the mechanism leading to restenosis. IVUS data is available for 55 patients; 26 patients were treated with Cypher(®) DES (Cordis, Miami Lakes, FL, USA) and 29 patients with DCB/BMS. A focal malapposition of the stent was seen in six patients; four after DES and two after DCB/BMS. Stent expansion, calculated as symmetric expansion index, was equal for both groups (0.89 and 0.90). Mean stent area was also equal for both groups (6.25 ± 1.7 vs. 5.65 ± 1.5 mm(2), p=n.s.). The neointimal hyperplasia (calculated as stent area minus lumen area) was significantly different between both groups (0.69 ± 0.49 [DES] vs. 1.08 ± 0.53 mm(2) [DCB/BMS], p<0.01). This resulted in a significantly higher in-stent restenosis in the DCB/BMS group (19.7 vs. 11 %, p<0.01). There is no evidence of geographical mismatch.
Conclusions: First IVUS insights for the DCB/BMS showed a comparable, low incidence of malapposition for the combination of drug-coated balloon and premounted bare metal stent compared to the DES, and stent expansion was good and comparable to DES. However, at nine-month follow-up, the combination of drug-coated balloon and premounted bare metal stent showed higher in-stent restenosis compared to sirolimus DES. Geographical mismatch can be excluded as a reason for this result.