Jeffrey J. Popma

Non-uniform distribution of drug-eluting stent struts may cause uneven drug deposition associated with an adverse neointimal response and clinical events. This study assesses circumferential stent strut distribution in bare-metal (BMS) and paclitaxel-eluting (Taxus) stents post implantation and at 9-month follow-up, as well as its impact on intimal hyperplasia (IH). In the current analysis, intravascular ultrasound (IVUS) substudies of the Taxus IV, V, and VI trials were combined. Among them, 242 stents (117 BMS and 125 Taxus) had paired IVUS images post procedure and at 9-month follow-up that were reassessed at 1 mm intervals. Post implantation, the maximum interstrut angle (71.5 ± 17.7° vs 70.0 ± 19.6°; P=.53) and minimum number of stent struts (7.1 ± 1.0 vs 7.2 ± 0.8; P=.32) were similar in Taxus vs BMS subgroups, respectively. At 9-month follow-up, the maximum angle increased (92.8 ± 22.1° and 81.7 ± 20.6°) and stent strut numbers decreased (6.1 ± 0.9 and 6.5 ± 1.0) for both Taxus and BMS, respectively, as compared to immediately post implantation (all P<.001). The increased stent angle was more pronounced for Taxus compared with BMS (P<.01). Non-uniform strut distribution did not affect IH pattern or clinical outcomes in either stent population. No complete stent fractures were identified. Stent strut distribution changed from implantation to follow-up with an increased interstrut angle and fewer visible stent struts. These changes were more pronounced for Taxus as compared to BMS; however, non-uniform strut distribution was unrelated to increased IH or clinical outcomes.

The safety and efficacy of direct stenting with the Endeavor stent is unknown. The acute and 9 month outcome after direct stenting vs. predilatation was tested in a multicentre, prospective, single-arm study. 300 patients were treated with the Endeavor stent for a single, previously untreated coronary artery stenosis (vessel diameter 2.25 to 3.75 mm; lesion length 14 to 27 mm). Predilatation was at discretion of the operator for lesions < 20 mm in length but mandatory for lesions > 20 mm. Angiographic follow-up at 8 months was prespecified for the first 150 consecutive patients. Out of 296 patients, 126 (42.6%) underwent direct stenting and 170 (57.4%) predilatation. Patients in the direct stenting group were younger (62.9 years vs 65.3 years, P=0.04) and lesions were predictably more proximally located and shorter (14.29 mm vs 18.16 mm, P<0.0001), with larger pre-procedural minimum lumen diameter. Success rate was 92.9% with direct stenting vs. 95.3% with predilatation (P=0.45). At 8 months, late loss was not significantly different between groups. The rate of MACE at 9 months was 10.6% with direct stenting vs. 10.2% with predilatation (P=1.00). There were no occurrences of stent thrombosis in either group. Direct stenting with the Endeavor stent as deemed feasible by the operator, was safe and effective, and comparable to the results of implantation following predilatation.

Background— Sirolimus-eluting stents (SESs) reduce angiographic restenosis in patients with focal, native coronary artery stenoses. This study evaluated the usefulness of SESs in complex native-vessel lesions at high risk for restenosis. Methods and Results— Angiographic follow-up at 240 days was obtained in 701 patients with long (15- to 25-mm) lesions in small-diameter (2.5- to 3.5-mm) native vessels who were randomly assigned to treatment with SESs or bare-metal stents (BMSs) in the SIRIUS trial. Quantitative angiographic measurements of minimal lumen diameter and percent diameter stenosis were obtained within the treated segment, within the stent, and within its 5-mm proximal and distal edges. Patients treated with SESs had lower rates of binary (>50% diameter stenosis) angiographic restenosis within the segment (8.9% versus 36.3% with the BMS; P P P Conclusions— Compared with BMSs, SESs reduced angiographic late lumen loss within the stent and its adjacent 5-mm margins in patients with complex native-vessel lesions.

Percutaneous coronary intervention (PCI) of saphenous vein grafts (SVG) and native coronary arteries may be associated with embolization of particulate debris into the distal microcirculation. The FilterWire uses a polyurethane filter bag contained on a radiopaque loop to trap embolic debris during native vessel and SVG intervention. The objectives of this study were to assess the feasibility and safety of the FilterWire during PCI and to examine the size and content of the particulate debris captured during SVG and native vessel intervention. Early angiographic, in‐hospital, and 30‐day clinical outcomes were reviewed in 35 patients with 36 lesions treated with the FilterWire during PCI. Lesions were located in 22 (61%) native coronary arteries and in 14 (39%) SVGs. Multivessel coronary artery disease was present in 75% of patients. Lesions were complex (ACC/AHA complexity B2 or C) in 81% of cases. The FilterWire was successfully delivered and deployed distal to the site of coronary intervention in 92% of lesions, including 95% of native vessels and 82% of SVG lesions. Embolic debris was entrapped in 82% of these cases. The average particulate debris had a mean major axis of 490 μm (range, 45–3,302 μm) and minor axis of 226 μm (range, 33–1,677 μm). Although reduced flow was common (36.1%) when the FilterWire was in place, there were no sustained episodes of abrupt closure and only one (2.8%) patient developed sustained no‐reflow after FilterWire removal. Distal branch vessel embolization was found in four (11.1%) cases. Major adverse cardiac events occurred in 5 (14%) of 35 patients treated with the device, although 2 of these patients were evolving an acute myocardial infarction at the time of the procedure; in patients meeting the prospectively defined inclusion criteria, the major adverse cardiac event was 6%. These results suggest that the FilterWire is a feasible and safe method of collecting particulate debris released during SVG and native vessel coronary intervention. Its benefit over conventional therapy and other distal protection devices is currently under study. Cathet Cardiovasc Intervent 2002;57:125–134.

Background— After conventional treatment of in-stent restenosis, the incidence of recurrent clinical restenosis may approach 40%. We report the first multicenter, blinded, and randomized trial of intracoronary radiation with the use of a ⁹⁰ Sr/ ⁹⁰ Y β-source for the treatment of in-stent restenosis. Methods and Results— After successful catheter-based treatment of in-stent restenosis, 476 patients were randomly assigned to receive an intracoronary catheter containing either ⁹⁰ Sr/ ⁹⁰ Y (n=244) or placebo (n=232) sources. The prescribed dose 2 mm from the center of the source was 18.4 Gy for vessels between 2.70 and 3.35 mm in diameter and 23.0 Gy for vessels between 3.36 and 4.0 mm. The primary end point, ie, clinically driven target-vessel revascularization by 8 months, was observed in 56 (26.8%) of the patients assigned to placebo and 39 (17.0%) of the patients assigned to radiation ( P =0.015). The incidence of the composite including death, myocardial infarction, and target-vessel revascularization was observed in 60 (28.7%) of the patients assigned to placebo and 44 (19.1%) of the patients assigned to radiation ( P =0.024). Binary 8-month angiographic restenosis (≥50% diameter stenosis) within the entire segment treated with radiation was reduced from 45.2% in the placebo-treated patients to 28.8% in the ⁹⁰ Sr/ ⁹⁰ Y-treated patients ( P =0.001). Stent thromboses occurred in 1 patient assigned to placebo 90 Sr/ ⁹⁰ Y at day 244. Conclusions— The results of this study demonstrated that β-radiation using ⁹⁰ Sr/ ⁹⁰ Y is both safe and effective for preventing recurrence in patients with in-stent restenosis.