Josep Rodés

Biocompatibility aspects of new stent technology

Stent implantation represents a major step forward since the introduction of coronary angioplasty. As indications continue to expand, better understanding of the early and late biocompatibility issues appears critical. Persisting challenges to the use of intracoronary stents include the prevention of early thrombus formation and late neointima development. Different metals and designs have been evaluated in animal models and subsequently in patients. Polymer coatings have been proposed to improve the biocompatibility of metallic stents or to serve as matrix for drug delivery and they are currently undergoing clinical studies. The promises of a biodegradable stent have not yet been fulfilled although encouraging results have recently been reported. Continuous low dose-rate brachytherapy combining the scaffolding effect of the stent with localized radiation therapy has witnessed the development and early clinical testing of radioactive stents. The combined efforts of basic scientists and clinicians will undoubtedly contribute to the improvement of stent biocompatibility in the future.

Prevention of Restenosis After Angioplasty in Small Coronary Arteries With Probucol

BACKGROUND Restenosis remains the major limitation of coronary angioplasty. Coronary stents have reduced the incidence of restenosis in selected patients with relatively large vessels. No strategies to date have demonstrated a beneficial effect in vessels < 3.0 mm in diameter. We have shown in the MultiVitamins and Probucol (MVP) Trial that probucol, a potent antioxidant, reduces restenosis after balloon angioplasty. The purpose of this study was to determine whether the benefit of probucol therapy is maintained in the subgroup of patients with smaller coronary vessels. METHODS AND RESULTS We studied a subgroup of 189 patients included in the MVP trial who underwent successful balloon angioplasty of at least one coronary segment with a reference diameter < 3.0 mm. One month before angioplasty, patients were randomly assigned to one of four treatments: placebo, probucol (500 mg), multivitamins (beta-carotene 30000 IU, vitamin C 500 mg, and vitamin E 700 IU), or probucol plus multivitamins twice daily. The treatment was maintained until follow-up angiography was performed at 6 months. The mean reference diameter of this study population was 2.49+/-0.34 mm. Lumen loss was 0.12+/-0.34 mm for probucol, 0.25+/-0.43 mm for the combined treatment, 0.35+/-0.56 mm for vitamins, and 0.38+/-0.51 mm for placebo (P=.005 for probucol). Restenosis rates per segment were 20.0% for probucol, 28.6% for the combined treatment, 45.1% for vitamins, and 37.3% for placebo (P=.006 for probucol). CONCLUSIONS Probucol reduces lumen loss and restenosis rate after balloon angioplasty in small coronary arteries.

Value of exercise electrocardiography in the detection of restenosis after coronary angioplasty in patients with one-vessel disease.

Exercise treadmill testing (ETT) is considered an unreliable method for detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA). The studies on which this belief is based have used quantitative coronary angiography (QCA) as a reference. The inherent limitations of angiography have been demonstrated by intravascular ultrasound (IVUS). To determine the value of ETT for detecting restenosis when IVUS criteria are used to define restenosis, we studied 29 patients with angiographically documented 1-vessel coronary disease (<35% stenosis in all nondilated segments) who underwent angioplasty. ETT was performed < or =2 weeks before follow-up angiography and IVUS imaging. Only patients without any abnormalities precluding an accurate reading of the ST segment during ETT were included. Restenosis was defined as a > or =50% diameter stenosis by QCA criteria and as a cross-sectional area narrowing of > or =75% by IVUS. The ETT was positive in 12 patients and restenosis was documented by QCA and IVUS in 38% and 48% of cases, respectively. Sensitivity, specificity, and positive and negative predictive values of ETT when QCA was used as a reference were 55%, 67%, 50%, and 71%, respectively. This corresponded to an accuracy of 62% when compared with QCA. Sensitivity, specificity, and positive and negative predictive values were 79%, 93%, 92%, and 82% when ETT was compared with IVUS, with an accuracy of 86% (p = 0.002). Thus, ETT is a reliable noninvasive method for detecting the presence of restenosis after PTCA in patients with 1-vessel coronary artery disease. The presence of > or =75% cross-sectional narrowing shown by IVUS is well correlated with > or =1-mm ST-segment depression at follow-up ETT after PTCA.

Management of resistant coronary lesions by the cutting balloon catheter: initial experience.

Resistant coronary lesions remain a challenge for modern angioplasty. Classical approaches include high-pressure inflations, prolonged inflations, or balloon oversizing. More recently, new technologies like rotablator, atherectomy, or laser have been proposed as adjunct to balloon angioplasty for the treatment of these specific lesions. However, all these technologies remain more difficult to handle, costly, and they do not offer long-term benefit over conventional methods. Therefore, a simple device such as the cutting balloon catheter which has been developed from a standard over the wire balloon catheter, may prove to be useful in resistant coronary lesions. We present our single center experience using the new cutting balloon catheter in six resistant lesions.

Transcatheter closure of apical ventricular muscular septal defect combined with arterial switch operation in a newborn infant.

This report describes a case of transposition of the great arteries and apical muscular ventricular septal defect in a newborn infant successfully treated by transcatheter closure of the septal defect with the Amplatzer duct occluder device followed by an arterial‐switch operation within the first 2 weeks of life. Cathet. Cardiovasc. Intervent. 49:173–176, 2000.

Development of coronary aneurysm after cutting balloon angioplasty: Assessment by intracoronary ultrasound

We report the case of a coronary aneurysm observed 6 mo after cutting balloon angioplasty complicated by a mild perforation. Intravascular ultrasound allowed characterization of the malformation as a true aneurysm. The clinical course was uneventful.

Angioscopic evaluation of thrombus removal by the POSSIS AngioJet thrombectomy catheter

Coronary angioplasty in a thombotic vein graft is associated with a low success rate and a high risk of periprocedural complications. The aspiration thrombectomy catheter is a new device designed to treat such cases. We report a first angioscopic description of thrombus removal by the AngioJet thrombectomy catheter.