Elsevier

Cardiovascular Radiation Medicine

Volume 4, Issue 4, October–December 2003, Pages 176-181
Cardiovascular Radiation Medicine

Effects of delayed (24 h postintervention) β-irradiation therapy after coronary angioplasty and stenting in de novo native coronary artery lesions: Results of a randomized clinical and intravascular ultrasound study☆

https://doi.org/10.1016/j.carrad.2003.12.001Get rights and content

Abstract

Background

The effects of brachytherapy performed 24 h postintervention in de novo native coronary artery lesions.

Methods and Results

Thirty-nine patients with 39 de novo coronary artery lesions were randomised to prompt (immediately after intervention, n=21) or delayed (24 h later, n=18) beta brachytherapy (90Sr/90Y) after been successfully revascularized with stenting. Clinical follow-up data up to 21 months (median time) were compared. After irradiation and at 6-month follow-up, paired volumetric analysis of the stented segment and the 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque, and media (external elastic membrane minus lumen), stent and intima hyperplasia (stent minus lumen).

Baseline clinical and angiographic characteristics were similar in the two groups. Postintervention measurements of stent, lumen, and intima hyperplasia volumes as well as postintervention minimum lumen cross-sectional areas were not different. In the stented segments and in the segments 5 mm proximal and distal to the stent, similar changes of all IVUS measurements were measured in the two patient groups, but in the lumen volume at the proximal stent edge of patients irradiated 24 h postinjury. At 21 months median follow-up time, target lesion revascularization (TLR) was performed in 8 patients (38%) in the prompt irradiation group compared with 3 (17%) in the delayed (P=.17).

Conclusion

Beta irradiation is similarly effective whether performed immediately after percutaneous coronary intervention or 24 h later.

Introduction

Although stent placement has become the predominant mode of coronary revascularization, restenosis remains the major limitation for percutaneous coronary interventions. Coronary brachytherapy carried out immediately after intervention is a promising therapy potentially reducing in-stent restenosis. However, the potential benefit of delayed coronary brachytherapy has not been tested clinically. The purpose of this randomized clinical and volumetric serial intravascular ultrasound (IVUS) study was to compare the effectiveness of delayed (24 h later) versus prompt (immediately after intervention) β-irradiation in de novo coronary lesions pretreated with balloon angioplasty and stenting.

Section snippets

Patients and study protocol

The study population included patients at high risk of restenosis (long lesions or chronic total occlusions) with de novo lesions of native coronary arteries scheduled to undergo elective coronary angioplasty and stenting. All patients had angina and/or objective evidence of ischemia. Patients' exclusion criteria were (a) evidence of myocardial infarction within 3 days before the procedure, (b) contraindication to aspirin and/or clopidogrel, (c) reference vessel diameter <2.5 or 4.0 mm (d)

Results

Baseline clinical and angiographic characteristics of the study patients, as well as radiation procedural data, are shown in Table 1. Thirty-nine patients with 39 long lesions (mean lesion length 31.7 mm, range 18 to 80 mm) were randomized to prompt (21/39) versus delayed irradiation (18/39). Patients treated with prompt irradiation were younger compared to the ones treated with delayed. The irradiation catheter and seeds were deployed and the prescribed dose was delivered successfully in all

Discussion

The injury caused by balloon angioplasty triggers a cascade of complex events that simulate recoil, intimal hyperplasia, and vessel remodeling. The former is linked with intense proliferation of adventitial myofibroblasts [5] and the latter with smooth cell and macrophage cell proliferation and migration [6], [7]. Stent implantation prevents vessel remodeling to a large extent. However, stent implantation enhances neointimal formation and it is neointima that is principally responsible for

Conclusion

Brachytherapy can be performed 24 h postrevascularization of de novo human coronary arteries without affecting its effectiveness and safety.

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☆

Study presented in part during the VII Cardiovascular Revascularization Therapy, January 26–29, 2003, Washington, DC, USA.

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