Deleterious Effect of Coronary Brachytherapy on Vasomotor Response to Exercise

Abstract

Background-Intracoronary radiotherapy (brachytherapy) has been proposed as treatment option for in-stent restenosis.Long-term results of brachytherapy with regard to vascular integrity and vasomotor responsiveness are unknown. The purpose of the present study was to determine the vasomotor response after brachytherapy and to assess its influence on vasomotion during exercise. Methods and Results-Biplane quantitative coronary angiography was performed at rest and during bicycle exercise in 27 patients with coronary artery disease. Fourteen patients underwent coronary stenting and were studied 10Ϯ3 months after intervention (control group). Thirteen patients were treated with brachytherapy (Guidant Galileo System) for in-stent restenosis with a mean dosis of 20 Gy at 1 mm into the vessel wall and were studied 9Ϯ1 months after radiation (brachytherapy group). Minimal luminal area, stent area, and proximal, distal, and a reference vessel area were determined. The reference vessel showed exercise-induced vasodilation (26Ϯ4%, PϽ0.001) in both groups. Vasomotion within the stented vessel segments was abolished. In control subjects, the proximal and distal segments showed exercise-induced vasodilation (17Ϯ2% and 22Ϯ7%, respectively; PϽ0.005). In contrast, there was exercise-induced vasoconstriction in the proximal and distal vessel segments of the brachytherapy group (Ϫ14Ϯ3% and Ϫ16Ϯ4%, respectively; PϽ0.01). Sublingual nitroglycerin was associated with maximal vasodilation of the proximal and distal vessel segments in both groups. Conclusions-Normal

Impact of Vessel Size on Outcome After Implantation of Sirolimus-Eluting and Paclitaxel-Eluting Stents

“…Digital angiograms were analyzed with the use of an automated edge-detection system (CAAS II, Pie Medical Imaging, Maastricht, the Netherlands). The intraobserver and interobserver reliabilities of the quantitative measurements have been reported previously (16).…”

“…With p values for interaction of Ն0. 16, there was little evidence for 1A). There were no significant differences between SES and PES in small-vessel disease patients with respect to death, cardiac death, or myocardial infarction at up to 2 years of follow-up.…”

Sirolimus-Eluting Stents Associated With Paradoxic Coronary Vasoconstriction

“…Because of vessel overlap, analysis had to be restricted to a single plane in 27% of control group and 36% of sirolimus group segments, respectively. Data analysis was performed with the quantitative coronary analysis package on Philips DCI/Integris systems and has been described in detail previously (11)(12)(13). Percent changes were calculated in all patients using the baseline angiogram as reference.…”

“…This measurement was performed to determine the response to exercise within and outside the zone where sirolimus might be effective. The intra-and interobserver variability was low for minimal luminal diameter (Ͻ0.10 mm for intraobserver and Ͻ0.11 for interobserver variability) (11)(12)(13). All measurements were done by an independent observer who was blinded to the protocol.…”

Impact of arterial injury on neointimal hyperplasia after implantation of drug-eluting stents in coronary arteries: an intravascular ultrasound study

“…The intraobserver and interobserver reliabilities of the quantitative measurements have been reported previously. 16 Quantitative measurements included the reference vessel diameter (RVD), the minimal lumen diameter (MLD), percentage of diameter stenosis (defined as the diameter of the reference vessel minus the minimal luminal diameter, divided by the reference diameter and multiplied by 100), and late luminal loss (the difference between the minimal luminal diameter after the procedure and the minimal luminal diameter at follow-up). Binary restenosis was defined as stenosis >50% in the target lesion at angiographic follow-up.…”