Evaluation of the long-term functional outcome assessed by myocardial perfusion scintigraphy following excimer laser angioplasty compared to balloon angioplasty in longer coronary lesions

Objectives: Evaluation of the long-term functional outcome assessed by exercise myocardial perfusion imaging following excimer laser angioplasty compared to balloon angioplasty in coronary lesions > 10 mm in length. Background: Previous randomized studies evaluating the effect of coronary interventions mainly focused on the long-term clinical and angiographic outcome. The functional outcome, assessed by myocardial perfusion scintigraphy, has not been evaluated in a randomized setting. Methods: A total of 308 patients with stable angina and a longer coronary lesion “> 10 mm” were randomized to excimer laser angioplasty or balloon angioplasty. A ^99mTechnetium-2-methoxy isobutyl isonitrile “MIBI” single-photon emission computed tomography “SPECT” study was performed in 139 patients before the initial angioplasty procedure and at 6 months follow-up “73 patients in the laser group versus 66 patients in the balloon group, respectively”. Exercise tolerance at follow-up was compared to baseline values by means of exercise duration and double product at peak exercise. Myocardial perfusion of the randomized vascular bed was assessed semi-quantitatively on the MIBI SPECT images. The reversible defects were graded as mild, moderate or severe. Myocardial perfusion at follow-up was expressed as a percentage reduction in incidence and grading of the reversible defects compared to baseline values. Results: Forty-four “61%” patients assigned to laser angioplasty were asymptomatic at 6 months follow-up compared to 34 “52%” patients assigned to balloon angioplasty “p = NS”. Improvement in exercise duration and double product were 0.7 ± 2.1 min and 4.3 ± 6.2 min/mmHg/1000, respectively, in the laser group, versus 0.3 ± 2.5 min and 3.1 ± 5.5 min/mmHg/1000, respectively, in the balloon group “both p = NS”. The percentage reduction of reversible defects was 23% in patients assigned to laser angioplasty vs. 29% in patients assigned to balloon angioplasty “Relative risk [RR]: 0.79, 95% confidence interval [CI]: 0.40-1.57; p = 0.50”. The mild, moderate and severe reversible defects improved in 44.4, 63.6 and 66.6%, respectively, in the laser angioplasty group vs. 66.6, 53.8 and 90%, respectively, in the balloon angioplasty group. None of the comparisons were significantly different. Conclusion: Excimer laser angioplasty compared to balloon angioplasty in coronary lesions > 10 mm in length yields a similar long-term functional outcome assessed by anginal status, exercise tolerance and myocardial perfusion.