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 exer cise myocardial perfusion imaging following excimer laser angioplasty compa red to balloon angioplasty in coronary lesions > 10 mm in length. Backgroun d: Previous randomized studies evaluating the effect of coronary interventi ons 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 wi th stable angina and a longer coronary lesion (> 10 mm) were randomized to excimer laser angioplasty or balloon angioplasty. A (99m)mTechnetium-2-meth oxy isobutyl isonitrile (MIBI) single-photon emission computed tomography ( SPECT) study was performed in 139 patients before the initial angioplasty p rocedure and at 6 months follow-up (73 patients in the laser group versus 6 6 patients in the balloon group, respectively). Exercise tolerance at follo w-up was compared to baseline values by means of exercise duration and doub le product at peak exercise. Myocardial perfusion of the randomized vascula r bed was assessed semi-quantitatively on the MIBI SPECT images. The revers ible defects were graded as mild, moderate or severe. Myocardial perfusion at follow-up was expressed as a percentage reduction in incidence and gradi ng of the reversible defects compared to baseline values. Results: Forty-fo ur (61%) patients assigned to laser angioplasty were asymptomatic at 6 mont hs 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, ve rsus 0.3 +/- 2.5 min and 3.1 +/- 5.5 min/mmHg/1000, respectively, in the ba lloon group (both p = NS). The percentage reduction of reversible defects w as 23% in patients assigned to laser angioplasty vs. 29% in patients assign ed to balloon angioplasty (Relative risk [RR]: 0.79, 95% confidence interva l [CI]: 0.40-1.57; p = 0.50). The mild, moderate and severe reversible defe cts improved in 44.4, 63.6 and 66.6%, respectively, in the laser angioplast y group vs. 66.6, 53.8 and 90%, respectively, in the balloon angioplasty gr oup. None of the comparisons were significantly different. Conclusion: Exci mer 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.