Distal protection with a filter device during coronary stenting in patients with stable and unstable angina

Background - Filter protection after percutaneous coronary intervention (PCI) is now available to prevent distal embolization. The aims of this study were (1) to evaluate the microembolization phenomenon during procedures of stent implantation in native coronary arteries of patients with stable and unstable angina, (2) to assess the amount and characteristics of the debris captured by the Angioguard, and (3) to investigate the relation between clinical and angiographic variables and pathological data. Methods and Results - Elective coronary stenting with the use of a protective filter was attempted in 39 consecutive coronary artery lesions with >60% stenosis (mean, 67.6 +/- 8.79%). Debris was present in 75.6% of the filters. Particle size ranged from 47.16 to 2503.48 mum (mean, 518.83 +/- 319.61 mum) in the major axis. Particles >300 mum were found in 24 of 28 filters with debris (85.7%), and particles >1000 mum were present in 10 of 28 filters (35.7%). Patients with unstable angina had greater particles (mean maximum longitudinal diameter, 1098.33 +/- 714.3 mum) than those with stable angina (412.91 +/- 453 mum; P < 0.001). The presence of unstable angina (OR, 65; CI, 1.2 to 3420; P = 0.03) and age >67 years (OR, 42; CI, 1 to 1698; P = 0.04) were found to be the only independent predictors of embolic particle size. Conclusions - By limiting embolization, protective devices may prevent a number of potentially unfavorable events, thereby improving outcome. Our data support the use of these devices, especially in lesions with higher embolic potential, such as those occurring in older patients and in those with unstable angina.