PLASMA ACTIVITY AND INSERTION DELETION POLYMORPHISM OF ANGIOTENSIN-I-CONVERTING-ENZYME - A MAJOR RISK FACTOR AND A MARKER OF RISK FOR CORONARY STENT RESTENOSIS/

Background-Tissue proliferation is almost invariably observed in recur rent-lesions within stents, and ACE, a factor of smooth muscle cell pr oliferation, may play an important role. Plasma ACE level is largely c ontrolled by the insertion/deletion (I/D) polymorphism of the enzyme g ene. The association among restenosis within coronary stents, plasma A CE level, and the I/D polymorphism is analyzed in the present prospect ive study. Methods and Results-One hundred seventy-six consecutive pat ients with successful, high-pressure, elective stenting of de novo les ions in the native coronary vessels were considered. At follow-up angi ography, recurrence was observed in 35 patients (19.9%). Baseline clin ical and demographic variables, plasma glucose and serum fibrinogen le vels, lipid profile, descriptive and quantitative angiographic data, a nd procedural variables were not significantly different in patients w ith and without restenosis: mean plasma ACE levels (+/-SEM) were 40.8/-3.5 and 20.7+/-1.0 U/L, respectively (P<.0001). Diameter stenosis pe rcentage and minimum luminal diameter at 6 months showed statistically significant correlation with plasma ACE level (r=.352 and -.387, resp ectively P<.001). Twenty-one of 62 patients (33.9%) with D/D genotype, 13 of 80 (16.3%) with I/D genotype, and 1 of 34 (2.9%) with I/I genot ype showed recurrence; the restenosis rate for each genotype is consis tent with a codominant expression of the allele D. Conclusions-In a se lected cohort of patients, both the D/D genotype of the ACE gene, and high plasma activity of the enzyme are significantly associated with i n-stent restenosis. Continued study with clinically different subsets of patients and various stent designs is warranted.