Impact of angiotensin II receptor blockers on the progression and regression of coronary atherosclerosis - An intravascular ultrasound study

Background: Although angiotensin II receptor blockers (ARB) have been found to reduce the coronary atherosclerotic plaque burden in animal models, it is unknown whether ARB have a similar effect on human coronary arteries. Methods and Results: Serial intravascular ultrasound (IVUS) studies of the left main (LM) coronary artery were performed in 64 patients at baseline and after 7-month follow-up. All patients were divided into 2 groups (ARB group: 23 patients; non-ARB group: 41 patients). Three-dimensional volumetric analysis was done throughout the LM coronary artery, and the volume index (VI; volume/length) was calculated for the vessel (VVI), lumen (LVI), and plaque (PVI). No significant difference was found between the 2 groups in baseline clinical characteristics, including age, gender, blood pressure levels, serum cholesterol levels, the presence of diabetes and smoking status. At baseline VVI, LVI and PVI were similar between the groups. In the non-ARB group, VVI, LVI, and PVI did not change between baseline and follow-up. In the ARB group, PVI significantly decreased during follow-up (9.9±3.1 mm ² vs 9.1±2.7 mm ², p<0.01), whereas VVI and LVI were unaffected. Conclusions: This preliminary IVUS study suggests that ARB could cause regression of coronary atherosclerosis in humans.