Atorvastatin, Etidronate, or Both in Patients at High Risk for Atherosclerotic Aortic Plaques: A Randomized, Controlled Trial

Background- Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta. Methods and Results- A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, -16.4 to -11.3) and 12.3% (95% confidence interval, -14.9 to -9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, -0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (-11.4%) than in the atorvastatin group (-0.9%; P<0.001) and the etidronate group (5.5%; P=0.006). Conclusions- Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy. Clinical Trial Registration- URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.