Bone modifiers and the quest to slow progression of aortic stenosis

Aortic stenosis (AS) will likely become increasingly frequent with the aging of the American population. The difficulties in treating elderly patients with critical AS emphasize the potential value of a strategy to slow the advancement of aortic valve calcification. Recent prospective trials of statins and angiotensin-converting enzyme inhibitors have been disappointing. New options are needed to achieve a truly effective strategy for retarding the advancement of AS. In this context, the observations of Skolnick et al appearing in this issue of The American Journal of Cardiology are particularly intriguing. In a retrospective review of patients followed for mild or moderate AS, these investigators found that 18 patients receiving treatment for osteoporosis had significantly less decrement in aortic valve area on follow-up echocardiography than 37 not receiving such treatment. The most attractive explanation is an action of drug therapy for osteoporosis, most often bisphosphonates, to retard aortic valve calcification. The mechanism for this action is not clear, although numerous possibilities can be postulated on the basis of the multiple complex processes controlling tissue calcification. In conclusion, the investigators' findings deserve further study to clarify drug impact on aortic valve calcification as well as confirm the clinical findings in a larger and more diverse population. Such investigation should also assess the role of vitamin D and calcium supplementation, common features of treatment for osteoporosis. Currently available results are too preliminary to justify the use of bisphosphonates or other osteoporosis therapies to slow the progression of AS.