MedicalResearch.com Interview with:
Andrew T. Yan, MD
Terrence Donnelly Heart Centre
St Michael’s Hospital
University of Toronto
Toronto, Ontario, Canada
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The pathogenesis of aortic stenosis is complex and incompletely understood. Previous experimental data and epidemiologic studies (mostly cross-sectional) have demonstrated an association between conventional cardiovascular risk factors such as hypertension, diabetes, and dyslipidemia, and aortic sclerosis or stenosis. However, there is a paucity of longitudinal data from large population studies. Therefore, we sought to examine the relationship between conventional cardiovascular risk factors and incident severe aortic stenosis during extended follow-up in a large unselected elderly population in Ontario, Canada.
In over 1 million individuals older than 65 who were followed for a median of 13 years, hypertension, diabetes and dyslipidemia were all significantly and independently associated with development of severe aortic stenosis requiring hospitalization or intervention. Furthermore, we observed a positive dose-response relationship between the number and duration of cardiac risk factors, and the risk of aortic stenosis. Together, these risk factors accounted for approximately one third of the incidence of severe aortic stenosis at a population level.
MedicalResearch.com: What should readers take away from your report?
Response: While this large population-based observational study alone cannot establish causality, it adds to the existing evidence that modifiable cardiovascular risk factors play an important and causative role in aortic stenosis. Beyond other proven benefits in atherosclerotic diseases, optimal risk factor management may also mitigate the burden of aortic stenosis in the aging population.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Response: The advanced stage of disease, the short duration of follow-up and the relatively small number of events might have contributed to the disappointing findings of prior randomized controlled trials of statins in aortic stenosis. To date, there has been no randomized controlled trial to specifically examine whether anti-hypertensive or anti-hyperglycemic therapy can prevent the development or retard the progression of aortic stenosis, but adequately powered trials with sufficient long-term follow-up will unlikely be conducted in the future. Thus, the totality of data from animal models, Mendelian randomization studies, and longitudinal population-based studies may represent the “best available” evidence implicating a causal relationship between cardiovascular risk factors and aortic stenosis. Future studies confirming these findings in diverse patient populations (e.g. younger inception cohorts, other ethnic groups, with more granular data on risk factors and severity of aortic stenosis) would be helpful.
MedicalResearch.com: Is there anything else you would like to add?
Response: The availability of “big data” has greatly enhanced the epidemiologic study of less common and emerging diseases in the general population.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
Journal of the American College of Cardiology
Volume 69, Issue 12, March 2017>DOI: 10.1016/j.jacc.2017.01.025
Association Between Cardiovascular Risk Factors and Aortic Stenosis
The CANHEART Aortic Stenosis Study
Andrew T. Yan, Maria Koh, Kelvin K. Chan, Helen Guo, David A. Alter, Peter C. Austin, Jack V. Tu, Harindra C.Wijeysundera, Dennis T. Ko
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