Author Contributions: Dr Roger had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Bursi, Jacobsen, Roger.
Acquisition of data: Bursi, Weston, Jacobsen, Pakhomov, Nkomo, Roger.
Analysis and interpretation of data: Bursi, Weston, Redfield, Jacobsen, Pakhomov, Nkomo, Meverden, Roger.
Drafting of the manuscript: Bursi, Roger.
Critical revision of the manuscript for important intellectual content: Weston, Redfield, Jacobsen, Pakhomov, Nkomo, Meverden.
Statistical analysis: Weston, Meverden.
Obtain funding: Bursi, Jacobsen, Roger.
Study supervision: Bursi, Roger.
Financial Disclosures: None reported.
Funding/Support: This work was supported in part by grants from the Public Health Service and the National Institutes of Health (AR30582, R01 HL72435) and by an American Heart Association Postdoctoral Greater Midwest Fellowship Award (Dr Bursi). Dr Roger is an Established Investigator by the American Heart Association.
Role of the Sponsor: The funding organizations did not participate in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review or approval of the manuscript.
Acknowledgment: We thank the following individuals at the Mayo Clinic: Ellen Koepsell, RN, and Kay Traverse, RN, for their assistance with patient enrollment and data collection; Amy Wockenfuss and Renee Scott, for assistance with sample processing and analysis; and Kristie Shorter, for secretarial assistance. We also thank the study sonographers: Jo-Ellen Ehrsam, RDCS, Tammy Green, RDCS, Mary E. Hagen, RN, RDCS, Anthony Joseph, RDCS, and Patricia L. Zummach, RDCS. These individuals were not compensated for their contributions.