Author Contributions: Dr Mills 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: Mills, Walker, Denvir, Fox, Newby.
Acquisition of data: Churchhouse, Lee, Anand, Gamble, Shah, Paterson, MacLeod.
Analysis and interpretation of data: Mills, Churchhouse, Lee, Anand, Graham, Walker, Denvir, Fox, Newby.
Drafting of the manuscript: Mills, Churchhouse, Newby.
Critical revision of the manuscript for important intellectual content: Mills, Churchhouse, Lee, Anand, Gamble, Shah, Paterson, MacLeod, Graham, Walker, Denvir, Fox, Newby.
Statistical analysis: Mills, Churchhouse, Lee, Graham.
Obtained funding: Mills, Newby.
Administrative, technical, or material support: Walker, Newby.
Study supervision: Mills, Denvir, Newby.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: This work was supported by a British Heart Foundation Intermediate Clinical Research Fellowship (FS/10/024/28266) (Dr Mills) and the British Heart Foundation Centre of Research Excellence award. The Wellcome Trust Clinical Research Facility is supported by National Health Service Research Scotland through National Health Service Lothian.
Role of the Sponsors: No funding organization or sponsor played a role in the design and conduct of the study, in the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.
Additional Contributions: Mary Stoddart (Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, Edinburgh, Scotland), performed the assessment of assay precision. No compensation was received for her contribution.