Research Highlights - Miami Center, United States

The Leducq program at the University of Miami is in a unique position to develop large clinical and genetic data sets that can be used for profiling high risk for VF and SCD in ethnically mixed populations. Our approach derives from observations that at least 2/3 of all victims of unexpected cardiac arrest have no prior diagnosis of cardiac disorders or are considered to be at low risk on existing clinical criteria. A major objective of the UM Leducq component is to identify genetic markers that will help to identify these previously unidentified individuals at risk for SCD by characterizing high-risk subgroups within the population at large.

To accomplish this goal, the clinical and genetics group at the University of Miami Medical Center have made a collaborative arrangement with the Metropolitan Miami-Dade County Medical Examiner Office to carry out genetic studies in out-of-hospital cardiac arrest victims who have postmortem examinations by the Medical Examiner's Office. The overwhelming majority of such events are due to coronary arteriolosclerosis and its consequences, and the incidence of other disorders generally reflects the prevalence of those disorders in the community. The original intent of the collaboration was to seek information on the prevalence of the rare cardiac disorders, most of which are genetically determined, among the SCD cohort in Metropolitan Miami-Dade County.

The Leducq network will allow expansion of these activities, being designed to seek genetic predispositions to cardiac arrest among the victims of acute coronary syndromes, as compared to those individuals who have other expressions of these acute events. It is anticipated that there will be some degree of favorable selection bias within a Medical Examiner population. Specifically, since individuals who have had prior manifestations of coronary artery disease, such as ischemic cardiomyopathy and heart failure, are less likely to appear in a Medical Examiner population, the bias will be towards subjects in whom cardiac arrest is the first event. Prior studies suggest that those circumstances are particularly favorable to the interests of the Leducq network application. An IRB-approved mechanism has been put in place for obtaining control subjects for our studies that will accurately reflect the distinctive demographics of the South Florida community.