@article {6071, title = {Cardiomyocyte injury assessed by a highly sensitive troponin assay and sudden cardiac death in the community: the Cardiovascular Health Study.}, journal = {J Am Coll Cardiol}, volume = {62}, year = {2013}, month = {2013 Dec 03}, pages = {2112-20}, abstract = {

OBJECTIVES: This study sought to determine the association between markers of cardiomyocyte injury in ambulatory subjects and sudden cardiac death (SCD).

BACKGROUND: The pathophysiology of SCD is complex but is believed to be associated with an abnormal cardiac substrate in most cases. The association between biomarkers of cardiomyocyte injury in ambulatory subjects and SCD has not been investigated.

METHODS: Levels of cardiac troponin T, a biomarker of cardiomyocyte injury, were measured by a highly sensitive assay (hsTnT) in 4,431 ambulatory participants in the Cardiovascular Health Study, a longitudinal community-based prospective cohort study. Serial measures were obtained in 3,089 subjects. All deaths, including SCD, were adjudicated by a central events committee.

RESULTS: Over a median follow-up of 13.1 years, 246 participants had SCD. Baseline levels of hsTnT were significantly associated with SCD (hazard ratio [HR] for +1 log(hsTnT): 2.04, 95\% confidence interval [CI]: 1.78 to 2.34]. This association persisted in covariate-adjusted Cox analyses accounting for baseline risk factors (HR: 1.30, 95\% CI: 1.05 to 1.62), as well as for incident heart failure and myocardial infarction (HR: 1.26, 95\% CI: 1.01 to 1.57). The population was also categorized into 3 groups based on baseline hsTnT levels and SCD risk [fully adjusted HR: 1.89 vs. 1.55 vs. 1 (reference group) for hsTnT >=12.10 vs. 5.01 to 12.09 vs. <= 5.00 pg/ml, respectively; p trend = 0.005]. On serial measurements, change in hsTnT levels was also associated with SCD risk (fully adjusted HR for +1 pg/ml per year increase from baseline: 1.03, 95\% CI: 1.01 to 1.06).

CONCLUSIONS: The findings suggest an association between cardiomyocyte injury in ambulatory subjects and SCD risk beyond that of traditional risk factors.

}, keywords = {Aged, Ambulatory Care, Biomarkers, Death, Sudden, Cardiac, Female, Heart Arrest, Humans, Longitudinal Studies, Male, Middle Aged, Myocardium, Myocytes, Cardiac, Proportional Hazards Models, Risk Assessment, Troponin T}, issn = {1558-3597}, doi = {10.1016/j.jacc.2013.07.049}, author = {Hussein, Ayman A and Gottdiener, John S and Bartz, Traci M and Sotoodehnia, Nona and DeFilippi, Christopher and Dickfeld, Timm and Deo, Rajat and Siscovick, David and Stein, Phyllis K and Lloyd-Jones, Donald} } @article {6662, title = {Fibroblast growth factor 23 and sudden versus non-sudden cardiac death: the Cardiovascular Health Study.}, journal = {Am J Kidney Dis}, volume = {66}, year = {2015}, month = {2015 Jul}, pages = {40-6}, abstract = {

BACKGROUND: Elevated fibroblast growth factor 23 (FGF-23) concentrations are associated with greater risk of cardiovascular events and mortality, especially among people with chronic kidney disease (CKD). Because individuals with CKD are at an increased risk of sudden cardiac death (SCD), we sought to understand whether FGF-23 level is a stronger risk factor for SCD versus non-SCD.

STUDY DESIGN: Cohort study.

SETTING \& PARTICIPANTS: 3,244 participants 65 years or older in the community-based Cardiovascular Health Study.

PREDICTOR: Plasma FGF-23 concentrations.

OUTCOMES: We assessed SCD and non-SCD in these analyses. SCD was adjudicated rigorously and was defined as a sudden pulseless condition of cardiac origin in a previously stable person occurring out of hospital or in the emergency department.

MEASUREMENTS: We estimated associations of baseline FGF-23 concentrations with SCD and non-SCD using Cox proportional hazards models after adjustment for demographics, cardiovascular risk factors, comorbid conditions, and kidney function. We also tested whether associations differed by CKD status.

RESULTS: During a median follow-up of 8.1 years, there were 118 adjudicated SCD and 570 non-SCD events. After multivariable adjustment for demographics, cardiovascular risk factors, comorbid conditions, and parameters of kidney function, higher FGF-23 concentrations were an independent risk factor for non-SCD (HR [per doubling], 1.17; 95\% CI, 1.06-1.30). However, elevated FGF-23 concentrations were not associated independently with SCD (HR [per doubling], 1.07; 95\% CI, 0.85-1.35). In stratified analysis by CKD status (36.5\% of cohort), doubling of FGF-23 concentrations was associated independently with non-SCD (adjusted HR, 1.26; 95\% CI, 1.10-1.45). A similar magnitude of association was observed between FGF-23 level and SCD in the CKD subgroup; however, it was not significant (HR, 1.20; 95\% CI, 0.89-1.62).

LIMITATIONS: Limited power to detect moderate-sized effects between FGF-23 level and SCD in both the primary and stratified analyses.

CONCLUSIONS: In this population-based study, FGF-23 level elevations were associated independently with non-SCD. Among individuals with CKD, the associations between FGF-23 level and SCD and non-SCD were similar.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, Comorbidity, Death, Sudden, Cardiac, Electrocardiography, Female, Fibroblast Growth Factors, Follow-Up Studies, Heart Arrest, Heart Diseases, Humans, Kaplan-Meier Estimate, Male, Prospective Studies, Renal Insufficiency, Chronic, Risk Factors, Sympathetic Nervous System, United States}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2014.10.025}, author = {Deo, Rajat and Katz, Ronit and de Boer, Ian H and Sotoodehnia, Nona and Kestenbaum, Bryan and Mukamal, Kenneth J and Chonchol, Michel and Sarnak, Mark J and Siscovick, David and Shlipak, Michael G and Ix, Joachim H} }