Cystatin C and sudden cardiac death risk in the elderly.
BACKGROUND
Recent studies have demonstrated an association between moderate kidney dysfunction and sudden cardiac death in people with cardiovascular disease.


RESULTS
The study was a longitudinal analysis among 4465 participants from the Cardiovascular Health Study without prevalent cardiovascular disease at baseline. Cystatin C and creatinine were measured from baseline sera. Sudden cardiac death (SCD) was defined as a sudden pulseless condition from a cardiac origin in a previously stable individual that occurred out of the hospital or in the emergency room. The association between cystatin C tertiles and SCD was determined with multivariate Cox proportional hazards. A similar analysis compared SCD incidence across creatinine-based estimated glomerular filtration rate (eGFR) tertiles. Over a median follow-up of 11.2 years, 91 adjudicated SCD events occurred. The annual incidence of SCD events increased across cystatin C tertiles: 10 events per 10 000 person years in tertile 1, 25 events per 10 000 person years in tertile 2, and 32 events per 10 000 person-years in the highest cystatin C tertile. These associations persisted after multivariate adjustment: hazards ratio=2.72; 95% confidence interval, 1.44 to 5.16 in tertile 2 and hazards ratio=2.67; 95% confidence interval, 1.33 to 5.35 in tertile 3. After multivariate adjustment, the rate of SCD also increased in a linear distribution across creatinine-based eGFR tertiles: 15 events per 10 000 person-years in tertile 1, 22 events per 10 000 person-years in tertile 2, and 27 events per 10 000 person-years in tertile 3. No significant associations, however, remained between creatinine-based eGFR and SCD after multivariable adjustment.


CONCLUSIONS
Impaired kidney function, as measured by cystatin C, has an independent association with SCD risk among elderly persons without clinical cardiovascular disease.
Deo
Rajat
R
Division of Cardiology, University of Pennsylvania, Philadelphia 19104, USA. Rajat.Deo@uphs.upenn.edu
Sotoodehnia
Nona
N
Katz
Ronit
R
Sarnak
Mark J
MJ
Fried
Linda F
LF
Chonchol
Michel
M
Kestenbaum
Bryan
B
Psaty
Bruce M
BM
Siscovick
David S
DS
Shlipak
Michael G
MG
D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000097:blood / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D015854:Up-Regulation
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D003404:Creatinine