Minimally elevated cardiac troponin T and elevated N-terminal pro-B-type natriuretic peptide predict mortality in older adults: results from the Rancho Bernardo Study.
OBJECTIVE
This study investigated the prognostic value of detectable cardiac troponin T (TnT) and elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in a population of community-dwelling older adults.


BACKGROUND
Minimally elevated levels of TnT, a marker of cardiomyocyte injury, have been found in small subsets of the general population, with uncertain implications. A marker of ventricular stretch, NT-proBNP has clinical utility in many venues, but its long-term prognostic value in apparently healthy older adults and in conjunction with TnT is unknown.


METHODS
Participants were 957 older adults from the Rancho Bernardo Study with plasma NT-proBNP and TnT measured at baseline (1997 to 1999) and followed up for mortality through July 2006.


RESULTS
Participants with detectable TnT (>/=0.01 ng/ml, n = 39) had an increased risk of all-cause and cardiovascular death (adjusted hazard ratio [HR] by Cox proportional hazards analysis: 2.06; 95% confidence interval [CI]: 1.29 to 3.28, p = 0.003 for all-cause mortality; HR: 2.06, 95% CI: 1.03 to 4.12, p = 0.040 for cardiovascular mortality); elevated NT-proBNP also predicted an increased risk of all-cause and cardiovascular mortality (adjusted HR per unit-log increase in NT-proBNP: 1.85, 95% CI: 1.36 to 2.52, p < 0.001 for all-cause mortality; HR: 2.51, 95% CI: 1.55 to 4.08, p < 0.001 for cardiovascular mortality). Those with both elevated NT-proBNP and detectable TnT had poorer survival (HR for high NT-proBNP and detectable TnT vs. low NT-proBNP and any TnT: 3.20, 95% CI: 1.91 to 5.38, p < 0.001). Exclusion of the 152 participants with heart disease at baseline did not materially change the TnT mortality or NT-proBNP mortality associations.


CONCLUSIONS
Apparently healthy adults with detectable TnT or elevated NT-proBNP levels are at increased risk of death. Those with both TnT and NT-proBNP elevations are at even higher risk, and the increased risk persists for years.
Daniels
Lori B
LB
Division of Cardiology, Department of Medicine, University of California at San Diego, San Diego, California, USA. lbdaniels@ucsd.edu
Laughlin
Gail A
GA
Clopton
Paul
P
Maisel
Alan S
AS
Barrett-Connor
Elizabeth
E
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002140:California / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain