Clinical relevance of a raised plasma N-terminal pro-brain natriuretic peptide level in a population-based cohort of nonagenarians.

OBJECTIVES: To investigate whether plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) remains a specific marker of cardiac illness in very old age and can be used to identify very elderly people at high risk for death independent of the presence of known cardiac diagnoses.

DESIGN: Prospective, observational, population-based follow-up study within the Leiden 85-Plus Study of a 2-year birth cohort (1912-1914).

SETTING: General population, municipality of Leiden, the Netherlands.

PARTICIPANTS: Two hundred seventy-four participants were followed up from age 90 onward (median follow-up 42.3 months, interquartile range 20.2-50.2 months).

MEASUREMENTS: Plasma NT-proBNP level, indicators of general health and functioning, and specific cardiac diagnoses at age 90 and mortality from age 90 onward.

RESULTS: Plasma levels of NT-proBNP were not correlated with indicators of poor health or poor functioning, but the level of NT-proBNP increased significantly with increasing numbers of cardiac diagnoses (P<.001). High NT-proBNP was associated with overall mortality in participants with (hazard ratio (HR)=2.8, 95% confidence interval (CI)=1.5-5.2) and without (HR=3.5, 95% CI=1.6-7.5) specific cardiac diagnoses. This was also found for cardiovascular mortality risks (with specific cardiac diagnoses HR=4.1, 95% CI=1.5-11 vs without HR=5.6, 95% CI=1.0-30) and noncardiovascular mortality risks (with specific cardiac diagnoses HR=1.9, 95% CI=0.84-4.5 vs without HR=3.4, 95% CI=1.3-8.6).

CONCLUSION: Plasma NT-proBNP is a disease-specific marker of cardiac illness in nonagenarians and can possibly be used as a predictor of mortality in elderly people with and without specific cardiac diagnoses.