Premorbid levels of high-sensitivity cardiac troponin T and natriuretic peptide and prognosis after incident myocardial infarction.

High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) at the time of myocardial infarction (MI) are strong predictors of prognosis. However, whether their premorbid (before MI occurrence) levels are associated with prognosis after incident MI is unknown.

METHODS: In 1,054 participants from the Atherosclerosis Risk in Communities Study with incident MI, we evaluated premorbid levels of hs-cTnT and NT-proBNP measured on median 5.8 (interquartile interval 3.0-11.5 [mean 5.5]) years prior to incident MI and their associations with subsequent composite and individual outcomes of all-cause mortality, cardiovascular mortality, recurrent MI, heart failure, and stroke.

RESULTS: During a median follow-up of 3.0 years after MI, 801 participants developed the composite outcome. Both hs-cTnT and NT-proBNP were independently associated with the composite outcome after incident MI. Among individual outcomes, all-cause mortality, cardiovascular mortality, and heart failure showed significant associations with both cardiac markers. Overall, NT-proBNP demonstrated a more evident relationship than hs-cTnT. Indeed, the addition of premorbid NT-proBNP alone, but not hs-cTnT alone, to conventional predictors at incident MI significantly improved risk prediction of the composite outcome after incident MI (Δc-statistic 0.013 [95% CI 0.005-0.022] from 0.691 with conventional predictors).

CONCLUSIONS: Premorbid levels of hs-cTnT and NT-proBNP assessed on average 6 years prior to incident MI were associated with adverse outcomes after incident MI. These results further highlight the importance of cardiac health at an earlier stage of life.