Sensitive troponin and N-terminal probrain natriuretic peptide in stable angina

Background: High-sensitivity cardiac troponin (hs-TnT) and N-terminal probrain natriuretic peptide (NT-proBNP) are powerful predictors of mortality in patients with stable coronary artery disease. Whether their combined use may further improve mortality prediction in these patients is unknown.

Materials and methods: The study included 869 patients with stable coronary artery disease who underwent percutaneous coronary intervention. Hs-TnT and NT-proBNP were measured before angiography. Using median values of hs-TnT (0·008 μg L(-1)) and NT-proBNP (250·0 ng L(-1)) as cut-off points, patients were divided into four groups: low hs-TnT/low NT-proBNP group (293 patients with hs-TnT and NT-proBNP < median); low hs-TnT/high NT-proBNP group (142 patients with hs-TnT < median and NT-proBNP ≥ median); high hs-TnT/low NT-proBNP group (142 patients with hs-TnT ≥ median and NT-proBNP < median) and high hs-TnT/high NT-proBNP group (292 patients with hs-TnT and NT-proBNP ≥ median). The primary end point was all-cause mortality.

Results: The 4-year follow-up was complete in 90·7% of the patients. There were 76 deaths during the follow-up: seven in low hs-TnT/low NT-proBNP, 8 in low hs-TnT/high NT-proBNP, 10 in high hs-TnT/low NT-proBNP and 51 in high hs-TnT/high NT-proBNP groups (mortality estimates, 2·5%, 5·9%, 7·4% and 18·1%, respectively; odds ratio = 8·64, 95% confidence interval 3·85-19·4, P < 0·001 for high hs-TnT/high NT-proBNP vs. low hs-TnT/low NT-proBNP). Inclusion of hs-TnT and NT-proBNP in the multivariable model increased the discriminatory power of the model regarding mortality prediction compared with the model without biomarkers (absolute and relative integrated discrimination improvement 0·039 and 26·0%, P = 0·0015).

Conclusions: Combined use of hs-TnT and NT-proBNP improves long-term risk prediction of mortality in patients with stable coronary heart disease.