Differential prediction of high-sensitivity cardiac troponin-I, but not N-terminal pro-brain natriuretic peptide, in different pitavastatin doses on cardiovascular events in stable coronary artery disease

Background: This study aimed to examine whether high-sensitivity cardiac troponin-I (hsTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) could predict future major adverse cardiovascular events (MACE) in stable coronary artery disease (CAD) patients with high- or low-dose of pitavastatin. Methods: This was a case-cohort analysis of the REAL-CAD study, a randomized trial of high- or low-dose (4 or 1 mg/day) pitavastatin therapy in patients with stable CAD. We examined the MACE risk according to the quartile of hsTnI and NT-proBNP at baseline. Results: A total of 1336 and 1396 patients including 582 MACE cases were randomly examined into the hsTnI and NT-proBNP cohort, respectively. Both higher levels of hsTnI and NT-proBNP at baseline were significantly associated with increased risk of MACE (p < 0.001, respectively). When separately analyzed in statin dose, the higher marker levels were significantly associated with higher MACE risk in all cohorts (p < 0.001 in all cohorts). After multivariable adjustment, hsTnI levels were significantly associated with MACE risk in low-dose statin group (HR 2.54, p = 0.0001); however, in high-dose pitavastatin therapy, a significant association was diminished in MACE risk among the quartiles of baseline hsTnI levels (p = 0.154). Conversely in the NT-proBNP cohort, the association between NT-proBNP levels and MACE risk was constantly observed regardless of pitavastatin dose even after multivariable adjustment (both p < 0.0001). Conclusions: Patients with high hsTnI levels had high risk of MACE in low-dose statin group, but not in high-dose, suggesting that high-dose statin treatment might decrease MACE risk in stable CAD patients with high hsTnI levels.