Background: The N-terminal-pro-B natriuretic peptide (Nt-pro-BNP) is of diagnostic and prognostic value in coronary artery disease (CAD). We assessed the relationship between Nt-pro-BNP and (1) the extent of ischemia on stress myocardial perfusion imaging (MPI), and (2) changes between the basal and postexercise ejection fraction (EF), in stable patients with a normal EF.
Methods and results: One hundred and two patients with stable, documented CAD (EF, 62% +/- 8%) underwent an exercise-rest thallium-201 gated-MPI and serial Nt-pro-BNP assays. Myocardial perfusion imaging produced abnormal results in 57 patients (56%; group 1), and normal results in 45 patients (44%; group 2). Median baseline, immediate postexercise, and 3-hour postexercise Nt-pro-BNP values were higher in group 1 than in group 2: 182 vs 85, 201 vs 86, and 212 vs 99 pg/mL, respectively (P < .001 for all). Postexercise EF decreased in group 1 (53% +/- 11% vs 62% +/- 10%, P < .001), but not in group 2 (61% +/- 9% vs 62% +/- 7%, NS). The Nt-pro-BNP ruled out significant ischemia with a negative predictive value of 0.90, whereas patients within the higher tertile of Nt-pro-BNP had a fivefold higher risk of ischemia compared with patients within the lower tertile.
Conclusions: The post-stress increase in Nt-pro-BNP is related to myocardial ischemia and to postischemic left-ventricular dysfunction, and accurately predicts the presence or absence of myocardial perfusion defects.