Effect of race on the diagnostic performance of novel cardiovascular biomarkers in patients with dyspnea: results from the BACH multinational study

Background: The Biomarkers in Acute Heart Failure (BACH) study examined the utility of a panel of novel prohormone cardiovascular biomarkers in diagnosing heart failure (HF), but little is known about how levels of these markers vary between racial groups. Methods: 1641 patients presenting to the ED with acute dyspnea were enrolled in the prospective, multinational, 15-center BACH trial, and plasma levels of several prohormone biomarker fragments were measured. The diagnosis of HF was determined by 2 independent cardiologists, blinded to the ED physicians’ diagnoses and to the biomarker levels being examined in the trial. Race was determined by self-report. Results: Of the 1626 patients of known race, 67% were white and 29% were black. White patients were more likely to have a final diagnosis of HF than black patients (40% vs. 25%, p <0.001). Median levels of all BACH markers except CT-proAVP were lower in blacks than in whites among patients with a final diagnosis other than acute HF; in those with acute HF, levels differed by race only for MR-proANP, which was higher in blacks (519 pmol/L vs. 395 pmol/L, p=0.002). All BACH markers were stronger predictors of HF in blacks than in whites, with MR-proANP emerging as an especially powerful predictor in blacks (AUC=0.946, Figure). Adjusting for age did not materially alter the results. Conclusions: Novel prohormone biomarkers performed better in blacks than in whites for diagnosing acute HF. MR-proANP proved an especially accurate predictor in black patients