Obesity may reduce diagnostic accuracy of B-type natriuretic peptide (BNP) and affect long-term outcome.

This study evaluated patients included in the BASEL study (N = 452). We compared BNP levels in patients with (n = 86) and without (n = 366) obesity (body mass index <30 and >30 kg/m²) and determined sensitivities and specificities of BNP in both patient groups by receiver-operating characteristic analysis. Impact of BNP measurements on patient management and outcome in obesity, as well as 360-day mortality, was assessed.

The BNP levels were lower in obese patients (172 pg/mL [interquartile range 31-515] vs 306 [interquartile range 75-1,040]). The optimal BNP cut-point to detect heart failure was 182 pg/mL in obese patients and 298 pg/mL nonobese patients. Obese patients had lower in-hospital mortality (3.5% vs 8.5%, P = .045) and 360-day mortality (15% vs 30%, P = .001). In obese patients, the determination of BNP levels reduced time to initiation of the appropriate treatment (96 ± 98 vs 176 ± 230, P < .05) without impacting other end points.

Adjustment of BNP values in the assessment of obese patients presenting with acute dyspnea seems necessary to improve diagnostic accuracy and patient management. Obese patients had half the short- and long-term mortality of nonobese patients, independent of their final discharge diagnosis.