Brain natriuretic peptide levels are associated with cycle length average and are different between Ben-Dov and Corra exercise oscillatory ventilation definitions in heart failure patients

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CAPES e FAPERGS. Background The brain natriuretic peptide (BNP) is a marker of ventricular dysfunction related to severity and prognosis in heart failure patients. Exercise oscillatory ventilation (EOV) is a phenomenon in the ventilatory pattern associated with a worse prognosis in heart failure patients. EOV diagnosis is defined by the interaction among amplitude, cycle length, and the total time of the oscillations. Ben-Dov and Corrà definitions are used to identify EOV-positive cases by different criteria, which may stratify EOV patients with distinct clinical characteristics. Purpose To assess the BPN levels in heart failure patients and to test BNP level correlation with amplitude, cycle length, and total oscillation time according to Ben-Dov and Corrà definitions. Methods Data from 242 cardiopulmonary exercise tests (CPETs) performed between 2011 and 2014 at an Italian heart centre were screened for EOV identification. CPETs were done in a cycle-ergometer with gas exchange analysed breath-by-breath. EOV cases were identified according to the definitions of Ben-Dov and Corrà. Mann-Whitney test was applied to compare BPN levels between the EOV-positive and negative in each definition and between EOV-positive from Ben-Dov and Corrà definitions. Spearman coefficient (rs) evaluated the association between amplitude and length average of the oscillatory cycle, percentage of total oscillation time, and BNP levels in each EOV definition. The BNP levels from EOV-positive identified by Corrà or Ben-Dov definition alone, and from patients who have met the criteria of both definitions were compared by the Kruskal-Wallis test. Results Sixty-seven patients were identified as EOV-positive. From them, 19 were identified exclusively by the Ben-Dov and 26 by Corrà. Twenty-two met the criteria for both definitions. Overall, no difference in EOV prevalence between Ben-Dov and Corrà definitions was found (20.4 vs 24.2%, p = 0.482). EOV-positive identified by the Ben-Dov definition have higher BNP levels than EOV-negative (p < 0.01) and the EOV-positive by Corrà definition (p = 0.025) (Table 1). Spearman correlation showed association just between BNP levels and cycle length average from EOV-positive by the Ben-Dov (rs = 0.566; p < 0.001) and by Corrà (rs = 0.339; p = 0.011) (Figure 1). When analysed by exclusive criteria identification, the BNP levels were higher in EOV-positive identified by Ben-Dov than Corrà (737 [562 to 1,178] vs 276 [221 to 603] pg/mL; p = 0.009). BNP levels in the EOV-positive identified by both definitions (475 [347 to 852] pg/mL) were not different from those identified by the Ben-Dov and Corrà definitions alone. Conclusion EOV-positive identified by the Ben-Dov have higher BNP levels than EOV-negative and the EOV-positive identified by Corrà, alone or not. BNP levels also are associated with the cycle length average, with a higher correlation for the Ben-Dov EOV-positive.