Preoperative, Postoperative and One-Year Follow-Up of N-Terminal Pro-B-Type Natriuretic Peptide Levels in Volume Overload of Aortic Regurgitation: Comparison with Pressure Overload of Aortic Stenosis

Abstract

Objectives: Limited data are available regarding the impact of pressure or volume overload on the clinical or echocardiographic parameters and the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with chronic severe aortic valve diseases. We aimed to investigate and compare the relationships between these parameters in such patients. Methods: One hundred twenty-four consecutive patients who underwent aortic valve replacement for chronic severe aortic valve diseases were enrolled. Plasma NT- proBNP was measured and echocardiographic parameters were recorded before surgery, before discharge and 12 months after surgery. Results: NT-proBNP levels were significantly higher in patients with aortic regurgitation (AR) (n = 63) than in those with aortic stenosis (n = 61) (1,836.0 ± 376.1 vs. 508.4 ± 74.5 pg/ml, p = 0.001). There was a significant relationship between NT-proBNP levels and left ventricular mass index (LVMI) in AR (r = 0.436, p = 0.002) and a weaker, but significant, relationship between NT-proBNP levels and LVMI in aortic stenosis patients (r = 0.290, p = 0.046). In the AR group, preoperative NT-proBNP levels positively correlated with LVMI regression during the 12 months after surgery (r = 0.488, p = 0.001). Conclusion: NT-proBNP levels may reflect LVMI changes that are caused by volume overload rather than pressure overload in chronic aortic valve diseases. Higher preoperative NT-proBNP levels may predict left ventricular reverse remodeling early after surgery for chronic severe AR.

Natriuretic Peptides for Risk Stratification of Patients With Valvular Aortic Stenosis

“…As shown in Table 2, natriuretic peptides may be useful to detect this maladaptive transition because elevated levels are associated with increased LV and left atrial dimensions, decreased LV function, and increased systolic pulmonary artery pressure. 2,13,16,21,27,29 Figure 4B demonstrates that in most studies, there is an inverse correlation between higher levels of natriuretic peptides and ejection fraction in patients with AS. 2,9,13,15,16,21,22,27,34 One large prospective study of 289 patients referred for TAVR found that higher levels of BNP were independently associated with lower ejection fraction (35.5% versus 55.4%).…”

“…2,13,16,21,27,29 Figure 4B demonstrates that in most studies, there is an inverse correlation between higher levels of natriuretic peptides and ejection fraction in patients with AS. 2,9,13,15,16,21,22,27,34 One large prospective study of 289 patients referred for TAVR found that higher levels of BNP were independently associated with lower ejection fraction (35.5% versus 55.4%). 24 Iwahashi et al 15 and several other studies confirmed this association.…”

“…9,13,15,16,21,22,[25][26][27][28][29] LV hypertrophy (LVH) develops initially as adaptive response to pressure overload in patients with AS. Increase BNP gene expression leading to greater levels of natriuretic peptides may reflect more pronounced hypertrophic myocardial growth from elevated LV wall stress caused by increased afterload.…”

“…Others have confirmed this relationship between natriuretic peptide levels and LVMI in patients with chronic severe AS. 5,13,15,16,20,21,23,26,27,29,31,32 Eccentric LVH-which may be indicative of a later stage of LV decompensation or mixed regurgitant/stenotic lesions-is associated with higher BNP levels than concentric LVH. 16 The same correlation between BNP levels and LVMI was found in a study of patients undergoing transapical TAVR.…”

“…24 Iwahashi et al 15 and several other studies confirmed this association. 2,9,13,16,21,22,27,34 In conservatively treated patients with AS, a reduced LV ejection fraction is associated with increased risk, suggesting that at this advanced stage, AVR, although high-risk, is urgently indicated. However, TAVR may be safer than SAVR in such patients.…”