B-type Natriuretic Peptide in VHD: a Non-imaging Helper for the Cardiologist Dr. Julien Magne, PhD Sart Tilman Liège, BELGIUM
Conflict of Interest Disclosure None
BNP Molecular Forms and Processing Brain Natriuretic Peptide: Sudoh et al, Nature, 1988 BNP and its inactive amino terminal portion are neurohormones released by the ventricles in response to increased LV wall stress Lam et al. JACC, 27
BNP Release Activation Furin N-terminal probnp 1-76 Volume overload Pressure overload NT-BNP 1-76 BNP 77-18 Secretion Wall stretch Pre-proBNP BNP mrna probnp 1-18 BNP 77-18 T1/2=22min Elimination: - Enzymatic: neutral endopeptidase - Receptor mediated: CNP-receptors Cardiac Myocyte
Characteristics of an ideal biomarker Specific High myocardium/serum ratio Not present in non-cardiac tissue, even pathologically Sensitive Zero baseline Marker of early, reversible cardiotoxicity Immediate release with injury Predictive Long half-life in blood Release proportionate to extent of injury Robust Rapid, simple, and accurate Non-invasive / accessible / unexpensive
The Place of BNP in current VHD Guidelines In Aortic stenosis: ESC Guidelines Natriuretic peptides have been shown in preliminary studies to predict symptom-free survival in AS. In Mitral regurgitation: Preliminary series have also suggested the value of elevated BNP levels as predictors of long-term outcome but this also remains to be validated
BNP level in AS BNP level is correlated with AS severity: ++ with AVA +- with pressure gradient BNP is correlated with the consequences of AS on LV Qi et al. AHC 21 Gerber et al. Circulation, 23 Lim et al. Eur Heart J, 24
BNP level in AS BNP level is well associated with the symptomatic status Bergler-Klein et al. Circulation 24 Gerber et al. Circulation 23
BNP level and Symptoms in AS BNP is more powerful than AS severity parameters to identify symptoms BNP level may predict the occurrence of symptoms: Bergler-Klein et al. Circulation 24
BNP for Risk Stratification in asymptomatic AS 17 pts followed in Créteil Risk score according to independent variables Validation in Liège (17 pts) > 75% Score = (Peak velocity x 2) + (nat log BNP x 1.5) + 1.5 (if female) < 1% 16 Monin et al. Circulation, 29
Brain natriuretic peptide, pg/ml BNP level in LF/LG AS BNP is significantly elevated in LF AS, even in paradoxical LF/LG AS. BNP level >55pg/mL strong predictor of outcome in LF/LG AS TOPAS study 6 5 4 3 2 1 p<.1 22 (13-44) 47.5 (32-74) * NF/LG group NF/HG group 114 (68-133) * LF/HG group Lancellotti, Magne et al. JACC, 212 78 (66-11) * LF/LG group Bergler-Klein et al. Circulation, 27
Combined end-point, % BNP level in Aortic Regurgitation Derivation (n=16) and validation (n=134) cohorts of asymptomatic severe AR and no LV dilatation/dysfunction Combined end-point defined as LV dysfunction, symptoms or death 1 8 6 4 2 p<.1 1 2 3 4 Follow-up, years Baseline BNP<13pg/mL HR=6.7 (2.3-16.6) Baseline BNP 13pg/mL 5 Pizarro et al. JACC, 211
Combined end-point, % BNP level in Aortic Regurgitation 1 8 6 4 ERO<5mm² + BNP<13pg/mL ERO 5mm² + BNP<13pg/mL ERO<5mm² + BNP 13pg/mL 2 p<.1 1 2 3 4 Follow-up, years ERO 5mm² + BNP 13pg/mL 5 Multivariate predictors of Cardiac events
BNP level in Mitral Regurgitation BNP level is not related to MR itself but to the atrial and ventricular consequences of MR 124 patients with primary MR; BNP vs. MR severity (ERO): r=.17, p=.6 Detaint et al. Circulation, 25
BNP level in Mitral Regurgitation Determinants of BNP level Impact of BNP level on survival Detaint et al. Circ, 25
BNP level in Asymptomatic MR BNP is a good marker of advanced stage of the disease Pizarro et al. JACC, 29
Combined end-point, % Combined end-point, % BNP level in Asymptomatic MR Multivariate predictor of combined end-point 1 Baseline BNP<15pg/mL 1 Validation cohort 8 6 p=.1 8 6 p<.1 4 2 Baseline BNP 15pg/mL 4 2 1 2 3 4 Follow-up, years 1 2 3 4 Follow-up, years Pizarro et al. JACC, 29
LV GLS, % Log BNP LV Longitudinal Function and BNP Level Bi-centric study, n=135 asymptomatic MR (moderate & severe) with no LV dysfunction/dilatation -5-1 Whole cohort (n=135) BNP Quartiles Q1 Q2 Q3 Q4 7 6 5 r=.64 p<.1-15 4-2 -25-3 -35-2±4% -16.5±4-21.2±3-19.6±3-23.3±3 * p<.1 3 2 1-35 -3-25 -2-15 -1-5 LV GLS, % Magne et al. Heart 212
Cardiac Event-free Survival, % BNP and Impact on Outcome KM curves: median of BNP 1 8 6 4 2 BNP <41pg/ml 75±6% 21±8% BNP >41pg/ml p<.1 6 12 18 24 3 36 42 48 Follow-up, months HR=3.5, 95%CI: 1.7-7.2, p=.1 Q4 Q3 Q2 Q1 Multivariable Analysis HR=8.8, 95%CI: 2.1-36.7, p=.2 HR=8.5, 95%CI: 2.2-32.5, p=.2 HR=3.5, 95%CI:.9-14.1; p=.75 HR=1, 95%CI: 1-1 1 5 1 15 2 3 35 4
Brain natriuretic peptide, pg/ml Exercise Log BNP Exercise BNP and Impact on Outcome BNP level significantly increase during exercise Exercise BNP is determined by ex. LV longitudinal function 7 6 5 4 3 2 1 37 (19-67) 57±67 Rest p<.1 41 (21.5-75) 67±72 Exercise 8 7 6 5 4 3 2 1 r=.65 p<.1-35 -3-25 -2-15 -1-5 Exercise LV global longitudinal strain, % Magne et al. Submitted 212
Adjusted incidence of cardiac events, % Prediction of cardiac events, χ² Exercise BNP and Impact on Outcome Exercise BNP level and outcome 1 Incremental prognostic value of exercise BNP 7 8 6 4 p=.2 Tertile 3 (Ex. BNP: 63-412pg/mL) Tertile 2 (Ex. BNP: 3-62pg/mL) 6 5 4 3 2 1 24.3 +47% 35.8 +27% 45.6 2 Tertile 1 (Ex. BNP: 5-29pg/mL) 6 12 18 24 3 Follow-up, months 38 34 3 23 18 15 38 32 27 18 8 6 37 29 17 11 6 6 Pt. at risk Demographic and echo. data + Resting BNP + Exercise BNP Magne et al. Submitted 212
BNP in VHD: Take Home Messages In severe AS, BNP is a powerful predictor of the occurrence of symptoms and of poor outcome in asymptomatic pts (when combined with AS severity and gender) In LF/LG AS, BNP>55pg/mL is associated with significant reduced survival. In severe AR, BNP>13pg/mL multiplies by 7 the risk of cardiac events. In severe primary MR, BNP>15pg/mL multiplies by 4.5 the risk of cardiac events. In asymptomatic primary MR, exercise BNP level may have important incremental prognostic value.
DON T MISS 5-8 December 212 MAICC Athens, Greece Abstract submission deadline 31 May Early bird registration 3 September
Thank you for your attention. In these matters the only certainty is that nothing is certain. Pliny The Elder, 23 AD-79 AD