Abstract 15775: The Impact of B-type Natriuretic Peptide Activation on the Association of Left Ventricular Longitudinal Strain With All-cause Mortality
Introduction: Left ventricular longitudinal strain (LV-LS) 1) predicts mortality in patients with aortic stenosis (AS) and 2) is highly correlated to type-B natriuretic peptide (BNP) values. The BNP ratio (measured BNP/maximal expected BNP value specific for age and sex) is a powerful independent predictor of death in patients with AS.
Hypothesis: we hypothesize that BNP activation (i.e. BNP ratio >1) affects the association between LV-LS and mortality in patients with asymptomatic AS and preserved LV ejection fraction (EF ≥50%).
Methods:315 patients (age 74±12 years, 56% men and mean aortic valve area = 1.02±0.15cm2) underwent simultaneous Doppler echocardiographic and BNP measurements. LV-LS was calculated as the average of 12 LV segments from apical 2- and 4-chamber views using Velocity Vector Imaging.
Results: Mean LV-LS was -16.8±3.2%, LV EF 66±7%, median BNP level 121 (interquartile 48-320) pg/ml. 58% of patients had BNP activation. Better LV-LS was associated with lower log BNPratio (regression coefficient 0.10, p<0.001). After a median follow-up of 6.5 yrs (interquartile: 3.6-8.2), 119 deaths occurred. After adjustment for age, sex, Charlson score index, hemoglobin level, aortic valve replacement (as a time dependent variable), LV-LS and log BNPratio were separately associated with increased risk for death (all p<0.01). Further adjustment for predictors of mortality, LV-LS and log-BNP ratio remained associated with increased risk for death (hazard ratio HR [95%CI]: 1.09 [1.03-1.15]; p=0.003 and 1.82 [1.52-2.19]; p<0.0001 respectively). In patients without BNP activation (i.e. normal BNP), LV-LS was associated with mortality (HR: 1.22 [1.04-1.43]; p=0.01) while it was not in patients with BNP activation (p=0.22).
Conclusions: In patients with asymptomatic AS, without clinically obvious myocardial impairment (i.e. normal LVEF), a notable proportion of patients present with myocardial alterations detected by an elevated BNPratio or reduced LV-LS. These signs of myocardial alterations were predictive of mortality after diagnosis. Thus both BNP and LV-LS should be assessed in the clinical setting to provide complementary information on prognosis in patients with asymptomatic AS and preserved LV EF.
Author Disclosures: Z. Ye: None. M. Enriquez-Sarano: None. J. Malouf: None. H.I. Michelena: None. A.S. Jaffe: None. R.M. Suri: None. M. Clavel: None.
- © 2015 by American Heart Association, Inc.