Assessment of left ventricular function with tissue Doppler echocardiography and of B-type natriuretic peptide levels in patients undergoing transcatheter aortic valve implantation

Abstract

IntroductionTranscatheter aortic valve implantation (TAVI) is an emerging minimally invasive treatment modality in high surgical risk or inoperable patients. AimThe aim of this study was to ascertain the effect of TAVI on left ventricular (LV) systolic and diastolic function and serum B-type natriuretic peptide (BNP) levels in high surgical risk or inoperable patients with severe aortic stenosis. MethodsFifty-five patients were included in our retrospective study. LV systolic and diastolic function was assessed with conventional and tissue Doppler imaging (TDI) prior to and after TAVI. Additionally, BNP was measured 24 h before and three months after the procedure. Echocardiographic controls were performed at one, three and six months and one year and mean values were taken. At the end of the study, LV systolic and diastolic function, serum BNP levels and New York Heart Association functional capacity were assessed and compared to baseline parameters. ResultsThe TAVI procedure was successful in all patients. In-hospital mortality was 1.8% (one patient). There was a substantial improvement in LV function and functional capacity at follow-up. In addition, a statistically significant decrease was detected in serum BNP levels post-TAVI (median 380 pg/ml [176.6-929.3] vs. 215 pg/ml [96.0-383.0], p=0.0001). Only one patient required a permanent pacemaker (1.8%) and there was no mortality after TAVI during follow-up. There were significant increases in LV ejection fraction and aortic valve area (51.0±13.1% vs. 58.4±9.1%, p<0.001, and 0.6±0.1 cm2 vs. 2.1±0.2 cm2, p=0.0001, respectively). At the end of the study, conventional Doppler echocardiography revealed improvement in diastolic function, with an increase in mitral E wave, a decrease in mitral A wave and an increase in E/A ratio. Deceleration time and isovolumetric relaxation time were shortened and myocardial performance (Tei) index decreased. TDI showed an increase in systolic myocardial velocity (Sm) and early diastolic velocity (Em). Septal mitral annular Sm and Em were increased, whereas MPI was reduced. ConclusionWe found that LV structural changes and diastolic dysfunction occur in patients with severe aortic stenosis and that TAVI is able to reverse these abnormalities, which we demonstrated by both conventional echocardiography and TDI. In addition, serum BNP levels were decreased after TAVI.