Assessment of Left Ventricular Function after Transcatheter Aortic Valve Implantation in Sever Aortic Stenosis: A Speckle Tracking Imaging Study

Abstract

Background: Long standing aortic stenosis leads to elevated left ventricular (LV) pressure and as a result LV hypertrophy and myocardial fibrosis shall increase. The left ventricular ejection fraction (EF) usually remains adequately-preserved until advanced and late stages of aortic stenosis. But the preserved muscle of the LV is only limited to a portion of the entire myocardium. Speckle tracking echocardiography has proved its superiority to the standard two-dimensional echocardiography method in the detection of Left Ventricular (LV) function. Global Longitudinal strain (GLS) is considered as the most robust myocardial strain component. Objective: The aim of the study is to assess the early course of left ventricular reverse remodelling after Transcutaneous Aortic Valve Implantation (TAVI) in patients with symptomatic severe aortic valve stenosis. Methods: 50 patients with severe symptomatic valvular aortic stenosis undergoing TAVI as decided by the heart team after comprehensive discussion. Standard transthoracic echocardiography including Doppler analysis was performed. 2D speckle-tracking strain assessment of Global radial, circumferential and longitudinal strain at parasternal mid-ventricular short-axis view (at the level of papillary muscle) and from the apical long-axis, two-chamber and four-chamber views with a frame rate between 40 and 80 frames per second. Tracing of endocardial borders was done. Patients with significant coronary artery disease were fully revascularized by percutaneous coronary intervention prior to the study and the procedure. Results: 23 (46%) patients were males, while 27 (54%) were females. The patients’ stratification according to comorbidities/associated risk factors revealed that 54% of the patients had DM, 86% were hypertensive, 38% had chronic kidney disease (CKD), and 32% had a previous percutaneous coronary intervention (PCI). The mean age for our study participants ranged from 60 to 92 years (Mean ± SD = 76.60 ± 5.96). Left ventricular diastolic diameter (LVDd) was 44.24 ± 2.8 mm before TAVI that became 45.5 ± 2.6 mm after TAVI, and ejection fraction (EF) increased from 52.82 ± 6.3 before TAVI to 56.70 ± 5.4 after TAVI, both with highly significant difference (P P value less than 0.001. Global circumferential strain (GCS) also improved significantly from -20.14 ± 1.8 before TAVI to -21.72 ± 1.7 after TAVI with a P value less than 0.001. Global radial strain (GRS) also increased significantly from 37.38 ± 8 before TAVI to 41.68 ± 6.3 after TAVI with a P value less than 0.001. Conclusion: TAVI is effective in improving left ventricular function presented not only by ejection fraction (EF%), but also in global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS).