Echocardiographic L-Wave as a Prognostic Indicator in TAVI Patients

Introduction: The L wave represents mid-diastolic trans-mitral flow. Its clinical and prognostic value is not completely understood. It is assumed that this wave represents decreased relaxation of the left ventricle and thus diastolic dysfunction. Patients with severe aortic stenosis are prone to left ventricular hypertrophy and diastolic dysfunction. It has been previously shown in this group of patients that Trans-catheter aortic valve replacement (TAVR) induces reverse remodeling and improves diastolic function and prognosis. Our aim was to examine the change in L wave after TAVR and its clinical importance.

Methods: We examined the clinical and echocardiographic data of 535 patients (mean age 82.58±5.9) undergoing TAVR. The presence and velocity of L-Wave was recorded at baseline and 1 and 6 months post procedure. The impact of the procedure on L-Wave and clinical outcomes were analyzed.

Results: Patients with L-wave on baseline echocardiography (n=64, 12%) had a smaller stroke volume index by 5.7±2.3ml/m² (p=0.01) and a lower systolic blood pressure by 17.2±6.6mmHg (p=0.01) compared to patients without L wave at baseline echocardiography. In patients with L-wave at baseline, in 31% the L-wave disappeared at 1 month and in 70% at 6 months follow up. In addition, baseline L wave velocity was 34.8±11.5 (cm/s) and decreased significantly at follow up. Patients with L-wave at baseline had higher 3 year mortality post procedure (HR 1.93, 95% CI 1.46-2.54, p<0.001). This was also true for patients with L-wave after 1 month (HR 5.03, CI 3.12-8.08, p<0.001). Multivariate analysis of survival was also statistically significant (p<0.001).

Conclusion: Post TAVR velocity of L wave decreases significantly and often disappears completely. The presence of L wave before TAVR is an independent risk factor for mortality.