Prognostic implications and alterations in left atrial deformation following transcatheter aortic valve implantation for severe aortic stenosis

Abstract Background Left atrial reservoir strain (LARS) as a single parameter estimate of left ventricular (LV) diastolic dysfunction (DD), may provide important prognostic insights into patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). Purpose To evaluate the prognostic implications of pre- and post TAVI LARS-defined DD (LARS-DD) grade in patients undergoing TAVI for severe AS and its association with new-onset atrial fibrillation. Methods Pre-TAVI LARS-DD was evaluated by speckle-tracking echocardiography and was assigned as grade 0 to 1 (LARS ≥24%), grade 2 (LARS ≥19 to <24%) and grade 3 (LARS <19%). Patients were followed-up for the primary endpoint of all-cause mortality from the date of TAVI. For the secondary endpoint, patients with pre- and post-TAVI LARS measurements, no history of atrial fibrillation and with clinical/ECG follow-up following the post-TAVI follow-up echocardiogram were evaluated for the occurrence of new-onset atrial fibrillation. Results A total of 601 patients (median age 81 [76-85] years, 53% male) undergoing TAVI for severe AS were included. Overall, 169 patients (28%) were LARS-DD grade 0/1, 96 patients (16%) were LARS-DD grade 2 and 336 (56%) were LARS-DD grade 3. Over a median follow-up of 40 (IQR 26 to 58) months, a total of 258 (43%) patients died (Figure 1). In a comprehensive multivariable Cox regression model adjusted for age, sex, EuroSCORE II, New York Heart Association class III to IV symptoms, LV ejection fraction, atrial fibrillation, LA volume index and LV stroke volume index, LARS-DD grade was independently associated with all-cause mortality (adjusted HR 1.28 per one grade increase above LARS-DD grade 0/1, 95% CI 1.07 to 1.53, P=0.007). For the secondary endpoint of new-onset atrial fibrillation, a total of 285 patients were evaluated (Figure 2). On multivariable Fine and Gray regression analyses adjusting for age and LA volume index, post-TAVI LARS (SDHR 1.14 per 1% <20%, 95% CI 1.05 to 1.23, P=0.0009), rather than pre-TAVI LARS (SDHR 1.00 per 1% <20%, 95% CI 0.91 to 1.11, P=0.93) was associated with the occurrence of new-onset atrial fibrillation. Conclusions Increasing LARS-DD grade was independently associated with long-term post-TAVI survival in patients with severe AS and may enhance risk stratification. In addition, post-TAVI LARS, but not pre-TAVI LARS, was closely related to the occurrence of new-onset atrial fibrillation, likely better reflecting intrinsic LA dysfunction.Figure 1:All-Cause MortalityFigure 2:New-Onset Atrial Fibrillation