The Prognostic Value of Left Atrial Global Longitudinal Strain and Left Atrial Phasic Volumes in Patients Undergoing Transcatheter Valve Implantation for Severe Aortic Stenosis.

INTRODUCTION: The changes and the prognostic implications of left atrial (LA) volumes (LAV), LA function, and vascular load in patients undergoing transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS) are less known. METHODS: We enrolled 150 symptomatic patients (mean age 82 ± 8 years, 58% female, and pre-TAVI aortic valve area 0.40 ± 0.19 cm/m2) with severe AS who underwent 2D transthoracic echocardiography and 2D speckle tracking echocardiography at average 21 ± 35 days before and 171 ± 217 days after TAVI. The end point was a composite of new onset of atrial fibrillation, hospitalization for heart failure and all-cause death (major adverse cardiac events [MACE]). RESULTS: After TAVI, indexed maximal LA volume and minimum volume of the LA decreased by 2.1 ± 10 mL/m2 and 1.6 ± 7 mL/m2 (p = 0.032 and p = 0.011, respectively), LA function index increased by 6.8 ± 11 units (p < 0.001), and LA stiffness decreased by 0.38 ± 2.0 (p = 0.05). No other changes in the LA phasic volumes, emptying fractions, and vascular load were noted. Post-TAVI, both left atrial and ventricular global peak longitudinal strain improved by about 6% (p = 0.01 and 0.02, respectively). MACE was reached by 37 (25%) patients after a median follow-up period of 172 days (interquartile range, 20-727). In multivariable models, MACE was associated with both pre- and post-TAVI LA global peak longitudinal strain (hazard ratio [HR] 0.75, CI 0.59-0.97; and HR 0.77, CI 0.60-1.00, per 5 percentage point units, respectively), pre-TAVI LV global endocardial longitudinal strain (HR 1.37, CI 1.02-1.83 per 5 percentage point units), and with most of the LA phasic volumes. CONCLUSION: Within 6 months after TAVI, there is reverse LA remodeling and an improvement in LA reservoir function. Pre- and post-TAVI indices of LA function and volume remain independently associated with MACE. Larger studies enrolling a greater diversity of patients may provide sufficient evidence for the utilization of these imaging biomarkers in clinical practice.

Left Ventricular Mass, Myocardial Structure, and Function in Severe Aortic Stenosis: an Echocardiographic and Cardiac Magnetic Resonance Imaging Study.

In severe aortic stenosis (AS), there are conflicting data on the prognostic implications of left ventricular (LV) hypertrophy (LVH). We aimed to characterize the LV geometry, myocardial matrix structural changes, and prognostic stratification using cardiac magnetic resonance imaging (CMR) and echocardiography in subjects with severe AS with and without LVH. Consecutive patients who had severe isolated AS and sufficient quality echocardiography and CMR within 6 months of each other were evaluated for LVH, cardiac structure, morphology, and late gadolinium-enhancement imaging. Kaplan-Meier curves, linear models, and proportional hazards models were used for prognostic stratification. There were 93 patients enrolled (mean age 74 ± 11 years, 48% female), of whom 38 (41%) had a normal LV mass index (LVMI), 41 (44%) had LVH defined at CMR by LVMI >2 SD higher than normal, and 14 (15% of the total) with >4 SD higher than the reference LVMI (severely elevated). The Society of Thoracic Surgeons scores were similar among the LVMI groups. Compared with those with normal LVMI, patients with LVH had higher LV end-diastolic and end-systolic volumes, increased late gadolinium-enhancement burden, and lower LV ejection fraction. Most notably, CMR feature-tracking global radial strain, 2-dimensional speckle-tracking echocardiography global longitudinal strain, and left atrial reservoir function were significantly worse. On the survival analyses, LVMI was not associated with a composite of all-cause mortality and/or heart failure hospitalization. In conclusion, compared with normal LVMI, elevated LVMI was not associated with a higher risk of adverse outcomes.