Left-sided cardiac remodeling in patients with severe aortic stenosis (AS) was associated with improved outcome; however, there are scarce data on remodeling process after transcatheter aortic valve implantation (TAVI). We sought to describe the remodeling process in patients with severe AS who underwent TAVI. Echocardiographic data were systematically collected at baseline, 30 days, 6 months, and 1 year, from a cohort of 333 patients who underwent TAVI. Patients were categorized according to left ventricular mass index (LVMi) and relative wall thickness (RWT) to the following geometries: (1) normal; (2) concentric remodeling; (3) concentric hypertrophy; and (4) eccentric hypertrophy. Reverse remodeling (partial or complete) was defined as normalization of LVMi and/or RWT and adverse remodeling as an increase in LVMi and/or RWT. The longitudinal change in LVMi and left atrial diameter index (LADi) was assessed using mixed models. Reverse LV remodeling at 1-year was observed in 24% of patients with available echo at follow-up, whereas 17% of patients had adverse remodeling at 1-year follow-up. This was especially noted in patients with normal geometry at baseline. Interestingly, LV reverse remodeling was not accompanied by a reduction in left atrial diameter. In conclusion, TAVI reverse ventricular remodeling and LV hypertrophy induced by aortic stenosis; however, this reversal is incomplete in most patients at 1-year and not followed by change in left atrial dimensions. Whether this favorable remodeling may impact clinical outcome needs to be further elucidated.
Left ventricular hypertrophy (LVH) and heart remodeling are classic adaptive responses in aortic stenosis (AS) that may not be fully reversible after surgical aortic valve replacement (SAVR). Additionally, residual LVH after SAVR provides an underlying substrate for subsequent morbidity and mortality in the population with operable AS. Although transcatheter aortic valve implantation (TAVI) represents a clinical breakthrough benefiting patients who cannot undergo SAVR, long-term mortality remains high, and up to 25% of patients fail to achieve functional improvement. Currently, there are few data on reverse left ventricular (LV) remodeling dynamics after TAVI. Accordingly, the aim of this study was to longitudinally assess left-sided cardiac heart remodeling 1 year after TAVI.
Patient population was derived from a cohort of patients with inoperable and high-risk, symptomatic AS who underwent transfemoral TAVI with a balloon or self-expandable device at a single high-volume center, at least 1 year after the procedure. All participants underwent a screening process including echocardiography demonstrating severe AS, coronary angiography, and risk assessment using the Society of Thoracic Surgeons score and were deemed high risk or inoperable according to the heart team. The analysis was in compliance with the local institutional review board.
Prespecified baseline variables were prospectively recorded during screening, immediately after procedure, during hospitalization, and at follow-up. Echocardiography was performed and analyzed at baseline, 30 days, 6 months, and 1 year. Clinical follow-up adhered to clinical trials requirements, and patients were contacted either by an office visit or through standardized telephone interview by independent personnel unaware of the study objectives. Procedural success included successful valve positioning and function. Outcomes followed the standardized Valve Academic Research Consortium-2 document. The adverse events were adjudicated by physicians from the local heart team.
A 2-dimensional Doppler transthoracic echocardiogram was performed using the Philips iE33 xMATRIX system (Andover, Massachusetts). Two-dimensional images were obtained with standard parasternal long- and short-axis views, in addition to 4 and 2 chamber views. Continuous wave Doppler was used to estimate transvalvular gradients using the Bernoulli simplified equation. Ventricular diameters and posterior and septal wall thickness were measured in 2 dimensions in the parasagittal view in accordance with guidelines recommendations.
Relative wall thickness (RWT) was calculated as RWT=(2×PWT)÷LVEDRWT=(2×PWT)÷LVED
R W T = ( 2 × P W T ) ÷ L V E D
. LVMi was based on Deveraux’s formula according to the joint recommendations of the American Society of Echocardiography and the European Association of Echocardiography as follows: LVM=0.8×(1.04×([LVEDD]+[PWT]+[SWT])3−[LVEDD]3)+0.6
L V M = 0.8 × ( 1.04 × ( [ L V E D D ] + [ P W T ] + [ S W T ] ) 3 − [ L V E D D ] 3 ) + 0.6
and subsequently indexed to body surface area (BSA).
LVH was defined as LVMi >95 g/m 2 in women and LVMi >115 g/m 2 in men. LVH severity (g/m 2 ) was defined as mild (96 to 108 g for women and 116 to 131 for men), moderate (109 to 121 for women and 132 to 148 for men), and severe (≥122 for women and ≥149 for men).
Left atrium diameter was measured in an anteroposterior view and indexed (LADi) to the BSA as a proxy of the diastolic function. LV remodeling patterns were categorized at baseline and at 1-year follow-up into 4 groups according to LVMi and RWT.
Complete left reverse remodeling was defined as normalization of ventricular geometry with respect to both LVMi and RWT. Partial reverse remodeling was defined as normalization in either LVMi or RWT at 1 year. Adverse ventricular remodeling was defined as an increase in LVMi and/or RWT at 1 year. LADi was measured as a proxy of diastolic function. Our primary objective was to depict the longitudinal change of the LVMi and LADi over time in patients with severe AS who underwent TAVI, according to the various LV geometries.
The study’s binary variables are reported by counts and percentages, whereas the continuous variables are reported as mean ± SD or median with interquartile range. Differences in binary data were tested by either the chi-square or the Fisher’s exact test. Analysis of variance was used for continuous variables with normal distribution and the Wilcoxon signed rank test was used to assess changes in LVH severity. Nonparametric tests were used as appropriate. Nonlinear mixed models were used to longitudinally assess the LVMi and LADi over time accounting for repeated measures data. An overall 4 × 4 table was used to assess the overall changes in remodeling patterns. Assuming the null hypothesis to be true, a p value <0.05 was considered statistically significant. Analyses were performed using the software SAS System Software version 9.2 (SAS Institute, Cary, North Carolina).