Abstract 2468: Is the LV Reverse Remodeling Imparted by Aortic Valve Replacement for Severe Aortic Stenosis Durable? A Cardiovascular MRI Study sponsored by the American Heart Association
Background In patients with severe aortic stenosis (AS), long-term data tracking surgically induced beneficial effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiac MRI (CMR) offers the ability to track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability.
Hypothesis We hypothesize that progressive changes following aortic valve replacement (AVR) are detectable by CMR and changes in LV structure and function, triggered by AVR, continue for an extended period following AVR.
Methods Ten patients (67±12 yrs, 6 female) with severe, but compensated AS, underwent CMR pre-AVR and post AVR at 6±2mo, 1yr±2mo, 4yrs±5mo. LV mass index (LVMI), LV geometry, volumetrics and EF were measured (GE, EXCITE 1.5T, Milwaukee, WI). A Kruskall-Wallis one-way ANOVA was performed.
Results All 10 pts survived AVR and underwent CMR at the 4-year time point (40 total time points). LVMI markedly decreased at 6 months (157±42 to 134±32g/m2, p<0.005) and continued to trend down at 4 yrs (127±32g/m2). Similarly, EF increased pre to post AVR (55±22 to 65±11%, (p<0.05)) and continued trending upward, remaining stable at years 1–4 (66±11 vs. 65±9%). LVEDV index, initially high pre AVR, normalized post AVR (83±30 to 68±11ml/m2, p<0.05) trending even lower by yr 4 (66±10 ml/m2). LV stroke volume increased rapidly from pre to post AVR (40±11 to 44±7ml) continuing to increase at 4 yrs (49±14ml, p=0.3). Most importantly, LVMI/volume, a 3D measure of LV geometry, remained unchanged initially but over 4 yrs markedly improved (1.07±0.2 to 0.94±0.24, p<0.05) all paralleling improvements in NYHA (3.2±1.0 to 1.5±1.1, p<0.05).
Conclusion After the initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. We have shown, via CMR, that surgically induced benefits to LV structure and function, including favorable alterations in LV geometry, are durable and, unexpectedly, show continued improvement past 4 years concordant with sustained improved clinical status. This supports down regulation of both mRNA and MMP activity acutely and robust suppression long term.