Abstract 3233: Plotting the Time Course of LVH Regression and Remodeling Imparted by Aortic Valve Replacement for Severe Aortic Stenosis; A Cardiovascular MRI Study Sponsored by the American Heart Association
In pts with severe aortic stenosis (AS), long-term data tracking surgically induced effects of afterload reduction via aortic valve replacement (AVR) on reverse LV remodeling are not available. Echocardiographic data is available short-term, but in limited fashion after one year. Cardiovascular MRI (CMR) offers the ability to track discrete changes in LV metrics with small numbers but high accuracy due to its inherent high spatial resolution and low variability.
Hypothesis Triggered by AVR, progressive changes in LV structure and function are detectable by CMR and continue to favorably improve over an extended period.
Methods Ten pts (67±12 yrs, 6F) with severe, but compensated AS underwent CMR pre and post AVR at 6±2mo, 1yr±2mo and up to 4yrs±5mo. LV mass index (LVMI), geometry, volumetrics and EF were measured (GE, EXCITE 1.5T, WI).
Results Despite advanced AS, all 10 pts survived AVR and underwent CMR at up to 4 years (40 time points). LVMI markedly decreased at 6 mo (157±42 to 134±32g/m2, p<0.005), continuing to gently trend downwards at 4 yrs (127±32g/m2). Similarly, EF increased post AVR (55±22 to 65±11%, (p<0.05)), remaining stable years 1– 4 (65±9 vs. 66±11%). LVEDV index, initially high pre AVR, normalized post AVR (83±30 to 68±11ml/m2, p<0.05), trending even lower by year 4 (66±10 ml/m2). LV stroke volume increased rapidly from pre to post AVR (40±11 to 44±7ml) continuing to gradually increase at 4 yrs (49±14ml, p=0.3). Importantly, LVMI/volume (3D 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 initial beneficial effects imparted by AVR in severe AS pts, marked improvements in LV reverse remodeling ensue. The pattern of this improvement is, however, previously unrecognized. Namely, a steep trajectory of improvement early in which fully 75% of the effect that was to be present by year 4 is completed within the first 6 months. Afterwards, the slope of LV remodeling is much less steep, becoming asymptotic. Further, surgical benefits to LV structure, function and geometry are durable and, unexpectedly, show continued improvement extending through 4 years post-AVR concordant with sustained improved clinical status.
This research has received full or partial funding support from the American Heart Association, National Center.