Effect of Transaortic Valve Intervention for Aortic Stenosis on Myocardial Mechanics.

ABSTRACT

Chronic afterload excess in aortic stenosis results in compensatory concentric hypertrophy which mitigates the increased systolic load. Surgical aortic valve replacement has been shown to decrease afterload and improve left ventricular (LV) ejection fraction (EF). The extent to which these changes take place in patients undergoing TAVI (transcatheter aortic valve intervention) may be different than what has been observed in the surgical aortic valve replacement patients who were generally younger with few co-morbidities. Accordingly, we analyzed indices of LV structure and ventricular mechanics pre- and 1-year after TAVI in 397 patients (mean age 81±9, 46% women) with severe symptomatic aortic stenosis, complete echocardiographic data was available in 156 patients and these patients compromised our study population. Our principal findings are (1) LV remodeling occurs after TAVI; (2) afterload decreases significantly; (3) LV chamber and myocardial function, assessed by left ventricular ejection fraction and midwall fractional shortening, and stroke volume, respectively, remain unchanged or decrease. In conclusion, TAVI effects LV remodeling despite significant co-morbidities. Thus, TAVI reduces afterload and leads to LV remodeling. Surprisingly, however, systolic function does not improve. These data run counter to the paradigm that afterload reduction improves systolic function and suggest that the response to afterload reduction is complex in the TAVI population.