Severe aortic stenosis with preserved ejection fraction and evidence of impairment in structure, myocardial strain and ventricular function: A new contribution to clinical decision making.

ABSTRACT

BACKGROUND: Left ventricular ejection fraction (LVEF) is among the parameters that are usually employed to define surgical timing of severe aortic stenosis (AS). Our hypothesis states that even when their LVEF is preserved, patients with severe symptomatic AS have impaired myocardial structure and function, and such impairment is related to the deleterious progression of left ventricular hypertrophy (LVH) from the compensated to the decompensated stage, as shown by the changes in diastolic function and the increase in left ventricular end-diastolic pressure (LVEDP). METHODS AND RESULTS: A total of 26 patients with severe AS and LVEF > 50% referred for aortic valve replacement underwent catheterization, echocardiography and an intraoperative biopsy. Patients with severe symptomatic AS were classified as group 1 (G1; compensated LVH, LVEDP < 15 mm Hg without coronary artery disease [CAD], n = 7), group 2a (G2a, decompensated LVH, without CAD, n = 7), and group 2b (G2b, decompensated LVH with CAD, n = 12). Differences were seen in the following myocyte area [µm2] G1 328 ± 66, G2a 376 ± 22, G2b 385 ± 13, p < 0.01; collagen volume [%] G1 4.77 ± 1.27, G2a 8.40 ± 1.27, G2b 11.05 ± 3.08, p < 0.01; LVEDP normalized by diastolic diameter [mm Hg/mm] G1 0.27 ± 0.01, G2a 0.39 ± 0.06, G2b 0.44 ± 0.11, p < 0.02; +dP/dtmax/LVEDP [mm Hg/s/mm Hg] G1 176 ± 45, G2a 89.6 ± 20, G2b 113.1 ± 41, p < 0.01; two-dimensional peak systolic longitudinal strain [%] G1 ­17.7 ± 4.75, G2a ­13.4 ± 3.04, G2b ­13.5 ± 3.13, p < 0.05. CONCLUSIONS: Patients with severe symptomatic AS and preserved ejection fraction who develop decompensated LVH characterized by increased LVEDP, exhibit an abnormal myocardial structure and diastolic and systolic impairment.