Relationship between Strain Rate and Myocardial Structure in Severe Aortic Stenosis

Introducción: En la estenosis aórtica sintomática grave (EASG), la alteración del strain global longitudinal sistólico (SGLS) tendría correlación con las modificaciones de la histoarquitectura y podría identificar compromiso contráctil temprano en pacientes con fracción de eyección conservada (FEyC). Objetivo: Analizar el SGLS, el volumen de colágeno (VC), el área miocitaria (ArMi) y el compromiso contráctil en pacientes con EASG y FEyC. Material y métodos: Se incorporaron 26 pacientes con EASG y FEyC (edad 67 ± 11 años, 53% hombres). Se realizaron un estudio hemodinámico preoperatorio y una biopsia endomiocárdica intraoperatoria para determinar el VC y el ArMi. Se identificaron tres grupos de pacientes: G1, hipertrofia ventricular izquierda (HVI) compensada sin enfermedad coronaria (n = 8); G2, HVI descompensada sin enfermedad coronaria (n = 7) y G3, HVI descompensada con enfermedad coronaria (n = 11). El SGLS se normalizó por volumen sistólico, estrés meridional de fin de sístole (δ) y diámetro de fin de diástole (DFD). Resultados: G1, G2 y G3, sin diferencias en volumen sistólico, δ y DFD y con diferencias en VC (%) (G1: 4,7 ± 1,2; G2: 8,4 ± 1,2; G3: 11,0 ± 3,0; p < 0,01), ArMi (mm2) (G1: 328,7 ± 66,2; G2: 376,7 ± 21,9; G3: 385,0 ± 13,0; p = 0,01), PFDVI (mm Hg) (G1: 13,1 ± 1,5; G2: 19,0 ± 3,8; G3: 23,6 ± 5,8; p < 0,01), +dP/dtmáx (mm Hg/seg / PFDVI, mm Hg) (G1: 176,4 ± 45,5; G2: 89,6 ± 20,1; G3: 113,1 ± 43,7; p < 0,01), SGLS (%) (G1: -17,9 ± 4,2; G2: -13,5 ± 2,5; G3: -13,6 ± 3; p = 0,021). El SGLS se correlacionó con VC y PFDVI y hubo tendencia con un índice de contractilidad (+dP/dtmáx mm Hg/seg / PFDVI, mm Hg). Conclusiones: Las alteraciones del SGLS en pacientes con EASG y FEyC son expresión de alteraciones estructurales delBackground: In severe symptomatic aortic stenosis (SSAS) altered global longitudinal systolic strain (GLSS) would correlate with changes in myocardial histological architecture and could identify early contractile involvement in patients with preserved ejection fraction (PEF). Objective: The aim of this study was to analyze GLSS, collagen volume (CV), myocyte area (MyAr) and contractile involvement in patients with SSAS and PEF. Methods: Twenty six patients with SSAS and PEF (67±11 years old, 53% male) were included in the study. A preoperative hemodynamic study and an intraoperative endomyocardial biopsy were performed to determine CV and MyAr. Three groups of patients were identified: G1: compensated left ventricular hypertrophy (LVH) without coronary disease (n=8); G2: decompensated LVH without coronary disease (n=7) and G3: decompensated LVH with coronary disease (n=11). GLSS was normalized by stroke volume, meridional end-systolic wall stress (δ) and end-diastolic diameter (EDD). Results: No significant differences in stroke volume, δ and EDD were observed between groups G1, G2 and G3. Differences between groups were observed in: CV (%) (G1: 4.7 ± 1.2, G2: 8.4 ± 1.2, G3: 11.0 ± 3.0; p < 0.01), MyAr (mm2) (G1: 328.7 ± 66.2, G2: 376.7 ± 21.9, G3: 385.0 ± 13.0; p = 0.01), LVEDP (mm Hg) (G1: 13.1 ± 1.5, G2: 19.0 ± 3.8, G3: 23.6 ± 5.8; p < 0.01), +dP/dtmax (mm Hg/sec / LVEDP, mm Hg) (G1: 176.4 ± 45.5, G2: 89.6 ± 20.1, G3: 113.1 ± 43.7; p < 0.01), and GLSS (%) (G1: -17.9 ± 4.2, G2: -13.5 ± 2.5, G3: -13.6 ± 3; p = 0.021). GLSS correlated with CV and LVEDP and it evidenced a trend to correlate with a contractility index (+dP/dtmax mm Hg/s / LVEDP, mm Hg). Conclusions: Altered GLSS in patients with SSAS and PEF expresses myocardial structural changes related to increase in C V, which is associated with enhanced LVEDP and probable myocardial contractile failure.Fil: Hita, Alejandro. Hospital Universitario Austral; Argentina. Sociedad Argentina de Cardiología; ArgentinaFil: Baratta, Sergio. Hospital Universitario Austral; Argentina. Sociedad Argentina de Cardiología; ArgentinaFil: Chejtman, Demian. Hospital Universitario Austral; ArgentinaFil: Benticuaga, Alejandro. Hospital Universitario Austral; ArgentinaFil: Constantini, Ricardo. Hospital Universitario Austral; ArgentinaFil: Vaccarino, Guillermo. Sociedad Argentina de Cardiología; Argentina. Hospital Universitario Austral; ArgentinaFil: Donato, Pablo Martín. Hospital Universitario Austral; Argentina. Sociedad Argentina de Cardiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gelpi, Ricardo Jorge. Sociedad Argentina de Cardiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Matoso, Miriam. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; ArgentinaFil: Morales, Celina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentin

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

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 &gt; 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 &lt; 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 &lt; 0.01; collagen volume [%]: G1: 4.77 ± 1.27, G2a: 8.40 ± 1.27, G2b: 11.05 ± 3.08, p &lt; 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 &lt; 0.02; +dP/dtmax/LVEDP [mm Hg/s/mm Hg]: G1: 176 ± 45, G2a: 89.6 ± 20, G2b: 113.1 ± 41, p &lt; 0.01; two-dimensional peak systolic longitudinal strain [%]: G1: –17.7 ± 4.75, G2a: –13.4 ± 3.04, G2b: –13.5 ± 3.13, p &lt; 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

Loss of dystrophin is associated with increased myocardial stiffness in a model of left ventricular hypertrophy

Transition from compensated to decompensated left ventricular hypertrophy (LVH) is accompanied by functional and structural changes. Here, the aim was to evaluate dystrophin expression in murine models and human subjects with LVH by transverse aortic constriction (TAC) and aortic stenosis (AS), respectively. We determined whether doxycycline (Doxy) prevented dystrophin expression and myocardial stiffness in mice. Additionally, ventricular function recovery was evaluated in patients 1 year after surgery. Mice were subjected to TAC and monitored for 3 weeks. A second group received Doxy treatment after TAC. Patients with AS were stratified by normal left ventricular end-diastolic wall stress (LVEDWS) and high LVEDWS, and groups were compared. In mice, LVH decreased inotropism and increased myocardial stiffness associated with a dystrophin breakdown and a decreased mitochondrial O2 uptake (MitoMVO2). These alterations were attenuated by Doxy. Patients with high LVEDWS showed similar results to those observed in mice. A correlation between dystrophin and myocardial stiffness was observed in both mice and humans. Systolic function at 1 year post-surgery was only recovered in the normal-LVEDWS group. In summary, mice and humans present diastolic dysfunction associated with dystrophin degradation. The recovery of ventricular function was observed only in patients with normal LVEDWS and without dystrophin degradation. In mice, Doxy improved MitoMVO2. Based on our results it is concluded that the LVH with high LVEDWS is associated to a degradation of dystrophin and increase of myocardial stiffness. At least in a murine model these alterations were attenuated after the administration of a matrix metalloprotease inhibitor.Fil: Donato, Pablo Martín. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Buchholz, Bruno. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morales, Celina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; ArgentinaFil: Valdez, Laura Batriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Zaobornyj, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Baratta, Sergio. Hospital Austral; ArgentinaFil: Paez, Diamela T.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; ArgentinaFil: Matoso, Mirian. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; ArgentinaFil: Vaccarino, Guillermo. Hospital Austral; ArgentinaFil: Chejtman, Demian. Hospital Austral; ArgentinaFil: Agüero, Oscar. Hospital Austral; ArgentinaFil: Telayna, Juan. Hospital Austral; ArgentinaFil: Navia, José. Hospital Austral; ArgentinaFil: Hita, Alejandro. Hospital Austral; ArgentinaFil: Boveris, Alberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Gelpi, Ricardo Jorge. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin