Impact of Prosthesis-Patient Mismatch on Left Ventricular Myocardial Mechanics After Transcatheter Aortic Valve Replacement

Abstract

Background: The aim of this study was to compare left ventricular (LV) remodeling using myocardial strain between patients with severe aortic stenosis (AS) treated with transcatheter aortic valve replacement (TAVR) with and without prosthesis-patient mismatch (PPM).

Methods and results: In a retrospective study, speckle-tracking echocardiography was used to measure global longitudinal strain (GLS) and strain rate (GLSR), circumferential strain, and rotation before and at mid-term follow-up post-TAVR. Moderate and severe PPM were defined as an effective orifice area ≤0.85 and <0.65 cm(2)/m(2), respectively. A total of 102 patients (median age, 83 years [77-88]) with severe AS were included. At 6±3 months post-TAVR, moderate and severe PPM were found in 32 (31%) and 9 (9%) patients. Patients without PPM had a significant regression in LV mass (from 134±41 to 119±38 g/m(2); P=0.001) at follow-up whereas those with PPM did not. There was a significant improvement in LV GLS (-12.8±4.0 to -14.3±4.3%; P=0.01), GLSR (-0.61±0.20 to -0.73±0.25 second(-1); P<0.001), and early diastolic strain rate (0.52±0.20 to 0.64±0.20 second(-1); P<0.001) in patients without PPM, but not in those with PPM. After adjustment for pre-TAVR ejection fraction and post-TAVR aortic regurgitation, patients without PPM had greater improvement in LV longitudinal strain parameters compared to those with PPM. After a median follow-up of 46.1 months (interquartile range, 35.4-60.8), there was no difference in survival between patients with and without PPM.

Conclusions: TAVR was associated with an incidence of PPM of 40%. Greater reverse LV remodeling using myocardial strain was evident in patients without PPM compared to PPM. Presence of PPM was not associated with mortality.

Keywords: aortic stenosis; effective orifice area; prosthesis‐patient mismatch; speckle‐tracking echocardiography; strain; transcatheter aortic valve replacement.

Figure 1

Summary of the pre‐TAVR alterations in myocardial mechanics (compared to the controls) and the expected changes post‐TAVR according to the presence of PPM. A, Multidirectional myocardial mechanics in control subjects (left panel) and in patients with severe AS (right panel). Increased (↑) parameters of myocardial deformation, as compared to healthy controls, represent compensatory mechanisms. See text for details. B, Changes in myocardial mechanics post‐TAVR in patients with severe AS and post‐TAVR PPM versus no‐PPM. Arrows represent the change in myocardial mechanics compared to the mechanics preceding TAVR (↑: “increases”, ↓: “decreases”, and ↔: “no change”). ApRot indicates apical rotation; AS, aortic stenosis ; CS, circumferential strain; LS, longitudinal strain; LV, left ventricle; PPM, prosthesis‐patient mismatch; SR, strain rate; TAVR, transcatheter aortic valve replacement.

Figure 2

Segmental longitudinal strain curves (apical 2‐chamber view) in representative patients pre‐ versus post‐TAVR. A, In a representative patient without PPM, longitudinal systolic strain is reduced at baseline with near normalization post‐TAVR. B, In a representative patient with PPM, longitudinal systolic strain is reduced at baseline with no change post‐TAVR. PPM indicates prosthesis‐patient mismatch; TAVR, transcatheter aortic valve replacement.

Figure 3

Kaplan–Meier survival curves stratified by the presence or absence of PPM. Kaplan–Meier curves were truncated at 5 years because of the paucity of data beyond 5 years. There was no difference in overall survival between the PPM and no‐PPM groups (log‐rank test, P=0.49; Gehan–Breslow–Wilcoxon test, P=0.48). PPM indicates prosthesis‐patient mismatch; TAVR, transcatheter aortic valve replacement.