Increased maximum left atrial volume and left ventricular end-diastolic volume were significant predictors of increased mitral annular area 1 year after STEMI (both p<0.05).
Observational (n=87)
Mitral annular remodeling 1 year after STEMI is driven by increases in both LA and LV volumes, with LA volume being the strongest predictor.
Effect estimate: beta 0.025 (LA volume) and 0.014 (LV volume)
p-value: p=<0.05
Abstract Background Dilatation of the mitral annulus (MA) is a main contributor to development of functional mitral regurgitation. The impact of left chamber remodeling following a myocardial infarction on the MA size and function has so far not been thoroughly explored. Purpose We aimed to investigate how altered size and function of the left atrium (LA) and left ventricle (LV) impacts the MA in patients with transmural myocardial infarction. Methods In a prospective, longitudinal observational study, patients admitted with ST-elevation myocardial infarction (STEMI) were examined during admission (baseline visit) and 1 year after the event (follow-up visit). The LV, LA and MA size and function were assessed by 3D echocardiography at both visits. Changes in MA area during the cardiac cycle were assessed using semi-automatic annotations. Significant MA remodeling was defined as an area increase at follow-up of 15% or more. The cohort was divided into two groups: patients with (n=16) or without (n=71) significant MA remodeling. Results One year after STEMI, patients without MA remodeling presented no change in LV end-diastolic volume (161 ml to 163 ml) or maximum LA volume (61 ml to 60 ml) compared to baseline. Moreover, they had improved LV ejection fraction (47% to 53%) and LV global longitudinal strain (-10.6% to -13.3%), as well as improved LA emptying fraction (47% to 51%), LA reservoir strain (14.6% to 17.7%) and LA contractile strain (-6.1% to -8.7%) (all p≤0.001) On the contrary, patients with significant MA remodeling had larger LV end-diastolic (157 ml to 175 ml) and maximum LA volume (64 to 74 ml) (both p0.05), and no change in LA emptying fraction (48% to 47%, p=0.668), LA reservoir strain (15.5% to 17.1%, p=0.238) or LA contractile strain (-6.3% to -7.0%, p=0.489) 1 year after STEMI. LV ejection fraction (48% to 52%) and global longitudinal strain (-10.5% to -14.1%) were improved also in this group (both p0.01). No change in LA conduit strain or MA fractional area change was found in patients with or without MA remodeling. In multivariable regression analysis, both 1-year increase in maximum LA volume and 1-year increase in LV end-diastolic volume predicted a significantly larger MA area, with increased LA volume being the stronger predictor: beta 0.025 (LA volume) vs. 0.014 (LV volume) (both p0.05). Conclusions Mitral annular remodeling after transmural myocardial infarction occurs in patients experiencing an increase in both LA and LV volumes, and no functional improvement of the LA. Increased maximum LA volume is the strongest predictor of increased MA area 1 year after STEMI. Our findings bring new insights into the pathophysiology of post-infarction mitral disease leading up to functional MR.
Valeur et al. (2026) conducted an observational in ST-elevation myocardial infarction (STEMI) (n=87). Increased maximum left atrial and left ventricular end-diastolic volumes vs. No increase in volumes was evaluated on Mitral annular area (beta 0.025 (LA volume) and 0.014 (LV volume), p=<0.05). Increased maximum left atrial volume and left ventricular end-diastolic volume were significant predictors of increased mitral annular area 1 year after STEMI (both p<0.05).