Left Atrial Function with MRI Enables Prediction of Cardiovascular Events after Myocardial Infarction: Insights from the AIDA STEMI and TATORT NSTEMI Trials

Abstract

CARDIAC IMAGINGL eft ventricular (LV) ejection fraction (EF) is used to assess systolic myocardial function after acute myocardial infarction (AMI), and reduced LV EF is associated with adverse cardiovascular events (1). Risk stratification can be optimized by assessing myocardial ventricular strain with incremental value over LV EF, suggesting an important role of ventricular function imaging in patients with recent AMI (2,3).The importance of left atrial (LA) function and structure is increasingly recognized and has led to the introduction of atrial cardiomyopathy as an independent entity (4). Greater atrial volume is commonly associated with cardiovascular diseases, such as ischemic heart disease, valvular heart disease, and heart failure (eg, dilated cardiomyopathy) (5). Elevated LA volume has been shown to predict cardiovascular mortality (6) beyond LV EF after AMI (7). Volumetric atrial function shows superior predictive value beyond atrial size and LV EF in ST-elevation myocardial infarction (STEMI) (8) and non-STEMI (NSTEMI) (9). However, the superior predictive value of atrial volumetric

Role of Cardiac Magnetic Resonance to Improve Risk Prediction following Acute ST-elevation Myocardial Infarction

“…The larger analysis by Ledwoch and colleagues including 684 STEMI patients measured LA function only by ejection fraction and could find an independent association between LA ejection fraction and adverse clinical events; however, the prognostic value of LA ejection fraction was not incremental to LV ejection fraction [48]. Hence, more comprehensive approaches of LA function assessment have been developed and tested [49,50]. Comparable with the LV, LA strain analysis has become available for CMR enabling a comprehensive evaluation of the complex function of the LA, comprising reservoir function, conduit function and contractile booster pump function [49].…”

“…Comparable with the LV, LA strain analysis has become available for CMR enabling a comprehensive evaluation of the complex function of the LA, comprising reservoir function, conduit function and contractile booster pump function [49]. In a large multicenter CMR study including 1046 patients with STEMI and non-STEMI, Schuster et al evaluated the prognostic implications of LA function parameters as determined by feature-tracking (LA reservoir function peak systolic strain, LA conduit strain, and LA booster pump function active strain) [50]. All three atrial strain measures showed strong associations with MACE, whereas only LA peak reservoir strain emerged as an independent and incremental prognosis marker, above and beyond LV ejection fraction, infarct severity markers, and even LV global longitudinal strain [50].…”

“…In a large multicenter CMR study including 1046 patients with STEMI and non-STEMI, Schuster et al evaluated the prognostic implications of LA function parameters as determined by feature-tracking (LA reservoir function peak systolic strain, LA conduit strain, and LA booster pump function active strain) [50]. All three atrial strain measures showed strong associations with MACE, whereas only LA peak reservoir strain emerged as an independent and incremental prognosis marker, above and beyond LV ejection fraction, infarct severity markers, and even LV global longitudinal strain [50]. These findings suggest that an integrative CMR approach incorporating upcoming parameters such as LV global longitudinal strain and LA reservoir strain, which can be interpreted as indicator of the atrial compensatory capacity, may distinctly optimize post-STEMI risk assessment.…”

Is myosin activation a new treatment for heart failure?

“…7,8 Another recent trial demonstrated quite convincingly that left atrial function yielded incremental prognostic value above left ventricular ejection fraction in patients after myocardial infarction. 9 The myosin activator danicamtiv acts similarly on both ventricular and atrial myocardium, although myosin isoforms differ in both chambers. Of course, the effects on diastolic function, likely associated with prolonged cross-bridge attachment and also reflected by prolonged systolic ejection time, are a concern.…”

“…The increase in left atrial function is particularly interesting since it was recently shown to be an independent predictor of cardiac performance and outcomes 7,8 . Another recent trial demonstrated quite convincingly that left atrial function yielded incremental prognostic value above left ventricular ejection fraction in patients after myocardial infarction 9 . The myosin activator danicamtiv acts similarly on both ventricular and atrial myocardium, although myosin isoforms differ in both chambers.…”