Left atrial strain by reperfusion strategy as a predictor for MACE in patients after ST-elevation myocardial infarction
Authors: Latapi-Ruizesparza X , Garcia-Villarejo M , Vargas-Estrada J L , Diaz-Herrera B A , Neri-Bale R R , Santiago-Hernandez A , Adib-Gracia A E , Cuellar-Vargas J , Gopar-Nieto R , Araiza-Garaygordobil D , Arias-Mendoza A , Sierra-Lara Martinez J D 
Published: January 2025

Abstract

Background
Left atrial electrical and mechanical remodelling (LAr) is a complex process attributable to multiple cardiovascular risk factors, it occurs as early as common cardiovascular risk factors are established and it’s a time-dependent response of the cardiomyocytes. Early reperfusion, the cornerstone in the STEMI management, prevents microvascular injury. Pharmacoinvasive strategy (PhI) via STEMI networks is rapidly gaining momentum to achieve optimal total ischemic time.

Purpose
To determine the importance of left atrial strain (LAS) as a marker of LAr and a predictor of MACE in patients after STEMI and (PhI).

Methods
Patients ≥18 years old diagnosed with STEMI at a single centre from April 2021 to February 2024 were included. Echocardiograms were performed by specialists within a month of the event. The main outcome was major adverse cardiovascular events, defined by reinfarction, heart failure, cardiogenic shock, major bleeding, or cardiovascular death. Events were prospectively recorded with a maximum follow-up of 900 days. Grouping was done according to two parameters: LAS below or above 25%, and reperfusion strategy, with 4 groups as a result. Baseline characteristics were analysed using an ANOVA test for normal variables, and Mann-Whitney test with a Kruskal-Wallis test for non-normal variables. Dichotomic variables were analysed using a Chi-square test. Survival analysis was done with a Kaplan-Meier Curve and Log-Rank test. All analyses were performed using StataMP 14.1.

Results
We included 144 patients, of which 87% (n=125) were male, and the median age was 60 years. The most common comorbidities were hypertension (52%), type 2 diabetes (40.3%), and tobacco use history (48%). The median total ischemic time was 283 minutes, with 12.7% having a total ischemic time &lt;120 minutes. Median LVEF was 50%, whereas median global longitudinal strain was -15%. There was no difference among groups in any of the baseline characteristics. Group 1 (LAS &lt;25% + PhI), had 35 patients, group 2 (LAS ≥25% + PhI) included 36 patients, group 3 (LAS&lt;25% + PCI) had 18 patients, and group 4 (LAS ≥25% + PCI) had 55 patients. Composite of MACE was significantly increased in group 3 (p=0.005). The individual components of cardiovascular death (p=0.0035) and heart failure (p=0.036) were also increased in group 3.

Conclusion
Left atrial function has been widely recognized as a cardiac biomarker, due to its capability to predict the risk for heart failure and arrhythmias. Group 3 patients, who had a LAS below 25% and underwent a PCI strategy, had a significantly increased risk of MACE. This might be explained by delayed reperfusion in areas with sparse PCI centres. Prevention of microvascular damage and LAr might be achieved by early reperfusion either with pharmacoinvasive or primary coronary intervention. LAS, as a marker of LAr and microvascular injury, could be used as a predictor for MACE in STEMI patients.
Table 1. Baseline Characteristics
Figue 1. Kaplan-Meier Survival Curve