# The Prognostic Value of Left Atrial Size and Strain Assessed by Cardiac Magnetic Resonance in the Coronary Chronic Total Occlusion

## TL;DR

This study finds that larger left atrial size, measured by MRI, is linked to worse outcomes in patients with a specific heart condition called coronary chronic total occlusion.

## Contribution

The study demonstrates that left atrial maximum volume index is an independent predictor of adverse events in CTO patients with preserved ejection fraction.

## Key findings

- LAVImax was independently associated with MACCE in CTO patients with LVEF ≥ 40%.
- Higher LAVImax quartiles showed significantly increased risk of MACCE compared to the first quartile.
- LA strain parameters did not show a significant association with MACCE after adjustment.

## Abstract

Background: The relationship between left atrial (LA) size, LA strain, and long-term prognosis in patients with coronary chronic total occlusion (CTO) remains unclear. This study aimed to evaluate the association of LA size and LA strain with clinical outcomes in CTO patients using cardiac magnetic resonance (CMR). Methods: This retrospective study included 168 patients with left ventricular ejection fraction (LVEF) ≥ 40%. The primary endpoint was the composite of major adverse cardiovascular and cerebrovascular events (MACCE). Model 1 was established by adjusting for clinically relevant parameters and standard CMR metrics. Models 2–4 were developed using Cox regression based on Model 1, with additional adjustment for each LA strain parameter separately. Results: A total of 168 patients with an LVEF ≥ 40% were analyzed, of whom 39 (23.2%) experienced MACCE during a mean follow-up of 45.9 months (median, 42 months). A preliminary model suggested that LA maximum volume index (LAVImax) was independently associated with MACCE (HR 1.05, 95% CI 1.02–1.08, p = 0.004). Specifically, compared to the first quartile of LAVImax, the second, third, and fourth quartiles were associated with an increased risk of MACCE (Q2: HR 4.50, 95% CI 1.42–14.27, p = 0.011; Q3: HR 4.40, 95% CI 1.29–14.96, p = 0.018; Q4: HR 5.55, 95% CI 1.71–18.06, p = 0.004). In Models 2–4, higher LAVImax remained independently associated with MACCE (all p < 0.05), after adjusting for LA reservoir strain, conduit strain and booster strain, separately. In contrast, none of the LA strain parameters were associated with MACCE. Conclusions: Among CTO patients with LVEF ≥ 40%, LAVImax was independently associated with MACCE.