Lower left atrial reservoir strain was associated with first heart failure rehospitalization and recurrent readmission burden in acute heart failure with atrial fibrillation, remaining associated after additional echocardiographic adjustment including left atrial diameter, though incremental predictive value was limited.
Key Findings
Results
Lower left atrial reservoir strain (LArs) was independently associated with first heart failure rehospitalization in acute heart failure patients with atrial fibrillation.
Adjusted subdistribution hazard ratio (sHR) was 0.920 per 1 percentage-point increase in LArs (95% CI 0.870–0.973)
This association persisted after additional echocardiographic adjustment including left atrial diameter (sHR 0.928, 95% CI 0.876–0.984)
Analysis was conducted in a 320-patient single-center subgroup where LArs was available
Fine-Gray competing-risk models were used, with same-day rehospitalization and death classified as death-first events
Results
Lower LArs was associated with a higher recurrent readmission burden in acute heart failure with atrial fibrillation.
Incidence rate ratio (IRR) was 0.877 per 1 percentage-point increase in LArs (p < 0.001)
Recurrent readmission burden was modeled using negative-binomial regression
This finding was observed in the 320-patient subgroup with available LArs measurements
Results
Left atrial diameter was associated with first rehospitalization but not with death-first events.
sHR for rehospitalization-first was 1.025 per mm increase in left atrial diameter (95% CI 1.011–1.039)
Left atrial diameter was not significantly associated with the death-first outcome
The diameter analysis cohort included 691 patients, of whom 189 had rehospitalization-first, 118 death-first, and 384 were censored
Results
Left atrial volume index (LAVI) was not significantly associated with first rehospitalization or death-first events, including when analyzed per standard deviation.
LAVI was evaluated in the 320-patient single-center subgroup alongside LArs
No significant association was found with rehospitalization-first or death-first outcomes
The authors noted that 'a general left atrial structural mechanism is not established' based on this finding
Per standard deviation analyses were also non-significant
Results
Only combined abnormality of left atrial indices (exploratory cutoffs) was associated with first rehospitalization, with no single index achieving significance alone at cutoff thresholds.
Combined abnormality was associated with first rehospitalization with sHR 2.12 (95% CI 1.16–3.85)
These were described as 'exploratory cutoffs' requiring external validation
Single-index cutoff analyses did not reach significance independently
Results
Left atrial indices did not significantly improve discrimination for predicting heart failure rehospitalization outcomes.
The authors stated 'left atrial indices did not significantly improve discrimination'
Incremental predictive value was characterized as 'limited'
Cohort-derived cutoffs were noted to require external validation before clinical application
Methods
The study enrolled 716 patients with acute heart failure and atrial fibrillation, with different cohort sizes depending on the index being evaluated.
716 total patients were enrolled; 691 had available left atrial diameter measurements forming that analysis cohort
LAVI and LArs were evaluated in a 320-patient single-center subgroup
Competing risks framework classified outcomes as rehospitalization-first, death-first, or censored
Of 691 patients: 189 rehospitalization-first, 118 death-first, 384 censored
What This Means
This research examined whether different measurements of the left atrium (the heart's upper-left chamber) could predict which patients hospitalized for heart failure with an irregular heart rhythm called atrial fibrillation were most likely to be readmitted to the hospital. The study looked at three measurements: left atrial reservoir strain (how stretchy or functional the left atrium is), left atrial diameter (how wide it is), and left atrial volume index (its size adjusted for body surface area). Among 716 patients, researchers found that patients with lower left atrial reservoir strain — meaning a less functional left atrium — were significantly more likely to be readmitted for heart failure and to have more repeated hospitalizations over time. This association held up even after accounting for other heart measurements, including left atrial diameter.
Interestingly, the three measurements did not behave the same way. Left atrial diameter was linked to a higher risk of rehospitalization, but left atrial volume index was not associated with readmission risk at all — even when analyzed in different ways. This inconsistency means researchers cannot yet conclude that left atrial size in general is a reliable predictor of outcomes in this patient group. Only when both structural and functional left atrial abnormalities were present together did the combination strongly predict rehospitalization risk (about twice the risk compared to those without combined abnormality).
This research suggests that measuring how well the left atrium functions — not just how big it is — may provide useful information about which heart failure patients with atrial fibrillation are at higher risk of repeated hospitalizations. However, the study found that these measurements did not meaningfully improve overall risk prediction beyond existing tools, and the specific numerical thresholds identified need to be tested in other patient populations before they could be applied clinically. The findings highlight that different ways of measuring the same heart structure can tell different clinical stories.