Left Atrial Strain predicts major cardiovascular events with HR 0.91 in general population

This systematic review and meta-analysis synthesized evidence on Left Atrial Strain (LAS) as a predictor of cardiovascular outcomes. The analysis included a total sample size of 13,156 participants from the general population and patients with specific cardiovascular diseases. The setting was not reported. The intervention or exposure was the measurement of Left Atrial Strain. No specific comparator was reported. The primary outcome was a composite of all-cause death and heart failure hospitalizations, though specific results for this composite were not detailed in the provided data. The main results focused on major cardiovascular events as a key outcome.

The primary analysis for major cardiovascular events in the general population showed that LAS was a significant predictor. The effect size was a hazard ratio (HR) of 0.91, with a 95% confidence interval (CI) of 0.86 to 0.96. This indicates a predictive association where higher LAS values are associated with a lower risk of events. In patients with heart failure (HF), LAS also predicted major cardiovascular events with an HR of 0.93 (95% CI 0.89 to 0.97). For patients with ischemic heart disease (IHD), the HR was 0.95 (95% CI 0.91 to 0.99). In patients with valvular heart disease (VHD), the HR was 0.94 (95% CI 0.90 to 0.97). In contrast, for patients with left ventricular hypertrophy (LVH), LAS did not significantly predict major cardiovascular events, with an HR of 0.98 (95% CI 0.84 to 1.15).

Key secondary outcomes were not reported in the provided data. Safety and tolerability findings were also not reported; adverse events, serious adverse events, discontinuations, and overall tolerability were all noted as not reported. This represents a significant gap in the evidence regarding the safety profile of measuring LAS.

These results can be compared to prior landmark studies in cardiovascular imaging and prognostication. While specific prior studies are not named in the input, the consistent predictive association across multiple disease states aligns with the growing body of evidence supporting strain imaging in heart failure and other cardiomyopathies. The finding that LAS was not predictive in LVH is a notable divergence that may inform future research priorities.

Key methodological limitations include the lack of reported setting, follow-up duration, and specific details on the primary composite outcome. The analysis is observational in nature, and the causality note explicitly states the findings are an association, not causation. The certainty of the evidence was not reported. Potential biases cannot be assessed due to the lack of detailed methodology in the input.

The clinical implications are that LAS represents a powerful predictor of major cardiovascular events in the general population and in patients with different cardiovascular diseases across left ventricular ejection fraction (LVEF) ranges, as noted in the practice relevance. This suggests LAS could be integrated into risk stratification models. However, clinicians must recognize this is a prognostic marker, and its measurement should not replace established clinical assessments.

Unanswered questions remain. The specific protocol for LAS measurement, the optimal cutoff values for risk prediction, and the clinical utility of guiding therapy based on LAS are not defined. The long-term impact of using LAS in routine practice is unknown. Future research should address these gaps, including prospective trials to test if acting on LAS measurements improves patient outcomes.