Comparative analysis of the 2016 diastolic guidelines and left atrial stiffness in predicting exercise tolerance and cardiac events

Abstract Background While the 2016 ASE/EACVI guideline for diastolic dysfunction is a robust tool for prognostication, their complexity and 20% rate of indeterminate limit their routine clinical practice. Purpose Left atrial (LA) stiffness, calculated as the E/e' ratio divided by LA strain, provides a simpler measure that indirectly reflects LA pressure. This study aims to evaluate whether LA stiffness can be better than the 2016 guidelines in predicting poor exercise tolerance and cardiac events (cardiac death or heart failure hospitalization) in patients with dyspnea. Methods In this retrospective single-center cohort study, 404 patients who underwent echocardiography and cardiopulmonary exercise test simultaneously were reviewed. Poor exercise tolerance was defined by a peak oxygen uptake (VO2) of <14 ml/kg/min or a minute ventilation-carbon dioxide production (VE/VCO2) slope of ≥ 40. The predictive abilities of LA stiffness for peak VO2, VE/VCO2 slope, and cardiac outcomes (cardiac death or heart failure hospitalization) were compared to those of the 2016 guidelines using ROC curve analysis. Results The mean left ventricular ejection fraction was 50% (IQR 58.58-66.70). Of the 404 patients (mean age 58.51, male 50.74%), peak VO2 < 14 and VE/VCO2 ≥ 40 were observed in 38 and 24 patients, and cardiac events occurred in 37 patients during median follow up of 85.45 months. ROC analysis showed that LA stiffness had AUC values of 0.697 (95% CI: 0.604-0.789) for peak VO2 < 14, 0.645 (95% CI: 0.529-0.760) for VE/VCO2 slope ≥ 40, and 0.628 (95% CI: 0.541-0.715) for cardiac events. The 2016 guidelines achieved AUCs of 0.685 (95% CI: 0.604-0.766), 0.586 (95% CI: 0.481-0.690), and 0.589 (95% CI: 0.505-0.674). Statistical comparison revealed no significant difference between the predictive capabilities of LA stiffness and the 2016 guidelines (p-values: 0.735, 0.165, and 0.439, respectively). (Figure) Conclusion LA stiffness offers comparable diagnostic accuracy to the 2016 ASE/EACVI guidelines in assessing poor exercise tolerance and cardiac events in patients with dyspnea. Given its simplicity and ease of measurement, LA stiffness represents a viable alternative for evaluating diastolic dysfunction.ROC curve