LEFT ATRIAL RESERVOIR STRAIN AS A NON-INVASIVE MARKER OF CORONARY ARTERY DISEASE SEVERITY IN PRESERVED-EF PATIENTS

Abstract

Left atrial reservoir strain (LARS) is an emerging echocardiographic marker of atrial dysfunction and diastolic impairment in patients with preserved left ventricular ejection fraction (LVEF). In coronary artery disease (CAD), ischemia and altered myocardial mechanics may impair LARS before conventional structural or functional abnormalities become evident. This study aimed to determine whether LARS differentiates CAD severity better than conventional left ventricular parameters in preserved-EF patients. We conducted a study involving 52 adults with preserved LVEF (>50%) who underwent transthoracic echocardiography for suspected or known CAD and other cardiovascular indications. Patients were classified into non-CAD, mild CAD, and severe CAD groups. LARS was assessed in relation to conventional diastolic indices, LV structural and systolic parameters, and CAD severity using comparative analysis, ordinal logistic regression, and ROC analysis. LARS progressively declined across increasing CAD severity, from 29.43±7.10% in the non-CAD group to 25.67±4.33% in mild CAD and 23.67±4.69% in severe CAD (p=0.025). In contrast, conventional LV parameters, including LVEF, LVEDV, LVEDD, LAVi, E/A, E/e′, and diastolic dysfunction grade, did not significantly distinguish CAD severity groups. On ordinal logistic regression, older age (OR 1.136; 95% CI 1.06–1.22; p<0.001) and lower LARS (OR 0.865; 95% CI 0.78–0.96; p=0.0049) were associated with greater CAD severity. ROC analysis showed that LARS had modest discriminatory performance. In preserved-EF patients, LARS decreases with increasing CAD severity and differentiates CAD burden better than conventional LV structural and functional parameters, supporting its potential utility as a non-invasive marker of CAD severity.Figure 1.Linear regression models predicting CVD mortality, DALY, YLL and YLD according to the development of cardiovascular infrastructures over 2016 to 2022. X1: catheterization laboratory growth in 2016-2022; density of cardiologist; X3: proportion of universal health coverage in provinces; X4: hospital bed ratio; X5: Gross Regional Domestic Product (GDRP); DALY: disability-adjusted life years; YLD: years of life lost.