How to incorporate left atrial strain in the diagnostic algorithm of left ventricular diastolic dysfunction

The combination of early trans-mitral inflow and mitral annular tissue Doppler velocities (E/e′ ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However, when E/e′ is between 8 and 14 its accuracy decreases substantially. Left atrial (LA) deformation analysis by speckle tracking echocardiography was recently proposed as an alternative approach to estimate LV filling pressures, but its role when E/e′ is between 8 and 14 has been under-investigated. We aimed to assess whether LA strain could help to identify elevated filling pressures in patients with E/e′ between 8 and 14. Among consecutive non-selected patients who underwent a comprehensive echocardiographic evaluation, we enrolled those with E/e′ ratio > 8 and ≤ 14. Exclusion criteria were: organic mitral valve disease or mitral surgery; presence of mitral regurgitation greater than moderate in severity; diseases associated with pre-capillary pulmonary hypertension; and undetectable systolic pulmonary artery pressure (PAP-S). Peak LA longitudinal (PALS) and contraction strain (PACS) values was obtained by averaging all segments, and by separately averaging segments measured in the 4-chamber and 2-chamber views. Seventy-six patients had E/e′ > 8 and ≤ 14 and formed the study cohort. Mean age 69 ± 12 years, LV ejection fraction (LVEF) 54.5 ± 11.2%, mean E/e′ 11.2 ± 1.9, PAP-S 33 ± 7 mmHg, PALS 31.6 ± 11.7%. PALS was significantly associated to PAP-S after adjustment for LVEF, E/e′, septal LV longitudinal shortening velocity (s′), LA volume indexed (p = 0.002) and also for ASE/EACVI diastolic dysfunction classification (p = 0.0002). Furthermore, PALS but not ASE/EACVI diastolic dysfunction grading, resulted independently associated to New York Heart Association (NYHA) class (p = 0.0004). PALS is able to predict increased intra-cardiac pressure and NYHA class in patients characterized by E/e′ between 8 and 14. Therefore, we propose that PALS might be incorporated in a simplified diagnostic algorithm based on E/e′ classes.