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.

Effects of Aortic Valve Replacement on Left Ventricular Diastolic Function in Patients With Aortic Valve Stenosis.

The afterload increase imposed by severe aortic valve stenosis (AS) creates concentric left ventricular (LV) remodeling and diastolic dysfunction (DD), which are both markers of poor clinical outcome. Ideally, a correctly timed surgery for isolated AS can reverse the LV remodeling. However, data on LV DD after aortic valve replacement (AVR) are sparse and contrasting. Aims of the study are to define the markers of a favorable evolution of the DD at follow-up. Patients with severe isolated AS, scheduled for AVR were prospectively enrolled. Transthoracic echocardiography with DD assessment was performed before surgery, and at 12 months after surgery. Global LV longitudinal and circumferential strain, peak atrial longitudinal and contraction strain (PALS, PACS) were obtained at baseline. LV septal biopsy to assess fibrosis was performed at the time of AVR. Sixty-seven patients were enrolled, age 72 ± 8 years, 66% female, ejection fraction 61 ± 8%, E/e' 13 ± 6, PALS 23 ± 7%. Normal estimated left atrial pressure was detected in 19/67 (28%) versus 43/67 (64%) at follow-up (p <0.0001). In the 37 patients with biopsy available, fibrosis was 24 ± 12%. PALS and AS severity were correlated with LV fibrosis (R2 = 0.19; p = 0.006, and R2 = 0.15; p = 0.02, respectively). PALS (odds ratio: 1.19 [1.05 to 1.41], p = 0.02) and PACS (odds ratio: 1.24 [1.06 to 1.50], p = 0.006) were the only baseline noninvasive parameters independently associated with normal left atrial pressure at follow-up. Mean follow-up time was 791 ± 245 days, and 8 (12%) patients had cardiovascular events (death, hospital admission due to heart failure or ischemic disease, and onset of atrial fibrillation). Myocardial fibrosis (p = 0.05), baseline PALS (p = 0.004), and PACS (p = 0.03) were associated with cardiovascular events. In conclusion, LV diastolic function generally improves after AVR for severe AS. Baseline PALS, PACS, and LV fibrosis were related to the DD and clinical outcome at follow-up; these parameters might cue a better diastolic response to the afterload correction.