Association of atrial strain ratio with invasive pulmonary hemodynamics in rheumatic mitral stenosis

Abstract

Type of funding sources: None. Background. Symptomatic rheumatic mitral stenosis (MS) results in elevation in left atrial (LA) pressure that is passively transmitted to derange pulmonary hemodynamics and subsequently elevate right ventricular afterload. We studied associations between LA to right atrial reservoir strain ratio (LA-RAs) and invasive pulmonary hemodynamics in addition to the ratio’s ability to identify subjects with elevated pulmonary vascular resistance (PVR). Methods.  Consecutive MS subjects undergoing right heart catheterization (RHC) and percutaneous transvenous mitral commissurotomy (PTMC) were enrolled. Subjects with atrial fibrillation, >mild mitral regurgitation, concomitant aortic valve or ischemic heart disease were excluded. LA-RAs was assessed by speckle-tracking echocardiography and stratified into high or low LA-RAs subgroups based on mean value. Correlations with invasive pulmonary hemodynamics was studied. ROC analysis was performed to identify pulmonary hypertension (PH) and PVR > 3 Wood Units. Results. 110 subjects were analysed (age: 32 ± 8; 72% female). LA and RA reservoir strain was feasible in 88 (80%) and 83 (75%) subjects respectively. Patients with low LA-RAs demonstrated more severe MS (0.8 ± 0.1 vs. 1.0 ± 0.2cm2), higher mean pulmonary artery (43 ± 13 vs. 33 ± 13mmHg) and capillary wedge pressure (28 ± 6 vs.23 ± 16mmHg) as compared with high LA-RAs (p < 0.001 for all). LA-RAs was associated with invasive PA systolic (r=-0.30;p = 0.05), diastolic (r=-0.28;p = 0.02) and mean (r=-0.33; p = 0.002) pressures, demonstrated modest ability to identify elevated PVR (AUC = 0.65;p = 0.03) and strong ability to identify PH (AUC = 0.75; p < 0.001). LA-RAs significantly increased after PTMC (0.43 ± 0.1 to 0.52 ± 0.1;p < 0.001). Conclusions. The novel atrial strain ratio is associated with measures of invasive pulmonary hemodynamics and demonstrates ability to identify PH and elevated PVR in MS.