Left atrial reservoir strain is an outstanding predictor of adverse cardiovascular outcomes in patients undergoing maintenance hemodialysis: Assessment via three-dimensional speckle tracking echocardiography

Background: There is a paucity of literature focusing left atrium (LA) in patients undergoing maintenance hemodialysis (MHD). Hypothesis: We used three-dimensional speckle tracking echocardiography (3DSTE) to evaluate LA in MHD patients and to explore its predictive value for adverse outcomes. Methods: Echocardiography was performed on 130 consecutively enrolled MHD patients without previous cardiac diseases. Conventional and 3DSTE parameters of LA were obtained. The MHD cohort was then followed and the end point was major adverse cardiovascular events (MACEs). LA strain indices, including reservoir strain (LASr), conduit strain (LAScd), and contractile strain (LASct), were measured and compared between patients with and without MACEs. Results: Patients were prospectively followed up for a median of 40.5 (interquartile range: 26.3-48.0) months. During follow-up, 43 patients met the end point. These patients had larger LA size and reduced LA strains (LA maximal volume indexed: 45.1 +/- 11.9 vs. 33.8 +/- 6.9ml/m(2); LASr: 20.2 +/- 3.5 vs. 27.2 +/- 3.3%; LAScd: -12.3 +/- 5.2 vs. -14.5 +/- 4.0%; LASct: -8.0 +/- 4.2 vs. -13.2 +/- 3.7%; all p<.05), compared with those without MACEs. Multivariable regression analysis showed LASr was the strongest predictor of MACEs (hazard ratio, 0.69; 95% confidence interval, 0.54-0.89; p=.004). Univarite Kaplan-Meier analysis revealed the incidence of MACEs in the impaired LASr (<24.2%) group was significantly higher than in the normal LASr group (log rank p<.001). Conclusions: LASr derived from 3DSTE is an independent predictor of MACEs and cardiac death in MHD patients, superior to LV parameters and LA volume indices.