Assessment of left atrial appendage filling pattern by using intravenous administration of microbubbles: comparison between mitral stenosis and mitral regurgitation

Clinical impacts of concomitant left atrial appendage occlusion during mitral valve surgery in patients with mitral regurgitation

Surgical occlusion of the left atrial appendage (LAA) during cardiac surgery in patients with atrial fibrillation (AF) is known to reduce thromboembolism. However, data on the clinical significance of LAA occlusion (LAAO) in patients with mitral regurgitation (MR) are lacking. A total of 237 AF patients with chronic severe MR who underwent mitral valve (MV) surgery were retrospectively analyzed. Patients were divided into two groups according to concomitant LAAO or LAA preservation. The primary outcome was a composite of all-cause death and thromboembolic events (ischemic stroke or systemic embolism). The LAA was surgically occluded in 98 (41%) patients and preserved in 139 (59%) patients. During the follow-up period (median, 37 months), 29 primary outcomes occurred. In the Kaplan-Meyer analysis, the LAA preservation group showed a greater cumulative incidence of the primary outcome (P = 0.002) and thromboembolic events (P = 0.003) than the LAAO group. In the univariate Cox regression analysis, coronary artery disease, CHA2DS2-VASc score, a cauliflower-shaped LAA, Maze, and no LAAO were significantly associated with the primary outcome. In the multivariate Cox regression analysis, concomitant LAAO was significantly linked to the primary outcome (hazard ratio [HR]: 0.30, 95% confidence interval [CI]: 0.10-0.91, P = 0.033) and thromboembolic events (HR: 0.19, 95% CI: 0.04-0.87, P = 0.032). These benefits from LAAO were consistent, even after propensity score-matched analysis. For patients undergoing surgery for chronic MR who also have AF, concomitant surgical LAAO is associated with favorable clinical outcome.

Left atrial appendage thrombus formation, potential of resolution and association with prognosis in a large real-world cohort

Comprehensive data on factors influencing left atrial appendage (LAA) thrombus formation, resolution and impact on survival are limited. In this single-center, retrospective study 7759 (2010-2015) patients with symptomatic ongoing atrial fibrillation (AF) on admission were screened for LAA thrombi. 450 patients had LAA thrombi. 481 patients without LAA thrombi were randomly selected as controls. We assessed clinical, echocardiographic, laboratory parameters and long-term survival of both groups. Patients with LAA thrombi compared to controls were older, had more strokes, higher CHA₂DS₂ -VASc scores, worse renal function, less controlled diabetes, advanced heart failure, lower LAA emptying velocities, higher levels of cardiac and inflammatory markers (all p < 0.001). 56.3% of followed-up patients (304) dissolved their LAA thrombi. Chances of thrombus resolution increased with rising LAA flow velocities (OR 1.061, p = 0.022), whereas advanced age (OR 0.950, p < 0.001) and presence of permanent AF (OR 0.354, p < 0.001) decreased chances of thrombus resolution. Presence of LAA thrombi was associated with a markedly reduced 10-year survival probability (31% versus 69%). LAA thrombus formation is promoted by advanced structural heart disease, inflammation, diabetes and impaired renal function. Younger age, non-permanent AF and higher LAA flow velocities were predictors of thrombus resolution. Thrombus formation was associated with poor prognosis.

The Thromboembolic Predictability of CHA2DS2-VASc Scores Using Different Echocardiographic Criteria for Congestive Heart Failure in Korean Patients with Nonvalvular Atrial Fibrillation

The association between congestive heart failure (CHF) of the CHA₂DS₂-VASc scores and thromboembolic (TE) events in patients with atrial fibrillation (AF) is a topic of debate due to conflicting results. As the importance of diastolic impairment in the occurrence of TE events is increasingly recognized, it is crucial to evaluate the predictive power of CHA₂DS₂-VASc scores with C criterion integrating diastolic parameters. We analyzed 4200 Korean nonvalvular AF patients (71 years of age, 59% men) to compare multiple echocardiographic definitions of CHF. Various guideline-suggested echocardiographic parameters for systolic or diastolic impairment, including left ventricular ejection fraction (LVEF) ≤ 40%, the ratio of early diastolic mitral inflow velocity to early diastolic velocity of the mitral annulus (E/E’) ≥ 11, left atrial volume index > 34 mL/m², and many others were tested for C criteria. Multivariate-adjusted Cox regression analysis showed that CHA₂DS₂-VASc score was an independent predictor for composite thromboembolic events only when CHF was defined as E/E’ ≥ 11 (hazard ratio, 1.26; p = 0.044) but not with other criteria including the original definition (hazard ratio, 1.10; p = 0.359). Our findings suggest that C criterion defined as diastolic impairment, such as E/E’ ≥ 11, may improve the predictive value of CHA₂DS₂-VASc scores.

Cardiac Structural or Functional Changes Associated with CHA2DS2-VASc Scores in Nonvalvular Atrial Fibrillation: A Cross-Sectional Study Using Echocardiography

BACKGROUND

CHA₂DS₂-VASc is the most widely accepted scoring system for atrial fibrillation (AF) to assess stroke risk, although little has been revealed regarding the accompanying cardiac functional/structural changes. This echocardiography study was undertaken to understand the changes related to CHA₂DS₂-VASc scores.

METHODS

A total of 4,795 nonvalvular AF patients were enrolled for the cohort, from which 591 were excluded as they did not meet the inclusion criteria. Based on the CHA₂DS₂-VASc scores, the remaining 4,204 patients included in the study were divided into 4 groups: 0 to 1 (n = 991); 2 to 3 (n = 1,642); 4 to 6 (n = 1,407); 7 to 9 (n = 164).

RESULTS

Increase in the left ventricular mass index and prevalence of left ventricular hypertrophy (LVH) were observed with elevating CHA₂DS₂-VASc scores (p < 0.05 for all). Diastolic parameters such as left atrial volume index (LAVI) and the ratio of early diastolic mitral inflow velocity to early diastolic velocity of the mitral annulus (E/E′) also increased significantly in the higher CHA₂DS₂-VASc score groups (p < 0.001 for all), although two-way ANOVA analysis showed that such incremental diastolic impairment was independent of hypertension. LVH (hazard ratio [HR], 3.609; confidence interval [CI], 2.426–5.369; p < 0.001) and E/E′ (HR, 1.087; CI, 1.054–1.121; p < 0.001) were independent risk factors for CHA₂DS₂-VASc scores 2 or higher.

CONCLUSIONS

Our findings suggest that increasing CHA₂DS₂-VASc scores are associated with impaired diastolic function that may represent high left atrial pressure favoring thrombogenic propensity.

Left atrial appendage functions in patients with severe rheumatic mitral regurgitation

AIM

The left atrial appendage (LAA) function was evaluated in patients with severe rheumatic mitral regurgitation, having sinus rhythm or atrial fibrillation, by standard and tissue Doppler echocardiographic examinations.

METHODS AND RESULTS

Sixty patients with rheumatic severe mitral regurgitation were enrolled. The patients (14 females and 6 males) having sinus rhythm were selected as group I and 20 patients (15 females and 5 males) with atrial fibrillation formed group II. 20 healthy subjects (15 female and 5 males) served as the control group (group III). In order to determine the LAA functions, LAA peak filling flow velocity (LAAPFV), LAA peak emptying flow velocity (LAAPEV) and percentage of LAA area change (LAAAC %) were measured. In the TDI records of the subjects with sinus rhythm, the first positive wave identical to the LAA late emptying wave (LEW) following the P-wave was accepted as LAA late systolic wave (LSW), and the second negative wave identical to the LAA late filling flow was accepted as late diastolic wave (LDW). In patients with atrial fibrillation, the positive wave was accepted as LAA late systolic wave (LSW), and the second negative wave identical to the LAA late filling flow was accepted as late diastolic wave (LDW). LAA outflow and inflow velocities were lower in the group having atrial fibrillation (P < 0.002, and P < 0.007, respectively). LAAAC% was also reduced in group II (P < 0.0001). The pulsed Doppler LSW and LDW velocities, measured with TDI method were found to be quite reduced in patients with AF (P: 0.002 and P: 0.001, respectively). The study parameters were statistically similar in patients with normal sinus rhythm and controls.

CONCLUSION

In this study, we found that the LAA functions are impaired in patients with severe mitral regurgitation, having AF, whereas preserved in patients with normal sinus rhythm, compared to controls.

The Left Atrial Appendage, a Small, Blind-Ended Structure

The increasing prevalence of stroke and atrial fibrillation is a stimulus for new therapeutic strategies and also warrants a review of imaging modalities of the most important source of cardiac systemic embolic events: the left atrial appendage (LAA). This blind-ended, complex structure is embryologically distinct from the body of the left atrium and is sometimes regarded as just a minor extension of the atrium. However, it should routinely be analyzed as part of a transesophageal echocardiographic (TEE) examination. A pulsed Doppler TEE analysis of LAA emptying flow should supplement a two-dimensional (2-D) analysis; these examinations have proven to be highly reproducible and to help assess thromboembolic risk. In 2-D imaging, potential thrombus and spontaneous echo contrast should be sought. In addition, LAA plays a hemodynamic role that participates in atrial function and is influenced by various hemodynamic conditions. In view of the embolic risks from a dysfunctional appendage, the LAA is often ligated during cardiac valve surgery. New devices are under evaluation for percutaneous closure of the LAA, and further studies should improve the definition, understanding, and treatment of LAA dysfunction.

Tissue Doppler Properties of the Left Atrial Appendage in Patients with Mitral Valve Disease

OBJECTIVE

The purpose of this study was to compare the left atrial appendage (LAA) tissue Doppler imaging (TDI) with the classical LAA function parameters in patients with mitral valve disease.

METHODS

Twenty patients who had pure mitral regurgitation (group 1), 20 patients who had pure rheumatic mitral stenosis (group 2), and 20 healthy patients (group 3) were included in this study. All the cases were sinus rhythm. In order to determine the LAA functions, LAA late filling (LAALF), and late emptying (LAALE) flow velocities and LAA fractional area change (LAAFAC) were measured. LAA tissue Doppler evaluations were obtained from the PW Doppler, which was placed on the LAA lateral wall in a transverse basal short-axis approach. LAA late systolic (LAALSW) and late diastolic (LAALDW) wave velocities were obtained from TDI records transesophageal echocardiography (TEE).

RESULTS

There were no significant differences among groups 1, 2, and 3 in terms of age, left ventricular (LV) ejection fraction, gender, and heart rate. No differences were observed between group 1 and the control group with respect to LAALE, LAALF, and LAAFAC. LAALE velocity and LAAFAC were significantly decreased in group 2 than group 1. LV diastolic diameter was significantly greater, whereas LAALSW and LAALDW velocities were significantly decreased in group 1 compared with group 3. There were no differences between groups 1 and 2 regarding to LAALSW and LAALDW velocities. LAALE, LAALF, LAALSW, LAALDW velocities, and LAAFAC were significantly decreased in group 2 than group 3.

CONCLUSION

The TDI method may detect the LAA systolic dysfunctions, which cannot be detected using classical methods, on tissue level in patients with mitral regurgitation. In addition, the deterioration of the LAA functions at tissue level in patients with rheumatic mitral stenosis was also detected.