Assessment of mitral annulus and mitral leaflet in nonvalvular atrial fibrillation patients with various degrees of mitral regurgitation: Real time 3D transesophageal echocardiography

Mitral valve regurgitation is associated with left atrial fibrosis in patients with atrial fibrillation

BACKGROUND

Low voltage zones (LVZ) are associated with poor outcomes in patients with atrial fibrillation (AF). The APPLE and DR-FLASH scores predict LVZ in patients undergoing catheter ablation. This study aimed to assess the relationship of mitral valve regurgitation (MR) and LVZ after adjusting for APPLE or DR-FLASH scores.

METHODS

This was a retrospective study on patients with AF who underwent their first catheter ablation. All patients underwent a transthoracic echocardiographic examination before ablation. The APPLE and DR-FLASH scores were calculated at baseline. LVZ determined by high-density mapping was defined as bipolar voltage amplitude <0.5 mV. LVZ presence was defined as LVZ covering >5% of the left atrial surface area.

RESULTS

Altogether, 152 patients (mean age 62.0 ± 10.8 years, 65.8% men, and 36.2% with persistent AF) were included. Of the 152 patients, 47 (30.9%) had LVZ. The patients with LVZ had more moderate-to-severe MR (17.0% vs. 3.8%, P = 0.014) and higher APPLE scores (1.7 ± 1.1 vs. 1.2 ± 1.1, P = 0.009) and DR-FLASH scores (3.0 ± 1.5 vs. 2.4 ± 1.4, P = 0.010). Using multivariate logistic regression analysis, we found moderate-to-severe MR was related to LVZ presence after adjusting for the APPLE (OR 4.040, P = 0.034) or DR-FLASH (OR 4.487, P = 0.020) scores. Furthermore, moderate-to-severe MR had an incremental predictive value for LVZ presence in addition to the APPLE (P = 0.03) or DR-FLASH (P = 0.02) scores.

CONCLUSION

In patients with AF, MR severity was related to LVZ after adjusting the APPLE score or DR-FLASH score.

Atrial fibrillation is associated with large beat-to-beat variability in mitral and tricuspid annulus dimensions

AIMS

Beat-to-beat variability in cycle length is well-known in atrial fibrillation (Afib); whether this also translates to variability in annulus size remains unknown. Defining annulus maximal size in Afib is critical for accurate selection of percutaneous devices given the frequent association with mitral and tricuspid valve diseases.

METHODS AND RESULTS

Images were obtained from 170 patients undergoing 3D echocardiography [100 (50 sinus rhythm (SR) and 50 Afib) for mitral annulus (MA) and 70 (35 SR and 35 Afib) for tricuspid annulus (TA)]. Images were analysed for differences in annular dynamics with a commercially available software. Number of cardiac cycles analysed was 567 in mitral valve and 346 in tricuspid valve. Median absolute difference in maximal MA area over four to six cycles was 1.8 cm2 (range 0.5-5.2 cm2) in Afib vs. 0.8 cm2 (range 0.1-2.9 cm2) in SR, P < 0.001. Maximal MA area was observed within 30-70% of the R-R interval in 81% of cardiac cycles in SR and in 73% of cycles in Afib. Median absolute difference in maximal TA area over four to six cycles was 1.4 cm2 (range 0.5-3.6 cm2) in Afib vs. 0.7 cm2 (range 0.3-1.7 cm2) in SR, P < 0.001. Maximal TA area was observed within 60-100% of the R-R interval in 81% of cardiac cycles in SR, but only in 49% of cycles in Afib.

CONCLUSION

MA and TA reach maximal size within a broad time interval centred around end-systole and end-diastole, respectively, with significant beat-to-beat variability. Afib leads to a larger beat-to-beat variability in both timing of occurrence and values of annulus size than in SR.

Long-term effect of atrial fibrillation on the evolution of mitral and tricuspid valve regurgitation

Objective: The present study aims to identify the long-term effects of atrial fibrillation (AF) on atrial remodelling and on the progression of mitral/tricuspid valve regurgitation (MR/TR). Methods: The severity of MR/TR was assessed by the colour jet area and by multi-integrative approach at baseline and after a period of 65 ± 10 months in 37 patients with permanent AF, in 80 patients with non-permanent AF (of whom 43 were treated with ablation) and in 53 control patients with sinus rhythm. Results: At baseline, AF patients had larger MR jet areas than control patients. At follow up, progression of MR, expressed as delta MR jet area, was 0.05 ± 1.3 cm² in the control group, 0.73 ± 2.1 cm² in the non-permanent AF group and 1.95 ± 3.6 cm² in the permanent AF group (p = .001). Severe MR at follow up was observed in 0%, 2.5%, 8%, respectively. There was a significant positive correlation between progression of MR and increase of left atrium volume (r = 0.31, p < .001). After adjustment for baseline clinical and echocardiographic parameters, permanent AF remained independently associated with the progression of MR. Although rhythm control was better with AF ablation than with medical treatment only, the MR evolution was similar. Comparable findings, albeit less pronounced, were observed for the association between of AF and TR progression. Conclusions: The presence of longstanding AF is associated with a significant progression of MR/TR mainly due to atrial remodelling. Our data showed a beneficial effect of sustained rhythm control, either medically or by ablation, on MR/TR progression.