Aggressive Atrial Volume Reduction for Bilateral Giant Atria Improves Respiratory Function

Blood flow analysis with computational fluid dynamics in the left atrium after left atrial plication: a prospective study

OBJECTIVE

This study aimed to evaluate blood flow stagnation in an enlarged left atrium (LA) and prove that left atrial plication (LAP) could alleviate the stagnation.

METHODS

Five patients with chronic atrial fibrillation who underwent mitral valve surgery followed by LAP for an enlarged LA with a ≥ 60-mm diameter were included. We performed computational fluid dynamics (CFD) analysis using preoperative and postoperative computed tomography and four-dimensional flow magnetic resonance imaging. Additionally, computer graphics were used to create virtual left atrial appendage resection (LAAR) images. We performed CFD analysis to assess blood flow stagnation in the LA for three groups: preoperative, LAAR, and LAP.

RESULTS

When the average and constant stagnation volumes were both set to 100 preoperatively, the average stagnation volumes of the LAAR and LAP groups were 67.42 ± 18.64 and 35.88 ± 8.20, respectively. The constant stagnation volumes of these groups reduced to 45.01 ± 7.43 and 21.14 ± 7.70, respectively. The LAP group also had significantly lower average and constant stagnation volumes than those in the LAAR group (p = 0.006 and p = 0.033, respectively).

CONCLUSIONS

Blood flow stagnation was noted in the LAA and enlarged LA. CFD analysis revealed that LAP for the enlarged LA improved blood flow stagnation more than the virtual LAAR alone.

CLINICAL TRIAL REGISTRY NUMBER

UMIN000049923.

Mitral valve repair with patch augmentation for atrial functional mitral regurgitation complicated with giant left atrium

OBJECTIVE

We aimed to assess the results of posterior leaflet augmentation with an autologous pericardial patch in atrial functional mitral regurgitation.

METHODS

Data of 16 patients with atrial functional mitral regurgitation who underwent posterior leaflet patch augmentation for mitral valve repair were retrospectively analyzed. This procedure was applied to a short posterior leaflet with a height of < 10 mm in P2. The median age was 72.5 [67.8-78.3] years. Preoperative New York Heart Association functional class was II in 7 (43.8%) and III or IV in 9 (56.2%) patients. Mitral regurgitation was moderate in 2 (12.5%) and severe in 14 (87.5%) patients.

RESULTS

Operative mortality occurred in 1 (6.2%) patient due to cerebral infarction. One patient required valve replacement because of patch perforation early after operation. Mitral regurgitation was reduced to less than mild in 15 (93.8%) patients and less than trivial in 11 (68.8%) patients (P < 0.01) postoperatively. As for mid-term results, New York Heart Association functional class improved to I or II in 12 (75%) patients (P < 0.01). Two cases of thrombotic complication were observed. Remote recurrent regurgitation occurred in one case due to small patch size. The 3-year free rate of valve-related morbidity and regurgitation recurrence was 65.6% and 87.1%, respectively. The 5-year survival rate was 93.8%.

CONCLUSIONS

Pericardial patch augmentation in atrial functional mitral regurgitation leads to good survival and mitral regurgitation recurrence-free rates. Steady anticoagulation and the use of larger patches would be necessary to reduce thrombotic complications and recurrent MR.

Patch augmentation vs. valve replacement for patients with atrial functional mitral regurgitation and long-standing atrial fibrillation

BACKGROUND

Long-standing atrial fibrillation is associated with atrial functional mitral regurgitation (AFMR) with atriogenic tethering. We compared the outcomes of patch augmentation (PA) and valve replacement (VR) for AFMR.

METHODS

We retrospectively compared the data of 16 patients who underwent PA for AFMR with the data of 15 patients who underwent VR between 2008 and 2021. Patients with a left ventricular ejection fraction (LVEF) of <50% were excluded. We also performed atrial plication and left appendage closure if the patients had no weak atrial wall that led to severe bleeding.

RESULTS

The median age was 72.5 and 76.0 years in the PA and VR groups, respectively. The PA group had a longer cardiopulmonary bypass time (206 vs. 172 min, P=0.012). Although there were no differences in hospital morbidity and mortality between the PA and VR groups, one patient underwent reoperation for patch perforation in the PA group. The overall 3-year survival rate was 93.8% and 100% in the PA and VR groups, respectively (P=0.878). The 3-year rate of freedom from major adverse cardiac events was 75.0% and 53.6% in the PA and VR groups, respectively (P=0.181). Three and six patients were readmitted for congestive heart failure in the PA and VR groups, respectively. Two patients in the PA group developed severe recurrent regurgitation, including one patient who required reoperation. No patients in the VR group required reoperation. The postoperative left atrial volume index (LAVI) was associated with thromboembolic events (P=0.016).

CONCLUSIONS

PA may achieve comparable outcomes to those of VR for AFMR. Operative procedures should be chosen based on each patient's background. Atrial reduction could be considered to prevent thromboembolic events.

Long-standing persistent effects of atrial volume reduction combined with pulmonary vein isolation

Although surgical left atrial (LA) volume reduction combined with mitral valve surgery and/or surgical ablation for atrial fibrillation has been reported to be effective, its long-term outcomes in the absence of mitral procedure are not well established. A 74-year-old man with two previous sternotomies-the first for pericardiectomy due to constrictive pericarditis and the second for mitral valve replacement with mechanical valve and tricuspid annuloplasty-presented with heart failure and thrombus in his giant left atrium (1291 mL), complicated by cerebral infarction. His electrocardiogram showed rate-controlled persistent atrial fibrillation. His mechanical valve was functioning well. A third atrial volume reduction combined with pulmonary vein isolation, without valve surgery, was performed. The postoperative course was uneventful, and the patient has remained asymptomatic with regular junctional rhythm and without any episodes of thromboembolism or re-dilation of LA (approximately 550 mL). His left ventricular filling improved with end-diastolic volume (96 mL vs 140 mL) and forced vital capacity (2.60 L vs 2.89 L) increased. Both remained relatively constant for 6 years. The combination of atrial volume reduction with pulmonary vein isolation prevented thromboembolism, improved left ventricular filling, and continued to improve symptoms associated with heart failure and respiratory condition for 6 years. <Learning objective: The long-term outcomes of surgical left atrial volume reduction combined with ablation for atrial fibrillation in the absence of mitral valve procedure are not well established. We hereby report a case of left atrial volume reduction combined with pulmonary vein isolation, without valve surgery, whose beneficial effects on symptoms associated with heart failure, particularly left ventricular filling, respiratory function, and stroke prevention, have persisted for 6 years postoperatively.>.

Right atrial volume reduction for severely impaired pulmonary function

We report a patient with giant right atrium and severe pulmonary dysfunction who underwent successful surgical volume reduction with significant improvement of pulmonary function studies.