Left Atrial Mechanics in Isolated Total Anomalous Pulmonary Venous Connection After Repair.

Introduction: Repaired total anomalous pulmonary venous connection (TAPVC) patients with preoperative pulmonary venous obstruction (PVO) have reductions in echocardiographic metrics, such as left atrial reservoir function and pulmonary venous variability index (PVVI). We hypothesized reduced preoperative left atrial strain mechanics in isolated TAPVC patients serve as risk factors for postoperative PVO. We also evaluated echocardiographic metrics and clinical characteristics associated with preoperative and postoperative PVO, as well as compared these to healthy controls.

Methods: A single-center retrospective study was conducted on 64 isolated TAPVC patients who underwent repair between 9/1/2003 and 12/31/2022 with an available preoperative, immediate postoperative, and follow-up echocardiogram (most recent or prior to reintervention). Twenty-five individual age and body surface area-matched healthy controls were compared at each echo time point. LA strain analysis was performed using TOMTEC software. Postoperative PVO was defined as peak Doppler velocity ≥1.2 m/s in an individual pulmonary vein or pulmonary venous confluence.

Results: Thirty-seven (58%) TAPVC patients had preoperative PVO. Twenty-eight (44%) patients developed postoperative PVO, of which twelve (19%) required reintervention. Preoperative PVO increased the risk of postoperative PVO (78.6% vs 41.7%, p = 0.004) and reintervention (91.7% vs 50%, p = 0.001). This was no longer true when preoperative PVO was defined as peak velocity ≥1.2 m/s (p = 0.2362), although it remained associated with reintervention (p = 0.02). In TAPVC patients there were no other preoperative echocardiographic metrics, including LA strain measurements and PVVI, significantly associated with postoperative PVO or reintervention. Immediately postoperative LA volumes and mechanics demonstrated no difference between TAPVC patients with and without postoperative PVO or reintervention. Compared to healthy controls, pulmonary vein Doppler absolute velocities, left ventricle length, and LA mechanics were diminished in TAPVC patients at all echo time points (p = 0.0149 to <0.0001). In contrast LA two-dimensional volumes, left ventricular volumes, and LA dyssynchrony index normalized over time.

Conclusions: Although preoperative pulmonary vein Doppler velocity ≥ 1.2 m/s increased the risk for reintervention in repaired isolated TAPVC patients, no preoperative LA mechanics or other echocardiographic metrics were associated with the development of postoperative PVO or reintervention. Immediately postoperative LA volumes do not appear to modify reintervention risk indicating pulmonary vein hypoplasia/stenosis is the primary driver for reintervention. Despite ongoing impaired LA mechanics and decreased LV length, LA and LV volumes normalize over time in repaired TAPVC patients.