Volume retention after left atrial appendage occlusion: incidence and risk factors

The LAA secretes ANP which has neurohormonal effects on fluid balance, but the effects of left atrial appendage occlusion (LAAO) on clinical volume status remains uncertain.

We compared patients who underwent LAAO with Watchman 2.5 (n = 151, 38% female) and Watchman FLX (n = 80, 31% female) to a control group with AF without LAAO (n = 186, 38% female). Clinical data was manually extracted from the EMR. Progressive volume retention was defined as initiation or increase in diuretic dose within 12 months of LAAO, or within last 12 months from most recent cardiology visit for controls.

A total of 49/231 (21.2%) of the LAAO cohort showed a rise in loop diuretic requirements compared to 27/186 (14.5%) of the controls (p = 0.078). There were 17/231 (7.4%) new diuretic prescriptions in the LAAO group compared to 6/186 (3.2%) for the controls (p = 0.066). In a multivariable model, only age, prior HF, and LAAO predicted a rise in loop diuretic use. The strongest predictors were presence of prior HF, OR 2.32 (95% CI 1.28-4.21, p = 0.005) and LAAO, OR 1.9 (95% CI 1.09-3.27, p = 0.023). Within the LAAO cohort, larger LAA size was the strongest predictor of symptomatic HF.

These results suggest that LAAO is associated with an almost twofold increased risk of volume retention. This risk is highest among patients with HF and larger LAAs. These findings may inform pre-implantation discussions and post-LAAO management.