Risk Stratification in Patients Who Underwent Percutaneous Left Atrial Appendage Occlusion

Abstract

Left atrial appendage occlusion (LAAO) is effective in preventing thromboembolism. Risk stratification tools could help identify patients at risk for early mortality after LAAO. In this study, we validated and recalibrated a clinical risk score (CRS) to predict risk of all-cause mortality after LAAO. This study used data from patients who underwent LAAO in a single-center, tertiary hospital. A previously developed CRS using 5 variables (age, body mass index [BMI], diabetes, heart failure, and estimated glomerular filtration rate) was applied to each patient to assess risk of all-cause mortality at 1 and 2 years. The CRS was recalibrated to the present study cohort and compared with established atrial fibrillation-specific (CHA₂DS₂-VASc and HAS-BLED) and generalized (Walter index) risk scores. Cox proportional hazard models were used to assess the risk of mortality and discrimination was assessed by Harrel C-index. Among 223 patients, the 1- and 2-year mortality rates were 6.7% and 11.2%, respectively. With the original CRS, only low BMI (<23 kg/m²) was a significant predictor of all-cause mortality (hazard ratio [HR] [95% CI] 2.76 [1.03 to 7.35]; p = 0.04). With recalibration, BMI <29 kg/m² and estimated glomerular filtration rate <60 ml/min/1.73 m² were significantly associated with an increased risk of death (HR [95% CI] 3.24 [1.29 to 8.13] and 2.48 [1.07 to 5.74], respectively), with a trend toward significance noted for history of heart failure (HR [95% CI] 2.13 [0.97 to 4.67], p = 0.06). Recalibration improved the discriminative ability of the CRS from 0.65 to 0.70 and significantly outperformed established risk scores (CHA₂DS₂-VASc = 0.58, HAS-BLED = 0.55, Walter index = 0.62). In this single-center, observational study, the recalibrated CRS accurately risk stratified patients who underwent LAAO and significantly outperformed established atrial fibrillation-specific and generalized risk scores. In conclusion, clinical risk scores should be considered as an adjunct to standard of care when evaluating a patient's candidacy for LAAO.