Left atrial reservoir strain as a novel predictor of new-onset atrial fibrillation in light-chain-type cardiac amyloidosis

Aims To investigate whether left arterial reservoir strain (LASr) could predict new-onset atrial fibrillation (NOAF) in patients with light-chain-type cardiac amyloidosis (ALCA).Methods and results This study enrolled 427 patients with CA from two tertiary centres between 2005 and 2019. LASr was measured using a vendor-independent analysis programme. The primary outcome was NOAF. A total of 287 patients with ALCA were included [median age 63.0 (56.0-70.0) years, 53.3% male]. The median LASr was 13.9% (10.5-20.8%). During the median follow-up of 0.85 years, AF occurred in 34 patients (11.8%). In the receiver operating characteristics curve analysis, the optimal cut-off of LASr for predicting NOAF was 14.4%. Patients with LASr <= 14.4% had a higher risk of NOAF than those with LASr > 14.4% (18.1% vs. 5.1%, P < 0.010). In the multivariate analysis adjusting for confounding factors, including left arterial volume index and left ventricular global longitudinal strain (LV-GLS), higher LASr (%) was independently associated with lower risk for NOAF [adjusted hazard ratio (aHR): 0.936, 95% confidence interval (95% CI): 0.879-0.997, P = 0.039]. Furthermore, LASr < 14.4% was an independent predictor for NOAF (aHR: 3.370, 95% CI: 1.337-8.492, P = 0.010). This remained true after accounting for all-cause death as a competing risk. Compared with Model 1 (LV-GLS) and Model 2 (LV-GLS plus LAVI), Model 3, including LASr showed a better reclassification ability for predicting NOAF (net reclassification index= 0.735, P < 0.001 compared with Model 1; net reclassification index= 0.514, P = 0.003 compared with Model 2).Conclusion LASr was an independent predictor of NOAF in patients with ALCA.

Automated summary

The study aimed to investigate whether left arterial reservoir strain (LASr) could predict new-onset atrial fibrillation (NOAF) in patients with light-chain-type cardiac amyloidosis (ALCA). The results showed that LASr was an independent predictor of NOAF in ALCA patients.