Low-density lipoprotein cholesterol is inversely associated with left atrial low-voltage areas in patients with persistent atrial fibrillation: a retrospective cohort study

Abbreviations: AF, atrial fibrillation; LAD, left atrial diameter; LDL-C, low-density lipoprotein cholesterol; LVA, low-voltage area; OR, odds ratio; Q1–Q4, quartiles 1–4

Fig. 1. Patient selection flowchart. A total of 454 consecutive patients with persistent atrial fibrillation who underwent catheter ablation were screened. After exclusion of patients with previous atrial fibrillation ablation, valvular atrial fibrillation, loss to follow-up, or no intraprocedural left atrial substrate mapping, 404 patients were included in the final analysis. Among them, 232 patients had LVAs, and 172 did not. Abbreviations: LVAs, left atrial low-voltage areas

Fig. 2. Subgroup analyses of associations between LDL-C levels and left atrial low-voltage areas. ORs and 95% CIs were estimated using univariable logistic regression models. P values for interaction were obtained from unadjusted interaction analyses. The association was broadly directionally consistent across subgroups; nominal heterogeneity was observed for LAD. Abbreviations: LDL-C, low-density lipoprotein cholesterol; LVAs, left atrial low-voltage areas; OR, odds ratio; CI, confidence interval; BMI, body mass index; LAD, left atrial diameter; eGFR, estimated glomerular filtration rate

Fig. 3. Mediation analysis of associations among LDL-C levels, left atrial diameter, and left atrial low-voltage areas. LAD was the only examined variable showing evidence consistent with a possible partial indirect association between LDL-C levels and the presence of LVAs. The indirect effect through LAD was significant (ACME = -0.013, P = 0.014), and the direct effect remained significant (ADE = -0.072, P = 0.020). Significance estimates were obtained using 1,000 bootstrap iterations. Abbreviations: LDL-C, low-density lipoprotein cholesterol; LAD, left atrial diameter; LVAs, left atrial low-voltage areas; ACME, average causal mediation effect; ADE, average direct effect

Fig. 4. Restricted cubic spline analysis of LDL-C levels and left atrial low-voltage area presence. Restricted cubic spline analysis based on logistic regression was used to evaluate the association between LDL-C levels and the presence of LVAs, with the median LDL-C level (2.35 mmol/L) as the reference. The model was adjusted for age and sex. Histogram bars indicate the distribution of LDL-C values. No significant evidence of nonlinearity was observed (P for nonlinearity = 0.191), although some visual variation across the LDL-C distribution was apparent. Abbreviations: LDL-C, low-density lipoprotein cholesterol; LVAs, left atrial low-voltage areas

Fig. 5. Kaplan-Meier curves for recurrence-free survival after catheter ablation according to LDL-C quartiles. Kaplan–Meier analysis demonstrated significant differences in recurrence-free survival after catheter ablation across LDL-C quartiles (P = 0.021 by log-rank test), with visible separation of the crude recurrence curves across categories. Numbers at risk are shown below the x-axis. Abbreviations: LDL-C, low-density lipoprotein cholesterol; Q, quartile