Joint association of hemoglobin glycation index and stress hyperglycemia ratio with atrial fibrillation recurrence after catheter ablation: a retrospective cohort study

Catheter ablation (CA) is a first-line interventional strategy for atrial fibrillation (AF), but post-ablation recurrence remains a major challenge affecting long-term prognosis. The hemoglobin glycation index (HGI) and stress hyperglycemia ratio (SHR), as novel glycemic indices, have been implicated in cardiovascular outcomes. However, their role in predicting AF recurrence remains unclear. This study aimed to examine the associations of HGI, SHR, and their combination with post-ablation recurrence. This retrospective cohort study included 813 AF patients who underwent CA between January 2021 and January 2024. Kaplan–Meier, Cox regression, and RCS analyses were applied to evaluate the associations of these indices with recurrence. Incremental predictive value was assessed by Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI). Sensitivity analyses were performed to assess robustness, and exploratory mediation analyses were conducted to explore potential mediators. AF recurrence occurred in 16.24% of patients. After multivariable adjustment, HGI exhibited a significant positive linear association with AF recurrence risk, with higher HGI quartiles consistently corresponding to higher risk. Conversely, SHR demonstrated a negative linear association, with higher SHR quartiles corresponding to reduced risk. Notably, both associations were significant in nondiabetic patients but absent in diabetic patients. Moreover, high HGI combined with low SHR was linked to the highest recurrence risk in the overall and nondiabetic populations, but not in diabetic patients. Adding HGI and SHR to the Base model produced a modest but statistically significant improvement in risk discrimination in the overall cohort (NRI: 0.217; IDI: 0.020) and nondiabetic patients (NRI: 0.341; IDI: 0.033), whereas no incremental value was observed in diabetic patients. WBC was identified as a potential mediator of the HGI–AF recurrence association in the overall and nondiabetic populations (12.1% and 14.8% of total effect, respectively; both P < 0.05), with no such effect observed for SHR. Elevated HGI and reduced SHR were independently associated with an increased risk of AF recurrence, and their combination exhibited incremental improvement in risk discrimination, particularly among nondiabetic patients. Joint assessment of HGI and SHR may offer additional risk stratification information for nondiabetic ablation candidates; prospective validation is warranted before clinical implementation.