Objective:

To evaluate the association between four non-insulin-based insulin resistance (IR) indices and long-term major adverse cardiovascular events (MACEs) in atrial fibrillation (AF) patients undergoing radiofrequency catheter ablation (RFCA), and to determine their incremental predictive value beyond established clinical risk factors.

Approach:

• Study Design: A retrospective observational study involving 922 non-valvular AF patients who underwent RFCA from March 2017 to July 2023.
• Endpoints: The primary endpoint was a composite of MACEs, including all-cause death, late AF recurrence, heart failure events, and stroke after a 3-month blanking period.
• Statistical Analysis: Multivariable Cox proportional hazards regression, restricted cubic spline analysis, and Kaplan-Meier survival estimation were used to examine associations and quantify predictive value.

Key Findings:

• MACEs occurred in 242 patients (26.25%) over a median follow-up of 36 months.
• METS-IR and TyG-BMI were significantly associated with elevated MACE risk (P < 0.001).
• METS-IR showed a linear dose-response relationship with MACEs.
• Adding METS-IR to the baseline clinical model improved the C-statistic from 0.702 to 0.717 (P < 0.001).
• METS-IR provided meaningful net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

Interpretation:

METS-IR demonstrated a statistically significant incremental improvement in predicting composite MACE in AF patients following RFCA.

Limitations:

• The study is retrospective and may have inherent biases.
• The findings are based on a single-center cohort, which may limit generalizability.

Conclusion:

METS-IR may contribute to improved risk assessment in post-ablation AF patients.