Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice, affecting an estimated 2%–4% of the adult population and conferring a substantially increased risk of stroke, heart failure, and all-cause mortality (1). The structural and electrophysiological remodeling underlying AF, characterized by atrial dilatation, interstitial fibrosis, and ion channel dysregulation, promotes the initiation and maintenance of disorganized atrial activation, resulting in impaired hemodynamics and an increased propensity for thromboembolic events. Catheter radiofrequency ablation (RFA) has become a cornerstone of interventional AF management and has demonstrated superiority over antiarrhythmic drug therapy in achieving freedom from atrial arrhythmia and improving quality of life (2, 3). Blanking period arrhythmia refers to atrial tachyarrhythmia episodes occurring during the early post-ablation blanking period, traditionally defined as the first 90 days after AF catheter ablation (4, 5). These events include atrial fibrillation, atrial flutter, or atrial tachycardia lasting at least 30 s. Previous studies indicate that atrial arrhythmias occur in approximately 20%–50% of patients during this early post-ablation phase; however, only a subset subsequently develop late recurrence, highlighting that early recurrence is a heterogeneous phenomenon rather than a uniform marker of ablation failure (6, 7). These arrhythmias are commonly driven by transient and potentially reversible mechanisms, such as ablation-related inflammation, autonomic imbalance, short-term electrical remodeling, and incomplete lesion maturation prior to stable scar formation (8). Therefore, arrhythmias during the blanking period do not invariably represent durable procedural failure. Nevertheless, blanking period arrhythmias are clinically relevant rather than benign (9). They occur in a substantial proportion of patients and provide prognostic information, particularly when considered in a time-dependent manner (5). Emerging evidence supports stratifying early recurrences into very early recurrence (for example, within 7 days or up to 30 days), which is more often linked to acute peri-procedural perturbations and is less predictive of late failure, vs. later blanking period recurrence (approximately 1–3 months), which more strongly reflects pulmonary vein reconnection and adverse atrial substrate remodeling and is associated with subsequent late recurrence (10, 11). Clinically, blanking period arrhythmia can be viewed as an early stress test of the post-ablation atrial substrate and may help identify patients who warrant intensified rhythm surveillance and risk-factor optimization (12–14).

Several clinical and procedural variables have been associated with early recurrence of atrial fibrillation (ERAF). Advanced age and longer AF duration before ablation are linked to higher risk, likely reflecting more extensive atrial substrate remodeling (15). Comorbidities such as hypertension, diabetes mellitus, and obesity may further aggravate atrial remodeling through systemic inflammation and oxidative stress. In addition, procedural factors, including inadequate lesion delivery and incomplete pulmonary vein isolation, may increase the likelihood of pulmonary vein reconnection and persistence of arrhythmogenic triggers (16). Although multivariable regression analyses have identified individual predictors, translation of these findings into individualized risk estimation remains limited. Nomograms provide a graphical representation of a predictive model that enables patient-specific risk assessment by integrating multiple heterogeneous variables into a single tool. Such models have demonstrated utility in oncology and cardiovascular medicine, often offering improved discrimination and calibration compared with conventional risk scores (17).

In this study, we retrospectively analyzed a cohort of patients undergoing first-time radiofrequency catheter ablation for AF to identify independent predictors of early arrhythmia recurrence. We then constructed and internally validated a nomogram incorporating clinical, echocardiographic, and biochemical variables. Our aim was to develop a practical prognostic tool with reliable discrimination and calibration to support personalized post-ablation management and potentially improve subsequent rhythm outcomes.

In this cohort of 276 patients undergoing first-time catheter radiofrequency ablation for AF, we observed that higher BMI, enlarged LAD, elevated BNP, persistent AF subtype, and coexisting OSAS each independently predicted early arrhythmia recurrence within three months of the procedure. In contrast, dyslipidemia, although more prevalent in those with recurrence on univariable analysis, did not retain significance after adjustment for these stronger predictors. These findings underscore that both structural cardiac changes (LAD), biomarkers of myocardial stress (BNP), AF chronicity (persistent vs. paroxysmal), systemic comorbidity (OSAS), and metabolic factors (BMI) collectively shape the post-ablation substrate that predisposes to AF relapse. This study offers several novel and clinically relevant contributions. First, it specifically addresses early atrial tachyarrhythmia recurrence during the post-ablation blanking period, an underexplored yet clinically important phase that reflects early atrial vulnerability and may influence subsequent rhythm outcomes. Second, by integrating readily available clinical, echocardiographic, and biochemical variables, we identified a concise set of independent predictors and translated them into a pragmatic nomogram for individualized risk estimation. Unlike studies focusing on isolated predictors, our multivariable framework captures the combined effects of metabolic burden, structural remodeling, neurohumoral stress, arrhythmia chronicity, and systemic comorbidity. The model demonstrated acceptable discrimination, stable internal validation, and potential clinical utility. Clinically, this tool may support risk-adapted rhythm surveillance, tailored follow-up strategies, and individualized management planning during the blanking period, thereby facilitating more efficient and personalized post-ablation care.

Mechanistically, elevated BMI reflects increased adiposity, which contributes to systemic inflammation, oxidative stress, and elevated cardiac workload. These factors accelerate atrial remodeling, characterized by interstitial fibrosis and myocyte hypertrophy, ultimately compromising the durability of electrical isolation achieved through ablation. Similarly, left atrial enlargement indicates chronic pressure and volume overload, resulting in a larger substrate of arrhythmogenic myocardium capable of sustaining focal or reentrant circuits despite pulmonary vein isolation. Elevated BNP serves as a surrogate marker for elevated intracardiac filling pressures and subclinical ventricular dysfunction; atrial stretch and wall tension promote electrophysiological heterogeneity, increasing susceptibility to arrhythmias (26, 27). Persistent AF represents a progression from episodic to sustained arrhythmia and is associated with more advanced electrical remodeling, including shortened refractory periods and atrial fibrosis. This pathological substrate is less responsive to pulmonary vein isolation alone compared to paroxysmal AF. Additionally, OSAS induces intermittent hypoxia and sympathetic activation, fostering atrial inflammation and fibrosis. Untreated OSAS impairs long-term maintenance of sinus rhythm following ablation. Collectively, these predictors underscore the multifactorial pathogenesis of early AF recurrence, involving mechanical, biochemical, electrophysiological, and systemic mechanisms, and identify potential targets for pre- and post-procedural optimization (28, 29).

Our identification of BMI, LAD, BNP, AF subtype, and OSAS as predictors of early recurrence aligns with and expands upon prior findings in the field. Obesity has consistently been associated with increased AF incidence and diminished ablation efficacy; clinical trials targeting weight reduction have demonstrated significant decreases in recurrence rates, supporting our conclusion that BMI is one of the most impactful modifiable risk factors. Likewise, left atrial enlargement has been validated in multiple large registries and meta-analyses as a strong marker of atrial substrate burden. Enlarged atria tend to contain greater degrees of fibrotic remodeling and are more likely to harbor non–pulmonary vein triggers, contributing to elevated relapse risk across diverse populations (30, 31). The use of BNP as a biomarker for predicting ablation outcomes is supported by previous studies showing that baseline natriuretic peptide levels are correlated with both short- and long-term procedural success. Although some investigations have utilized N-terminal pro-BNP instead of BNP, both markers reflect adverse hemodynamic load and myocardial stretch. Incorporating BNP into our predictive nomogram is consistent with these prior reports and highlights the emerging role of cardiac biomarkers in stratifying recurrence risk following catheter ablation (32, 33).

Persistent AF is widely acknowledged as a more complex substrate for ablation, with consistently lower success rates compared to paroxysmal AF across nearly all comparative studies (34, 35). Our finding that persistent AF independently increases the odds of early recurrence by more than fourfold aligns with this established trend. To address this challenge, many centers have adopted adjunctive lesion sets or hybrid strategies, recognizing that pulmonary vein isolation alone is frequently insufficient in this subgroup. The role of OSAS in ablation outcomes has gained increasing recognition, with accumulating evidence indicating that untreated sleep apnea significantly elevates recurrence risk. Studies have shown that continuous positive airway pressure therapy can mitigate this risk (36, 37). Our observation of a three- to fourfold increased risk of early recurrence in patients with OSAS highlights the critical importance of routine screening and treatment for sleep-disordered breathing, as endorsed by current consensus guidelines, although not yet universally implemented in clinical practice (38). Finally, the absence of an independent association between dyslipidemia and early recurrence in our cohort is consistent with the heterogeneous findings reported in the literature (1, 39–42). While statins may offer anti-inflammatory and pleiotropic benefits in AF, serum cholesterol levels alone have not reliably predicted ablation outcomes when more robust determinants, such as atrial size and metabolic syndrome components, are considered (43, 44).

The ATLAS score, developed by Mesquita et al. (42), was designed to estimate AF recurrence after first pulmonary vein isolation using a large two-center cohort with a mean follow-up of approximately 4.2 years. It incorporates demographic factors (age and sex), arrhythmia phenotype (non-paroxysmal AF), lifestyle exposure (current smoking), and indexed left atrial volume, and demonstrated good long-term discriminative performance (c-statistic ≈ 0.75). The ATLAS score is primarily intended for long-term risk stratification and pre-procedural patient selection, whereas early recurrence is more closely related to transient post-ablation mechanisms such as inflammation, atrial stunning, and autonomic imbalance, which are not explicitly captured by this model. The APPLE score, proposed by Kornej et al. (45), was developed to predict AF recurrence between 3 and 12 months after ablation and includes persistent AF, left atrial diameter, renal dysfunction, advanced age, and reduced left ventricular systolic function. Although APPLE showed better performance than CHADS₂ and CHA₂DS₂-VASc for mid-term rhythm outcomes, its discriminative ability remained modest (AUC ≈ 0.63). In addition, APPLE was not designed for use during the blanking period and does not account for factors potentially relevant to early recurrence, such as obstructive sleep apnea syndrome or biochemical markers of atrial wall stress. The MB-LATER score, developed by Mujović et al. (46), targets a distinct clinical context by predicting very late AF recurrence (>12 months) in patients who remained arrhythmia-free during the first post-ablation year. Early recurrence is incorporated as a component of this score, reflecting its role as a predictor of subsequent late relapse rather than as an outcome to be estimated. These differences indicate that individual models address different phases of the post-ablation course. ATLAS and APPLE are more applicable to pre-procedural assessment and mid- to long-term prognosis, whereas MB-LATER informs long-term surveillance. The present nomogram is specifically tailored to the early post-ablation blanking period and provides individualized risk estimation to support targeted monitoring and early post-procedural management.

This study has several notable strengths. Most importantly, a comprehensive multivariable framework was applied to integrate clinical, echocardiographic, biochemical, and comorbidity-related factors, which were subsequently translated into a practical and user-friendly nomogram. The model demonstrated acceptable discrimination (AUC 0.761), stable internal validation (optimism-corrected C-index 0.758), and net clinical benefit on DCA. Importantly, the nomogram is intended to support individualized post-ablation risk stratification rather than to imply short-term reversibility of structural or biochemical determinants (47, 48). By focusing specifically on the three-month blanking period, this study addresses a clinically relevant phase characterized by frequent atrial tachyarrhythmias and ongoing management flexibility, including intensified rhythm monitoring, tailored follow-up strategies, and individualized patient counseling (49). Despite uniform short-term amiodarone use, early recurrences persisted, highlighting residual inter-individual risk heterogeneity that can be operationalized through risk stratification (50). Identification of higher-risk patients may further facilitate early reinforcement of longer-term risk-factor modification strategies, such as weight management and treatment of sleep-disordered breathing, extending beyond the blanking period (51, 52). The use of a real-world cohort enhances generalizability, and a worked example illustrating nomogram application is provided in Supplementary Table S1.

Several limitations of this study warrant consideration. First, the retrospective, single-center design limits causal inference and generalizability and may be subject to residual confounding despite multivariable adjustment. Although internal bootstrap validation demonstrated stable discrimination with minimal overfitting, external validation across different populations, centers, and ablation strategies is required. Second, early recurrence was defined using a three-month blanking period in accordance with conventional practice; however, evolving guideline recommendations may refine this temporal framework, and future studies should evaluate alternative definitions and extend risk prediction to longer-term outcomes. Third, all patients received standardized short-term amiodarone therapy; given its long half-life and delayed pharmacodynamic effect, early recurrence may occur before full therapeutic exposure, and uniform post-ablation antiarrhythmic protocols may limit external applicability. In addition, reliance on prior clinical diagnoses of obstructive sleep apnea syndrome may have resulted in under-recognition of undiagnosed cases, potentially attenuating observed associations. The absence of detailed procedural variables, such as lesion set completeness and operator experience, may also have precluded identification of additional determinants of early recurrence. Finally, left atrial diameter was used as a surrogate of atrial structure, whereas volumetric and three-dimensional echocardiographic measures may provide incremental prognostic value. Future prospective, multicenter studies incorporating standardized volumetric imaging, procedural metrics, larger cohorts, and longer follow-up are warranted to validate and refine the proposed nomogram and to determine whether early risk stratification can translate into improved outcomes through targeted risk-factor optimization, particularly weight management and treatment of sleep-disordered breathing.

Elevated BMI, enlarged LAD, increased BNP, persistent AF, and OSAS emerged as independent predictors of early recurrence following radiofrequency ablation. A nomogram integrating these factors demonstrated robust discrimination and calibration, offering a practical tool for individualized risk stratification. However, external validation in larger, multicenter cohorts is required to confirm these findings.