A systematic literature search was conducted. Electronic databases, including MEDLINE (via PubMed), EMBASE, and the Cochrane Library, were systematically queried from inception to January 2026 using a combination of Medical Subject Headings (MeSH) and free-text keywords. Terms related to periodontitis (e.g., “periodontal disease”, “periodontitis”, “gingivitis”, “oral inflammation”) were combined with terms pertaining to atrial fibrillation recurrence (e.g., “atrial fibrillation recurrence”, “AF ablation failure”, “post-ablation AF”, “arrhythmia recurrence”) using Boolean operators (AND/OR). No language restrictions were applied. To ensure comprehensiveness, additional studies were identified through manual screening of reference lists from included articles and relevant reviews.

Eligibility criteria were defined according to the PICOS framework. The population comprised adults (≥18 years) undergoing catheter ablation for AF. The exposure of interest was periodontitis, diagnosed through clinical criteria (e.g., probing depth, clinical attachment loss, and bleeding on probing), radiographic evidence, or validated indices such as the periodontal inflamed surface area (PISA). The comparator consisted of patients without periodontitis. The primary outcome was documented AF recurrence following ablation, confirmed by electrocardiogram (ECG), ambulatory monitoring, or implantable devices after the blanking period. Observational studies evaluating periodontal status or periodontal treatment (non-randomized) in relation to AF recurrence were eligible.

Exclusion criteria encompassed animal studies, reviews, editorials, conference abstracts, cross-sectional studies, and studies lacking explicit data on AF recurrence or periodontal status. Randomized controlled trials were not identified in this domain and thus were not included.

Two independent reviewers (X.L. and C.Z.) screened titles and abstracts, followed by full-text assessments for eligibility. Disagreements were resolved by consensus. A standardized data extraction form was used to collect key study characteristics (author, year, country, design), patient demographics (sample size, age, comorbidities), periodontal assessment methods, AF recurrence ascertainment techniques, and adjusted effect estimates [hazard ratios (HRs) or odds ratios (ORs)] with 95% confidence intervals (CIs), including covariates controlled for in multivariate models.

The methodological quality of included cohort and case-control studies was evaluated using the Newcastle-Ottawa Scale (NOS), which assesses three core domains: selection (e.g., representativeness, exposure ascertainment), comparability (adjustment for confounders such as age, sex, hypertension, diabetes), and outcome (AF recurrence assessment, adequacy of follow-up). Studies scoring ≥6 were classified as moderate-to-high quality (16–18). Risk of bias was assessed independently by two reviewers (X.L. and C.Z.), and discrepancies were resolved by consensus.

Due to anticipated heterogeneity in periodontitis definitions (e.g., clinical vs. serologic vs. PISA index) and AF recurrence monitoring protocols (e.g., variable follow-up intervals, ablation techniques), a meta-analysis was not conducted. Instead, a narrative synthesis was performed, focusing on the direction, consistency, and magnitude of associations across studies, along with study quality and mechanistic insights (e.g., systemic inflammation, microbial translocation).

Although the protocol was not registered, the review question, eligibility criteria, and analysis plan were predefined before literature screening to minimize selective reporting bias. This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement (19). A completed PRISMA 2020 checklist, indicating the location of each reporting item within the manuscript, is provided as Table 1.

Figure 1 presents the PRISMA flow diagram depicting the study selection process. The initial search identified 365 records. After removing duplicates and screening titles and abstracts, 335 records were excluded. Eleven full-text articles were then assessed for eligibility. Of these, 8 studies were excluded due to methodological ineligibility: one employed a Mendelian randomization design (20), while the others did not specifically address AF recurrence in post-ablation patients (11, 12, 21–25). Ultimately, three observational studies (13–15) met all inclusion criteria and were included in this systematic review.

Baseline characteristics of the included studies are summarized in Table 1. The three included studies collectively enrolled 1,016 patients undergoing AF ablation, with individual sample sizes ranging from 132 to 596. The mean age ranged from 62.2 to 64.9 years, reflecting an older adult cohort typical of AF populations. Male predominance was consistent across studies (69%–72.7%). Common cardiovascular comorbidities included hypertension (49.2%–61%), diabetes mellitus (9.8%–20%), and dyslipidemia (30.3%–49.2%).

Periodontal status was assessed via differing methodologies: Miyauchi et al. (13) measured serum IgG antibody titers against Porphyromonas gingivalis subtypes; Tashiro et al. (14) employed clinical probing depth (≥4 mm with bleeding on probing); Miyauchi et al. (15) utilized the PISA index. The prevalence of periodontitis ranged from 54% to 57%. Echocardiographic parameters, particularly left atrial volume (68.4–78.7 ml) and diameter (37.3–40.5 mm), were elevated among patients with AF recurrence. Post-ablation antiarrhythmic drug use varied (22%–67%), while procedural success, particularly pulmonary vein isolation, was consistently high. These characteristics indicate a patient population with a substantial burden of cardiovascular and periodontal disease.

The methodological quality of the three included observational studies was assessed using the NOS tool, with all studies achieving scores ≥6. Miyauchi et al. (13) received a score of 7, demonstrating strengths in selection (e.g., a representative cohort and validated periodontal exposure based on serum Porphyromonas gingivalis antibody titers) and outcome assessment (standardized monitoring for AF recurrence). However, the study's comparability was limited by incomplete adjustment for relevant confounders, such as smoking status and oral hygiene practices. Tashiro et al. (14) achieved a score of 8, with detailed periodontal assessments by certified specialists and robust adjustment for age, sex, and CRP levels, although the duration of follow-up varied. Miyauchi et al. (15) also scored 7, supported by rigorous exposure measurement using the PISA index and multimodal methods for AF recurrence ascertainment. Nonetheless, potential residual confounding remained due to limited data on behavioral and socioeconomic factors. All studies adequately addressed attrition bias through structured and complete follow-up protocols, reinforcing the reliability of findings despite inherent limitations of observational study designs.

Two studies (13, 14) evaluated periodontitis as an exposure, whereas one study primarily evaluated the association between periodontal treatment during the blanking period and AF recurrence (15). Given this methodological distinction, results from the observational study were interpreted separately and not pooled with exposure-based associations.

Miyauchi et al. (13) observed that elevated serum IgG antibody titers against P. gingivalis type IV (a key periodontal pathogen) were independently associated with late AF recurrence (paroxysmal AF subgroup: HR = 1.57; 95% CI, 1.01–2.43; non-paroxysmal AF subgroup: HR = 1.91; 95% CI, 1.21–3.01) (Figure 2), particularly among patients with non-paroxysmal AF. Similarly, Tashiro et al. (14) found that clinically diagnosed periodontitis, defined by probing depth ≥4 mm with bleeding on probing, was associated with worse arrhythmia-free survival (HR 2.06, 95% CI 1.02–4.18) (Figure 2), with a stronger effect observed after the first post-ablation year.

The periodontal intervention in the recent study by Miyauchi et al. (15) was a standardized nonsurgical periodontal treatment protocol conducted during the 3-month blanking period following radiofrequency catheter ablation. Specifically, treatment was performed at 1 and 3 months post-ablation. It consisted of oral hygiene instruction followed by full-mouth debridement (both supragingival and subgingival) using an ultrasonic device and Gracey curettes, administered by an experienced dental clinician. After debridement, all tooth surfaces were polished with rubber cups and prophylaxis paste. The treatment did not require interruption of anticoagulation therapy, and no treatment-related complications were reported. This structured protocol ensured consistent delivery of care, allowing for clear clinical interpretation and reproducibility of the intervention. The authors found that high PISA values (>615 mm²) were predictive of AF recurrence (HR 2.31, 95% CI 1.23–4.32) (Figure 2). Notably, periodontal treatment during the blanking period was associated with a significant reduction in recurrence risk (HR 0.39, 95% CI 0.22–0.72), highlighting the therapeutic relevance of a modifiable oral inflammatory burden.

The underlying mechanisms proposed across studies converged on systemic inflammation and microbial-driven atrial remodeling. Miyauchi et al. (13) identified elevated inflammatory cytokines, including IL-6 and TNF-α, in patients with high P. gingivalis antibody titers. Miyauchi et al. (15) further reported increased levels of CRP and other interleukins in the high-PISA group. Tashiro et al. (14) added to this evidence, demonstrating elevated CRP levels (≥0.1 mg/dl) in patients with periodontitis. Additionally, P. gingivalis and Fusobacterium nucleatum were specifically implicated in recurrence among patients with non-paroxysmal AF (13, 15).