Late effect after PVC ablation: more than a myth?

Background

Evidence on the late improvement in premature ventricular contraction (PVC) burden after ablation, or Late Effect (LE), is scarce. Indeed, its true prevalence and mechanism remain underexplored, hindered by heterogeneous definitions and follow-up schemes.

Purpose

To quantify the proportion of LE after PVC ablation across a consecutive cohort and to explore clinical and procedural correlates.

Methods

We retrospectively included all consecutive PVC ablations performed at our center from July 2021 to November 2024 (n=82). Ten cases were excluded due to absent or poor-quality periprocedural data, leaving 72 patients for analysis. To be deemed successful, an ablation required:

(1) Post-procedural non-inducibility of PVCs (spontaneous or with isoproterenol).

(2) ≥80% reduction in PVC burden within the first 3 months.

(3) ≤10% absolute PVC burden within the first 3 months, when baseline burden was >20%.

Thus, in patients with an unsuccessful ablation, LE was defined as fulfilling the mentioned criteria at 6 months, reflecting a delayed improvement after the procedure (Figure 1).

Among patients with and without LE, clinical variables (age, sex, left ventricular ejection fraction (LVEF), atrial fibrillation, implantable cardioverter defibrillator and frequent comorbidities), baseline pharmacological therapy, ablation site and procedural metrics (radiofrequency (RF) time, RF dose, total procedure duration) were compared using Chi-square, Fisher’s exact tests or Mann–Whitney U, as appropriate.

Results

Of the 72 analyzed patients, 24 (33%) met the specified criteria for unsuccessful ablation -18 for PVC inducibility after the procedure and 6 for persistence of a significant burden within the first 3 months-. Among these, 18 (75%) fulfilled the criteria at 6 months and subsequently demonstrated LE. Overall, considering the LE, ablation success rate was 91.6% at 6 months.

In the between-group analysis (LE vs no-LE), the only variable that differed significantly was baseline PVC burden, which was higher in the LE group: 20.0% [15.0–26.5] vs 13.5% [10.5–17.0]; p=0.01. All other clinical characteristics (age, sex, LVEF, atrial fibrillation, ICD, hypertension, COPD, smoking) and basal pharmacological therapy were similar between groups (Figure 2). Radiofrequency time and applications showed no significant difference. Likewise, the ablation site distribution did not differ significantly (p=0.33).

Conclusions

In a single-center cohort spanning from 2021 to 2024, late improvement in PVC burden was common among patients lacking early procedural success, occurring in three out of four cases and yielding a 6-month overall ablation success rate over 90%. These findings suggest caution before labeling an ablation as definitively unsuccessful or considering early re-intervention. Larger cohorts and multivariate analysis are warranted to define potential predictors.Study flow and operational definitions.Summary of the main results.