Ablating Misconceptions to Prevent Failure of Interpretation: Revisiting the CLAPHAF Study

We read with interest the critical appraisal of our manuscript from Ahmad and colleagues. Our prospective, multicenter cohort study included 286 patients undergoing radiofrequency ablation (RFA) for atrial fibrillation (AF) at three centers in disparate parts of the United States. Though we acknowledge several limitations to our study, we believe it is topical, impactful, and answers an important question about immediate postoperative complications from this very common procedure. The letter writers mention lack of echocardiographic assessment for diastolic dysfunction in our study. This was also brought up by both reviewers in the peer review process: we acknowledge this limitation in Section 4.1. However, echocardiographic diastolic dysfunction is only a measure of impaired relaxation, and invasively measured LA pressure is the gold standard for assessment of diastolic function [1]. Indeed, in smaller cohorts, higher LA pressure had a direct relationship to incident HF after AF ablation [2, 3]. The Rosenberg and Manning citation [4] evaluates long term remodeling and not acute effects after ablation. Second, the writers take issue with exclusion of cryoablation and pulsed-field ablation in this study. However, they then ask for more procedural standardization: we specifically included only RFA to help standardize the patient population. Additionally, it is entirely plausible that LAP differences seen after ablation vary by the energy delivered, an argument supported by their Mirazaki et al. reference [5]. The writers also state that ablation strategy differences could confound results; but strategy (PVI, or PVI+) did not affect outcomes in our study, which was larger than the cited STAR-AF substudy [6]. We also addressed interoperator variability in section 3.0, with high volume operators having lower risk of incident HF. Next, they claim 30 d is not long enough of a time period to assess acute effects of ablation. However, the study from Lim et al. [7] that they cite actually supports our choice as it showed most profound effects within the first month; it is included as reference #12 in our own manuscript. Importantly, as 30 d comprises the global period of billing for certain payors, it is of prime importance to assess acute ablation effects and early incidence of HF, which can increase utilization and health care costs. We stand by our conclusion that risk factors including hypotension and fluid administration should prompt consideration of postoperative diuretic use to avoid early incident HF after AF ablation. Certainly, a prospective randomized study can confirm this hypothesis.