Interplay between natriuretic peptides and left atrial mechanics and the relation to recurrence of atrial fibrillation following catheter ablation

Abstract

The relationship between natriuretic peptides and atrial distension is not fully understood. We sought to examine their interrelationship and how they relate to atrial fibrillation (AF) recurrence following catheter ablation. We analyzed patients enrolled in the AMIO-CAT trial (amiodarone vs. placebo for reducing AF recurrence). Echocardiography and natriuretic peptides were assessed at baseline. Natriuretic peptides included mid-regional proANP (MR-proANP) and N-terminal proBNP (NT-proBNP). Atrial distension was assessed by left atrial strain measured by echocardiography. The endpoint was AF recurrence within 6 months after a 3-month blanking period. Logistic regression was used to assess the association between log-transformed natriuretic peptides and AF. Multivariable adjustments were made for age, gender, randomization, and left ventricular ejection fraction. Of 99 patients, 44 developed AF recurrence. No differences in natriuretic peptides nor echocardiography were observed between the outcome groups. In unadjusted analyses, neither MR-proANP nor NT-proBNP were significantly associated with AF recurrence [MR-proANP: OR = 1.06 (0.99-1.14), per 10% increase; NT-proBNP: OR = 1.01 (0.98-1.05), per 10% increase]. These findings were consistent after multivariable adjustments. However, atrial strain significantly modified the association between MR-proANP and AF (p for interaction = 0.009) such that MR-proANP was associated with AF in patients with high atrial strain [OR = 1.24 (1.06-1.46), p = 0.008, per 10% increase] but not in patients with low atrial strain. In patients with high atrial strain, an MR-proANP > 116 pmol/L posed a fivefold higher risk of AF recurrence [HR = 5.38 (2.19-13.22)]. Atrial natriuretic peptide predicts AF recurrence in patients with preserved atrial distension. Assessing atrial strain may assist the interpretation of natriuretic peptides.

Keywords: Atrial fibrillation; Echocardiography; Left atrium; Natriuretic peptides.

Fig. 1

Continuous association between MR-proANP and AF. Restricted cubic spline curve shows a non-linear continuous association between MR-proANP and the incidence rate of AF in patients with high LA strain (> 23%). The risk increases steadily with increasing MR-proANP until MR-proANP reaches a level of approximately 140 pmol/L, after which the risk slightly decreases. MR-proANP mid-regional pro atrial natriuretic peptide, AF atrial fibrillation, LA left atrial

Fig. 2

Predictive value of MR-proANP. Forest plot showing the association between MR-proANP and recurrence of AF after the 3-month blanking period. The upper panel shows the estimates for the entire population. The middle panel shows the unadjusted estimates stratified by high and low LA strain (cutoff: 23%). The lower panel shows the adjusted estimates stratified by high and low LA strain. Dots denote unadjusted estimates and error bars represent 95% confidence intervals. Adjustments were made for LVEF, age, gender, and randomization. MR-proANP mid-regional pro atrial natriuretic peptide, LA left atrial

Fig. 3

Risk of AF according to MR-proANP concentration. Kaplan–Meier estimates for developing AF recurrence in the subset of patients with a high left atrial strain stratified by high vs. low MR-proANP (defined by population median value of 116 pmol/L). AF atrial fibrillation, MR-proANP mid-regional pro atrial natriuretic peptide