Right and left heart functional indices and coupling parameters in the prediction of arrhythmia recurrence among patients with paroxysmal atrial fibrillation

Abstract Background Accurate prediction of atrial fibrillation recurrence remains challenging despite rhythm control strategies. Echocardiographic markers such as left atrial (LA) strain components have shown predictive value, but their utility may be affected by technical and clinical factors. Indices reflecting atrioventricular (A-V), ventriculo-atrial (V-A), and right atrial-right ventricular (RA-RV) coupling remain underexplored and may offer additional prognostic insight. Purpose To assess the prognostic significance of established echocardiographic markers and coupling indices for AF recurrence in a homogeneous cohort of patients with paroxysmal AF (PAF). Methods We prospectively studied 73 patients (mean age 59.6±11.6 years; 52% female) with PAF in sinus rhythm at baseline. All underwent comprehensive transthoracic echocardiography including strain and volumetric analysis. AF recurrence was documented over 12 months via ECG, Holter monitoring, or clinical documentation of symptomatic episodes. Variables and coupling indices, including LA volume index (LAVI), LA strain components, E/e’, LA coupling index (LACI), right ventricular fractional area change (RV FAC)/right atrial (RA) volume, tricuspid annular plane systolic excursion (TAPSE)/pulmonary arterial systolic pressure (PASP), were assessed using univariable logistic regression. Significant predictors were entered into multivariable analysis. Results At baseline, recurrence (n=31) and non-recurrence (n=42) groups were similar in age, sex, cardiovascular risk factors, and medication use (all p>0.05), confirming group homogeneity. Most conventional markers, including LAVI, LAEF, E/e’, and LA reservoir or conduit strain, were not associated with recurrence. Coupling indices across the left and right heart also lacked predictive value (all p>0.05). Univariable analysis identified 3 significant predictors: lower RV FAC (OR=0.918 per 1% increase; 95% CI: 0.854–0.987; p=0.020), reduced LA contraction strain (OR=0.886, 95% CI: 0.790–0.994, p=0.039), and a higher LA contraction strain/LAVI ratio (OR=12.238; 95% CI: 1.294–115.775; p=0.029), possibly reflecting mechanical-structural mismatch. In multivariable analysis, RV FAC remained independently predictive (OR=0.921; p=0.034), while the LA contraction strain/LAVI ratio showed a borderline association (OR=14.769, 95% CI: 0.806–84.792, p=0.076) (Table 1). LA contraction strain alone lost significance. Our findings are illustrated in Figure 1, showing measurement of LA contraction strain and RV FAC, two key predictors of AF recurrence in this cohort. Conclusions In this homogeneous PAF cohort, conventional left heart indices and coupling markers were not predictive of recurrence. Instead, impaired RV systolic function and reduced atrial contractile efficiency indexed to atrial size emerged as more relevant predictors. These findings highlight the underrecognized importance of RV function and LA mechanical–structural mismatch in AF risk stratification.