Atrial fibrillation increases left and right atrial pressures in patients with chronic heart diseases

Pulmonary capillary wedge pressure (PCWP) and right atrial pressure (RAP) are key haemodynamic indicators of cardiac congestion. Atrial fibrillation (AF) often coexists with several heart diseases, making it challenging to determine AF's independent contribution to atrial pressure elevation. Therefore, the impact of AF on PCWP and RAP requires clarification. We sought to quantify the contribution of AF on PCWP and RAP within patients with various chronic heart diseases.

We performed a single-center retrospective analysis on 1452 patients (age: 68.0 ± 13.6 years, 58.7% male, 26% AF) with chronic heart diseases undergoing right heart catheterization (RHC). PCWP and RAP were measured during RHC, and the underlying AF or sinus rhythm (SR) was annotated. To isolate AF effect from clinical, haemodynamic, and echocardiographic confounders, two propensity score matching analyses yielded two balanced cohorts for PCWP (n = 496) and RAP (n = 494) analysis.

After matching, PCWP was higher in the AF than the SR group (18.4 ± 0.49 mmHg vs 15.7 ± 0.49 mmHg; P < .001). Similarly, RAP was higher in the AF than the SR group (8.7 ± 0.34 mmHg vs 7.5 ± 0.34 mmHg; P = .02). The findings were highly robust for PCWP (E-value = 10.8) and moderately robust for RAP (E-value = 2.78) to unmeasured confounders. Additionally, patients in the SR cohort with a prior history of AF had significantly higher PCWP and RAP compared to patients with no AF history.

In our cohort, AF increased PCWP by 2.6 mmHg and RAP by 1.1 mmHg. Furthermore, a previous history of AF is linked to higher atrial pressures in patients later in SR.