Association of arteriovenous fistulae with precapillary pulmonary hypertension - A single center retrospective analysis of invasive hemodynamic parameters.

BACKGROUND

Pulmonary hypertension (pH) is a well-known complication among patients with chronic kidney disease (CKD). Arteriovenous fistulae (AVF) have been associated with pH mainly by increasing cardiac output. However, the burden of precapillary pH in individuals with CKD and an AVF is unclear.

OBJECTIVES

To better and more fully understand the mechanism and development of precapillary pH in patients with AVF, as well as the consequences of precapillary pH in these patients.

METHODS

This was a large retrospective study of patients with CKD stage 4 or 5 who underwent right heart catheterization (RHC) from 2018 to 2023. The data were stratified according to the presence of AVF. To determine if AVF was independently associated with precapillary pH, we used a multivariable logistic regression analysis adjusting for demographics and potential comorbidities associated with precapillary pH, including diagnosis of chronic lung disease, obstructive sleep apnea, connective tissue disease, history of venous thromboembolism, chronic anemia, and heart failure.

RESULTS

Of 651 patients with CKD4 or CKD5, 145 (22 %) had AVF and 506 (78 %) did not have AVF. Within the AVF group, the median age was 64 years (IQR 54-71), and they were predominantly males (61 %, n = 88) and African American (77 %, n = 111). A total of 31 % (n = 45) had evidence of precapillary pH, 30 % (n = 43) of combined pH, and 14 % (n = 20) of isolated postcapillary pH. Compared to the non-AVF group, precapillary pH was more likely in the AVF group (31% vs 17 %, p < 0.0001). On multivariable analysis, AVF was independently associated with precapillary pH (OR 2.47, CI 1.56-3.89; p < 0.0001). The median time from dialysis initiation to RHC date (and precapillary pH diagnosis) was 6 years (IQR 3-8).

CONCLUSION

Based on RHC findings, almost one-third of patients with CKD and AVF had precapillary pH. The presence of AVF was independently associated with precapillary pH.