BACKGROUND: Cardiopulmonary recirculation (CPR) is a known risk factor for heart failure (HF). Typically, the assessment is performed on the interdialytic day. Hemodialysis (HD) sessions can induce significant hemodynamic changes, which may be important for patients with HF and preserved ejection fraction (EF), in whom the risk may be underestimated.

OBJECTIVE: To evaluate the dynamics of CPR due to a HD session following a long interdialytic gap in patients with HF and preserved EF.

METHODS: The prospective cohort single-arm study included 20 adult HD patients who met the inclusion criteria: EF ≥ 50%, NYHA I-II, AVF volume blood flow (Qa) ≥ 1 L/min, CPR < 30%, interdialytic weight gain < 5%, and eKt/V > 1.2. All patients underwent transthoracic echocardiography on the third day after the previous HD session (Monday/Tuesday), 1 h prior to and 2 h after the session. In addition, the Qa of the brachial artery was measured. ClinicalTrials Id: NCT06394986 (May 01, 2024).

RESULTS: A reduction in cardiac preload after HD was evidenced by a decrease in the volume of cardiac chambers, as well as a reduction in pulmonary artery systolic pressure and arterial blood pressure. The EF and Qa slightly decreased (2.46% [95% CI 1.47; 3.45], p  < 0.001 and 0.12 L/min [95% CI 0.09; 0.14], p  < 0.001, respectively), whereas cardiac output decreased significantly (1.71 L/min [95% CI 0.8; 2.6], p  < 0.001). This led to an increase in CPR of 5.1% [95% CI 3.9; 6.4], p  < 0.001. As a result, in 5 patients, the CPR exceeded 30% after HD. In the sensitivity analysis, no parameters significantly associated with the variance CPR were identified.

CONCLUSIONS: Some patients experience a significant increase in CPR after HD. However, the prognostic value of this phenomenon remains unclear. For patients with HF and normal or subnormal CPR measured on the interdialytic day, it is advisable to determine the CPR shortly after HD. This may serve as a ‘stress test’ to identify hidden hemodynamic disorders and manifest the cardiotoxic effect of AVF.