Objectives: The only curative treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary endarterectomy (PEA). PEA requires cardiopulmonary bypass (CPB) which is associated with a high acute kidney injury (AKI) risk. Circulating endothelin-1 (ET-1) levels are elevated in CTEPH, and ET-1 plays a pivotal role in AKI. Because AKI is burdened by high morbidity and mortality, we aimed to evaluate the association between preoperative ET-1 and the risk to develop AKI in CTEPH individuals who undergo PEA. We also evaluated the association of AKI and ET-1 with kidney function and mortality at 1 year after PEA.
Methods: In 385 consecutive patients diagnosed with CTEPH who underwent PEA at the Foundation IRCC Policlinico San Matteo (Pavia, Italy) from January 2009 to April 2015, we assessed preoperative circulating ET-1 by ELISA and identified presence of AKI based on 2012 KDIGO criteria.
Results: AKI occurred in 26.5% of the 347 patients included in the analysis, and was independently associated with preoperative ET-1 (p = 0.008), body mass index (BMI) (p = 0.022), male gender (p = 0.005) and duration of CPB (p = 0.002). At 1-year post PEA, estimated glomerular filtration rate (eGFR) significantly improved in patients who did not develop AKI [ΔeGFR 5.6 ml/min/1.73 m2 (95% CI 3.6-7.6), p < 0.001] but not in those with perioperative AKI. AKI (p < 0.001), age (p < 0.001), preoperative eGFR (p < 0.001) and systemic hypertension diagnosis (p = 0.015) were independently associated with 1-year ΔeGFR. Neither perioperative AKI nor preoperative ET-1 was associated with 1-year survival.
Conclusion: Perioperative AKI is associated with higher preoperative circulating ET-1 and it negatively influences long-term kidney function in patients with CTEPH who undergo PEA.
Keywords: Acute kidney failure; Cardiopulmonary bypass; Chronic thromboembolic pulmonary hypertension; ET-1.