Pulmonary hypertension in chronic dialysis patients with arteriovenous fistula: pathogenesis and therapeutic prospective.

PURPOSE OF REVIEW: End-stage renal disease patients receiving chronic haemodialysis via arteriovenous access often develop various cardiovascular complications, including vascular calcification, cardiac-vascular calcification and atherosclerotic coronary disease. This review describes recently published studies that demonstrate a high incidence of pulmonary hypertension among patients with end-stage renal disease receiving long-term haemodialysis via a surgical arteriovenous fistula. Both end-stage renal disease and long-term haemodialysis via arteriovenous fistula may be involved in the pathogenesis of pulmonary hypertension by affecting pulmonary vascular resistance and cardiac output.

RECENT FINDINGS: Morbidity and mortality from cardiovascular disease are greatly increased in patients on maintenance haemodialysis therapy. Using Doppler echocardiography, we found a significant increase in cardiac output in 40% of chronic haemodialysis patients, probably related to the large arteriovenous access or altered vascular resistance as a result of the local vascular tone and function expressed by the imbalance between vasodilators such as nitric oxide, and vasoconstrictors such as endothelin-1.

SUMMARY: We propose different potential mechanisms as explanations for the development of pulmonary hypertension. Hormonal and metabolic derangement associated with end-stage renal disease might lead to pulmonary arterial vasoconstriction and an increase in pulmonary vascular resistance. Pulmonary arterial pressure may be further increased by high cardiac output resulting from the arteriole-venous access itself, worsened by commonly occurring anaemia and fluid overload.