Potential determinants of the E/e' ratio in non-dialysis compared with dialysis patients

We hypothesized that arterial function and N-terminal natriuretic peptide (NT-proBNP) levels as a marker of volume overload, relate differently to E/e' as an index of diastolic function in dialysis compared with non-dialysis patients with chronic kidney disease. We further examined whether cardiovascular risk factors attenuated these relationships.

We assessed cardiovascular risk factors and determined arterial function indices by applanation tonometry using SphygmoCor software and E/e' by echocardiography in 103 (62 non-dialysis and 41 dialysis) patients.

In established confounder adjusted analysis, dialysis status impacted the pulse wave velocity-E/e' relationship (interaction p = .01) but not the NT-proBNP level-E/e' association (interaction p = .1). Upon entering arterial function measures and NT-proBNP levels simultaneously in regression models, arterial function measures were associated with E/e' (p = .008 to .04) in non-dialysis patients whereas NT-proBNP levels were related to E/e' in dialysis patients (p = .009 to .04). Bivariate associations were found between diabetes (p < .0001) and E/e' in non-dialysis patients, and haemoglobin concentrations and E/e' (p = .02) in those on dialysis. Upon adjustment for diabetes in non-dialysis patients, only central pulse pressure remained associated with E/e' (p = .02); when haemoglobin concentrations were adjusted for in dialysis patients, NT-proBNP levels were no longer associated with E/e' (p = .2). In separate models, haemoglobin levels were associated with E/e' independent of left ventricular mass index and preload and afterload measures (p = .02 to .03).

The main determinants of E/e' may differ in non-dialysis compared with dialysis patients. These include arterial function and diabetes in non-dialysis patients, and volume overload and anaemia in dialysis patients.