MP402TRENDS ON RIGHT VENTRICULAR FUNCTION ACROSS STAGES OF CKD IN A COHORT WITH MINIMAL CONVENTIONAL RISK FACTORS OF CARDIOVASCULAR DISEASE

Abstract

INTRODUCTION AND AIMS: Right ventricular dysfunction is associated with CKD and prospectively predicts survival in outpatients with chronic systolic heart failure. In this population group, reduced right ventricular ejection fraction (RVEF <40%) and a low tricuspid annular plane systolic excursion (TAPSE; marker of systolic right ventricular function) are independent predictors of all-cause mortality. This is an observational study that sought to understand what happens to right ventricular function in stable CKD patients in the absence of conventional cardiovascular risk factors, compared with a sample of healthy controls. METHODS: 55 patients with chronic kidney disease (stages 2 to 5) were studied who met the following inclusion criteria: i) pre-dialysis and without a functioning arteriovenous fistula; ii) no known cardiovascular disease (IHD, valvular heart disease, EF<50%, cerebrovascular / peripheral vascular / renovascular disease); iii) not diabetic. Myocardial ischaemia was excluded by exercise stress echocardiography or 99m technetium tetrofosmin single photon electron computed tomography. Significant underlying pulmonary disease was excluded using spirometry, and the maximal tricuspid regurgitation velocity (TRVmax) was used as a surrogate to assess for pulmonary hypertension. All patients also underwent cardiac magnetic resonance imaging to assess myocardial structure and function. These data were compared to data from 21 healthy controls who met the criteria for live kidney donation, and cardiopulmonary dysfunction was excluded on a comprehensive workup. RESULTS: Table 1 compares the mean values of key left and right ventricular parameters across the stages of CKD to those of healthy controls. All patients had TRVmax <2.8m/s suggesting that pulmonary hypertension was unlikely. Both left and right ventricular ejection fraction were preserved in all groups. However both mean MAPSE (mitral annular plane systolic excursion; a marker of systolic LV function) and mean TAPSE were reduced in the overall CKD cohort compared with healthy controls (p<0.001 and p=0.012 respectively). MAPSE was also positively correlated with eGFR (r=0.483, p<0.001), and it was negatively correlated with left ventricular (LV) mass (r=-0.235, p=0.043), however there was no correlation between LV mass and right ventricular systolic function. LV mass increased with worsening eGFR (r=-0.421, p<0.001), and it was positively correlated with left and right ventricular end diastolic volumes (LVEDVi r=0.728, p<0.001; RVEDVi r=0.560, p<0.001). CONCLUSIONS: Even in a CKD population without conventional cardiovascular risk factors or significant underlying lung disease, right ventricular systolic dysfunction as measured by TAPSE is reduced. Larger studies are needed to help determine the reason for declining right ventricular function in CKD, but volume status and left ventricular mass may be significant factors.