Exercise E/e' is a determinant of exercise capacity and adverse cardiovascular outcomes in chronic kidney disease

OBJECTIVES: This study sought to assess the relationship between E/e' and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its prognostic role. BACKGROUND: Patients with CKD have diastolic dysfunction, reduced physical fitness, and elevated risk of cardiovascular disease. METHODS: Patients with stage 3 and 4 CKD without previous cardiac disease underwent resting and exercise stress echocardiograms with assessment of exercise E/e'. Patients were compared to age-, sex-, and risk factor-matched control individuals and were followed annually for 5 years for cardiovascular death and major adverse cardiovascular event(s) (MACE). Exercise capacity was assessed as metabolic equivalents (METs), with reduced exercise capacity defined as METs of ≤7. Raised exercise E/e' was defined as >13. RESULTS: A total of 156 patients with CKD (age 62.8 ± 10.6 years; male: 62%) were compared to 156 matched control individuals. Patients with CKD were more likely to be anemic (p < 0.01) and had increased left ventricular mass (p < 0.01), larger left atrial volumes (p < 0.01), and higher resting (p < 0.01) and exercise E/e' (p < 0.01). Patients with CKD achieved lower exercise METs (p < 0.01), and more patients with CKD had METs of ≤7 (p < 0.01). Receiver-operating characteristic curves showed exercise E/e' (area under the curve [AUC]: 0.89; 95% CI: 0.84 to 0.95; p < 0.01) as the strongest predictor of reduced exercise capacity in patients with CKD. Over a follow-up period of 41.4 months, a raised exercise E/e' of >13 was an independent predictor of cardiovascular death and MACE on unadjusted and adjusted hazard models. CONCLUSION: E/e' is a strong predictor of exercise capacity and METs achieved by patients with CKD. Exercise capacity was reduced in patients with CKD, presumably consequent to diastolic dysfunction. Elevated exercise E/e' in patients with CKD is an independent predictor of cardiovascular death and MACE.