A cardiac magnetic resonance imaging study of long-term and incident hemodialysis patients.

Background: The cardiovascular morphology and function in long-term survivors of hemodialysis are not well described.

Methods: Single-center cross-sectional study nested within a prospective cohort study of 15 long-term (> 7.5 years) and 15 matched incident (< 6 months) hemodialysis patients with 15 external matched controls. Evaluations included heart structure, function and fibrosis (myocardial longitudinal relaxation time, native T1), and aortic dimensions and elasticity, using cardiovascular magnetic resonance (CMR). Coronary artery calcification (CAC) scores were evaluated from computed tomography (CT).

Results: Incident hemodialysis patients had significantly increased left ventricular mass, greater aortic dimensions and reduced aortic distensibility compared to long-term survivors, whereas the CAC score was significantly higher in long-term than incident patients, median (95% CI) 1127 (10-3861) vs 14 (0-268). Both incident and long-term hemodialysis groups had significantly higher native T1 values compared to controls, mean (95% CI) 1300 ms (1273-1326), 1274 ms (1243-1305) versus 1224 ms (1202-1246), respectively, suggesting interstitial fibrosis or edema. Compared to controls, both hemodialysis groups also had significantly lower left ventricular ejection fraction: 48.7% (43.6-53.9), 54.0% (48.3-59.7) versus 62.2% (58.0-66.4) and longitudinal strain: 14.0% (11.7-16.2), 15.2% (12.7-17.7) versus 19.6% (17.8-21.5).

Conclusions: Incident hemodialysis patients had larger left ventricular mass and unfavorable aortic structure and function compared to long-term survivors, despite a lower CAC burden. Long-term survivors, despite normal ventricular mass and volumes, had signs of fibrosis or edema, given their significantly increased native T1 values.