Determinants of hypertension and left ventricular function in end stage renal failure: a pilot study using cardiovascular magnetic resonance imaging

• Published in: Clinical physiology and functional imaging Vol. 24; no. 6; pp. 387 - 393
• Main Authors: Stewart, Graham A., Mark, Patrick B., Johnston, Nicola, Foster, John E., Cowan, Michael, Rodger, R. Stuart C., Dargie, Henry J., Jardine, Alan G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-11-2004; Blackwell Science
• Subjects: Adult; anaemia; Anemia - diagnosis; Anemia - etiology; Biological and medical sciences; Blood Pressure; cardiac magnetic resonance imaging; Cardiac Output; Female; haemodialysis; Humans; hypertension; Hypertension - diagnosis; Hypertension - etiology; Kidney Failure, Chronic - complications; Kidney Failure, Chronic - diagnosis; Kidney Failure, Chronic - therapy; Magnetic Resonance Imaging - methods; Medical sciences; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Pilot Projects; Prognosis; Renal Dialysis; Renal failure; Reproducibility of Results; Risk Assessment - methods; Risk Factors; Sensitivity and Specificity; Statistics as Topic; Stroke Volume; Treatment Outcome; Ventricular Dysfunction, Left - diagnosis; Ventricular Dysfunction, Left - etiology; Heart; Kidney disease; Human; Hypertension; Urinary system disease; anaemia; cardiac magnetic resonance imaging; haemodialysis; Cardiovascular disease; Exploration; Terminal stage; Nuclear magnetic resonance imaging; Left ventricle; cardiac output; Renal failure; Circulatory system; Left ventricle performance
• ISSN: 1475-0961; 1475-097X
• DOI: 10.1111/j.1475-097X.2004.00583.x

Summary
Cardiovascular disease is the principal cause of mortality in patients with renal failure. Left ventricular (LV) abnormalities are adverse prognostic indicators for cardiovascular outcome. The aim of this study was to use cardiac magnetic resonance scanning (CMR) to define LV functional abnormalities in haemodialysis (HD) patients and clarify the determinants of blood pressure (BP) and the effect of anaemia in this population. We studied 44 HD patients and 11 controls with CMR performed following dialysis. Forty patients and 11 controls completed the study. LV mass (P<0·001) and estimated systemic vascular resistance (SVR) (P = 0·002) were significantly higher in the dialysis group compared to controls. LV ejection fraction (P = 0·002) and SV (P = 0·043) were lower than controls. In the HD patients, BP correlated significantly with cardiac output (CO; r = 0·569, P<0·001) and end diastolic volume (EDV; r = 0·565, P<0·001) but there was no correlation between BP and SVR (r = 0·201, P = 0·594). Haemoglobin was inversely correlated with both CO (r = −0·531, P<0·001) and EDV (r = −0·493, P = 0·001) and positively with SVR (r = 0·402, P = 0·009). HD patients had a higher LV mass and lower ejection fraction than controls. The relationship of BP with CO, but not SVR, supports the theory that a major determinant of BP is intravascular volume and CO rather than vascular resistance although there was a fixed increase in SVR in this population. Improved understanding of the mechanisms underlying increased SVR and improved control of CO and intravascular volume may allow better therapeutic strategies. CMR provides insights into the pathophysiology of hypertension and LV dysfunction in HD patients.