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To determine the risk of nephrotoxicity induced by the infusion of radiographic contrast material, we undertook a prospective study of consecutive patients undergoing radiographic procedures with intravascular contrast material. There were three study groups: patients with diabetes mellitus and normal renal function (n = 85), patients with preexisting renal insufficiency (serum creatinine level, greater than or equal to 150 mumol per liter) without diabetes (n = 101), and patients with both diabetes and renal insufficiency (n = 34). The control group consisted of patients undergoing CT scanning or abdominal imaging procedures without the infusion of contrast material who had diabetes mellitus (n = 59), preexisting renal insufficiency (n = 145), or both (n = 64). Clinically important acute renal failure (defined as an increase of greater than 50 percent in the serum creatinine level) attributable to the contrast material did not occur in nondiabetic patients with preexisting renal insufficiency or in diabetics with normal renal function. The incidence of clinically important contrast-induced renal failure among the diabetic patients with preexisting renal insufficiency was 8.8 percent (95 percent confidence interval, 1.9 to 23.7 percent), as compared with 1.6 percent for the controls. The incidence of acute renal insufficiency, more broadly defined as an increase of greater than 25 percent in the serum creatinine level after the infusion of contrast material, was 11.8 percent among all patients with preexisting renal insufficiency. After the exclusion of patients whose acute renal insufficiency could be attributed to other causes, the incidence was 7.0 percent (95 percent confidence interval, 3.2 to 12.8 percent), as compared with 1.5 percent in the control group. The risk of acute renal insufficiency attributable to the contrast material was therefore 5.5 percent, and the relative risk associated with the infusion of contrast material was 4.7. These rates were similar whether the osmolarity of the contrast material was high or low. We conclude that there is little risk of clinically important nephrotoxicity attributable to contrast material for patients with diabetes and normal renal function or for nondiabetic patients with preexisting renal insufficiency. The risk for those with both diabetes and preexisting renal insufficiency is about 9 percent, which is lower than previously reported.

To determine the prevalence of left ventricular hypertrophy (LVH; left ventricular wall thickness > 1–2 cm in diastole) among end-stage renal disease (ESRD) patients and the most important risk factors that independently relate to LVH, 189 non-diabetic ESRD patients without dilated cardiomyopathy in two centres had echocardiography and full clinical review. 104 of 189 (55%) patients had LVH consisting of 52 of 83 (65%) patients on haemodialysis, 18 of 20 (90%) peritoneal dialysis patients and 34 of 86 (40%) transplanted patients. Using multiple logistic regression, the most important factors which independently related to LVH, in all patients studied, were dialysis as current ESRD treatment (p < 0.001), followed by age (p = 0.008), hypertension as defined by number of blood pressure medications (p = 0.007), followed by high serum alkaline phosphatase which probably reflects hyperparathyroidism (p = 0.03). In a subset of patients with severe LVH (left ventricular wall thickness > 1.4 cm), a high serum alkaline phosphatase level was the best predictor of LVH (p < 0.001), followed by high diastolic blood pressure (p = 0.004) and age (p = 0.02). In dialysis patients, the most important variables were age (p = 0.009) and high serum alkaline phosphatase (p = 0.03). In the transplant group, patients with LVH were taking significantly more antihypertensive medications than those without LVH (p = 0.002). This variable was the only predictor of LVH in the transplant group. It is concluded that the most important factors associated with LVH in ESRD are age, hypertension, hyperparathyroidism and some factors associated with dialysis treatment, which are not functioning vascular access, anaemia or high serum creatinine. Hyperparathyroidism may be particularly important in the pathogenesis of severe LVH.

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Congestive heart failure in dialysis patients is associated with dilated cardiomyopathy, hypertrophic hyperkinetic disease and ischemic heart disease. To determine the natural history of these four diseases, 150 dialysis patients were prospectively followed for 3–5 years. The 2-year cumulative survival rate was 33% in those with recurrent or persistent congestive heart failure vs. 80% in dialysis patients without. Survival was significantly worse in patients with an echocardiographic diagnosis of dilated cardiomyopathy compared to patients with normal echocardiogram (2-year survival rate 67 vs. 90%). In hypertrophic hyperkinetic disease the 2-year survival rate was 30% after entry into the study, and 43 % after first admission with congestive heart failure. Symptomatic ischemic heart disease did not have an adverse impact on mortality when compared to those without ischemic heart disease. We conclude that congestive heart failure in dialysis patients has a bad prognosis. Its associated disorders include dilated cardiomyopathy and hypertrophic hyperkinetic disease, the latter being associated with a high mortality. As the prognosis for patients with overt ischemic heart disease was not different from patients without, it is likely that the underlying cardiomyopathy directly influenced survival.