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Cardiac Disease in Patients with End-Stage Renal Disease
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SPECIAL TOPICS FOR THE CARDIOLOGY CONSULTANT
CARDIAC DISEASE IN PATIENTS WITH END-STAGE RENAL DISEASE Catherine G. Staffeld, MD, and Stephen 0. Pastan, MD
Before the widespread availability of renal replacement therapy, the development of end-stage renal failure (ESRF) was uniformly fatal. Despite the availability of dialysis, it is clear that these patients continue to be at high risk for premature death: The most recent survey of morbidity and mortality in patients with ESRF in the United States reported an annual mortality rate of 23%. Although sepsis and withdrawal of dialysis account for a significant number of deaths, cardiovascular complications remain the leading cause of death in this group. Myocardial infarctions and other cardiac causes together account for about 45% of deaths in dialysis patients.92 Acute myocardial infarctions are noted in 26% of autopsies of dialysis patients2 and account for 25.8 deaths per 1000 patient years. 92 Other cardiac causes account for 63.4 deaths per 1000 patient years. 92 In an autopsy review of dialysis patients, 31 % were noted to have pericarditis or pericardia! fibrosis. Ventricular dilatation was observed in 47%. Left ventricular hypertrophy (LVH) was noted in 66%, right ventricular hypertrophy was seen in 33%, and biventricular hypertrophy was seen in 33%. 2 The most common cardiovascular complications seen with ESRF are reviewed in this article. The pathophysiology of these conditions as well as management strategies is discussed.
HYPERTENSION
Hypertension is found in up to 80% of patients with chronic renal failure before the start of dialysis.64 The high prevalence is multifactorial, but the major factor is the expanded extravascular volume seen in most patients with advanced renal insufficiency.64• 72 Blood pressure can be controlled with adequate salt and water removal during hemodialysis and adherence to a sodium and fluid restricted diet in more than 60% of dialysis patients. Many other factors have been implicated as contributing to hypertension in chronic renal failure patients. Plasma renin activity may significantly help maintain an elevated blood pressure; levels may be elevated or found to be higher than expected for the degree of extracellular volume expansion exhibited. Vasoconstriction mediated by overactivity of the sympathetic nervous system has also been documented. This overactivity seems to be caused by stimulation of renal afferent nerves by unknown factors, a response that is abolished in anephric patients. 19 Decreased production of vasodepressor substances (such as prostaglandins) by the nonfunctional kidney has also been implicated in subsets of dialysis patients. 64• 72 Prostaglandins have been demonstrated to affect vascular tone and thus nelp regulate blood pressure. 15 In patients with hypertension and
From the Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
CARDIOLOGY CLINICS VOLUME 13 •NUMBER 2 •MAY 1995 t'
It
~-
209
SPECIAL TOPICS FOR THE CARDIOLOGY CONSULTANT
CARDIAC DISEASE IN PATIENTS WITH END-STAGE RENAL DISEASE Catherine G. Staffeld, MD, and Stephen 0. Pastan, MD
Before the widespread availability of renal replacement therapy, the development of end-stage renal failure (ESRF) was uniformly fatal. Despite the availability of dialysis, it is clear that these patients continue to be at high risk for premature death: The most recent survey of morbidity and mortality in patients with ESRF in the United States reported an annual mortality rate of 23%. Although sepsis and withdrawal of dialysis account for a significant number of deaths, cardiovascular complications remain the leading cause of death in this group. Myocardial infarctions and other cardiac causes together account for about 45% of deaths in dialysis patients.92 Acute myocardial infarctions are noted in 26% of autopsies of dialysis patients2 and account for 25.8 deaths per 1000 patient years. 92 Other cardiac causes account for 63.4 deaths per 1000 patient years. 92 In an autopsy review of dialysis patients, 31 % were noted to have pericarditis or pericardia! fibrosis. Ventricular dilatation was observed in 47%. Left ventricular hypertrophy (LVH) was noted in 66%, right ventricular hypertrophy was seen in 33%, and biventricular hypertrophy was seen in 33%. 2 The most common cardiovascular complications seen with ESRF are reviewed in this article. The pathophysiology of these conditions as well as management strategies is discussed.
HYPERTENSION
Hypertension is found in up to 80% of patients with chronic renal failure before the start of dialysis.64 The high prevalence is multifactorial, but the major factor is the expanded extravascular volume seen in most patients with advanced renal insufficiency.64• 72 Blood pressure can be controlled with adequate salt and water removal during hemodialysis and adherence to a sodium and fluid restricted diet in more than 60% of dialysis patients. Many other factors have been implicated as contributing to hypertension in chronic renal failure patients. Plasma renin activity may significantly help maintain an elevated blood pressure; levels may be elevated or found to be higher than expected for the degree of extracellular volume expansion exhibited. Vasoconstriction mediated by overactivity of the sympathetic nervous system has also been documented. This overactivity seems to be caused by stimulation of renal afferent nerves by unknown factors, a response that is abolished in anephric patients. 19 Decreased production of vasodepressor substances (such as prostaglandins) by the nonfunctional kidney has also been implicated in subsets of dialysis patients. 64• 72 Prostaglandins have been demonstrated to affect vascular tone and thus nelp regulate blood pressure. 15 In patients with hypertension and
From the Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
CARDIOLOGY CLINICS VOLUME 13 •NUMBER 2 •MAY 1995 t'
It
~-
209