Cardiac involvement in RENAL DISEASES ZAHRA JAVADY NEJAD, MD
Coronary artery disease Pericardial disease Overview of hypertension
Risk factors and epidemiology of coronary artery disease in end-stage renal disease (dialysis)
The presence of cardiovascular disease is an important predictor of mortality in patients with end-stage renal disease, as it accounts for almost 50 percent of deaths .
Patients with varying degrees of chronic kidney dysfunction but who are not yet dialysis-dependent also have a markedly increased risk of morbidity and mortality from cardiovascular disease, including CAD.
RISK FACTORS traditional risk factors for cardiovascular disease :
Additional risk factors include the following Dyslipidemia Physical inactivity Smoking
Some other proposed risk factors for coronary artery disease, including: uremic toxins, dialysis therapy, abnormalities in mineral metabolism, and other factors, are unique to those with kidney dysfunction.
These factors may provide the proper milieu for the development of accelerated atherosclerosis .
A role for increased inflammation, due in part to renal replacement therapy and other factors, is supported by the observation that increased serum levels of C-reactive protein, an acute phase protein released in inflammatory disorders, is associated with an enhanced risk of cardiovascular mortality in hemodialysis patients .
Inhibition of nitric oxide (NO) synthesis in those with ESRD may cause vasoconstriction and hypertension, thereby resulting in adverse cardiovascular outcomes.
In dialysis patients, increased oral intake of calcium (which is given as a phosphate binder to treat hyperphosphatemia and may result in a high serum calcium-phosphorus product) may directly enhance coronary arterial calcification.
EPIDEMIOLOGY The incidence/prevalence of coronary disease in the dialysis population depends in part upon the definition that is used .
A confounding issue is that coronary disease often presents in atypical fashion in dialysis patients. As a result, the presence of CHD is frequently overlooked due to the absence of classic symptoms and/or signs of heart disease.
Silent ischemia is a concern clinically because it has been associated with an increased risk of myocardial infarction, serious arrhythmias, and sudden death in patients with and without end-stage renal disease.
Clinical manifestations and diagnosis of coronary heart disease in end-stage renal disease (dialysis):
●As in those without kidney disease, dialysis patients with stable coronary artery disease (CAD) can have angina and other classic symptoms. Additional manifestations may include exertionaldyspnea, intradialytic or interdialytichypotension, sudden cardiac arrest or death, and arrhythmias.
Screen incident dialysis patients and kidney transplant candidates for the presence of heart disease. If the initial evaluation is negative, asymptomatic kidney transplant waitlist patients should be reevaluated at regular intervals.
Evaluation for heart disease should be performed in asymptomatic incident dialysis patients and kidney transplant candidates and dialysis patients with symptoms and/or signs of CAD.
A change in symptoms and signs, including recurrent hypotension; heart failure that is unresponsive to changes in dry weight; and hypotension that prevents attaining dry weight.
The initial evaluation should include a careful history and physical examination, an electrocardiogram (ECG), and an echocardiogram. Based upon this initial assessment, further studies may be required.
With respect to noninvasive tests, the diagnostic test selected will depend upon local experience and expertise. In general, prefer dobutamine echocardiography rather than other noninvasive tests.
As in the general population, the evaluation and diagnosis of the dialysis patients with anacute coronary syndromeis based upon the constellation of symptoms and signs, findings on ECG, and levels of cardiac biomarkers.
Chronic kidney disease (CKD) is an independent risk factor for the development of coronary artery disease, and for more severe coronary heart disease (CHD) .
Patients with CKD often have numerous traditional and nontraditional risk factors for the development of cardiovascular disease. Traditional risk factors (hypertension, smoking, diabetes, dyslipidemia, and older age) appear to be more important risk factors during the earlier stages of CKD.
Nontraditional risk factors : • uremic toxins, • anemia, • elevated levels of certain cytokines, • an increased calcium load, • abnormalities in bone mineral metabolism, • an increased inflammatory-poor nutrition state.
Among those with CKD, the risk of death ▓, particularly due to cardiovascular disease, is typically higher than the risk of eventually requiring renal replacement therapy.
In many studies, older patients with less severe CKD and lower levels of proteinuria are more likely to die (usually due to cardiovascular disease) before needing renal replacement therapy, while younger patients with proteinuria and diseases localized to the kidney are more likely to ultimately need renal replacement therapy.
General approach to reduce the risk of atherosclerotic cardiovascular disease in most patients with CKD not requiring dialysis includes the following :
Individualized decisions about antiplatelet therapy : depending upon the patient's overall risk for CHD (for example, a prior history of myocardial infarction) and for bleeding, and also upon their preferences.
The prescription of low-dose aspirin is probably safe in most patients with CKD.
Secondary prevention of cardiovascular disease in end-stage renal disease (dialysis)
Adverse outcomes appear to be generally associated with very high blood pressure in dialysis patients. We aim for a predialysis blood pressure value below 140/90 on minimal medications, if possible.
However, this target blood pressure level should be individualized, partly depending upon symptoms of intradialytic hypotension. In some patients, targeting predialysis blood pressure of 140/90 may not be appropriate.
Among dialysis patients with abnormal calcium/phosphorus metabolism, there are no convincing data from prospective, randomized studies demonstrating a decrease in clinical events and/or a survival advantage with any specific phosphorus binder or serum calcium x phosphorus product.
Despite this, generally aim for a calcium x phosphate product <55 mg2/dL2 using current therapeutic options.