Chronic renal failure due to atheromatous renovascular disease in the elderly

Ischemic nephropathy

Ischemic nephropathy is an independent pathway towards end-stage renal disease. Its prevalence is estimated to be significant and increasing among populations with vascular disease, hypertension, and chronic renal failure. Angiography remains the gold standard for evaluation of ischemic nephropathy; however, selection by clinical criteria and noninvasive screening with ultrasound are recommended for most patients. Surgical revascularization of ischemic kidneys can halt or reverse deterioration of renal function and is preferable to medical treatment. Direct comparison of angioplasty and stent placement with surgery is needed.

Prévalence des sténoses des artères rénales dépistées au cours de coronarographies diagnostiques : dans quels cas doit-on réaliser une aortographie abdominale ?

PURPOSE

To define a subgroup of patients at increased risk of renal artery stenosis (RAS) in a population of patients undergoing cardiac catheterization.

MATERIALS AND METHODS

A total of 467 patients (mean age of 64 Years +/-11) underwent cardiac catheterization and aortography Results were evaluated to detect correlations between the presence or absence of RAS and clinical and biological parameters.

RESULTS

A total of 42 (9%) patients had a renal artery stenosis. Univariate analysis defined parameters correlated with the presence of RAS: systolic blood pressure (p=0.03), pulse pressure (p=0.005), age (p<0.0001), creatinine clearance (p<0.0001), 2-vessel (p=0.028) and 3-vessel (p=0.037) coronary artery diseases. Multivariate analysis showed that the presence of RAS correlated to creatinine clearance (p=0.02) and 2-vessel coronary artery disease. A creatinine clearance between 30 and 60 ml/min and multi-vessel coronary artery disease defined a subgroup at increased risk of RAS with sensitivity, specificity, positive and negative predictive values of: 47.6, 90.1, 32.3 and 94.6%. The prevalence of renal artery stenosis was 5.2% when both parameters were absent.

CONCLUSION

Patients with mild renal insufficiency and multi-vessel coronary artery disease defined a subgroup of patients at increased risk of RAS (32.5%) that may benefit from abdominal aortography performed at the time of cardiac catheterization.

Prevalence and predictors of renal artery stenosis in Chinese patients with coronary artery disease

BACKGROUND

Ischaemic nephropathy is currently a major public health issue in atherosclerotic populations. Although atherosclerotic cardiovascular disease in Asia has reached epidemic proportions over the last two decades, there is little published data on the prevalence of atherosclerotic renal artery stenosis (ARAS) in Oriental subjects. Because ARAS may be clinically silent until end-stage renal failure sets in, it is important to identify patients with significant but clinically unsuspected ARAS. ARAS and coronary artery disease (CAD) often coexist.

AIMS

The purpose of the present study was to evaluate the prevalence and predictors of ARAS among Chinese patients with CAD.

METHODS

A total of 230 consecutive Chinese patients with CAD confirmed by coronary angiography underwent an abdominal aortogram in the same sitting to screen for ARAS. Patient demographics and comorbidities were analysed for any association with ARAS.

RESULTS

A total of 34 (14.8%) patients was found to have significant ARAS. Age and multivessel CAD were independent predictors of ARAS. Hypertension, renal insufficiency, extracranial cerebrovascular disease and female gender were also associated with a higher risk of ARAS but did not independently predict ARAS.

CONCLUSION

Clinically silent yet angiographically significant ARAS is common among CAD patients. The prevalence and predictors of ARAS among Chinese patients with CAD are similar to those reported for Caucasian subjects. Underlying ARAS should be suspected in CAD patients with such comorbidities as hypertension, renal insufficiency, extracranial cerebrovascular disease, and more so in the elderly and those with multivessel disease.

Spectrum of renal diseases in the elderly: single center experience from a developing country

From November 1998 to March 2000, two hundred patients over the age of 60 years (Elderly) with clinical renal disease were studied. 144 patients were between ages of 60-69 years, 46 between 70-79 years and 10 were above 80 years. The elderly patients (Male 165; Female 35) with renal disease constituted 11% (200/1816) of the total nephrology consultation during the study period. The clinical presentation included chronic renal failure (42.5%); acute renal failure (28%); nephrotic syndrome (14.5%); acute glomerulonephritis (7.5%); renal vascular disease (5%) and renal cystic disease (2.5%). Diabetic nephropathy, obstructive uropathy and hypertensive nephrosclerosis were the major causes of CRF, accounting for 80% of total CRF in the elderly. Chronic glomerulonephritis and chronic pyelonephritis (CPN) were less common and etiology of CRF was uncertain in 5.9% of cases. However, diabetic nephropathy was the commonest (49.4%) cause of chronic renal failure. We did not see a single case of ischemic nephropathy causing CRF in the present study. Prerenal ARF, obstructive uropathy and sepsis were contributing factors for ARF in 82% of the cases. Volume depletion due to gastrointestinal fluid loss and urinary tract obstruction on account of enlarged prostate were the leading causes of ARF in 20 (35.7%) and 8 (14.3%) cases respectively. Sepsis with or without multiorgan failure was the major (46.7%) cause of mortality in patients with ARF and overall mortality was 26.8%. The commonest (31%) cause of nephrotic syndrome was the idiopathic membranous nephropathy. Diabetic nephropathy related to type-2 diabetes mellitus was the second most common (24.1%) cause of nephrotic syndrome. Diffuse endocapillary proliferative GN of post infectious etiology was the commonest (73.3%) type of acute GN in our elderly patients. Renal cystic diseases were noted in 5 (ADPKD 3; Simple cyst-2) patients. Thus, overall spectrum of renal disease in our elderly patients is similar to that of developed nations except in two ways: (i) Endocapillary proliferative GN of post infectious origin was the commonest type of acute GN and (ii) Rarity or absence of ischemic nephropathy and atherosclerotic renal artery occlusive disease.

The impact of atherosclerotic renovascular disease on diabetic renal failure

Atherosclerotic renovascular disease (ARVD) is common in the general population, and its prevalence increases with age. Parallel studies show it is also common in patients with diabetes. The widespread use of angiotensin converting enzyme inhibitors and angiotensin receptor antagonists for heart and kidney disease might therefore expose arteriopathic diabetic patients to potential harm if they had critical renal artery stenosis. This review looks at the natural history of ARVD in the diabetic and non-diabetic populations: while it is common, it only rarely leads to renal failure. Hence intervention to revascularize ischaemic kidney son the basis of radiological appearances alone may subject some patients to unnecessary therapy. Although untested by randomized trial, a policy of watchful waiting may be the simplest strategy for most diabetic patients with suspected ARVD, reserving angiography and angioplasty (usually backed up by a stent) for those with an abrupt decline in renal function and no other cause for renal deterioration. Future clinical trials may better define subgroups of patients who will truly benefit from renal revascularization.

Prevalence and predictors of renal artery stenosis in patients with myocardial infarction

In recent years, the importance of renovascular disease as a cause of end-stage renal disease has been emphasized. Among 1,788 cases autopsied during the 12-year period between 1981 and 1992 at the National Cardiovascular Center Hospital, we examined cases over 40 years of age with autopsy evidence of myocardial infarction to determine the prevalence and predictors of atherosclerotic renal artery stenosis in the atherosclerotic population. Two hundred ninety-seven patients remained for analysis. In this population, atherosclerotic renal artery stenosis was found in 35 patients (12%), and 10 of them had bilateral renal artery stenosis. In patients with hypertension, proteinuria, and renal insufficiency, renal artery stenosis was found in 19%, 39%, and 39%, respectively. As the number of coronary vessels with significant stenosis increased, the prevalence of renal artery stenosis increased. The severity of stenotic lesions of coronary artery was also correlated with the presence of renal artery stenosis. Multiple logistic regression analysis identified age, hypertension, proteinuria, and renal insufficiency as independent predictors of renal artery stenosis. Patients with hypertension, proteinuria, and renal insufficiency had 3.4-, 13.5-, and 4.8-fold increased risk of renal artery stenosis in the population with myocardial infarction. The number of coronary arteries with severe stenosis was also an independent predictor of renal artery stenosis, and had a relative risk of 2.1. These results indicated that atherosclerotic renal artery stenosis is common in patients with myocardial infarction, particularly when hypertension, proteinuria, or renal insufficiency is present. The presence of severe multivessel coronary artery disease suggests a higher incidence of renal artery stenosis.