Abstract
Atherosclerotic renal artery disease is a common disease entity that may be identified in patients with difficult-to-control hypertension and/or chronic kidney disease but is probably underdiagnosed. Current evidence from both observational and randomized studies offers mixed results regarding the support for renal artery revascularization. There is lack of equipoise with regard to the efficacy of renal artery revascularization among the interventional and renal communities, as well as disagreements on the appropriate endpoints to measure in clinical trials, which have led to selection bias confounding the scant available data. We report a patient who does not fit any clinical trial inclusion criteria with acute on chronic kidney injury and new-onset heart failure whose symptoms and renal function improved significantly after renal artery intervention.
1
Introduction
Atherosclerotic renal artery stenosis (ARAS) is a common disease with a prevalence ranging from 6.8% in an elderly population screened by renal Doppler ultrasonography to 53% in patients with coronary artery disease risk factors undergoing coronary angiography . The true prevalence is difficult to pinpoint but generally increases with age, atherosclerotic risk factors, and disease in another vascular bed . Patients with ARAS may be identified as having difficult-to-control hypertension and/or chronic kidney disease (CKD) without obvious etiology. Worsening of renal function or hyperkalemia following the initiation of angiotensin-converting enzyme inhibitor (ACE-I)/angiotensin receptor blocker (ARB) should prompt a differential diagnosis that involves ARAS. Acute presentations such as pulmonary edema or anuric renal failure are uncommon but may represent significant bilateral ARAS. Currently, the American College of Cardiology (ACC)/American Heart Association (AHA) recommends medical treatment for ARAS in the form of ACE-I/ARB, calcium channel blockers, and beta-blockers to control blood pressure. The ACC/AHA class I recommendation for the use of percutaneous revascularization for ARAS is limited to those patients with recurrent, unexplained congestive heart failure or unexplained pulmonary edema thought to be due to ARAS, particularly with bilateral or unilateral ARAS in the setting of a single functioning kidney. The evidence supporting this class 1b recommendation is limited to nonrandomized, observational data and expert opinion . Class II recommendations for percutaneous revascularization for ARAS exist for the indications of hypertension, preservation of renal function, and even asymptomatic patients, although the evidence for this is poor. The recently completed, randomized Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) study will add a significant amount to our knowledge base and may impact the guidelines on how to treat patients with stable ARAS . However, treatment of acute occlusion within a renal artery represents a separate entity. We report a patient with an acute presentation who underwent successful percutaneous revascularization resulting in both symptomatic improvement and return to baseline renal function.
2
Case presentation
A 79-year-old man with past medical history of coronary artery disease, repaired mitral valve regurgitation with annuloplasty ring, CKD stage IV (baseline creatinine of 1.6 mg/dl), hypertension, and stable abdominal aortic aneurysm was referred from an outside hospital for worsening heart failure symptoms, acute renal failure, and uncontrolled hypertension. He had been treated with daily aspirin, statin therapy, beta-blocker and ACE-I for more than 5 years. Two years prior to admission, a contrast-enhanced abdominal magnetic resonance angiogram demonstrated an atretic left kidney (7 cm) with occluded left renal artery and a normal-sized right kidney with a 70% lesion of the proximal right renal artery. He had a discussion with his physician regarding this finding and elected for medical management of his ARAS. His renal function had been stable until his current presentation.
Physical examination showed a blood pressure of 170/90 mmHg, heart rate of 70 bpm, estimated jugular venous pressure of 10 cm H 2 O with positive hepatojugular reflux, trace pedal edema of both ankles and egophony of both lower lungs. Cardiac examination demonstrated normal S1, S2 and presence of a third heart sound. Electrocardiogram showed normal sinus rhythm, left ventricular hypertrophy, and no evidence of myocardial infarction or ischemia. Initial laboratory results showed serum creatinine of 2.7 mg/dl, negative serial cardiac biomarkers, and elevated NT-proBNP of 30,000 pg/ml. He was started on intravenous diuretic, hydralazine, and nitrates. ACE-I was discontinued.
His renal function continued to deteriorate with serum creatinine levels rising to 5.4 mg/dl, and the patient became anuric. Renal ultrasound demonstrated an atretic left kidney and a 9.8-cm right kidney. Given his history of renal artery stenosis and rapid clinical deterioration heading toward dialysis, we elected to perform renal angiography despite his rising serum creatinine. This demonstrated a totally occluded left renal artery and a 99% thrombotic lesion of the proximal right renal artery with sluggish antegrade flow ( Fig. 1 ) suggestive of acute thrombotic occlusion. Angioplasty and stenting of the proximal right renal artery ( Fig. 2 ) were performed successfully with subsequent improvement in urine output and renal function. Serum creatinine levels decreased to 1.5 mg/dl within 4 days along with improvement of blood pressure and resolution of heart failure symptoms.
2
Case presentation
A 79-year-old man with past medical history of coronary artery disease, repaired mitral valve regurgitation with annuloplasty ring, CKD stage IV (baseline creatinine of 1.6 mg/dl), hypertension, and stable abdominal aortic aneurysm was referred from an outside hospital for worsening heart failure symptoms, acute renal failure, and uncontrolled hypertension. He had been treated with daily aspirin, statin therapy, beta-blocker and ACE-I for more than 5 years. Two years prior to admission, a contrast-enhanced abdominal magnetic resonance angiogram demonstrated an atretic left kidney (7 cm) with occluded left renal artery and a normal-sized right kidney with a 70% lesion of the proximal right renal artery. He had a discussion with his physician regarding this finding and elected for medical management of his ARAS. His renal function had been stable until his current presentation.
Physical examination showed a blood pressure of 170/90 mmHg, heart rate of 70 bpm, estimated jugular venous pressure of 10 cm H 2 O with positive hepatojugular reflux, trace pedal edema of both ankles and egophony of both lower lungs. Cardiac examination demonstrated normal S1, S2 and presence of a third heart sound. Electrocardiogram showed normal sinus rhythm, left ventricular hypertrophy, and no evidence of myocardial infarction or ischemia. Initial laboratory results showed serum creatinine of 2.7 mg/dl, negative serial cardiac biomarkers, and elevated NT-proBNP of 30,000 pg/ml. He was started on intravenous diuretic, hydralazine, and nitrates. ACE-I was discontinued.
His renal function continued to deteriorate with serum creatinine levels rising to 5.4 mg/dl, and the patient became anuric. Renal ultrasound demonstrated an atretic left kidney and a 9.8-cm right kidney. Given his history of renal artery stenosis and rapid clinical deterioration heading toward dialysis, we elected to perform renal angiography despite his rising serum creatinine. This demonstrated a totally occluded left renal artery and a 99% thrombotic lesion of the proximal right renal artery with sluggish antegrade flow ( Fig. 1 ) suggestive of acute thrombotic occlusion. Angioplasty and stenting of the proximal right renal artery ( Fig. 2 ) were performed successfully with subsequent improvement in urine output and renal function. Serum creatinine levels decreased to 1.5 mg/dl within 4 days along with improvement of blood pressure and resolution of heart failure symptoms.
