Renal artery stenosis-when to screen, what to stent?

Renal artery stensosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed

The contrast-enhanced Doppler ultrasound with perfluorocarbon exposed sonicated albumin does not improve the diagnosis of renal artery stenosis compared with angiography

There are no studies investigating the effect of the contrast infusion on the sensitivity and specificity of the main Doppler criteria of renal artery stenosis (RAS). Our aim was to evaluate the accuracy of these Doppler criteria prior to and following the intravenous administration of perfluorocarbon exposed sonicated albumin (PESDA) in patients suspected of having RAS. Thirty consecutive hypertensive patients (13 males, mean age of 57 ± 10 years) suspected of having RAS by clinical clues, were submitted to ultrasonography (US) of renal arteries before and after enhancement using continuous infusion of PESDA. All patients underwent angiography, and haemodynamically significant RAS was considered when ≥50%. At angiography, it was detected RAS ≥50% in 18 patients, 5 with bilateral stenosis. After contrast, the examination time was slightly reduced by approximately 20%. In non-enhanced US the sensitivity was better when based on resistance index (82.9%) while the specificity was better when based on renal aortic ratio (89.2%). The predictive positive value was stable for all indexes (74.0%–88.0%) while negative predictive value was low (44%–51%). The specificity and positive predictive value based on renal aortic ratio increased after PESDA injection respectively, from 89 to 97.3% and from 88 to 95%. In hypertensives suspected to have RAS the sensitivity and specificity of Duplex US is dependent of the criterion evaluated. Enhancement with continuous infusion of PESDA improves only the specificity based on renal aortic ratio but do not modify the sensitivity of any index

"Apparent" heart failure: a syndrome caused by renal artery stenoses

OBJECTIVE—To report on renal artery stenosis presenting as congestive heart failure.
DESIGN—Case series.
SETTING—Tertiary referral centre.
PATIENTS—Nine hypertensive subjects (five male, four female) seen in the blood pressure unit, St George's Hospital, between 1991 and 1997 with clinical signs and symptoms of congestive cardiac failure but without overt coronary or valvar heart disease. Mean (SEM) age was 67 (3) years. Eight patients had renal artery revascularisation with percutaneous angioplasty and one had surgery.
RESULTS—Renal revascularisation was followed by a large fall in blood pressure from 191/94 (7/3) to 150/75 (8/5) mm Hg two days after intervention (p < 0.01). There was also a large natriuresis and weight reduction. One week after revascularisation there was a mean loss in weight of 3.8 (0.6) kg. The largest fall in weight was seen in those patients with stenosis in a single functioning kidney. Furthermore, plasma atrial natriuretic factor fell from 120 (28) to 48 (9) pg/ml (p < 0.05; n = 6; normal value = 8.6 (0.8) pg/ml), and serum creatinine fell from 200 (37) to 140 (11) µmol/l (p < 0.025). The clinical signs and symptoms of heart failure resolved and the diuretics were then withdrawn in all patients. On long term follow up, patients remained free from symptoms and signs of heart failure and the blood pressure was better controlled.
CONCLUSIONS—In hypertensive patients with symptoms and signs of congestive heart failure who do not have obvious ischaemic or valvar heart disease, renal artery stenosis should be considered as a possible underlying cause. Relief of the stenosis can result in resolution of the apparent heart failure.


Keywords: renal artery stenosis; heart failur

Intracerebral haematoma masquerading as ventricular standstill

An 82 year old man was referred to the emergency room by his general practitioner for a right frontoparietal headache. The preceding day he had tripped and fallen, hitting the back of his head on the floor. Computed tomography showed a cortical contre coup haematoma. In view of ventricular standstill noted on ECG, a temporary pacing wire was inserted and a dual chamber permanent pacemaker was subsequently implanted. Intracerebral bleeding was treated conservatively and the patient made a good recovery. All patients admitted with head injury and sinus bradycardia or sinus arrest should be nursed at 15° to 30° with instructions to avoid the head up and supine positions. Furthermore, brain CT should be promptly recorded to assess for intracerebral haematoma and raised intracranial pressure and, if they are confirmed, these patients with cardiovascular compromise should benefit from close collaboration between neurosurgeon and cardiologist. Urgent pacing should be considered for all patients with head injury who experience symptomatic bradycardia or ventricular standstill