Although, atherosclerotic renovascular disease (ARVD) is an important cause of acute pulmonary oedema (APO) and congestive heart failure (CHF) it is unclear whether best treatment for ARVD with APO or CHF should be medical therapy only or medical therapy with revascularization.1 The randomized controlled trials do not help here as they exclude heart failure.2 Evidence in favour of revascularization comes from case reports3 and observational studies of patients with APO4–6 and CHF7,8 with impressive improvements reported in heart failure symptoms, blood pressure and renal function following revascularization. The question therefore is how to identify such patients and whether to intervene early or watch and wait. Against this background we report a patient with bilateral renal artery stenoses and APO who declined intervention at presentation, and did well for 4 years before representing with cardiorenal failure requiring dialysis. Intervention even at this late stage led to a significant recovery of renal function.
A 73-year-old woman presented in 2002 with pulmonary oedema due to acute coronary syndrome with Troponin I 17.5 ng/ml (normal 0–1). Serum creatinine was raised at 256 µmol/l (eGFR 17 ml/min). There had been no previous measurement of renal function. Both kidneys were 8 cm in bipolar diameter and CT renal angiogram showed 87% left and 82% right renal artery stenoses. Echocardiography showed left ventricular hypertrophy. We did not randomize her to the angioplasty and stent for renal artery lesions (ASTRAL) Trial because we were convinced she would benefit from stenting, while she declined both coronary angiography and renal revascularization as she was certain that neither were necessary. She subsequently did well for 4 years with blood pressure around 154/69 mmHg, creatinine between 160–180 µmol/l and no further episodes of pulmonary oedema (Figure 1). Drug therapy during this time included atenolol, felodipine and frusemide. She presented in December 2007 with pulmonary oedema and oligoanuric renal failure. Blood pressure was 120/70 mmHg. Repeat echocardiography showed a mildly dilated ventricle with moderately reduced LV systolic function. Two weeks of dialysis dependence ensued before she was fit for further renal angiography which confirmed bilateral, tight, ostial stenoses which were stented. She began to diurese within 24 h and has remained off dialysis since. During 42 months further follow-up she developed atrial fibrillation with symptoms of mild congestive failure which were well controlled with digoxin and frusemide. Her most recent blood pressure was 140/72 mmHg. Serum creatinine is stable at 149 µmol/l (eGFR 30 ml/min).
ARVD is associated with increased morbidity and mortality. The challenge is to identify those who will benefit from revascularization. For discussion we consider three categories of patients:
ARVD without acute pulmonary oedema or congestive heart failure
Observational studies suggest benefit from revascularization while randomised controlled trial (RCTs) do not. Following ASTRAL, the largest RCT thus far, revascularization is best considered a drug sparing procedure for patients with unilateral and bilateral disease without APO or CHF, with no clear evidence of an improvement in renal function, even in those with bilateral renal artery (or single functioning kidney) stenosis >70%.2
ARVD with APO
Pickering et al.4 reported improvement in APO in a series of 11 patients who were hypertensive and uraemic with multiple episodes of APO. Nine patients had bilateral disease. Ten had no further APO after revascularization.4 Messina et al.5 described 17 patients with ARVD, including 16 with bilateral disease, hypertension and renal impairment and 11 with recurrent APO. Only one developed APO after revascularization, during 2.4 years of follow-up.5 Weatherford revascularized five patients with bilateral disease, hypertension, uraemia and APO, all with >70% stenosis with no recurrence of APO during 57 months follow-up.6 These studies suggest bilateral ARVD may be a specific and treatable predisposing factor for pulmonary oedema in uraemic, hypertensive patients.
ARVD with congestive heart failure
Kane et al.7 reported a series of 163 patients with ARVD, hypertension and chronic kidney disease (CKD). Fifty of these patients had CHF and underwent angioplasty with stenting. Outcomes were compared with 50 age-matched controls with ARVD and CHF who were not revascularized. Angioplasty with stenting was associated with a significant decrease in breathlessness and a 5-fold reduction in hospitalization for CHF but no improvement in survival.7 Prior to this, Missouris revascularized nine patients with bilateral ARVD and CHF. All had ≥70% stenosis. All nine patients remained free from CHF during an average follow-up of 8 months.8
Evidence thus far supports limiting revascularization for ARVD to specific circumstances in selected patients. There no longer seems to be any good reason to intervene for hypertension or chronic renal impairment alone.1 It is likely that some patients with ARVD and APO or CHF will benefit and unlikely that this hypothesis will ever be tested in an RCT. What our case report adds is that a policy of watchful waiting may be acceptable. By accident rather than design our patient remained well on medical therapy for a considerable period after presenting with bilateral disease and APO, but still benefited from revascularization when she represented with APO 4 years later. Kane et al.'s7 case control study supports this approach in that patients undergoing revascularization had no survival advantage.
Renal revascularization is an invasive intervention with a significant serious complication rate (10% in the ASTRAL Trial2). The focus on hypertension and renal impairment in RCTs has shown that stenting does not confer additional benefit when recommended for these reasons. We believe the focus should shift towards ARVD with APO and CHF, bearing in mind that not all patients develop progressive disease.9 Unnecessary stenting of lesions that are not going to cause further problems exposes a patient to unnecessary risks. Pending the results of the Cardiovascular Outcomes with Renal Atherosclerotic Lesions (CORAL) Study,10 we suggest revascularization for ARVD and either APO or CHF be limited to those whose symptoms and signs do not respond to or recur despite optimal medical therapy.
We thank Mrs Josephine Campbell for her help in the preparation of this manuscript and the Glasgow Interventional Radiologists for successfully revascularising this patient's kidneys.
Conflict of interest: None declared.