Clinical predictors of blood pressure response after renal artery stenting.

OBJECTIVE: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial, a multicenter randomized controlled trial, failed to demonstrate a benefit of renal artery stenting (RAS) over medical therapy in patients with renal artery stenosis and hypertension. However, there are patients for whom RAS is a consideration because of failure of medical therapy. Unfortunately, selection of patients for RAS is complicated by a lack of validated predictors of blood pressure (BP) response. A previous single-center study identified three preoperative markers of BP response to RAS: requirement for four or more antihypertensive medications, preoperative diastolic BP >90 mm Hg, and preoperative clonidine use. To date, these markers of outcome have not been independently validated. The aim of this study was to validate these markers using data from the CORAL trial. METHODS: All patients randomized in the CORAL trial to RAS were included. American Heart Association guidelines were used to categorize patients as BP responders or nonresponders to RAS. BP responders were defined by a postoperative BP <160/90 mm Hg with a reduced number of antihypertensive medications or a reduction in diastolic BP to <90 mm Hg with the same medications after RAS. Patients with stable or worsened BP were labeled nonresponders. Variables associated with a favorable BP response were identified by multivariable logistic regression analysis. RESULTS: There were 436 patients who underwent RAS with a median age of 70 years (interquartile range [IQR], 63-76 years). The median systolic and diastolic BPs of the stented cohort at baseline were 149 mm Hg (IQR, 132-164 mm Hg) and 78 mm Hg (IQR, 70-87 mm Hg), respectively. A positive BP response occurred in 284 of 436 (65.1%) stented patients. Multivariable logistic regression analysis identified three independent markers of a positive BP response: requirement for four or more medications (odds ratio, 5.9; P < .001), preoperative diastolic BP >90 mm Hg (odds ratio 13.9; P < .001), and preoperative clonidine use (odds ratio, 4.52; P = .008). The percentage of patients with a positive BP response increased incrementally as the number of markers per patient increased, based on the Cochran-Armitage test for trend (P < .0001). CONCLUSIONS: In patients from the CORAL trial who underwent RAS, the previously reported clinical markers of BP response were validated. A prospective trial to validate their utility as predictors of BP response to RAS is warranted.

Calcium channel blockers are associated with improved survival and lower cardiovascular mortality in patients with renovascular disease.

BACKGROUND AND OBJECTIVE: Results of interventional trials in renovascular hypertension have been disappointing, and medical therapy is the current recommended gold standard. However, the comparative long-term benefits of different antihypertensive drug classes in atherosclerotic renal artery stenosis are not known. We aim to assess the effect of different antihypertensive drug classes on outcomes in renovascular hypertension DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Using Tayside Health Informatics Centre database, anonymized data over a 6-year period was analyzed. Biochemistry, prescribing data, morbidity, mortality, and demographic data were accessed via hospital medical records and electronic data stored in the Tayside Health Informatics Centre Safe Haven. General Registrar's Office data were used to identify patients who died from cardiovascular disease. Independent predictors of survival in each group were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models, adjusted for a range of covariates, using time-updated drug analysis. Blood pressure data were obtained from primary and secondary care clinic blood pressure records for each patient. Adjustments for mean systolic blood pressure over the follow-up period and baseline blood pressure were made. RESULTS: A total of 579 patients with atherosclerotic renal artery stenosis were identified. In the unilateral renal artery stenosis cohort, calcium channel blockers but not ACE inhibitors/ARBs were associated with a significant reduction in all-cause (HR = 0.45, CI = 0.31, 0.65; P = <0.0001) and cardiovascular (HR = 0.51, CI = 0.29-0.90 P = 0.019) mortality. This was maintained after adjustment for blood pressure. In the bilateral renal artery stenosis cohort, both classes of drugs reduced all-cause but not cardiovascular mortality. Patients with moderate disease benefitted more than those with mild or severe disease. CONCLUSIONS: Calcium channel blockers are associated with significantly increased survival and lower cardiovascular mortality particularly in patients with moderate RAS disease.

A randomized, multi-center, prospective study comparing best medical treatment versus best medical treatment plus renal artery stenting in patients with hemodynamically relevant atherosclerotic renal artery stenosis (RADAR) - one-year results of a pre-maturely terminated study.

BACKGROUND: The indications for conservative "best medical treatment" (BMT) versus additional renal artery stenting are a matter of ongoing debate. The RADAR study aimed to evaluate the impact of percutaneous renal artery stenting on the impaired renal function in patients with hemodynamically significant atherosclerotic renal artery stenosis (RAS). METHODS: RADAR is an international, prospective, randomized (1:1) controlled study comparing BMT alone versus BMT plus renal artery stenting in patients with duplex sonographic hemodynamically relevant RAS. Follow-up assessments were at 2, 6, and 12 months and at 3 years. The primary endpoint was change in estimated glomerular filtration rate (eGFR) at 12 months. RESULTS: Due to slow enrollment, RADAR was terminated early after inclusion of 86 of the scheduled 300 patients (28.7%). Change in eGFR between baseline and 12 months was 4.3 ± 15.4 ml/min/1.73 m2 (stent group) and 3.0 ± 14.9 ml/min/1.73 m2 (BMT group), p > 0.999. Clinical event rates were low with a 12-month composite of cardiac death, stroke, myocardial infarction, and hospitalization for congestive heart failure of 2.9% in the stent and 5.3% in the BMT group, p = 0.526, and a 3-year composite of 14.8% and 12.0%, p = 0.982. At 3 years, target vessel (re-)vascularization occurred in one patient (3.0%) in the stent group and in 8 patients (29.4%) in the BMT group. CONCLUSION: In RADAR, outcomes of renal artery stenting were similar to BMT. These results have to be interpreted with the caveat that the study did not reach its statistically based sample size. TRIAL REGISTRATION: Clinicaltrials.gov, NCT00640406. Registered on 17 March 2008.

Clinical characteristics and treatment of renal artery fibromuscular dysplasia with percutaneous transluminal angioplasty: a long-term follow-up study.

BACKGROUND: Renal artery fibromuscular dysplasia (RAFMD) is a non-atherosclerotic cause of renal artery stenosis often affecting the young. Percutaneous transluminal renal angioplasty (PTRA) is the treatment of choice but there are few studies of the outcome of the procedure. METHODS: This retrospective analysis included 64 patients (56.2 % female; mean age at diagnosis, 28.0 years) with RAFMD who underwent PTRA between November 2003 and August 2015. Technical and clinical success rates and restenosis rates were evaluated. RESULTS: Seventy-six procedures were performed on 64 RAFMD patients. Technical success was 96.9 %, as defined by <30 % residual stenosis, with stent placement required in 11 patients (17.2 %). In the short term (1 month), the majority (79.7 %) had an immediate clinical benefit, with cure of hypertension in 35.9 %, and improvement in hypertension and a lower requirement for antihypertensive medications in 43.8 %. In the long term (mean, 47.5 months; range, 5-141 months), the survival rate was 96.9 %, freedom from restenosis was 84.4 %, and 76.6 % of patients showed a sustained clinical benefit (cure rate 40.6 %, improvement rate 35.9 %). Eight patients were treated with a second procedure and two had a third procedure, with half of these patients showing an improvement in hypertension. CONCLUSION: PTRA for symptomatic RAFMD is safe and clinically successful. More than half of patients experience an immediate clinical benefit with sustained long-term effects. For patients with restenosis, there was a good response to a second PTRA.

Update on intervention versus medical therapy for atherosclerotic renal artery stenosis.

Atherosclerotic renal artery stenosis is known to be one of the most common causes of secondary hypertension, and early nonrandomized studies suggested that renal artery stenting (RASt) improved outcomes. The vascular community embraced this less invasive treatment alternative to surgery, and RASt increased in popularity during the late 1990s. However, recent randomized studies have failed to show a benefit regarding blood pressure or renal function when RASt was compared with best medical therapy, creating significant concerns about procedural efficacy. In the wake of these randomized trial results, hypertension and renal disease experts along with vascular interventional specialists now struggle with how to best manage atherosclerotic renal artery stenosis. This review objectively analyzes the current literature and highlights each trial's design weaknesses and strengths. We have provided our recommendations for contemporary treatment guidelines based on our interpretation of the available empirical data.

Extrarenal atherosclerotic disease blunts renal recovery in patients with renovascular hypertension.

BACKGROUND: Atherosclerotic renovascular disease (ARVD) is associated with high rates of coronary events and predicts mortality among patients with coronary artery disease (CAD). However, the impact of coronary atherosclerosis on renal outcomes after revascularization of ARVD is unclear. We hypothesized that CAD negatively impacts renal functional outcomes among patients with ARVD undergoing renal artery revascularization. METHODS: Patients with ARVD who underwent echocardiography at Mayo Clinic, Rochester, Minnesota, USA between 2004 and 2012 were identified retrospectively and included if they had ejection fraction more than 50%. Renal and overall outcomes were compared among atherosclerotic renovascular disease patients with coronary artery disease (ARVD-C, n = 75) and without coronary artery disease (ARVD, n = 56), within 1 year from initial revascularization and included blood pressure control, renal function, and incident cardiovascular/cerebrovascular events. RESULTS: Degree of renal artery stenosis was similar in both groups. ARVD-C had higher prevalence of diabetes, peripheral artery disease (PAD), and cerebrovascular disease, and lower baseline renal function. Risk of developing end-stage renal disease was higher in ARVD-C (11 vs. 2%, P = 0.05). Despite better control of blood pressure and cholesterol levels, renal function postrevascularization worsened in 15% of ARVD-C compared with 2% of ARVD (P = 0.01). Differences in clinical outcomes remained statistically significant after adjustment for covariables, including sex, baseline blood pressure, renal function, underlying diabetes, cholesterol levels, and medications. Similar differences in clinical outcomes were also associated with PAD and cerebrovascular disease. CONCLUSION: CAD in patients with ARVD is a predictor of worse outcomes after renal revascularization, likely reflecting diffuse atherosclerotic disease. Further studies are needed to develop strategies to manage patients with vascular comorbidities and improve their outcomes.

Cardiac function in renovascular hypertensive patients with and without renal dysfunction.

BACKGROUND: Hypertension impairs left ventricular (LV) diastolic and systolic function, which might be aggravated by inflammation or neurohumoral activation. We hypothesized that LV diastolic dysfunction is more common in patients with renovascular hypertension (RVHT) compared with essential hypertension (EHT). METHODS: Hypertensive patients who underwent both renal imaging to exclude RVHT and cardiac echocardiography within a 3-year period were identified retrospectively. Patients with significant renovascular disease were included in the RVHT group (n = 75); those without significant renovascular disease were included in the EHT group (n = 69). Cardiac function and structure were compared. RESULTS: Baseline renal function was preserved (serum creatinine ≤ 2mg/dl) in EHT patients and impaired (serum creatinine > 2mg/dl) in only 9 RVHT patients. RVHT patients had higher systolic blood pressure, E/e' ratio, and greater prevalence of concentric hypertrophy but lower estimated glomerular-filtration-rate (eGFR) compared with EHT patients. Increased prevalence of LV diastolic dysfunction remained statistically significant in patients with RVHT after multivariable adjustment for age, sex, blood pressure, eGFR, diabetes, smoking, and statin use, with a relative risk (95% CI) for abnormal E/e' of 1.70 (95% confidence interval = 1.05-2.90; P = 0.03) compared with EHT. RVHT patients with severe renal dysfunction showed greater impairments in cardiac systolic and diastolic function compared with those in EHT patients or preserved renal function RVHT patients. CONCLUSIONS: Among hypertensive patients undergoing echocardiography, cardiac structure and diastolic function are impaired in RVHT patients compared with EHT patients and remain different after adjustment for multiple significant covariables. When associated with significant renal dysfunction, RVHT aggravates LV hypertrophy and both systolic and diastolic dysfunction. Hence, identification of RVHT and renal dysfunction warrants development of targeted management strategies.

Assessing outcomes to determine whether symptoms related to hypertension justify renal artery stenting.

OBJECTIVE: The goal of the study was to determine the blood pressure (BP) response to renal artery stenting (RAS) for patients with hypertension urgency, hypertension emergency, and angina with congestive heart failure (angina/congestive heart failure [CHF]). METHODS: Patients who underwent RAS for hypertension emergencies (n = 13), hypertension urgencies (n = 25), and angina/CHF (n = 14) were included in the analysis. By convention, hypertension urgency was defined by a sustained systolic BP ≥ 180 mm Hg or diastolic BP ≥ 120 mm Hg, while the definition of hypertension emergency required the same BP parameters plus hypertension-related symptoms prompting hospitalization. Patient-specific response to RAS was defined according to modified American Heart Association reporting guidelines. RESULTS: The study cohort of 52 patients had a median age of 66 years (interquartile range 58-72). The BP response to RAS varied significantly according to the indication for RAS. Hypertension emergency provided the highest BP response rate (85%), while the response rate was significantly lower for hypertension urgency (52%) and angina/CHF (7%; P = .03). Only 1 of 14 patients with angina/CHF was a BP responder. Multivariate analysis showed that hypertension urgency or emergency were not independent predictors of BP response to RAS. Instead, the only independent predictor of a favorable BP response was the number of preoperative antihypertensive medications (odds ratio 7.5; 95% confidence interval 2.5-22.9; P = .0004), which is another indicator of the severity of hypertension. Angina/CHF was an independent predictor of failure to respond to RAS (odds ratio 118.6; 95% confidence interval 2.8-999.9; P = .013). CONCLUSIONS: Hypertension urgency and emergency are clinical manifestations of severe hypertension, but the number of preoperative antihypertensive medications proved to be a better predictor of a favorable BP response to RAS. In contrast, angina/CHF was a predictor of failure to respond to stenting, providing further evidence against the practice of incidental stenting during coronary interventions.

Short- and long-term outcomes of percutaneous transluminal angioplasty/stenting of renal fibromuscular dysplasia over a ten-year period.

OBJECTIVES: The purpose of this study was to evaluate short and long-term outcomes of percutaneous transluminal intervention in patients with symptomatic renal artery stenosis due to fibromuscular dysplasia (RAFMD) and/or the combination of RAFMD with aorto-ostial atherosclerotic disease. METHODS: A retrospective analysis of all patients with renal artery RAFMD who underwent transcatheter therapy between January 1999 and December 2009 was performed. Blood pressure (BP) measurement, number of BP medications, and hypertension defined by a systolic BP >140 ± diastolic BP >90 were recorded. Renal function was defined by estimated glomerular filtration rate (eGFR). Restenosis was defined by stenosis >60% and was determined by renal artery duplex and/or angiography. Freedom from event (restenosis, renal failure, or recurrent hypertension) was performed using life table analysis. RESULTS: Forty-three procedures were performed on 35 patients with RAFMD. Thirty-two patients (91%) were women, with mean age of 61.9 years old. Technical success was 100% with adjunctive stent placement required in the FMD segment for dissection in 1 patient (2.3%) and in the non-FMD aorto-ostial atherosclerotic lesion in 4 patients (9.3%). Short-term outcomes: the majority (69%) had an immediate clinical benefit for hypertension, 6% were cured without BP medications, and 63% improved with less than or equal to preoperative BP medications. Postintervention, 17% remained at moderately reduced renal function (<60), whereas the percent above >60 mL/minute eGFR increased significantly (from 51% to 69%; P = .002). For the entire cohort, renal function (mean eGFR) significantly increased from 71.9 mL/minute + 5.8 to 80.8 mL/minute + 5.2 (P = .007). Long-term outcomes: freedom from recurrent or worsening hypertension (>140 systolic blood pressure [SBP] and >90 diastolic blood pressure [DBP]) was (93%, 75%, and 41%) and freedom from reduced renal function (eGFR <30 mL/minute) was (100%, 95%, and 64%) at 1, 5, and 8 years, respectively. Patients with reduced baseline renal function (<60 mL/minute) and combined atherosclerotic disease were more likely to experience long-term reduced renal function (eGFR <30 mL/minute; P = .003). Primary and assisted primary patency was (95%, 71%, and 50%) and (100%, 100%, and 100%) at 1, 5, and 9 years, respectively. CONCLUSION: Renal angioplasty is a safe and durable modality for treating RAFMD with favorable short and long-term clinical outcomes. Patients with combined atherosclerotic disease and FMD were older and were more likely to have declining renal function over time. Early intervention may be imperative to achieve possible cure of hypertension.

Predicting blood pressure response after renal artery stenting.

BACKGROUND: Although technical success of renal artery stenting (RAS) is high and adverse events are infrequent, clinical success (improved blood pressure and renal function) and durability have been less predictable. Identifying those patients who will respond to RAS could improve overall outcomes of the procedure. METHODS: This was a retrospective analysis of all patients who underwent RAS for treatment of renovascular hypertension (RVH) between 2001 and 2007 at Dartmouth-Hitchcock Medical Center. The primary outcome measure was blood pressure improvement or cure as judged by American Heart Association criteria. Estimated glomerular filtration rate (eGFR), number of antihypertensive medications, and survival were evaluated as secondary outcomes. Univariate and multivariate analyses were performed to identify factors associated with blood pressure improvement at the last follow-up. RESULTS: During the 6-year period, 129 patients (179 renal arteries) underwent stent placement for RVH. Procedural complications occurred nine patients (7.0%). Average length follow-up was 1.5 years. Follow-up data were obtained in 122 patients (95%). At last follow-up, there were significant improvements in systolic blood pressure (161 vs 144 mm Hg, P < .001), diastolic blood pressure (80 vs 73 mm Hg, P < .001), and number of antihypertensive medications (3.1 vs 2.8, P = .034). The eGFR was improved in 16% of patients, stable in 60%, and worse in 24%. By multivariate analysis, a baseline eGFR <40 mL/min/1.73 m2 (odds ratio, 1.6; 95% confidence interval [CI], 1.0-2.9; P = .02) and female gender (OR, 1.3; 95% CI, 1.0-2.1; P = .04) were independent predictors of failure to achieve blood pressure improvement. By 2 and 4 years of follow-up, sustained blood pressure improvement was present in 67% of patients with a baseline eGFR of > or = 40 mL/min/1.73 m2 and in 31% of patients with a baseline eGFR <40 mL/min/1.73 m2. During 2 years of follow-up, survival was similar between patients with sustained blood pressure response and those without. CONCLUSION: Patients treated for RVH who have a baseline eGFR of > or = 40 mL/min/1.73 m2 demonstrate a better response to RAS at each follow-up interval, with a significant difference at 2 to 4 years, compared with patients with an eGFR <40 mL/min/1.73 m2.

Comparison of early and late efficacy of percutaneous transluminal renal angioplasty with or without subsequent brachytherapy: the effect on blood pressure in patients with renovascular hypertension.

BACKGROUND: Scarce data exist concerning the long-term effect of percutaneous transluminal renal angioplasty (PTRA) enhanced with intravascular gamma brachytherapy (IVBT) in patients with renovascular hypertension. METHODS: Seventy one patients aged 52 +/- 8 years with refractory renovascular hypertension were randomized to Group I (PTRA + IVBT) or Group II (PTRA). For the IVBT procedure, the PARIS catheter and Microselectron HDR (Nucletron) system was employed. Both baseline and 9-month follow-up quantitative computerized angiography (QCA) and ambulatory blood pressure monitoring analysis was performed to assess luminal parameters of restenosis and the effect of treatment on blood pressure. RESULTS: Thirty three patients from Group I and 29 patients from Group II underwent successful procedure. During nine months of follow-up, three patients died; including two patients in Group I (cardiac causes) and one patient in Group II (stroke). The follow-up lumen diameter stenosis was 30.6 +/- 13.7% and 40.4 +/- 11% in Groups I and II, respectively (p = 0.004). Late lumen loss in quantitative computerized angiography was 1.2 +/- 0.7 mm and 1.7 +/- 0.7 mm in Groups I and II, respectively (p = 0.004). CONCLUSIONS: Intravascular gamma brachytherapy using self-centering source performed after balloon angioplasty is a safe and effective method of prevention of restenosis after PTRA in patients with renovascular hypertension.

Renal artery revascularization: outcomes stratified by indication for intervention.

OBJECTIVES: Application of endovascular therapy has led to increasing rates of renal artery intervention with unclear effect on hypertension (HTN) and/or renal salvage (RS). We evaluated the role of procedure indication on outcomes of both open (OR) and percutaneous (PR) revascularization. METHODS: Retrospective review of all consecutive renal artery interventions performed from January 1, 2002 to December 31, 2006 was conducted. OR patients were included for analysis only if independent renovascular indications for revascularization existed. RESULTS: Forty-seven OR and 203 PR (97% stent) patients were treated with 98% initial technical success. Patients with OR were younger (65 +/- 11 vs 72 +/- 9; P < .01), on more blood pressure (BP) medications (2.3 +/- 1.2 vs 1.8 +/- 1.2; P < .05), had more peripheral arterial disease (75% vs 37%; P < .01), and higher baseline creatinine (2.2 +/- 1.6 mg% vs 1.8 +/- 1 mg%; P < .05). Indications for PR were HTN in 46% and RS in 54%, and indications for OR were HTN in 51% and RS in 49% of cases. PR was unilateral in 169 (83%) and bilateral in 44/203 (17%). OR consisted of bypass in 26 (53%) and endarterectomy in 21/47 (47%) with 20 (43%) bilateral procedures. Peri-procedural complications were different (P < .01) and more frequent in OR (23% vs 12%). Survival was similar at three years (72% +/- 4% PR vs 71% +/- 9% OR; P = .9). Assisted patency was similar (P = .6) at one (94% +/- 2% PR vs 97% +/- 3% OR) and three years (90% +/- 3% PR vs 91% +/- 5% OR). One year (97% +/- 1% PR vs 97% +/- 3% OR) and three year (93% +/- 3% PR vs 91% +/- 7% OR) freedom from reintervention was similar (P = .8). Clinical outcomes showed patients with OR and PR having similar rates of cure or improvement in BP (76% PR vs 90% OR; P = .1) and favored OR with stable or improved renal function (97% vs 89%; P < .01) by the first postoperative visit. Hypertension control remained similar (P = .2) in both groups with cure/improvement in BP in 74% of PR and 89% of OR patients at one year. OR remained durable in regards to renal salvage with 52% of OR patients having improved renal function compared with 24% of PR (P < .01) patients at one year. At one year, BP control was achieved if treatment indication was HTN in 100% (18/18) of OR patients and 74% (46/63) (P = .04) of those having PR. Renal function stabilized or improved in 16/19 (85%) of OR and 70/81 (86%) of PR patients when performed for RS (P = .4). CONCLUSIONS: PR and OR are similarly efficacious for treatment of HTN associated with renal artery stenosis. While immediate and long-term outcomes favor OR for RS, this may impart from the triage of patients more likely to benefit from renal artery revascularization to OR.

Predictors of long-term beneficial effects on blood pressure after percutaneous transluminal renal angioplasty in atherosclerotic renal artery stenosis.

AIM: This retrospective study evaluated long-term effects of percutaneous transluminal renal angioplasty (PTRA) in atherosclerotic renal artery stenosis (ARAS), and predictors of benefit on blood pressure (BP). METHODS: During 1997-2003, 234 patients (age 69+/-11 years, 138 [59%] males) underwent PTRA for ARAS at Malmö Vascular Centre. Cure was defined as diastolic (D)BP<90 mmHg and systolic (S)BP <140 mmHg off antihypertensive medication. Improvement was defined as DBP <90 mmHg and/or SBP <140 mmHg on the same or reduced number of medications, or reduction in DBP of >or=15 mmHg with the same or reduced number of medications. Benefit was defined as cure or improvement. RESULTS: After PTRA, SBP and DBP decreased (P<0.001), and remained lower (P<0.001) until last follow-up after 4.1+/-3.3 years. Antihypertensive medication decreased (P<0.001), and remained lower at one month (P<0.001), one year (P<0.01), and last follow-up (P<0.05). Renal function was unchanged until last follow-up, when it deteriorated (P<0.001). Patients showing benefit of PTRA on BP at last follow-up (N.=150 [64%]) used more antihypertensive drugs before PTRA (P=0.012), especially angiotensin converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs) (P=0.010), and diuretics (P=0.015). In logistic regression, use of ACEi or ARBs failed to reach significancy (P=0.054). Patients dying during follow up (N.=100 [43%]) showed higher age (P<0.0001) and s-creatinine (P<0.0001), lower glomerular filtration rate (P<0.0001), and higher frequency of diabetes mellitus (P<0.005). In logistic regression only age (P=0.009) and diabetes mellitus (P=0.014) predicted mortality. CONCLUSIONS: We confirmed beneficial effects on BP with PTRA in ARAS. ACEi, ARB and diuretic treatment before PTRA predict favourable long-term BP-response in univariate analysis.

Prospective randomized trial of operative vs interventional treatment for renal artery ostial occlusive disease (RAOOD).

INTRODUCTION AND OBJECTIVES: Patients with either renovascular hypertension (RVH) and/or renal insufficiency (RI) due to renal artery ostial occlusive disease (RAOOD) can successfully undergo an open surgical reconstruction procedure (OSRP), but since the publication of Blum et al(1) percutaneous balloon stent angioplasty (PTRA + stent) leaving a small part of the stent within the aorta has become very popular. However, balloon dilatation and stenting does not remove the atherosclerotic plaque, which is often heavily calcified but leads to disruption of the plaque causing myointimal hyperplasia and recurrent stenosis. Therefore, a comparison of the two treatment modalities concerning complications and durability in a prospective randomized design was felt to bring more insight to the discussion. METHODS: From 1998 to 2004, we performed OSRP in 330 patients with RVH and/or RI for various locations of RAOOD. During this time period, 50 patients (female 18, male 32, mean age 64.4 years) with RAOOD of at least 70% stenosis (DSA and duplex criteria) in one or both renal arteries, who did not require other aorto/mesenteric/iliac reconstructive procedures agreed and were randomized to either OSRP (n = 25 patients, 49 arteries) or PTRA + stent (n = 25 patients, 28 arteries). Two patients crossed over to surgical treatment. Patients were followed on a regular basis for 4 years and longer. Endpoints were re-occurrence of RAOOD and impairment of either kidney function or RVH. RESULTS: We approached 77 arteries. There was no early mortality in either group, but directly procedure-related morbidity was 13% in the interventional group and 4% in the surgical group. Four-year follow-up mortality was 18% in the interventional group and 25% in the surgical group. Both groups showed significant improvement of RVH (P < .001 in each group) as well as improvement or stabilization in patients with insufficient renal function. Freedom from recurrent RAOOD (>70%) was achieved in 90.1% of the surgical group and 79.9% of the interventional group. CONCLUSION: Both treatment modalities showed good early results concerning RVH, kidney function, and renal perfusion. Despite a higher number of bilateral renal artery reconstructions in patients undergoing OSRP, which was probably due to the preferred technique of transaortic endarterectomy eliminating the plaque originating in the aorta and usually extending into both renal arteries, mortality was not higher and procedure-related morbidity was even lower compared to PTRA + stent. These findings and also longer durability of OSRP imply that surgical reconstruction remains the gold standard for patients with RAOOD before PTRA + stent may be considered.

Outcome after endovascular revascularization of atherosclerotic renal artery stenosis.

BACKGROUND: With an aging population, more patients might be treated for atherosclerotic renal artery stenosis (ARAS). The goal of this treatment is to achieve a dialysis-free life or a well-controlled blood pressure with reduced risks of cardiovascular complications. PURPOSE: To analyze the clinical outcome of percutaneous transluminal renal artery angioplasty without stenting (PTRA) or with stenting (PTRS) for ARAS at one center. MATERIAL AND METHODS: The study group comprised 152 patients who underwent 203 PTRA/PTRS. All had hypertension, and 45% had azotemia. A retrospective collection of baseline and postprocedural number of antihypertensive drugs, blood pressure, and serum creatinine were analyzed during a follow-up of 3-18 months. RESULTS: Technical success rate was 95%, and clinical benefit was seen in 63% of patients. Complications included a 30-day mortality rate of 1.5%, a total complication rate of 35%, and major adverse events in 13%. The major adverse events were highly related to azotemia. Major adverse events within 30 days, with permanent disability, were seen in 5% and almost exclusively in patients with moderate or severe renal impairment. A subgroup analysis of 28 patients with renal duplex resistive index (RI) pre-PTRA/S and 6 months' follow-up showed a benefit of PTRA/PTRS in 17 (68%) of the 25 patients with RI <80 and in all three (100%) of the patients with RI >or=80. CONCLUSION: Endovascular treatment of ARAS has an excellent technical success rate, with a clinical improvement rate of >60%. However, it is associated with a considerable complication rate. Serious complications are seen mainly in azotemic patients. Predictors of clinical response could not be identified. Renal duplex RI is questioned as a predictor of clinical outcome.

Clinical utility of the resistive index in atherosclerotic renovascular disease.

OBJECTIVE: This retrospective study examines the relationship between the renal resistive index (RI) and blood pressure and renal function response after open and percutaneous intervention for atherosclerotic renovascular disease (AS-RVD). METHODS: From March 1997 to December 2005, 86 patients (46 women, 40 men; mean age, 68 +/- 10 years) underwent renal duplex sonography (RDS), including main renal artery and hilar vessel Doppler interrogation, before treatment of AS-RVD. Of these, 56 patients had open operative repair, and 30 had percutaneous intervention. The RI (1-[EDV/PSV]) was calculated from the kidney with the highest peak systolic velocity (PSV). Hypertension response was graded from preprocedural and postprocedural blood pressure measurements and medication requirements. Renal function response was graded by a >or=20% change in estimated glomerular filtration rate (eGFR) calculated from the serum creatinine concentration. RESULTS: Comorbid conditions, baseline blood pressure, and preoperative renal function were not significantly different between open and percutaneous groups. Baseline characteristics that differed between the percutaneous vs open group were higher mean age (71 +/- 11 years vs 67 +/- 9 years; P = .05), kidney length (11.3 +/- 1.3 cm vs 10.7 +/- 1.2 cm; P = .02), proportion of patients with RI >or=0.8 (50% vs 21%; P = .01), and proportion of bilateral AS-RVD (37% vs 80%; P < .01). After controlling for preintervention blood pressure and extent of repair, postoperative eGFR differed significantly for RI <0.8 or >or=0.8 when all patients (P = .003) and percutaneous intervention (P = .008) were considered. Specifically, eGFR declined from preprocedure to postprocedure in the patients with RI >or=0.8 after percutaneous repair and in the group analyzed as a whole. Neither systolic nor diastolic pressure after intervention demonstrated an association with RI. Considering all patients and both groups, multivariable proportional hazards regression models demonstrated that RI was predictive of all-cause mortality. RI was the most powerful predictor of death during follow-up (hazard ratio, 6.7; 95% confidence interval, 2.6-17.2; P < .001). CONCLUSION: After intervention for AS-RVD, RI was associated with renal function, but not blood pressure response. A strong, independent relationship between RI and mortality was observed for all patients and both treatment groups.

Percutaneous and open renal revascularizations have equivalent long-term functional outcomes.

Atherosclerotic renal artery stenosis is a significant cause of poorly controlled hypertension and progressive renal dysfunction leading to ischemic nephropathy and other end-organ damage. The optimal treatment of renovascular disease contributing to hypertension and renal dysfunction is not known. This study compares the anatomic and functional outcomes of both open and endovascular therapy for chronic, symptomatic atherosclerotic renal artery disease. We performed a retrospective analysis of records from patients who underwent renal arterial interventions, endovascular or open bypass, between January 1984 and January 2004. Principal indications for intervention were hypertension (51%), chronic renal insufficiency (13%), and hypertension and elevated creatinine (36%). A total of 247 patients (109 males; mean age 69 +/- 10, range 44-89 years) underwent 314 interventions (109 open procedures; 205 angioplasties, 71% with stent placement). There was a significant difference in 30-day mortality (4% vs. <1%; p < 0.005) between the open and endoluminal groups, but not at 1, 3, or 5 years. Patients in the open group had a higher primary patency rate at 5 years (83 +/- 5% vs. 76 +/- 6%; p = 0.03), but patients in the endoluminal group had a higher assisted primary patency rate at 5 years (92 +/- 5% vs. 84 +/- 5; p = 0.03). There was no significant difference between both treatment groups in cumulative freedom from presenting symptom or in freedom from dialysis and renal-related death. Patients who presented with hypertension were more likely to have shown improvement in their blood pressure with endoluminal intervention at 1, 3, and 5 (59 +/- 6% endoluminal vs. 83 +/- 5% open; p = 0.01) years. From these results we conclude that open repair and endoluminal repair of atherosclerotic renal artery stenosis have similar immediate and long-term functional and anatomic outcomes. Patients who present with hypertension may have greater benefit with an endoluminal repair.