The utility of myocardial perfusion imaging before renal transplantation: a retrospective analysis.

BACKGROUND: Renal transplantation (RT) reduces morbidity and mortality in patients with end-stage renal failure. Myocardial perfusion imaging provides prognostic information in patients with renal failure, but its role before transplantation remains unclear. We performed a retrospective review assessing the prognostic value of technetium-99m sestamibi myocardial perfusion imaging at a tertiary UK centre. PATIENTS AND METHODS: We included scans performed between 2005 and 2012. Available scans were reanalysed to calculate the semiquantitative summed scores: sum rest score (SRS), sum stress score (SSS), sum difference score and sum motion score (SMS). Kaplan-Meier survival estimates assessed all-cause mortality and cardiac events according to scan findings, transplant decision and SSS. Cox-proportional hazards tested for an association between clinical/scan variables and all-cause mortality, and combined all-cause mortality/cardiovascular (CV) events. RESULTS: One hundred and thirty-eight scans were identified with complete follow-up. During a median 40.4-month follow-up, 21 patients died, with 11 nonfatal CV events. There was no significant difference between groups according to scan findings for mortality (log-rank P=0.17) or mortality/CV events (P=0.06). An SSS greater than 8 was associated with higher mortality and CV events combined (P=0.028). An abnormal baseline ECG [hazard ratio (HR): 16.1] and higher SRS (HR: 2.3) were associated independently with higher mortality; an abnormal ECG (HR: 3.4) also predicted higher cardiac events/mortality. CONCLUSION: Moderate to severe perfusion defects by SSS were associated with higher mortality and CV events. Higher SRS was associated independently with increased mortality on multivariable analysis, highlighting a key role for semiquantitative analysis methods for risk stratification. An abnormal ECG was associated strongly with both endpoints, and may be a useful screening tool to select patients for further investigation.

Effect of renal artery revascularization upon cardiac structure and function in atherosclerotic renal artery stenosis: cardiac magnetic resonance sub-study of the ASTRAL trial.

BACKGROUND: Cardiac abnormalities are frequent in patients with atherosclerotic renovascular disease (ARVD). The Angioplasty and Stenting for Renal Artery Lesions (ASTRAL) trial studied the effect of percutaneous renal revascularization combined with medical therapy compared with medical therapy alone in 806 patients with ARVD. METHODS: This was a pre-specified sub-study of ASTRAL (clinical trials registration, current controlled trials number: ISRCTN59586944), designed to consider the effect of percutaneous renal artery angioplasty and stenting on change in cardiac structure and function, measured using cardiac magnetic resonance (CMR) imaging. Fifty-one patients were recruited from six selected ASTRAL centres. Forty-four completed the study (medical therapy n = 21; revascularization n = 23). Full analysis of CMR was possible in 40 patients (18 medical therapy and 22 revascularization). CMR measurements of left and right ventricular end systolic (LV and RVESV) and diastolic volume (LV and RVEDV), ejection fraction (LVEF) and mass (LVM) were made shortly after recruitment and before revascularization in the interventional group, and again after 12 months. Reporting was performed by CMR analysts blinded to randomization arm. RESULTS: Groups were well matched for mean age (70 versus 72 years), blood pressure (148/71 versus 143/74 mmHg), degree of renal artery stenosis (75 versus 75%) and comorbid conditions. In both randomized groups, improvements in cardiac structural parameters were seen at 12 months, but there were no significant differences between treatment groups. Median left ventricular changes between baseline and 12 months (medical versus revascularization) were LVEDV -1.9 versus -5.8 mL, P = 0.4; LVESV -2.1 versus 0.3 mL, P = 0.7; LVM -5.4 versus -6.3 g, P = 0.8; and LVEF -1.5 versus -0.8%, P = 0.7. Multivariate regression also found that randomized treatment assignment was not associated with degree of change in any of the CMR measurements. CONCLUSIONS: In this sub-study of the ASTRAL trial, renal revascularization did not offer additional benefit to cardiac structure or function in unselected patients with ARVD.

Revascularization versus medical therapy for renal-artery stenosis.

BACKGROUND: Percutaneous revascularization of the renal arteries improves patency in atherosclerotic renovascular disease, yet evidence of a clinical benefit is limited. METHODS: In a randomized, unblinded trial, we assigned 806 patients with atherosclerotic renovascular disease either to undergo revascularization in addition to receiving medical therapy or to receive medical therapy alone. The primary outcome was renal function, as measured by the reciprocal of the serum creatinine level (a measure that has a linear relationship with creatinine clearance). Secondary outcomes were blood pressure, the time to renal and major cardiovascular events, and mortality. The median follow-up was 34 months. RESULTS: During a 5-year period, the rate of progression of renal impairment (as shown by the slope of the reciprocal of the serum creatinine level) was -0.07x10(-3) liters per micromole per year in the revascularization group, as compared with -0.13x10(-3) liters per micromole per year in the medical-therapy group, a difference favoring revascularization of 0.06x10(-3) liters per micromole per year (95% confidence interval [CI], -0.002 to 0.13; P=0.06). Over the same time, the mean serum creatinine level was 1.6 micromol per liter (95% CI, -8.4 to 5.2 [0.02 mg per deciliter; 95% CI, -0.10 to 0.06]) lower in the revascularization group than in the medical-therapy group. There was no significant between-group difference in systolic blood pressure; the decrease in diastolic blood pressure was smaller in the revascularization group than in the medical-therapy group. The two study groups had similar rates of renal events (hazard ratio in the revascularization group, 0.97; 95% CI, 0.67 to 1.40; P=0.88), major cardiovascular events (hazard ratio, 0.94; 95% CI, 0.75 to 1.19; P=0.61), and death (hazard ratio, 0.90; 95% CI, 0.69 to 1.18; P=0.46). Serious complications associated with revascularization occurred in 23 patients, including 2 deaths and 3 amputations of toes or limbs. CONCLUSIONS: We found substantial risks but no evidence of a worthwhile clinical benefit from revascularization in patients with atherosclerotic renovascular disease. (Current Controlled Trials number, ISRCTN59586944.)

Efficacy of renal artery angioplasty and stenting in a solitary functioning kidney.

OBJECTIVE: The aim of this study was to share our experience of percutaneous renal artery angioplasty and stenting (PTRAS) in our patients with a solitary functioning kidney over a 10-year period. METHODS: The procedures were performed on 75 patients from 1995 to 2004. Data were collected retrospectively from case notes of patients. The definition for solitary functioning kidney was a contralateral kidney size of <8 cm, complete occlusion of contralateral renal artery or previous nephrectomy. Serum creatinine was considered improved or worse if the deviation from the baseline value was >20%. RESULTS: For the purpose of halting renal deterioration (n=47), there were improvement and stabilization in 21% and 55% at 3 months and 28% and 28% at 12 months. Systolic blood pressure (n=27) improvement and stabilization were achieved in 33% and 56% both at 3 and 12 months. Diastolic blood pressure (n=27) improvement and stabilization were 22% and 70% at 3 months and 33% and 48% at 12 months. Five out of seven patients with acute renal failure (serum creatinine>500 micromol/l and requiring haemodialysis) pre-procedure were dialysis-free at 12 months. Complications occurred in 19 (25%) patients and these included bleeding (n=16), pseudoaneurysm (n=3), renal artery dissection (n=2) and cholesterol embolization (n=1). CONCLUSION: PTRAS in a solitary functioning kidney produced clinical benefits in the majority of patients with resistant hypertension and renal function deterioration.