Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation.

OBJECTIVE: The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. BACKGROUND: Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. METHODS: Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. RESULTS: Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p=0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p=0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p=0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. CONCLUSIONS: Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in future clinical trials may improve RDN therapeutic efficacy.

Coronary computed tomographic angiographic findings in patients with Kawasaki disease.

Kawasaki disease (KD) is the leading cause of acquired coronary disease in children and may lead to subsequent myocardial ischemia and infarction. Because coronary computed tomographic angiography (CTA) is the most sensitive noninvasive test in patients with atherosclerosis, the aim of this study was to retrospectively evaluate coronary CTA performed in patients with KD for aneurysm, stenosis, and calcified and noncalcified coronary artery disease (CAD). Clinical histories and prior stress and imaging test results were reviewed. Thirty-two patients underwent coronary CTA for KD, and 385 coronary segments were evaluated. Twenty-three of 32 patients had ≥1 diseased coronary segment. There were 20 aneurysms, 7 lesions, and 75 segments (20%) with nonobstructive CAD (16% noncalcified, 2% calcified, and 2% mixed). All nonobstructive and obstructive CAD was in patients with histories of acute-phase coronary artery dilatation or aneurysm (echocardiographic z score 4 to 44), and were almost always associated with normal stress imaging test results on follow-up. No lesion or CAD was found in coronary computed tomographic angiographic studies performed in a control group referred for other indications (n = 32, 422 segments evaluated). The median coronary computed tomographic angiographic dose-length product was 59 mGy cm (interquartile range 32 to 131), the median unadjusted radiation dose was 0.8 mSv (interquartile range 0.4 to 1.8), and the median age- and size-adjusted radiation dose was 1.3 mSv (interquartile range 0.7 to 2.3). In conclusion, high-risk patients with histories of KD had nonobstructive and obstructive CAD not visualized by other noninvasive imaging tests. In properly selected high-risk patients with KD, coronary CTA may identify a subset at increased risk for future coronary pathology who may benefit from medical therapy.

Non-sedated, free breathing cardiac CT for evaluation of complex congenital heart disease in neonates.

BACKGROUND: Neonates with complex congenital heart disease (CHD) are at risk of adverse events from anesthesia. CT angiography (CTA) performed free breathing and without sedation has not been reported for evaluation of complex CHD in neonates. OBJECTIVES: The aim was to evaluate the image quality and risk of free breathing, non-sedated cardiac CTA for definition of CHD in the neonatal period and to determine accuracy compared with interventional findings. METHODS: This is a combined retrospective-prospective single institution review of all non-sedated, free breathing cardiac CT angiograms performed in patients <1 month of age with complex CHD. Diagnosis, scan acquisition parameters, image quality (1- to 4-point scale), adverse events, radiation dose estimates, and accuracy compared with operative and interventional catheterization findings were recorded. Results are reported as median and interquartile range. RESULTS: Nineteen non-sedated, free breathing, neonatal cardiac CT angiograms were performed during the time of review. All studies were diagnostic with a mean image quality score of 1.1 ± 0.3. Median total procedural dose-length product was 11 (range, 10-14), CT dose index volume was 0.47 (range, 0.31-0.5). Median unadjusted radiation dose was 0.15 mSv (range, 0.14-0.2 mSv), age- and size-adjusted radiation dose was 0.86 mSv (range, 0.78-1.1 mSv). No adverse events and no discrepancies compared with surgical or catheterization findings were found in the 17 of 19 patients that had subsequent intervention. CONCLUSIONS: Cardiac CTA can be performed in the neonatal period free breathing and without sedation. Image quality is excellent, and there is high accuracy compared with surgical and catheterization findings at the time of intervention.

Cardiovascular imaging trends in congenital heart disease: a single center experience.

BACKGROUND: Cardiac magnetic resonance imaging (MRI) and CT are available in the recent era at many pediatric cardiac centers. OBJECTIVE: The aim was to provide a contemporary description of diagnostic imaging trends for definition of congenital heart disease (CHD). METHODS: Echocardiography, cardiac catheterization, cardiac MRI, and cardiac CT use in patients with congenital heart disease at a single institution was retrospectively recorded (2005-2012). Surgical procedures were recorded. Total and modality-specific rates were estimated by Poisson regression and compared. The median age, studies in patients aged >17 years, and referral diagnosis were tabulated for the last year of review. RESULTS: An average of 11,940 cardiovascular diagnostic tests was performed annually. The number of total studies, echocardiograms, catheterizations, and surgical procedures, did not change significantly across time. Echocardiography comprised 95% to 97% of all studies performed during each year of review. The use of cardiac MRI (2%) and cardiac CT (1%) increased linearly (P < .001), and the use of diagnostic catheterization decreased (0.7%; P = .0005). The median age was 3 years for echocardiography, 15 years for MRI, 11 years for CT, and 3 years for catheterization. The percentage of patients aged >17 years was 9% for echocardiography, 33% for cardiac MRI, 29% for cardiac CT, and 8% for catheterization. Most patients undergoing CT, MRI, and diagnostic catheterization had moderate or complex CHD. CONCLUSION: Cardiac CT is used increasingly in the recent era for evaluation of CHD. The increased use of both cardiac CT and cardiac MRI are temporally associated with a decrease in diagnostic cardiac catheterization.