Arm-leg Blood Pressure Gradient Research Articles

Long-Term Outcomes of the Coarctation of the Aorta Stent Trials.

Long-term outcome data of stent-implantation for coarctation of the aorta are limited. We report up to 5 years of postimplant follow-up in patients enrolled into the COAST (Coarctation of the Aorta Stent Trial) and the COAST II trial (Covered Cheatham-Platinum Stents for Prevention or Treatment of Aortic Wall Injury Associated With Coarctation of the Aorta), evaluating the bare and Covered Cheatham-Platinum Stents for the treatment of coarctation of the aorta and associated aortic wall injury. Data was prospectively collected during the 2 multi-center studies, enrolling 248 patients (COAST: n=121, COAST II: n=127). Late follow-up data (48–60 month) was compared with immediate (1 month) and early (12 months) follow-up. There was a notable decrease in the use of antihypertensive medication, from 53% at immediate, to 42% at early, and 29% at late follow-up. The cumulative incidence of stent fractures was 0% immediately, 2.9% at early, and 24.4% at late follow-up. Independent predictors for stent fractures at late follow-up were age <18 years, male sex, minimum stent diameter ≥12 mm, and use of bare metal stent. The cumulative incidence of reintervention was 1.6% at immediate, 5.1% at early, and 21.3% at late follow-up. Independent predictors for reinterventions at late follow-up were age <18 years, post implantation systolic arm-leg blood pressure gradient ≥10 mm Hg, minimum stent diameter at implantation <12 mm, and initial coarctation minimum diameter <6 mm. There were 13 patients with aortic aneurysms, with a cumulative incidence of 6.3% at late follow-up. Coarctation stenting is effective at maintaining obstruction relief up to 60 months postimplant with reduction in the number of patients requiring antihypertensive medication. However, an increase in-stent fractures and reinterventions were observed between medium and long-term follow-up. Covered stents appear to confer some protection from the development of stent fractures but do not provide complete protection from late aneurysm formation. URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00552812 and NCT01278303.

Arm-Leg Blood Pressure Gradient in Clinic to Predict Arch Hemodynamics and Ventricular Size after Coarctation Repair

Objective: Patients with successfully repaired coarctation of the aorta (CoA) need continued follow-up due to risks of restenosis and abnormal arterial compliance, causing early onset hypertension/coronary artery disease. We hypothesize that subtle hemodynamic and structural abnormalities can be predicted in the clinic by an abnormal arm-leg blood pressure (BP) gradient (i.e. arm &gt; leg systolic BP). Design: Uncomplicated CoA patients repaired between 1990 and 2007 with follow-up clinic visits documenting right arm and leg systolic BPs, along with a recent echocardiogram, were studied. Data included the Doppler peak instantaneous (PeakV) and mean velocities (MeanV) in the descending aorta along with measures of the proximal transverse arch (TA) diameter and left ventricular wall (LVPWd) thickness. Measurements were indexed by Z-scores. Patients were grouped by higher systolic BP in the leg (Group 1) or arm (Group 2). Results: Eighty-one patients met the criteria with 52 in Group 1 (median 12.5 years follow-up) and 29 in Group 2 (median 12 years follow-up). Group 2 group had significantly increased arm systolic BP Z-scores (p &lt;0.01), PeakV (p &lt;10-4 ), MeanV (p &lt;10-6 ), and LVPWd (p &lt;0.01) compared to Group 1. There was no difference, however, in arm diastolic BP (p =0.7) or TA diameter (p =0.5). These relationships held true even in otherwise “silent” patients without clinical hypertension. Conclusion: Abnormal arm-leg blood pressure gradients accurately identified CoA patients with elevated arch velocities and increased ventricular wall thickness years after repair. The arm-leg pressure measurements could more accurately select patients in need of further imaging studies and therapeutic interventions.

Procedural risk factors, incidence and timing of reintervention after treatment for native coarctation of the aorta in children: a population-based study†.

The aim of the present study was to evaluate procedural risk factors, incidence and timing of reintervention because of recurrent aortic coarctation in children. The study cohort consisted of 304 patients with isolated coarctation: 251 underwent surgery and 53 were treated percutaneously (40 balloon angioplasty, 13 stent) at the Helsinki Children's Hospital in 2000-2012. Characteristics, intervention and reintervention data were retrospectively collected from clinical records until 2014 (median follow-up 7.9 years). Age- and sex-matched comparisons between the treatment groups were performed in 86 patients (surgery n = 43, percutaneous n = 43). Forty of the 251 (16%) patients after surgery, 9/40 (23%) patients after balloon angioplasty and 4/13 (31%) patients after stent placement underwent a reintervention after a median time of 3.4, 11.7 and 19.5 months (P < 0.05), respectively. In the surgery group, all reinterventions occurred in children operated on ≤12 months of age and were related to lower body weight and smaller dimensions of the aorta. In the balloon angioplasty group, a higher post-procedure systolic arm-leg blood pressure gradient was associated with reintervention. After stent placement, three-fourths of the reinterventions were performed in a planned postinterventional catheterization. In the age- and sex-matched comparisons (median 5,7 years, range 0,5-17,6), post-procedure blood pressure gradients were higher (mean 10 vs 4 mmHg, P = 0.03), and reinterventions were more common (28%, 95% confidence interval 17-43 vs 2%, 95% confidence interval 0-12) in the percutaneous group compared to the surgery group. Reinterventions after surgery in neonates were relatively common. In older children, percutaneous treatment carried a higher risk of reinterventions, which were mainly related to residual coarctation after primary treatment.

Persistent transverse arch hypoplasia is associated with systemic hypertension after coarctation of aorta repair

Methods A retrospective review of clinical, CMR and exercise data on patients after coarctation repair was performed to include patients who had CMR from 2005-2014. Patients with atypical coarctation, major heart defects, residual coarctation (right arm-leg blood pressure gradient > 20 mm Hg) or >mild semilunar or atrioventricular valve stenosis/regurgitation were excluded. Patients satisfying standard criteria for resting hypertension and those on anti-hypertensive medication were classified as being “hypertensive”. In a subset of patients, exercise testing was used to evaluate the increase in right arm systolic blood pressure (SBP) and arm-leg SBP gradient during peak exercise. CMR images were analyzed to calculate the minimum TAA diameter z-score, the ratio of TAA and thoracic descending aorta (DAO) diameters, isthmus diameter z-score and, LV mass/BSA.

Exercise Evaluation of Upper- versus Lower-Extremity Blood Pressure Gradients in Pediatric and Young-Adult Participants

The aim of this study was to provide a normal reference for arm-leg blood pressure gradients in normal pediatric and young-adult patients before and after exercise. We assessed 216 normal participants by physical or echocardiographic exam, maximally tested using the James Cycle Protocol, with arm and leg blood pressures taken pre- and postexercise. Arm-leg gradients significantly increased from -5 mmHg at rest to 4, 2, and 1 mmHg 1, 3, and 4 min postexercise (p < .05). There was a small, statistically significant increase in arm-leg blood pressure with exercise, which is probably clinically insignificant. These data serve as a normal reference.

Development of exercise-induced arm-leg blood pressure gradient and abnormal arterial compliance in patients with repaired coarctation of the aorta

Often, the lack of systemic arterial hypertension and the lack of a resting arm-leg blood pressure gradient are used to assess the adequacy of the anatomic result after intervention for coarctation of the aorta (CoA). Some patients with no arm-leg gradient at rest may develop a gradient with exercise, leading caregivers to question the success of the repair. It is not clear what the prevalence is of patients who have undergone a successful intervention for CoA and have no arm-leg gradient at rest but develop a significant gradient with exercise and which factors may predict the development of an arm-leg gradient with exercise. This study evaluates the prevalence and predictors of an exercise-induced arm-leg gradient in subjects who have undergone an apparently successful intervention for CoA.

MR findings of collateral circulation are more accurate measures of hemodynamic significance than arm-leg blood pressure gradient after repair of coarctation of the aorta.

To determine the relationship between percent stenosis and three indicators of hemodynamic significance-arm-leg blood pressure gradient, direct visualization of collaterals, and percent increase flow from proximal to distal descending thoracic aorta-in patients with prior repair of coarctation of the aorta (CoA). Magnetic resonance imaging (MRI) examinations of 19 patients with prior repair of CoA were retrospectively reviewed. Percent stenosis was compared to the arm-leg blood pressure gradient as obtained from chart review, the depiction of collaterals by gadolinium-enhanced magnetic resonance angiography (MRA), and the percent increased flow in the distal thoracic aorta as measured by velocity-encoded cine MRI. Some imaging series or blood-pressure values were not available in some patients. All of the data were available for 15 of the 19 patients. The arm-leg blood pressure gradient showed no statistical association with percent stenosis (R(2) = 0.10, P = 0.22), direct visualization of collaterals (P = 0.80), or percent increase in flow (R(2) < 0.01, P = 0.85). Percent stenosis did show association with visualization of collaterals (P = 0.01) and increase flow (R(2) = 0.62, P < 0.01). The arm-leg blood pressure gradient is not a reliable indicator of hemodynamic significance of restenosis in patients with prior repair of CoA. Direct visualization of collateral vessels by MRA and percent increase in flow from proximal to distal descending thoracic aorta are reliable indicators of hemodynamic significance.

Isolated Aortic Coarctation in Neonates and Infants: Results of Resection and End-to-End Anastomosis

Operative resection is the treatment of choice for native aortic coarctation in most institutions. The ideal timing for elective repair is still a matter of debate. This study evaluated one institution's results with resection and end-to-end anastomosis in the first year of life. Between January 1987 and December 1993, 46 neonates and infants with functionally isolated aortic coarctation underwent operative resection and end-to-end anastomosis. For the patients included in the study, all hospital records, catheterization data, and operative protocols were evaluated for retrospective analysis. To obtain valid follow-up information, all patients were systematically seen on an outpatient basis during 1994. After a mean follow-up of 49 +/- 24 months (range, 13 to 95 months), recoarctation (arm-leg blood pressure gradient > 20 mm Hg) occurred in 5 of 26 patients with neonatal operations (19%) and in 1 of 20 patients with operations in infancy (5%, p = not significant). Four of these 6 children with recoarctation needed reintervention. The other 2 patients had only mild recoarctation (gradients of 22 and 30 mm Hg, respectively) and were not treated. In all 6 patients, recoarctation was diagnosed within the first 6 months postoperatively. During the whole follow-up period, right arm systolic blood pressures slightly above the 90th percentile of normal developed in 11 of the patients (24%) (7 in the group with neonatal operation and 4 after operation in infancy; p = not significant). Resection with end-to-end anastomosis was shown to be an adequate therapeutic strategy for isolated aortic coarctation in neonates and infants. The results indicate that already beyond the neonatal age, there is a relatively low incidence of recoarctation.

Increased stiffness and persistent narrowing of the aorta after successful repair of coarctation of the aorta: Relationship to left ventricular mass and blood pressure at rest and with exercise

Fifteen children and adolescents who had repair of coarctation of the aorta before age 15, who were not hypertensive at rest, and who had resting arm-leg blood pressure gradients of <20 mm Hg underwent noninvasive evaluation of left ventricular structure and function, aortic stiffness, and residual coarctation as well as bicycle exercise testing. These results were compared with those in 15 age- and sex-matched control subjects. The mean resting age-related systolic blood pressure percentiles (63% versus 46%), transverse aortic stiffness measured by the elastic modulus (Ep) (42.1 versus 23.2 kPa), stiffness index beta (β) (3.66 versus 2.17), echocardiographic left ventricular fractional shortening (0.42 versus 0.36), left ventricular mass index (99.3 versus 81.0 gm/m 2), maximum exercise right arm systolic blood pressure (173 versus 156 mm Hg), and exercise arm-leg blood pressure gradient (35 versus 6 mm Hg) were significantly increased in the coarctectomy patients compared with controls. Univariate correlations in the coarctectomy group showed significant relationships of residual aortic narrowing with left ventricular mass index ( r = 0.68, p < 0.01) and resting systolic blood pressure percentile for age ( r = 0.55, p < 0.05). Residual aortic narrowing did not significantly correlate with aortic stiffness, resting blood pressure gradient, or exercise blood pressure gradient. Neither left ventricular mass index nor resting systolic blood pressure percentile significantly correlated with age of repair or years after repair. These results demonstrate persistent abnormalities in aortic stiffness and left ventricular mass and function after successful repair of coarctation of the aorta in childhood and adolescence. Mild degrees of residual aortic narrowing may affect resting blood pressure and left ventricular mass. Elevated blood pressure and blood pressure gradients between upper and lower extremities during exercise may be a reflection of increased arterial stiffness in the upper body as well as mild persistent coarctation.

Long-term follow-up of coarctation of the aorta repaired by patch angioplasty

The long-term complications of patch plasty repair for coarctation of the aorta were assessed retrospectively in 119 patients who were operated upon from 4 days to 13 years of age. There were 7 late deaths and 17 patients were lost to follow-up. Thus 95 patients were followed up for a minimum period of 3 years (mean 6.3 years). In addition, graded exercise tests were performed on 15 patients and 11 normal controls, measuring systolic blood pressure response and arm-leg blood pressure gradients. In this series, 16 patients (17%) were hypertensive, while 25 (26%) had a resting systolic arm-leg gradient > 20 mm Hg. Re-coarctation occurred more frequently when surgery had been undertaken under 1 month of age. Review of chest X-rays revealed calcification in the patch in 4 patients, one of whom subsequently went on to aneurysm formation. In a second child aneurysm formation was detected at repeat operation. Exercise tests showed a significantly higher systolic arm pressure in patients (mean: 165.3 mm Hg) when compared to controls (mean: 139.2 mm Hg) ( P = 0.017) and a significant increase in arm-leg systolic gradient viz. 36 and 5.9 mm Hg, respectively ( P = 0.0016). A good correlation was found between the systolic arm pressure and the systolic arm-leg gradient after exercise ( r = 0.822; P = 0.0001). We conclude that the most important long-term complication following an aortic patch plasty, is re-stenosis. The development of an aneurysm was observed only twice. We believe that this apparently rare occurrence, as assessed on chest radiographs; is related to the young age (53% under 1 year) at which the repairs were carried out. Another possible reason may be that the follow-up period is not yet long enough.

Stress testing for comparison of synthetic patch aortoplasty with resection and end to end anastomosis for repair of coarctation in childhood

Excellent clinical results have been achieved by both resection with end to end anastomosis and synthetic patch aortoplasty for the repair of coarctation of the aorta in older children. Increasing experience with exercise stress testing in the postoperative evaluation of patients with coarctation has allowed the discovery of less obvious differences between the two procedures. To evaluate these differences further, the stress tests of 50 postoperative patients who underwent coarctation repair were reviewed: 26 patients with end to end anastomosis and 24 with synthetic patch aortoplasty. Twenty normal control subjects were similarly exercised. Systolic blood pressure in the arm and leg was evaluated before and after the test. Heart rate, electrocardiogram and arm blood pressure were monitored during the test. The mean arm systolic blood pressure was higher at all points of measurement in the patients who underwent repair by end to end anastomosis than in the group who underwent patch aortoplasty. These systolic pressure differences reached statistical significance only for standing arm blood pressure before exercise (p less than 0.05) and for supine arm systolic blood pressure immediately after exercise (p less than 0.01). There was no difference in arm-leg pressure gradient between the two study groups before exercise; however, after exercise the group with end to end anastomosis had significantly higher arm-leg pressure gradients (p less than 0.001). Significant differences between the two types of repair not apparent at rest were found immediately after exercise. The long-term prognostic importance of an exercise-induced arm-leg blood pressure gradient remains to be determined. However, exercise stress testing is sensitive in demonstrating these differences.