The Safety and Efficacy of Clonidine in Hemodialysis Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Clonidine is a frequently prescribed long-term antihypertensive medication in hemodialysis (HD) patients in the USA, but its safety and efficacy has not been clearly established in the HD population. OBJECTIVE: To evaluate, we conducted a systematic review and meta-analysis on the safety and efficacy of clonidine in HD patients. METHODS: Keyword search of "clonidine" and "dialysis" was conducted through April 2021 in PubMed, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov databases. Inclusion criteria were as follows - study design: randomized controlled trials, cohort studies, prospective studies, retrospective studies, or case series; subjects: adult HD patients; main outcome: blood pressure (BP) and safety; language: English; and article type: peer-reviewed publications. Studies that examined the effects of clonidine in populations other than adult HD patients were excluded. Meta-analysis was performed on BP reduction outcomes. RESULTS: Eight studies met the inclusion criteria for the systematic review, including prospective pre-post studies (2), double-blind controlled trial (1), single-blinded placebo-controlled trial (1), crossover open-label clinical trial (1), retrospective analysis (1), and case report series (2). Three studies included in the meta-analysis ranged from 2 to 12 weeks duration, with a collective sample size of 24 (ages 12-77 years). Risk of bias, assessed using the ROBINS-1 tool, was high for all included studies. Significant adverse effects reported included hypotension, light-headedness, drowsiness, dry mouth, rebound hypertension, and contact dermatitis from patch application. Short-term clonidine use was associated with significant improvement in systolic BP (pooled effect: -12.985 mm Hg, 95% CI [-7.878, -18.092], p < 0.001), while changes in diastolic BP were not statistically significant (-11.119 mm Hg, 95% CI [-22.725, 0.487], p = 0.060). No data currently support the long-term efficacy of clonidine in HD patients. This study was unfunded and was developed using PRISMA guidelines and registered on PROSPERO (CRD42018112042). CONCLUSIONS: There is no evidence supporting the long-term use of clonidine in the HD population and a significant side-effect profile. There is low-quality evidence demonstrating the efficacy of clonidine in lowering BP in HD patients in short-term use, but significant safety concerns remain. Fluid removal strategies and other antihypertensives should be used over clonidine for long-term BP control in the HD population.

Working on Wellness: Impact of a Pilot Workplace Wellness Program in a Hemodialysis Center.

This article describes the impact of a 12-week workplace wellness program on staff (n = 14) of an outpatient hemodialysis center. The program focused on decreasing dietary sodium and increasing habitual physical activity. The average systolic and diastolic blood pressure of participants decreased by 16.9±21.6 mmHg (p < 0.05) and 4.1±14.0 mmHg (p < 0.05), and body weight decreased by 2.7±1.9kg (p < 0.05). The mean step count at baseline was 7,052±3,278 but increased to 10,388±2,882 (p < 0.05) during a walking challenge. There was a reduction in self-reported barriers to making healthy nutritional changes (p < 0.05) and engaging in habitual physical activity (p < 0.05). Our pilot findings suggest that workplace wellness programs in hemodialysis centers are feasible and effective.

Lower spatial QRS-T angle rules out sustained ventricular arrhythmias in children with hypertrophic cardiomyopathy.

Introduction The spatial peaks QRS-T angle accurately distinguishes children with hypertrophic cardiomyopathy from their healthy counterparts. The spatial peaks QRS-T angle is also useful in risk stratification for ventricular arrhythmias. We hypothesised that the spatial peaks QRS-T angle would be useful for the prediction of ventricular arrhythmias in hypertrophic cardiomyopathy patients under 23 years of age. METHODS: Corrected QT interval and spatial peaks QRS-T angles were retrospectively assessed in 133 paediatric hypertrophic cardiomyopathy patients (12.4±6.6 years) with versus without ventricular arrhythmias of 30 seconds or longer. Significance, positive/negative predictive values, and odds ratios were calculated based on receiver operating characteristic curve cut-off values. RESULTS: In total, 10 patients with ventricular arrhythmias were identified. Although the corrected QT interval did not differentiate those with versus without ventricular arrhythmias, the spatial peaks QRS-T angle did (151.4±19.0 versus 116.8±42.6 degrees, respectively, p<0.001). At an optimal cut-off value (124.1 degrees), the positive and negative predictive values of the spatial peaks QRS-T angle were 15.4 and 100.0%, respectively, with an odds ratio of 25.9 (95% CI 1.5-452.2). CONCLUSION: In children with hypertrophic cardiomyopathy, the spatial peaks QRS-T angle is associated with ventricular arrhythmia burden with high negative predictive value and odds ratio.

Takotsubo Cardiomyopathy in a 22-Year-Old Single-Ventricle Patient.

We report a highly unusual case of a 22-year-old woman with single-ventricle anatomy and a history of Fontan palliation who developed takotsubo cardiomyopathy. To our knowledge, takotsubo cardiomyopathy has not previously been described in a patient with single-ventricle anatomy, or more generally in any patient with congenital heart disease. The patient presented at our clinic for urgent examination after a 2-day history of chest pain that had begun upon the death of her dog. Invasive evaluation was refused by the patient; instead, she underwent electrocardiogram-gated coronary computed tomographic angiography, to rule out obstructive coronary disease. A physician who suspects takotsubo cardiomyopathy in a patient should look for new-onset chest pain and dyspnea coupled with these features: immediate onset of segmental akinesia in the midventricular or apical aspects of the heart, elevation of brain natriuretic peptide level 12 to 24 hours after onset of akinesia, elevation of troponin level 24 to 48 hours after onset, and disappearance of the segmental akinesia a few days after onset.

The spatial QRS-T angle outperforms the Italian and Seattle ECG-based criteria for detection of hypertrophic cardiomyopathy in pediatric patients.

INTRODUCTION: The spatial peaks QRS-T angle has been shown to differentiate adult patients with hypertrophic cardiomyopathy (HCM) from controls. We hypothesized that the spatial peaks QRS-T angle would, in isolation, be more accurate than the Italian 12-lead ECG Pre-participation Screening criteria or the Seattle criteria for detecting hypertrophic cardiomyopathy (HCM) in pediatric patients. METHODS: A retrospective study of pediatric patients with HCM compared to age and gender-matched control patients was undertaken. Significance, odds ratios, sensitivity and specificity of HCM detection of the visually derived spatial peaks QRS-T angle were compared to those of traditional 12-lead ECG criteria using: 1) Italy's National Pre-participation Screening Programme criteria; and 2) described criteria from Seattle. RESULTS: ECG results from 130 pediatric HCM patients (14.2±4.4years) were compared to 470 control patients (normal echocardiograms, mean age 13.4±4.6years). Mean±standard deviation (SD) values for spatial peaks QRS-T angles were 120.4±40.7 and 21.3±13.7 degrees for HCM and controls, respectively (P<0.001). A spatial peaks QRS-T angle cutoff value of >54.9 degrees yielded greater sensitivity and specificity (93.1% and 98.7%, respectively) for detecting HCM over ECG criteria from Italy (68.5% and 48.1%, respectively) or Seattle (64.6% and 78.9%, respectively) with odds ratios at 1039.70 (95% CI 363.03 to 2977.67), 2.01 (95% CI 1.33 to 3.04) and 6.84 (4.49-10.44), respectively. CONCLUSION: In our cohort, a visually derived spatial peaks QRS-T angle has increased sensitivity and specificity for detection of HCM in pediatric patients compared to currently utilized Italian or Seattle ECG criteria.

Efficacy of endothelin blockade in adults with Fontan physiology.

OBJECTIVE: Phosphodiesterase-5 inhibitors have shown to improve cardiac output and functional capacity in Fontan patients. We sought to test the efficacy and safety of endothelin blockade with bosentan in adult patients with Fontan physiology. DESIGN: Ten patients were enrolled and seven patients completed this single-center open-label clinical trial. Patients were treated with bosentan for 4 months. Cardiac magnetic resonance imaging (MRI), 6-minute walking distance (6MWD), brain natriuretic peptide, and New York Heart Association functional class were compared before and after treatment using paired t-test. RESULTS: The 6MWD improved by 73 m, from a mean of 435 m (standard deviation [SD] = 92, standard error [SE] = 35) to 508 m (SD = 93, SE = 35) (P = .03). MRI resting aortic flow increased from 3.3 L/minute (SD = 1.27, SE = 0.73) to 4.4 L/minute (SD = 0.9, SE = 0.54) (P = .03). New York Heart Association class was unchanged in three patients, improved in three patients and worsened in one patient. Brain natriuretic peptide, aspartate aminotransferase, and alanine aminotransferase did not change significantly. Of the three patients with elevated baseline bilirubin, two normalized at the completion of the study, while the other was unchanged. Mean duration of therapy was 4.1 ± 0.51 months. Three adverse advents occurred. One patient complained of fatigue and chest pain after 87 days and withdrew from the study. After extensive workup, it was determined that her symptoms were not related to treatment. The second patient suffered palpitations and fatigue after 75 days; no concerning arrhythmias were identified and symptoms improved with increased antiarrhythmic dose. The third patient developed fatigue on therapy and decided to stop therapy; fatigue improved following drug discontinuation. There were no deaths or hospitalizations. CONCLUSIONS: In this cohort of adult patients with Fontan physiology, endothelin blockade with bosentan resulted in improved 6MWD and MRI-derived resting cardiac output, suggesting a positive effect on pulmonary vascular resistance and pulmonary blood flow. Bosentan was well tolerated and hepatic function was not adversely affected.

Novel techniques of mechanical circulatory support for the right heart and Fontan circulation.

BACKGROUND: Currently available ventricular assist devices are designed primarily for use in patients with left sided heart failure. This study evaluated the efficacy of the Jarvik 2000 ventricular assist device (VAD) as a pulmonary pump to power a Fontan circuit in a large animal model. METHODS: Without the use of cardiopulmonary bypass, Fontan circulations were surgically created in 4 pigs (50 kg) using synthetic grafts from the inferior and superior vena cavas to the main pulmonary artery. Subsequently, the VAD was implanted within the common Fontan graft to provide a pulmonary pump. Direct chamber pressures and epicardial Doppler images were taken during the various phases of the experiment. Heart rate, femoral artery blood pressure, oxygen saturation, and aortic flow rate were continuously recorded. The outflow cannula of the VAD was then partially banded by 50% and then 75% to mimic increased afterload. RESULTS: Fontan and VAD implantation was successfully performed in all 4 animals. Arterial pressure and aortic flow decreased dramatically with institution of the Fontan but were restored to baseline upon activation of the VAD. The pressure within the systemic venous circulation rose precipitously with institution of the Fontan circulation and improved appropriately with activation of the VAD. Adequate perfusion was maintained during increased afterload. CONCLUSIONS: An axial flow VAD can restore normal hemodynamics and cardiac output when used as a pulmonary pump in a Fontan circulation. A VAD can rescue a failing Fontan as a bridge to transplant or recovery, even in the setting of high pulmonary resistance.

Hybrid Melody pulmonary valve replacement in an adult with severe pulmonary hypertension and pulmonary artery aneurysm.

A 48-year-old female with D-TGA, ventricular septal defect (VSD), pulmonary stenosis, pulmonary hypertension (PAH), and total anomalous pulmonary venous connection underwent hybrid intervention for a pulmonary artery (PA) aneurysm and replacement of a dysfunctional pulmonary valve (PV). She underwent a hemi-Mustard procedure at 9 years of age but remained cyanotic. She developed atrial fibrillation, heart failure, and functional decline at 43 years of age. A chest CT demonstrated a 6 cm PA aneurysm that upon re-imaging at 48 years had increased to 11 cm. A catheterization procedure revealed severe PS, PR, residual VSD, severe PAH with a pulmonary vascular resistance of 30 Wood units. She was evaluated and turned down for heart-lung transplantation at another institution. She was subsequently referred to our institution for heart-lung transplantation but was felt to be at unacceptably high risk given the complexity of her anatomy, imaging suggesting liver cirrhosis and liver biopsy with extensive fibrosis. After extensive discussion of risk and benefits, the patient agreed to proceed with a hybrid intervention, consisting of surgical aneurysm resection/PA repair, tricuspid valve repair; PV replacement with a Melody valve, and VSD closure. There were no complications and she was discharged home within 2 weeks. Six months post procedure, she is not on oxygen, her resting room air saturation is 94%, and echocardiography shows stable Melody valve function. This case highlights the utility of a hybrid approach in the treatment of an adult with complex congenital heart disease, heart failure and severe PAH, considered at the highest risk for adverse surgical outcomes. The short-term efficacy of the Melody valve in severe PAH is reassuring.