Role of amiodarone in the management of atrial arrhythmias in adult Fontan patients.

BACKGROUND: Patients with Fontan circulation are known to be at high risk for developing atrial tachyarrhythmias (AAs). Our objective was to examine the efficacy and safety of amiodarone in the management of ATs in adult Fontan patients. METHODS: Primary outcomes of this single-centre, retrospective study included freedom from AAs and incidence of adverse effects of amiodarone on Fontan patients. Heart failure (HF) events and composite outcomes of death from any cause, Fontan revision and heart transplantation were evaluated as secondary outcomes. Predictors of HF and discontinuing amiodarone were also evaluated. RESULTS: A total of 61 patients (mean age 31.6±11.3 years, 40.9% female), who were treated with amiodarone in between 1995 and 2018, were included. AAs free survival at 1, 3 and 5 years were 76.2%, 56.9% and 30.6%, respectively. During a median follow-up of 50.5 months, 34 (55.7%) patients developed side effects, and 20 (32.8%) patients discontinued amiodarone due to side effects. Thyroid dysfunction was the most common side effect (n=26, 76.5%), amiodarone-induced thyrotoxicosis (AIT) (n=16, 27.1%) being most common thyroid dysfunction. Young age (age <28.5 years) was associated with discontinuing amiodarone (HR 5.50, 95% CI 1.19 to 25.4, p=0.029). AIT significantly increased risk of HF (HR 4.82, 95% CI 1.71 to 13.6, p=0.003). CONCLUSIONS: Short-term efficacy of amiodarone in Fontan physiology is acceptable. However, long-term administration is associated with a reduction of efficacy and a significant prevalence of non-cardiac side effects. AIT is associated with exacerbation of HF. The judicious use of amiodarone administration should be considered in this population.

Noncardiac determinants of death and intensive care morbidity in adult congenital heart disease surgery.

OBJECTIVES: Predicting perioperative morbidity and mortality in cardiac surgery for adult congenital heart disease is challenging because it encompasses a wide spectrum of disease. There is a paucity of published outcome data, and there are no perioperative risk score calculators for this population group. We set out to identify robust determinants of morbidity and mortality in this patient population under going cardiac surgery. METHODS: We collected data on 20 socioeconomic and pathophysiologic variables in 784 consecutive adults with congenital heart disease who underwent cardiac surgery between 2004 and 2015 at a single center. Using logistic regression, we sought to identify which of these factors were associated with the primary composite adverse outcome of in-hospital mortality, prolonged ventilation exceeding 7 days, and severe acute renal failure requiring dialysis. Secondary outcome analysis identified variables that were significant predictors for 1-year mortality. RESULTS: Composite adverse outcome occurred in 54 of 784 patients (6.9%). Significant predictors of the composite adverse outcome by multivariate regression include Mayo End-Stage Liver Disease modified score, cognitive impairment, number of chest wall incisions from previous cardiac surgery, body mass index, and cardiac anatomic category. Two survivors of the composite adverse outcome died within a few weeks postdischarge. Only 657 of 784 patients had 1-year follow-up data; 40 of 657 patients died at 1 year. One-year mortality was predicted by anticoagulation, Mayo End-Stage Liver Disease modified score, and anatomic category. CONCLUSIONS: Recognition and quantification of noncardiac comorbidities preoperatively predict the risk of adverse events and mortality in addition to cardiac anatomic factors.

Comparison of transforming growth factor beta expression in healthy and diseased human tendon.

BACKGROUND: Diseased tendons are characterised by fibrotic scar tissue, which adversely affects tendon structure and function and increases the likelihood of re-injury. The mechanisms and expression profiles of fibrosis in diseased tendon is understudied compared to pulmonary and renal tissues, where transforming growth factor (TGF)ß and its associated superfamily are known to be key drivers of fibrosis and modulate extracellular matrix homeostasis. We hypothesised that differential expression of TGFß superfamily members would exist between samples of human rotator cuff tendons with established disease compared to healthy control tendons. METHODS: Healthy and diseased rotator cuff tendons were collected from patients presenting to an orthopaedic referral centre. Diseased tendinopathic (intact) and healthy rotator cuff tendons were collected via ultrasound-guided biopsy and torn tendons were collected during routine surgical debridement. Immunohistochemistry and quantitative real-time polymerase chain reaction were used to investigate the protein and gene expression profiles of TGFß superfamily members in these healthy and diseased tendons. RESULTS: TGFß superfamily members were dysregulated in diseased compared to healthy tendons. Specifically, TGFß-1, TGFß receptor (R)1 and TGFß R2 proteins were reduced (p < 0.01) in diseased compared to healthy tendons. At the mRNA level, TGFß R1 was significantly reduced in samples of diseased tendons, whereas TGFß R2 was increased (p < 0.01). BMP-2, BMP-7 and CTGF mRNA remained unchanged with tendon disease. CONCLUSIONS: We propose that downregulation of TGFß pathways in established tendon disease may be a protective response to limit disease-associated fibrosis. The disruption of the TGFß axis with disease suggests associated downstream pathways may be important for maintaining healthy tendon homeostasis. The findings from our study suggest that patients with established tendon disease would be unlikely to benefit from therapeutic TGFß blockade, which has been investigated as a treatment strategy in several animal models. Future studies should investigate the expression profile of fibrotic mediators in earlier stages of tendon disease to improve understanding of the targetable mechanisms underpinning tendon fibrosis.

Inflammation activation and resolution in human tendon disease.

Improved understanding of the role of inflammation in tendon disease is required to facilitate therapeutic target discovery. We studied supraspinatus tendons from patients experiencing pain before and after surgical subacromial decompression treatment. Tendons were classified as having early, intermediate, or advanced disease, and inflammation was characterized through activation of pathways mediated by interferon (IFN), nuclear factor κB (NF-κB), glucocorticoid receptor, and signal transducer and activator of transcription 6 (STAT-6). Inflammation signatures revealed expression of genes and proteins induced by IFN and NF-κB in early-stage disease and genes and proteins induced by STAT-6 and glucocorticoid receptor activation in advanced-stage disease. The proresolving proteins FPR2/ALX and ChemR23 were increased in early-stage disease compared to intermediate- to advanced-stage disease. Patients who were pain-free after treatment had tendons with increased expression of CD206 and ALOX15 mRNA compared to tendons from patients who continued to experience pain after treatment, suggesting that these genes and their pathways may moderate tendon pain. Stromal cells from diseased tendons cultured in vitro showed increased expression of NF-κB and IFN target genes after treatment with lipopolysaccharide or IFNγ compared to stromal cells derived from healthy tendons. We identified 15-epi lipoxin A4, a stable lipoxin isoform derived from aspirin treatment, as potentially beneficial in the resolution of tendon inflammation.