Differential remodeling in small and large murine airways revealed by novel whole lung airway analysis.

Airway remodeling occurs in chronic asthma leading to increased airway smooth muscle (ASM) mass and extracellular matrix (ECM) deposition. Although extensively studied in murine airways, studies report only selected larger airways at one time-point meaning the spatial distribution and resolution of remodeling are poorly understood. Here we use a new method allowing comprehensive assessment of the spatial and temporal changes in ASM, ECM, and epithelium in large numbers of murine airways after allergen challenge. Using image processing to analyze 20-50 airways per mouse from a whole lung section revealed increases in ASM and ECM after allergen challenge were greater in small and large rather than intermediate airways. ASM predominantly accumulated adjacent to the basement membrane, whereas ECM was distributed across the airway wall. Epithelial hyperplasia was most marked in small and intermediate airways. After challenge, ASM changes resolved over 7 days, whereas ECM and epithelial changes persisted. The new method suggests large and small airways remodel differently, and the long-term consequences of airway inflammation may depend more on ECM and epithelial changes than ASM. The improved quantity and quality of unbiased data provided by the method reveals important spatial differences in remodeling and could set new analysis standards for murine asthma models.

Benefits and Adverse Events Associated With Extended Antibiotic Use in Total Knee Arthroplasty Periprosthetic Joint Infection.

BACKGROUND: Total knee arthroplasty (TKA) periprosthetic joint infection (PJI) can be managed with debridement, antibiotic therapy, and implant retention (DAIR). Oral antibiotics can be used after DAIR for an extended time period to improve outcomes. The objective of this study was to compare DAIR failure rates and adverse events between an initial course of intravenous antibiotic therapy and the addition of extended treatment with oral antibiotics. METHODS: A multicenter observational study of patients diagnosed with a TKA PJI who underwent DAIR was performed. The primary outcome of interest was the failure rate derived from the survival time between the DAIR procedure and future treatment failure. RESULTS: One hundred eight patients met inclusion criteria; 47% (n = 51) received an extended course of oral antibiotics. These patients had a statistically significant lower failure rate compared to those who received only intravenous antibiotics (hazard ratio, 2.47; P = .009). Multivariable analysis demonstrated that extended antibiotics independently predicted treatment success, controlling for other variables. There was no significant difference in failure rates between an extended course of oral antibiotics less or more than 12 months (P = .23). No significant difference in the rates of adverse events was observed between patients who received an initial course of antibiotics alone and those who received a combination of initial and extended antibiotic therapy (P = .59). CONCLUSIONS: Extending therapy with oral antibiotics had superior infection-free survival for TKA PJI managed with DAIR. There was no increase in adverse events, demonstrating safety. After 1 year, there appears to be no significant benefit associated with continued antibiotic therapy.

Long-Term Outcomes of Childhood Left Ventricular Noncompaction Cardiomyopathy: Results From a National Population-Based Study.

BACKGROUND: Long-term outcomes for childhood left ventricular noncompaction (LVNC) are uncertain. We examined late outcomes for children with LVNC enrolled in a national population-based study. METHODS: The National Australian Childhood Cardiomyopathy Study includes all children in Australia with primary cardiomyopathy diagnosed before 10 years of age between 1987 and 1996. Outcomes for subjects with LVNC with a dilated phenotype (LVNC-D) were compared with outcomes for those with dilated cardiomyopathy. Propensity-score analysis was used for risk factor adjustment. RESULTS: There were 29 subjects with LVNC (9.2% of all cardiomyopathy subjects), with a mean annual incidence of newly diagnosed cases of 0.11 per 100 000 at-risk individuals. Congestive heart failure was the initial symptom in 24 of 29 subjects (83%), and 27 (93%) had LVNC-D. The median age at diagnosis was 0.3 (interquartile interval, 0.08-1.3) years. The median duration of follow-up was 6.8 (interquartile interval, 0.7-24.0) years for all subjects and 24.7 (interquartile interval, 23.3 - 27.7) years for surviving subjects. Freedom from death or transplantation was 48% (95% confidence interval [CI], 30-65) at 10 years after diagnosis and 45% (95% CI, 27-63) at 15 years. In competing-risk analysis, 21% of subjects with LVNC were alive with normal left ventricular systolic function, and 31% were alive with abnormal function at 15 years. Propensity-score matching between subjects with LVNC-D and those with dilated cardiomyopathy suggested a lower freedom from death/transplantation at 15 years after diagnosis in the subjects with LVNC-D (LVNC-D, 46% [95% CI, 26-66] versus dilated cardiomyopathy, 70% [95% CI, 42-97]; P=0.08). Using propensity-score inverse probability of treatment-weighted Cox regression, we found evidence that LVNC-D was associated with a greater risk of death or transplantation (hazard ratio, 2.3; 95% CI, 1.4-3.8; P=0.0012). CONCLUSIONS: Symptomatic children with LVNC usually present in early infancy with a predominant dilated phenotype. Long-term outcomes are worse than for matched children with dilated cardiomyopathy.

Adult Congenital Heart Disease in Australia and New Zealand: A Call for Optimal Care.

BACKGROUND: Adult congenital heart disease (ACHD) is a relatively new subspecialty in the cardiology field. The prevalence of ACHD is estimated at ∼ 3,000 per million adult population. The ACHD patient group is estimated to grow at ∼ 5% per year and in the next decade it is forecast that 1 in 150 young adults will carry some form of ACHD diagnosis. These estimates translate to ∼ 72,000 ACHD patients in Australia and ∼ 14,000 in New Zealand, although no current numbers are available. The Cardiac Society of Australia and New Zealand (CSANZ) has recently published Recommendations for Standards of Care for Adult Congenital Heart Disease (ACHD) in 2016. There is currently no long-term plan or proposal to address this huge health care burden within the federal government. This document details the size of the problem insofar as it is known and recommends solutions to be implemented. METHODS: This document was developed by the Adult Congenital Heart Disease Working Group of the Paediatric and Congenital Council (the Congenital Heart Alliance of Australia and New Zealand) as a response to the chronic under resourcing in this area, the risk this poses to patients and clinicians, and the clear need for long-term planning to develop safe care pathways. RESULTS: These issues were raised with the CSANZ Board in December 2015 and the document was developed in response to the Board's request for more information. The current iteration was finalised on 14 November 2017. CONCLUSIONS: The authorship group comprised participants in the CSANZ adult CHD standards of care recommendations from 2013 with the inclusion of some newly trained ACHD cardiologists, who represented most states and territories across ANZ. None of the authors has any academic or professional conflict of interest.

A Multicenter Study of Irrigation and Debridement in Total Knee Arthroplasty Periprosthetic Joint Infection: Treatment Failure Is High.

BACKGROUND: In total knee arthroplasty (TKA) periprosthetic joint infection (PJI), irrigation and debridement (I&D) with component retention is a treatment option with a wide variation in reported failure rates. The purpose of this study was to determine failure rates, outcomes, and factors that predict failure in I&D for TKA PJI. METHODS: A multicenter observational study of patients with a TKA PJI and subsequently undergoing an I&D with retention of components was conducted. The primary outcome was failure rate of I&D, where failure was defined as any subsequent surgical procedures. RESULTS: Two hundred sixteen cases of I&D with retention of components performed on 206 patients met inclusion criteria. The estimated long-term failure rate at 4 years was 57.4%. Time-to-event analyses revealed that the median survival time was 14.32 months. Five-year mortality was 19.9%. Multivariable modeling revealed that time symptomatic and organism were independent predictors of I&D failure. Culture-negative status had a higher hazard for failure than culture-positive patients. When primary organism and time symptomatic were selected to produce an optimized scenario for an I&D, the estimated failure rate was 39.6%. CONCLUSION: I&D with retention of components has a high failure rate, and there is a high incidence of more complex procedures after this option is chosen. The patient comorbidities we investigated did not predict I&D success. Our results suggest that I&D has a limited ability to control infection in TKA and should be used selectively under optimum conditions.

Outcomes of Subaortic Obstruction Resection in Children.

BACKGROUND: Studies of long-term outcomes of discrete subaortic stenosis are rare. Therefore, we reviewed the long-term outcomes of fibromuscular resection in children with subaortic stenosis over 26 years from a single institution. METHODS: We conducted a retrospective review of all children (n=72) who underwent resection of subaortic obstruction for discrete subaortic stenosis between 1989 and 2015. RESULTS: Median age at surgery was 5.0 years (2.7-7.6 years). There were no operative deaths but three late deaths (4.2%, 3/72). Overall Kaplan-Meier survival at 10 years was 93.0 ± 3.9% (95% CI: 79.6, 97.7). Peak instantaneous left ventricular outflow tract Doppler gradient decreased from 74.2±36.7mmHg (16.0-242.0mmHg) preoperatively to 12.8±7.4mmHg (2.6-36.0mmHg) postoperatively (p<0.001). Mean left ventricular outflow tract Doppler gradient decreased from 42.4±17.2mmHg (12.0-98.0) preoperatively to 7.5±2.7mmHg (1.4-19.3mmHg) postoperatively (p<0.001). However, over the mean follow-up period of 7.8±6.1 years (0.1-25.2 years), 29.0% (20/69) of patients had recurrence and 18.8% (13/69) required reoperation at median time of 4.8 years (3.1-9.1 years) after the initial repair. Freedom from reoperation at 10 years was 71.1±7.1% (95% CI: 54.6, 82.3). Risk factors for reoperation were age less than five years at initial repair (p=0.036) and extension of the membrane to the aortic valve (p=0.001). Aortic insufficiency was present in 54.2% (39/72) of patients preoperatively. Progression of aortic insufficiency occurred in 38.9% (28/72). Involvement of the aortic valve at initial repair was associated with need for subsequent aortic valve repair or replacement (p=0.01). CONCLUSIONS: Resection of subaortic obstruction is associated with low mortality and morbidity. Recurrence and reoperation rates are high and progression of aortic insufficiency following subaortic resection is common. Therefore, these patients warrant close follow-up into adult life.

Redefining expectations of long-term survival after the Fontan procedure: twenty-five years of follow-up from the entire population of Australia and New Zealand.

BACKGROUND: The life expectancy of patients undergoing a Fontan procedure is unknown. METHODS AND RESULTS: Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975-1995), 271 lateral tunnels (1988-2006), and 532 extracardiac conduits (1997-2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%-93%) for AP and 97% (95% confidence interval [CI], 94%-99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%-82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P<0.001; 95% CI, 2.4-16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%-76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P<0.001; 95% CI, 2.0-7.1). Ten-year freedom from failure was 79% (95% CI, 61%-89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%-95%) for other morphologies. CONCLUSIONS: The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

Interrupted aorta diagnosed in a 51-year-old woman.

A 51-year-old lady presented with increasing heart failure symptoms and palpitations. She had recently been diagnosed with a congenital ventricular septal defect, bicuspid aortic valve, and Eisenmenger's syndrome. There was clinical evidence of right heart failure and differential clubbing and cyanosis affecting the feet but not hands. A cardiac magnetic resonance imaging demonstrated interruption of the aortic arch beyond the left subclavian artery, with the descending aorta perfused entirely through a large patent ductus arteriosus.

Atrioventricular septal defect in Fontan circulation: Right ventricular dominance, not valve surgery, adversely affects survival.

OBJECTIVE: The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation. METHODS: We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021. RESULTS: Of 174 patients with AVSD, 60% (105/174) had right ventricular (RV) dominance and 40% (69/174) had left ventricular (LV) dominance. The cumulative incidence of moderate or greater AVV regurgitation at 25 years after Fontan operation in patients with LV dominance was 56% (95% CI, 35%-72%), compared with 54% (95% CI, 40%-67%) in patients with RV dominance (P = .6). Nonetheless, transplantation-free survival at 25 years in patients with LV dominance was 94% (95% CI, 86%-100%), compared with 67% (95% CI, 52%-87%) in patients with RV dominance (hazard ratio, 5.9; 95% CI, 1.4-25.4; P < .01). Of note, transplantation-free survival was not different in patients who underwent AVV surgery before or at Fontan completion compared with those who did not (15 years: 81% [95% CI, 62%-100%] vs 88% [95% CI, 81%-95%]; P = .3). CONCLUSIONS: In patients with AVSD and Fontan circulation the rate of moderate or greater common AVV regurgitation is similar in those with LV and RV dominance. RV dominance, rather than previous AVV surgery, is a risk factor for death or transplantation.

Impact of Fontan Fenestration on Long-Term Outcomes: A Propensity Score-Matched Analysis.

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry. Data were collected on preoperative demographics, operative details, and follow-up. Propensity-score matching was performed to account for the various preoperative and operative differences and risk factors. Primary outcomes were survival and freedom from failure. Median follow-up was 10.6 years. After propensity-score matching (407 matched pairs), there was no difference in survival (87% versus 90% at 20 years; P=0.16) or freedom from failure (73% versus 80% at 20 years; P=0.10) between patients with and without fenestration, respectively. Although patients with fenestration had longer bypass and cross-clamp times (P<0.001), there was no difference in hospital length of stay or prolonged pleural effusions (P=0.80 and P=0.46, respectively). Freedom from systemic and Fontan circuit thromboembolism was higher in the nonfenestrated group (89%; 95% CI, 88%-95%) than the fenestrated group (84%; 95% CI, 77%-89%; P=0.03). There was no difference in incidence of plastic bronchitis, protein-losing enteropathy, New York Heart Association Class III/IV symptoms, or Fontan takedown. Conclusions In the propensity score-matched analysis we have demonstrated no difference in long-term survival or freedom from Fontan failure in patients with and without fenestration. There was a higher incidence of long-term thromboembolic events in patients with fenestration. Overall, it appears that fenestration in Fontan circulation does not bring long-term benefits.

Natural and Modified History of Atrioventricular Valve Regurgitation in Patients With Fontan Circulation.

BACKGROUND: Atrioventricular valve (AVV) regurgitation is increasingly prevalent in patients with a Fontan circulation. OBJECTIVES: We sought to determine the impact of ventricular dominance and AVV operation on outcomes in patients with a Fontan circulation and ≥moderate AVV regurgitation. METHODS: We conducted a retrospective study, including propensity score matching analysis, of 1,703 patients who survived Fontan operation in Australia and New Zealand from 1987 to 2021. RESULTS: Patients undergoing AVV operation were more likely to have right ventricular (RV) dominance or an atrioventricular septal defect. In the entire cohort, death or transplantation after Fontan operation was significantly higher in patients who underwent AVV operation before or at Fontan completion compared with those who did not (20 years: 18%; 95% CI: 8%-26% vs 13%; 95% CI: 10%-15%; P = 0.03). After propensity score matching, including for RV dominance, there was no significant difference in death or transplantation between the groups (20 years: 18%; 95% CI: 8%-26% vs 16%; 95% CI: 10%-22%; P = 0.41). Only patients with RV dominance who developed ≥moderate AVV regurgitation after Fontan operation were at increased risk of death or transplantation (HR: 2.8; 95% CI: 1.4-5.3; P < 0.01). In patients with left ventricular dominance, there was no significant difference in death or transplantation between patients with ≥moderate AVV regurgitation compared with those with 

Long-term outcomes of the arterial switch operation.

OBJECTIVES: The arterial switch operation (ASO) has excellent early outcomes in the modern era. We sought to determine the long-term outcomes in patients who underwent an ASO at a single institution. METHODS: Patients who underwent an ASO between 1983 and 2015 were identified from the hospital database and retrospectively reviewed using hospital records. RESULTS: From 1983 to 2015, 844 patients with a biventricular circulation underwent an ASO. There were 28 (3.3%, 28/844) early deaths. Follow-up was available for 94% (729/774) of local patients after hospital discharge. Median follow-up was 15 years (interquartile range, 8-20 years). There were 187 (26%, 187/729) patients with more than 20 years of follow-up and 95 (13%, 95/729) patients with more than 25 years of follow-up. Overall survival was 95% (95% confidence interval [CI], 94%-97%) at 10 and 25 years after the ASO. At 25 years after ASO, freedom from overall reintervention was 77% (95% CI, 73%-81%), freedom from reoperation on the neoaortic root or neoaortic valve was 92% (95% CI, 88%-95%), and freedom from coronary reoperation was 99% (95% CI, 98%-99.7%). Left ventricular (LV) systolic function was normal in 595 of 609 (98%) of patients who had LV function quantified at latest follow-up. Of the 95 patients with more than 25 years of follow-up after ASO, 6 (6.3%) had at least moderate neoaortic valve regurgitation (AR) and 8 (8.4%) had undergone replacement of the neoaortic valve. CONCLUSIONS: Overall, survivors of ASO have excellent late survival and normal LV systolic function into adult life. However, AR and reoperation on the neoaortic valve remains an issue for older patients.

The impact of 2007 infective endocarditis prophylaxis guidelines on the practice of congenital heart disease specialists.

BACKGROUND: the impact of the 2007 American Heart Association endocarditis prophylaxis guidelines on clinician practice has not been well established. Our objective was to evaluate how the American Heart Association endocarditis guidelines changed the practice of cardiologists who manage congenital heart disease and to ascertain the degree of practice variation among cardiologists. METHODS: a cross-sectional Web-based survey was e-mailed to Canadian (n = 134), Australian (n = 33), New Zealand (n = 9), and a random sample of American (n = 250) pediatric and adult congenital heart disease cardiologists in 2008. Nonrespondents received the survey 4 times by e-mail and once by regular post. RESULTS: the response rate was 55%. The lesions for which cardiologists were most evenly divided between recommending versus not recommending prophylaxis were "rheumatic mitral stenosis of moderate severity" (45% recommended prophylaxis) and "perimembranous ventricular septal defect (VSD) status post surgical patch closure with no residual shunt 3 months post-operatively" (54% recommended prophylaxis). The lesions for which the greatest proportion of cardiologists discontinued prophylaxis were "small muscular VSD, no previous endocarditis" (80% discontinued prophylaxis) and "small audible patent ductus arteriosus" (83% discontinued prophylaxis). Only 69% recommended prophylaxis for "VSD s/p surgical patch closure with small residual shunt" despite current guidelines recommending prophylaxis for this scenario. Twenty-eight percent of respondents felt that the new guidelines leave some patients at risk, and 6% would not recounsel any low-risk patients following these guidelines. CONCLUSIONS: the 2007 guidelines have resulted in a substantial change in endocarditis prophylaxis. There remains considerable heterogeneity among cardiologists regarding the prophylaxis of certain cardiac lesions.

Benefits of an international working exchange in pediatric cardiology.

This report describes a 1-year exchange between members of two pediatric cardiology centers: one in Canada and one in Australia. Five cardiologists participated in sequence, fully engaging in the activities of the host department. The motivation of the exchange was broadly educational including clinical experience, shared expertise, teaching, and research collaboration. Structured debriefing confirmed the value of the exchange. In addition to the experience of working in a different medical system, eight research papers were developed, with two research projects ongoing as well as subsequent exchanges of nursing and technical personnel. Interchange between two academic departments can add strength to both and allow development of new skills and research activity.

Sexual Function in Men Living With a Fontan Circulation.

Introduction: It is unknown if the Fontan circulation has an impact on sexual health in men. This study assessed self-reported sexual health and fertility in men with a Fontan circulation. Aims: In this prospective, cross-sectional study, Australian men ≥18 years enrolled in the Fontan Registry of Australia and New Zealand were invited to complete the International Index of Erectile Function (IIEF), alongside questions assessing fertility. These data were compared to historical, age-matched controls. Results: Of 227 eligible men, 54 completed the survey; of those 37 were sexually active and included in the final analysis. Mean age was 28 ± 3 years, age at Fontan was 5 ± 3 years. Fontan type was extra-cardiac conduit in 15 (41%), lateral tunnel in 12 (32%), and atriopulmonary connection (APC) in 10 (27%). Ventricular function was normal in 24 (83%), and all were New York Heart Association Class I (23 patients, 79%) and II (six patients, 21%). Nine participants (24%) had erectile dysfunction (IIEF-EF score ≤25). The severity was mild (IIEF 22-24) in six (16%), mild-moderate (IIEF 17-21) in two (5%), and moderate (IIEF 11-16) in one (3%). Baseline characteristics and current medication usage were similar in those with and without erectile dysfunction. Compared with historical control values, erectile function was not significantly impaired in the Fontan population (p =0.76). Men with a Fontan circulation had decreased levels of sexual desire and overall satisfaction (p < 0.001). There was no correlation between the presence of erectile dysfunction and any assessed parameter. Eleven (30%) of the cohort reported a pregnancy with a prior partner. Conclusion: In our cohort, overall erectile function was comparable between men with a Fontan circulation and historical controls, however sexual desire and overall satisfaction were reduced. There was no correlation between study parameters and the presence of erectile dysfunction. The proportion of the cohort who had a prior pregnancy was congruent with population data.