Pre- and Post-operative determinants of transplantation-free survival after Fontan. The Australia and New Zealand experience.

BACKGROUND: This review identifies the predictors of late mortality and heart transplantation that remain relevant in the contemporary population of patients with a Fontan circulation, focusing on the potential impact of post-Fontan morbidities on the late outlook of these patients. METHODS AND RESULTS: A total of 1561 patients who had survived the Fontan operation in Australia or New Zealand from 1975 to 2018 were included in this review. Over a median duration of 11.4 years, there was a total of 117 deaths (7%) and 32 heart transplantations (2%). Freedom from death and heart transplantation at 10, 20 and 35 years post Fontan surgery were 94% (95% CI 93-95%), 87% (95 %CI 85-90%) and 66% (95 %CI 57-78%) respectively. Being male, having an atriopulmonary Fontan, pre-Fontan atrioventricular valve intervention, or prolonged pleural effusions post Fontan were predictive of late death or heart transplantation. However, time-dependent variables such as the development of atrial arrhythmia, protein/losing enteropathy or late ventricular dysfunction were stronger predictors of the same outcome. Patients who developed a time-dependent risk factor had a freedom from death and heart transplantation rate of 54% (95 %CI 43-66) at 15 years and 44% (95 %CI 33-57) at 25 years post Fontan. However, 95% (95 %CI 91-99) of patients without any of the identified risk factors were free from death or heart transplantation rate at 25 years post Fontan. CONCLUSION: In conclusion, the occurrence of post-operative complications such as PLE, arrhythmia and ventricular dysfunction will likely precede the late demise of these patients.

Pacemakers are associated with a higher risk of late death and transplantation in the Fontan population.

BACKGROUND: The need for permanent pacing has been identified as a predictor of poor outcomes in the late survivors of Fontan surgery. However, it is not clear if the need for a pacemaker is a surrogate marker of a declining Fontan state, or if pacing is deleterious to the Fontan circulation. OBJECTIVES: We sought to compare the long-term outcomes of propensity-matched Fontan patients with and without a permanent pacemaker. METHODS: Patients who have survived Fontan completion with a documented history of cardiac arrhythmia were identified from the Australia and New Zealand Fontan Registry. Pacemaker insertion details, cardiac function and electrophysiological data were obtained for the patients with a permanent pacemaker. Survival analysis was performed with propensity score matching to compare late survival and outcomes in patients with versus without a pacemaker. RESULTS: There was a total of 310 patients with a history of cardiac arrhythmia, of which 126 (41%) had a permanent pacemaker. After propensity-score matching, 99 pairs were generated (n = 198). Patients with a permanent pacemaker had a higher risk of death (HR 3.32 95% CI 1.60-6.90, p = 0.001) and death or transplantation (HR 3.55 95% CI 1.87-6.73, p < 0.001). Patients who were only paced atrially were not at a significantly increased risk of death or transplantation. However, patients who were ventricular paced >50% of the time were much more likely to encounter late death or transplantation (HR 3.82 95% CI 1.64-8.95, p = 0.002). CONCLUSIONS: Having a permanent pacemaker and needing ventricular pacing is likely associated with an increased risk of death and transplantation in patients with a Fontan circulation.

The impact of morphological characteristics on late outcomes in patients born with hypoplastic left heart syndrome†.

OBJECTIVES: Patients with hypoplastic left heart syndrome are at high risk of late adverse events after Fontan completion, but it is unclear whether their morphological characteristics influence these outcomes. METHODS: Retrospective review of the data from the Australian and New Zealand Fontan Registry identified 185 patients with hypoplastic left heart syndrome who survived to hospital discharge after Fontan completion. Their outcomes were reviewed to identify predictors of adverse events with a particular focus on the impact of morphological characteristics. All available echocardiographic parameters were collected, and the hypoplasia of the left ventricle was subjectively considered to be mild, moderate or severe. RESULTS: The mean follow-up after the Fontan procedure was 6.4 ± 4.7 years. The median age at Fontan procedure was 4.41 years, 95% (176/185) of patients underwent an extracardiac conduit Fontan procedure and 71% (132/185) of those were fenestrated. At 15 years after Fontan, freedom from death and cardiac transplantation was 90% [95% confidence interval (CI) 85-97], freedom from Fontan failure was 78% (95% CI 70-87) and freedom from adverse events was 32% (95% CI 22-46). Morphological parameters did not influence transplant-free survival or Fontan failure. Independent risk factors predicting higher incidence of adverse events included aortic atresia (P = 0.003). CONCLUSIONS: The long-term survival of Fontan survivors with hypoplastic left heart syndrome is excellent and appears comparable to that of the general Fontan population. However, intrinsic morphological characteristics may continue to burden patients with late morbidity.

The Ross procedure in adults presenting with bicuspid aortic valve and pure aortic regurgitation: 85% freedom from reoperation at 20 years.

OBJECTIVES: The Ross procedure has demonstrated excellent results when performed in patients with aortic stenosis or mixed aortic valve disease [aortic stenosis and aortic regurgitation (AR)]. However, due to its reported risk of late reoperation, it is not recommended under current guidelines for patients presenting with bicuspid aortic valve and pure AR. We have analysed our own results in light of this recommendation. METHODS: Between 1993 and 2016, 129 consecutive patients with a mean age of 34.7 ± 10.6 years (range 16-64 years) presented with bicuspid aortic valve and pure AR and underwent the Ross procedure. Patients were reviewed annually and had 2nd yearly transthoracic echocardiograms during follow-up. The unit had a liberal reoperation policy where reoperation was performed if patients developed recurrent moderate or greater AR during follow-up. RESULTS: There was 1 inpatient death, and 3 late deaths over a mean follow-up duration of 9.6 ± 6.8 years. Late survival at 10 and 20 years post-surgery were 99% [95% confidence interval (CI) 94-100] and 95% (95% CI 85-99), respectively. Eleven patients underwent redo aortic valve replacement (AVR) and 4 patients had redo pulmonary valve replacement. Freedom from reoperation for AVR and more-than-mild AR at 10 and 20 years post-surgery were 89% (95% CI 81-94) and 85% (95% CI 74-92), respectively. Having longer aortic cross-clamp (hazard ratio 1.03, 95% CI 1.00-1.06; P = 0.05) and cardiopulmonary bypass times (hazard ratio 1.02, 95% CI 1.00-1.05; P = 0.05), and having a larger preoperative sinotubular junction diameter (hazard ratio 1.15, 95% CI 1.03-1.30; P = 0.02) were significant predictors of having redo AVR or significant AR at follow-up. CONCLUSIONS: With a 20-year freedom from redo AVR and greater-than-mild residual AR of 85%, the utilization of the Ross procedure in bicuspid aortic valve patients with pure AR should be considered.

Improved Survival After the Ross Procedure Compared With Mechanical Aortic Valve Replacement.

BACKGROUND: It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR). OBJECTIVES: This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR. METHODS: Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment. RESULTS: Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018). CONCLUSIONS: In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise.

Ventricular assist device support in patients with single ventricles: the Melbourne experience.

OBJECTIVES: The capacity and limitations of ventricular assist device (VAD) support in single-ventricle physiology remains poorly understood. We aimed to review our experience in the use of VAD support in the single-ventricle circulation to determine its feasibility in this population. METHODS: We reviewed our experience with VAD support in patients with single ventricles over the past 25 years. Fifty-seven patients received 64 runs of VAD support between 1990 and 2015 at a median age of 13 days [interquartile range (IQR) 4.1-99.4 days], of which 55 were supported for post-cardiotomy failure. The majority of patients received short-term VAD support, while 4 patients were either directly supported (1) or transitioned onto the Berlin Heart EXCOR (3). RESULTS: The median duration of support was 3.5 days (IQR 2.8-5.2 days). Twelve patients suffered significant neurological complications, and thromboembolic events occurred in 8 patients. Twenty-nine of the 55 patients were successfully weaned off support (53%). There were 37 inpatient deaths, with a survival-to-hospital discharge rate of 33% (18 of 55). Of the 4 patients supported after early Fontan failure, 3 died. Having a higher mean arterial blood pressure on initiation of VAD support was the only significant predictor of death (hazards ratio 1.08; 95% confidence interval 1.03-1.14; P = 0.002). Patients who required a second run of support had higher hospital mortality (83% vs 63%; P = 0.84). Of the hospital survivors, 12 patients (63%) remain alive without heart transplantation at median 7.2 years (IQR 3.5-14.0) post VAD support. CONCLUSIONS: VAD support in patients with a single ventricle has a high hospital mortality, with 1 of 3 patients surviving to discharge. Systemic VAD support is likely futile in the setting of early Fontan failure or when re-initiation of support is required.

Surgical palliation in patients with a single ventricle and dextrocardia.

BACKGROUND: Dextrocardia is found in a significant proportion of patients undergoing a single-ventricle repair. Surgical outcomes in this cohort are unclear. METHODS: The records of 41 consecutive patients with single-ventricle physiology and dextrocardia presenting in a single institution from 1990 to 2008 were reviewed. Of this cohort, 19 patients had heterotaxy syndrome. Twenty-five of the 41 patients had atrioventricular valve regurgitation (AVVR) on presentation (mild, 13; moderate, 9; severe, 3). RESULTS: One patient died before intervention. Initial surgical palliation was performed in 31 patients. Four patients died postoperatively and 4 interim deaths occurred between initial palliation and bidirectional cavopulmonary shunt (BCPS). Thirty of the surviving 32 patients underwent BCPS, with 2 perioperative deaths. There were 4 additional deaths before Fontan surgery. Twenty-two of the surviving 25 patients underwent a Fontan procedure. There was 1 postoperative mortality. Survival to the age of 15 years was 56% (95% confidence interval [CI], 39%-70%). Patients with moderate or severe regurgitation had higher mortality if they were managed conservatively rather than by surgery (5 of 6 vs 2 of 6; P=.24). Patients with bilateral BCPS had better operative outcomes and survival compared with peers with unilateral anastomosis (odds ratio, 27; P=.005; 95% CI, 2.7-269). The side of the systemic venous pathway did not seem to influence outcomes. CONCLUSIONS: Surgical outcomes of single-ventricle palliation seem poor in patients with dextrocardia. Aggressive management of congenital AVVR might improve the long-term prognosis.