Alireza S. Mahani

Indications and results of systemic to pulmonary shunts: results from a national database

OBJECTIVES The systemic-to-pulmonary shunt (SPS) remains an important palliative therapy in many congenital heart defects. Unlike other surgical treatments, the mortality after shunt operations has risen. We used an audit dataset to investigate potential reasons for this change and to report national results. METHODS A total of 1993 patients classified in 13 diagnoses underwent an SPS procedure between 2000 and 2013. Indication trends by era and also results before repair or next stage are reported. A dynamic hazard model with competing risks and modulated renewal was used to determine predictors of outcomes. RESULTS The usage of SPS in Tetralogy of Fallot (ToF) has significantly decreased in the last decade, with cases of single ventricle (SV) and pulmonary atresia (PA) with septal communication increasing (P < 0.001 for trends). This is correlated with an increase of early mortality from 5.1% in the first half of the decade to 9.8% in the latter (P = 0.007 for trend). At 1.5 years, 13.9% of patients have died, 17.8% had a shunt reintervention and 68.3% of patients are alive and reintervention-free. Low weight, PA-intact septum, SV and central shunt type are among the factors associated with increased mortality, whereas PA-ventricular septal defect, corrected transposition, isomerism, central shunt and low weight are among those associated with increased reintervention, also having a dynamic effect on the relative risk when compared with ToF patients. Shunt reinterventions are not associated with worse outcomes when adjusted by other covariates, but they do have higher 30-day mortality if occurring earlier than 30 days from the index (P < 0.001). Patients operated in later years were found to have significantly lower survival at a distance from index. CONCLUSIONS The observed historical rise in mortality for shunt operations relates to complex factors including changing practice for repair of ToF and for univentricular palliation. PA and SV patients are the groups of patients at the highest risk of death. Small size, shunt type and underlying anatomical defect are the main determinants of outcomes. Trends in indication and mortality seem to indicate that more severely ill patients benefit from shunting, but with an increase in mortality.

Primary repair versus surgical and transcatheter palliation in infants with tetralogy of Fallot

Objectives Treatment of infants with tetralogy of Fallot (ToF) has evolved in the last two decades with increasing use of primary surgical repair (PrR) and transcatheter right ventricular outflow tract palliation (RVOTd), and fewer systemic-to-pulmonary shunts (SPS). We aim to report contemporary results using these treatment options in a comparative study. Methods This a retrospective study using data from the UK National Congenital Heart Disease Audit. All infants (n=1662, median age 181 days) with ToF and no other complex defects undergoing repair or palliation between 2000 and 2013 were considered. Matching algorithms were used to minimise confounding due to lower age and weight in those palliated. Results Patients underwent PrR (n=1244), SPS (n=311) or RVOTd (n=107). Mortality at 12 years was higher when repair or palliation was performed before the age of 60 days rather than after, most significantly for primary repair (18.7% vs 2.2%, P<0.001), less so for RVOTd (10.8% vs 0%, P=0.06) or SPS (12.4% vs 8.3%, P=0.2). In the matched groups of patients, RVOTd was associated with more right ventricular outflow tract (RVOT) reinterventions (HR=2.3, P=0.05 vs PrR, HR=7.2, P=0.001 vs SPS) and fewer pulmonary valve replacements (PVR) (HR=0.3 vs PrR, P=0.05) at 12 years, with lower mortality after complete repair (HR=0.2 versus PrR, P=0.09). Conclusions We found that RVOTd was associated with more RVOT reinterventions, fewer PVR and fewer deaths when compared with PrR in comparable, young infants, especially so in those under 60 days at the time of the first procedure.

P9 Indications and results of systemic to pulmonary shunts – results from a national database

Objective The systemic-to-pulmonary shunt (SPS) remains an important palliative therapy in many congenital heart defects. Unlike other surgical treatments, the mortality after shunt operations has risen. We used an audit dataset to investigate potential reasons for this change and to report national results. Patients and methods A total of 1993 patients classified in 13 diagnoses underwent an SPS procedure between 2000 and 2013. Indication trends by era and also results before repair or next stage are reported. A dynamic hazards model with competing risks and modulated renewal were used to determine predictors of outcomes. Results Usage of SPS in Tetralogy of Fallot (ToF) has significantly decreased, in the last decade, with cases of single ventricle (SV) and pulmonary atresia (PA) with septal communication increasing (p < 0.001 for trends). This is correlated with an increase of early mortality from 5.1% in the first half of the decade to 9.8% in the latter (p = 0.007 for trend). At 1.5 years, 13.9% of patients have died, 17.8% had a shunt reintervention and 68.3% of patients are alive and reintervention-free. Survival and freedom from reintervention in the main diagnosis groups can be seen in Figures A and B. Low weight, PA-IVS, SV and central shunt type are among the factors associated with increased mortality, while PA-VSD, corrected transposition, isomerism, central shunt and low weight are among those associated with increased reintervention, also having a dynamic effect on the relative risk when compared to ToF patients. Shunt reinterventions are not associated with worse outcomes when adjusted by other covariates, but they do have higher 30-day mortality if occurring earlier than 30 days from the index (p < 0.001). Patients operated in later years were found to have significantly lower survival at distance from index. Abstract P9 Figure 1 Freedom from death (panel A), or reintervention (panel B) following placement of a systemic to pulmonary shunt. Conclusions The observed historical rise in mortality for shunt operations relates to complex factors including changing practice for repair of ToF and for univentricular palliation. PA and SV patients are the groups of patients at the highest risk of death. Small size, shunt type and underlying anatomical defect are the main determinants of outcomes. Trends in indication and mortality seem to point that more severely ill patients benefit from shunting, but with an increase in mortality.