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Dive into the research topics where Ajay J. Iyengar is active.

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Featured researches published by Ajay J. Iyengar.


Circulation | 2007

The Fontan Procedure Contemporary Techniques Have Improved Long-Term Outcomes

Yves d'Udekem; Ajay J. Iyengar; Andrew Cochrane; Leeanne Grigg; James Ramsay; Gavin Wheaton; Daniel J. Penny; Christian P. Brizard

Background— To determine whether patients undergoing the lateral tunnel and extracardiac conduit modifications of the Fontan procedure have better outcomes than patients undergoing a classical atriopulmonary connection. Methods and Results— Between 1980 and 2000, 305 consecutive patients underwent a Fontan procedure at our institution. There were 10 hospital deaths (mortality: 3%) with no death after 1990. Independent risk factors for mortality were preoperative elevated pulmonary artery pressures (P=0.002) and common atrioventricular valve (P=0.04). Fontan was taken down during hospital stay in 7 patients. A mean of 12±6 years of follow-up was obtained in the 257 nonforeign Fontan survivors. Completeness of concurrent follow-up was 96%. Twenty-year survival was 84% (95% CI: 79 to 89%). Recent techniques improved late survival. The 15-year survival after atriopulmonary connection was 81% (95% CI: 73% to 87%) versus 94% (95% CI: 79% to 98%) for lateral tunnel (P=0.004). Nine pts required heart transplantation (8 atriopulmonary connection, 1 lateral tunnel). Undergoing a Fontan modification independently predicted decreased occurrence of arrhythmia, and 15-year freedom from SVT was 61% (95% CI: 51% to 70%) for atriopulmonary connection versus 87% (95% CI: 76% to 93%) for lateral tunnel (P=0.02). Freedom from Fontan failure (death, take-down, transplantation, or NYHA class III-IV) was 70% (95% CI: 58% to 79%) at 20 years. After extra-cardiac conduits, no death, SVT, or failure was observed. Conclusions— The Fontan procedure remains a palliation, but outcomes of patients have improved. Better patient selection minimizes hospital mortality. Patients with lateral tunnel and extracardiac conduit modifications experience less arrhythmia and are likely to have failure of their Fontan circulation postponed.


Circulation | 2014

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

Yves d’Udekem; Ajay J. Iyengar; John C. Galati; Victoria Forsdick; Robert G. Weintraub; Gavin Wheaton; Andrew Bullock; Robert Justo; Leeanne Grigg; Gary F. Sholler; Sarah A. Hope; Dorothy J. Radford; Thomas L. Gentles; David S. Celermajer; David S. Winlaw

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.


Journal of the American College of Cardiology | 2012

Predictors of survival after single-ventricle palliation: the impact of right ventricular dominance.

Yves d'Udekem; Mary Y. Xu; John C. Galati; Siming Lu; Ajay J. Iyengar; Igor E. Konstantinov; Gavin Wheaton; James Ramsay; Leeanne Grigg; Johnny Millar; Michael M. Cheung; Christian P. Brizard

OBJECTIVES This study examined survival after surgical palliation in children with single-ventricle physiology. BACKGROUND Contemporary surgical outcomes for the entire population of newborns undergoing single-ventricle palliation are unclear. METHODS In a single-center review of 499 consecutive patients undergoing univentricular palliation from 1990 to 2008, predictors of mortality were determined using multivariate risk analysis, stratified for each post-operative stay and interim states. RESULTS After 2000, the population comprised more patients with dominant right ventricle (66% vs. 36%) and hypoplastic left heart syndrome (HLHS) (47% vs. 13%). Median age at bidirectional cavopulmonary shunt (BCPS) decreased from 15 months (10 to 22 months) before 2000 to 4 months (3.3 to 9 months) thereafter. Survival rates at 1, 5, and 10 years were, respectively, 82% (95% confidence interval [CI]: 79% to 85%), 74% (95% CI: 70% to 78%), and 71% (95% CI: 67% to 75%). Throughout the study, atrioventricular valve regurgitation (hazard ratio [HR]: 1.8; p = 0.008), not having transposition (HR: 2.0; p = 0.013), and heterotaxia (HR: 2.0; p = 0.026) were predictors of mortality. The most potent risk factor was right ventricular (RV) dominance (HR: 2.2; p = 0.001) because of its impact before BCPS. HR for death in patients with RV dominance went from 2.8 (95% CI: 1.4 to 5.7; p = 0.005) before BCPS to 1.0 (95% CI: 0.5 to 2.1; p = 0.98) thereafter. Survival of patients with RV dominance, adjusted for the risk factors noted here, improved over the study period (p = 0.001). CONCLUSIONS Considerable mortality is still observed during the first years of life among patients with single ventricle. RV dominance is the most important risk factor for death but only before BCPS.


Journal of the American College of Cardiology | 2013

Surgical valvotomy and repair for neonatal and infant congenital aortic stenosis achieves better results than interventional catheterization.

Javariah Siddiqui; Christian P. Brizard; John C. Galati; Ajay J. Iyengar; Darren Hutchinson; Igor E. Konstantinov; Gavin Wheaton; James Ramsay; Yves d'Udekem

OBJECTIVES This study sought to compare outcomes after surgical valvuloplasty and balloon dilation of the aortic valve in neonates and infants. BACKGROUND Surgical techniques of aortic valve repair have improved and there is today controversy on the best approach to treat neonatal congenital aortic valve stenosis. METHODS Retrospective review of data and follow-up of 123 consecutive neonates and infants (35 females, 88 males) undergoing intervention for congenital aortic stenosis. RESULTS From 1977 to 2009, 123 consecutive neonates (<30 days) and infants (31 days to 1 year) underwent relief of congenital aortic stenosis. Median age at procedure was 27 days (6 to 76 days). Twenty-year survival was 80 ± 7%. Fifty-four patients required a re-intervention and freedom from re-intervention was 55 ± 6% at 10 years and 40 ± 6% at 20 years. By multivariate analysis, having the relief of stenosis by balloon valvuloplasty and undergoing initial treatment as a neonate were predictive of re-intervention. Freedom from re-intervention at 5 years was 27% after balloon valvuloplasty versus 65% after surgery. At latest follow-up, an additional 16 patients had moderate or severe stenosis and 8 had regurgitation. Freedom from re-intervention or stenosis was 39 ± 5% at 15 years. By multivariate analysis, balloon valvuloplasty (p < 0.001) and treatment as a neonate (p = 0.003) were again predictive of stenosis or re-intervention. Thirty-five patients ultimately needed a valve replacement. Significant predictor of the requirement of valve replacement was unicuspid aortic valve (p < 0.001). Freedom from valve replacement was 55 ± 7% at 20 years. CONCLUSIONS Surgical valvuloplasty remains the best approach to treat neonates and infants with congenital aortic stenosis. After surgery, a higher proportion of patients remain free of re-intervention than after interventional catheterization and the relief of their stenosis lasts longer.


European Journal of Cardio-Thoracic Surgery | 2014

The extracardiac conduit Fontan procedure in Australia and New Zealand: hypoplastic left heart syndrome predicts worse early and late outcomes

Ajay J. Iyengar; David S. Winlaw; John C. Galati; Gavin Wheaton; Thomas L. Gentles; Leeanne Grigg; Robert Justo; Dorothy J. Radford; Robert G. Weintraub; Andrew Bullock; David S. Celermajer; Yves d'Udekem

OBJECTIVES To identify factors associated with hospital and long-term outcomes in a binational cohort of extracardiac conduit (ECC) Fontan recipients. METHODS All patients who underwent an ECC Fontan procedure from 1997 to 2010 in Australia and New Zealand were identified, and perioperative, follow-up, echocardiographic and reintervention data collected. Risk factors for early and late mortality, failure and adverse outcomes were analysed. RESULTS A total of 570 patients were identified, and late follow-up was available in 529 patients. The mean follow-up was 6.7 years (standard deviation: 3.5) and completeness of the follow-up was 98%. There were seven hospital mortalities (1%) and 21 patients (4%) experienced early failure (death, Fontan takedown/revision or mechanical circulatory support). Prolonged length of stay occurred in 10% (57 patients), and prolonged effusions in 9% (51 patients). Overall survival at 14 years was 96% (95% confidence interval [CI]: 93-98%), and late survival for patients discharged with intact Fontan was 98% (95% CI: 94-99%). The rates of late failure (late death, transplantation, takedown, New York Heart Association class III/IV or protein-losing enteropathy) and adverse events (late failure, reoperation, percutaneous intervention, pacemaker, thromboembolic event or supraventricular tachycardia) per 100 patient-years were 0.8 and 3.8, and their 14-year freedoms were 83% (95% CI: 70-91%) and 53% (95% CI: 41-64%), respectively. After adjustment for confounders, hypoplastic left heart syndrome (HLHS) was strongly associated with prolonged effusions (OR: 2.9, 95% CI: 1.4-5.9), late failure (hazard ratio [HR]: 2.8, 95% CI: 1.1-7.5) and adverse events (HR: 3.6, 95% CI: 1.3-7.5). CONCLUSIONS The extracardiac Fontan procedure provides excellent survival into the second decade of life, but half of patients will suffer a late adverse event by 14 years. Patients with HLHS are at higher risk of late adverse events than other morphological groups, but their survival is still excellent.


Internal Medicine Journal | 2014

The Australia and New Zealand Fontan Registry: description and initial results from the first population-based Fontan registry

Ajay J. Iyengar; David S. Winlaw; John C. Galati; T. Gentles; Robert G. Weintraub; Robert Justo; Gavin Wheaton; Andrew Bullock; David S. Celermajer; Yves d'Udekem

The Fontan procedure is the final in a series of staged palliations for single‐ventricle congenital heart disease, which encompasses rare and heterogeneous cardiac lesions. It represents an unusual and novel physiological state characterised by absence of a subpulmonary ventricle.


The Journal of Thoracic and Cardiovascular Surgery | 2010

Twenty-three years of single-stage end-to-side anastomosis repair of interrupted aortic arches

Aisyah Hussein; Ajay J. Iyengar; Bryn Jones; Susan Donath; Igor E. Konstantinov; Leeanne Grigg; Gavin Wheaton; Andrew Bullock; Christian P. Brizard; Yves d'Udekem

OBJECTIVE This study defined long-term results of a policy of single-stage repair of interrupted aortic arch with end-to-side anastomosis. METHODS Records of 112 consecutive patients undergoing interrupted aortic arch repair between 1985 and 2007 were reviewed. Single-stage repair was performed in 95 patients, with 90 having end-to-side repair. RESULTS There were 11 in-hospital deaths (10%). Twelve patients needed arch reintervention during the same hospital stay: 7 for residual arch obstruction and 5 for left main bronchus obstruction. Nine patients were unavailable for follow-up. After a mean of 10 +/- 7 years, 6 late deaths occurred, for 18-year survival of 92% (95% confidence interval [CI], 84%-97%). Patients with end-to-side anastomoses had better 18-year survival (97%, 95% CI, 87%-99%, vs 74%, 95% CI, 44%-89%, P < .01). After discharge, 19 patients underwent further aortic arch intervention. The only factors predictive of late arch reintervention were technique other than end-to-side (P < .001) and reoperation for left outflow tract obstruction. Freedom from arch reintervention after end-to-side repair was 78% at 18 years (95% CI, 59%-89%). Another 16 patients had significant residual obstruction. The 18-year freedom from hypertension was 88% (95% CI, 72%-95%). CONCLUSIONS Single-stage repair with end-to-side anastomosis seems the best approach for most neonates with interrupted aortic arch, because it provides relief of the arch obstruction with low early mortality. After 2 decades of experience with this approach, incidence of late hypertension seems minimal. The need for further arch reintervention warrants close follow-up of these patients.


The Annals of Thoracic Surgery | 2012

Long-Term Outcomes After Atrioventricular Valve Operations in Patients Undergoing Single-Ventricle Palliation

Daniel J. Wong; Ajay J. Iyengar; Gavin Wheaton; James Ramsay; Leeanne Grigg; Stephen Horton; Igor E. Konstantinov; Christian P. Brizard; Yves d'Udekem

BACKGROUND Outcomes after atrioventricular (AV) valve operations in patients with functional single ventricles are unclear. METHODS From 1988 to 2010, 76 consecutive patients with single ventricles underwent AV valve operations for regurgitation at a single institution. Five replacements, 66 repairs, and 5 valve closures were performed at a median age of 1 year (range, 1 day-14 years) on 43 tricuspid, 9 mitral, and 24 common AV valves. RESULTS Hospital mortality was 17% (13/76). The follow-up was 100% complete. There were 15 late deaths. There were 48 survivors with a mean follow-up of 8.3±6 years. One- and 10-year Kaplan-Meier survival after AV valve operations was 72% (95% confidence interval [CI], 60%-81%) and 61% (95% CI, 48%-71%), respectively. Independent predictors of overall mortality were presence of a common AV valve (p=0.03), requirement for postoperative mechanical circulatory support (p=0.02), and timing of valve operations between initial palliation and performance of a bidirectional cavopulmonary shunt (BCPS) (p=0.047). Ten-year freedom from valve reoperation and from thromboembolic events of hospital survivors was 56% (95% CI, 38%-70%) and 70% (95% CI, 56%-80%), respectively. At last follow-up, 11 of 48 surviving patients (23%) had moderate to severe regurgitation, and pacemaker implantation was required in 6 patients. Only 34 patients reached the stage of Fontan completion. CONCLUSIONS AV valve regurgitation is a considerable burden for the patient with a single ventricle, especially when appearing at a young age. A quarter of patients died within the first year after operation, and they had considerable morbidity in terms of reoperation, thromboembolic events, and pacemaker implantation. Their chances of reaching Fontan completion seemed decreased.


Interactive Cardiovascular and Thoracic Surgery | 2013

Poor outcomes after surgery for coarctation repair with hypoplastic arch warrants more extensive initial surgery and close long-term follow-up

Sandeep S. Rakhra; Melissa G.Y. Lee; Ajay J. Iyengar; Gavin Wheaton; Leeanne Grigg; Igor E. Konstantinov; Christian P. Brizard; Yves d'Udekem

OBJECTIVES Late outcomes of repair of coarctation with arch hypoplasia have not yet been described. Hypertension and arch reobstruction frequently occur after standard coarctation repair and thus we sought to determine the long-term results of repair in the subset of patients with arch hypoplasia at a single institution over a 20-year period. METHODS We reviewed the files of the 305 consecutive patients quoted to have arch hypoplasia who had undergone a coarctation repair in a single institution between 1984 and 2004. Repair was performed through a sternotomy in 74 patients (24%), 58 of them undergoing a repair consisting of an end-to-side anastomosis. RESULTS Early mortality was 9% but there was only 1 death among patients without a major associated anomaly. Eight patients required reintervention before discharge due to residual obstruction. The follow-up was available in 96% of the patients. Only 45% of the patients over 15 years of age had cardiology review in the last 2 years. Survival at 10 and 20 years was 94% (95% CI: 91-97%) and 92% (95% CI: 86-95%), respectively. There were a total of 66 late reinterventions in 49 (18%) patients. Ten- and 20-year freedom from reintervention was 84% (95% CI: 78-88%) and 72% (95% CI: 63-80%), respectively. Ten- and 20-year freedom from reobstruction was 75% (95% CI: 69-80%) and 45% (95% CI: 34-55%), respectively. Patients undergoing end-to-side repair from sternotomy had less arch reobstruction than those undergoing extended end-to-end repair by thoracotomy (92 vs 61% freedom from reobstruction at 10 years, P < 0.001). Only 68% of the patients were normotensive at the last follow-up. Arch obstruction on echocardiogram was associated with an increased prevalence of hypertension (P = 0.018). CONCLUSIONS After coarctation repair, half of the patients with hypoplasia of the transverse arch will develop arch reobstruction and a third will become hypertensive. The technique of end-to-side repair performed through a sternotomy seems to alleviate these issues, and could be offered to a larger proportion of patients with hypoplasia of the aortic arch. Many of these patients are lost to follow-up during adolescence, at a time when ongoing care seems mandatory.


European Journal of Cardio-Thoracic Surgery | 2010

Fontan completion rate and outcomes after bidirectional cavo-pulmonary shunt.

Ann-Marie Tan; Ajay J. Iyengar; Susan Donath; Andrew Bullock; Gavin Wheaton; Leeanne Grigg; Christian P. Brizard; Yves d'Udekem

OBJECTIVE To determine outcomes of patients undergoing a bidirectional cavo-pulmonary shunt (BCPS) in the Fontan era. METHODS From 1990 to 2000, 212 patients underwent a BCPS in a single institution at a mean age of 2.6+/-5 years. RESULTS Hospital mortality was 6% (13 patients). Five patients were lost to follow-up (3%). After a mean of 9+/-4 years, 15 patients had not yet been referred for Fontan surgery and their status was deemed satisfactory (11 1(1/2) ventricle repair, three BCPS and one patient converted to a bi-ventricular repair). Out of the remaining 179 patients who could potentially have reached a Fontan status, 141 had undergone the procedure and seven were awaiting Fontan completion. The expected completion rate of Fontan surgery after BCPS was 83% (148/179). Thirteen patients died and heart transplantation was necessitated in nine patients. Nine were deemed unsuitable for Fontan surgery for cardiac (seven), respiratory (one) or neurologic (one) reasons. After BCPS, the only predictors of late failure (death, heart transplantation or NYHA class III-IV) were not reaching Fontan status and the presence of bilateral superior vena cava (SVC). Ten-year survival was 99% (95% confidence interval (CI): 95-99%) for Fontan patients and 67% (95%CI: 50-80%) for those left with a BCPS. CONCLUSION In the present era, staging with BCPS represents a selection process in the Fontan pathway. Almost a fifth of the patients will not reach Fontan status. Outstanding results after Fontan surgery may hide a high attrition rate between BCPS and Fontan.

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Yves d'Udekem

Royal Children's Hospital

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Leeanne Grigg

Royal Melbourne Hospital

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Gavin Wheaton

Boston Children's Hospital

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Yves d’Udekem

Royal Children's Hospital

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Andrew Bullock

Princess Margaret Hospital for Children

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