Critical left ventricular outflow tract obstruction: The disproportionate impact of biventricular repair in borderline cases

Hickey, Edward J.; Caldarone, Christopher A.; Blackstone, Eugene H.; Lofland, Gary K.; Yeh, Thomas; Pizarro, Christian; Tchervenkov, Christo I.; Pigula, Frank; Overman, David M.; Jacobs, Marshall L.; McCrindle, Brian W.; Congenital Heart Surgeons’ Society,

doi:10.1016/j.jtcvs.2007.07.052

« Previous Next »The Journal of Thoracic and Cardiovascular Surgery
Volume 134, Issue 6 , Pages 1429-1437.e7, December 2007

Critical left ventricular outflow tract obstruction: The disproportionate impact of biventricular repair in borderline cases

Read at the Eighty-seventh Annual Meeting of The American Association for Thoracic Surgery, Washington, DC, May 5-9, 2007.

Edward J. Hickey, MD
- The Congenital Heart Surgeon’s Society Data Center, Toronto, Ontario, Canada
- Address for reprints: Edward J. Hickey, MD, the Congenital Heart Surgeons’ Society, Hospital for Sick Children, 555 University Ave, Toronto, Ontario M5G 1X8, Canada.
Christopher A. Caldarone, MD
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Co-senior authors.
Eugene H. Blackstone, MD
- The Cleveland Clinic Foundation, Cleveland, Ohio
Gary K. Lofland, MD
- Children’s Mercy Hospital, Kansas City, Mo
Thomas Yeh Jr, MD
- University of Texas Southwestern Medical Center, Dallas, Tex
Christian Pizarro, MD
- Alfred duPont Hospital for Children, Wilmington, Del
Christo I. Tchervenkov, MD
- Montreal Childrens Hospital, Montreal, Quebec, Canada
Frank Pigula, MD
- Boston Children’s Hospital, Boston, Mass
David M. Overman, MD
- Children’s Heart Clinic, Minneapolis, Minn
Marshall L. Jacobs, MD
- St Christopher Hospital for Children, Philadelphia, Penn.
Brian W. McCrindle, MD
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Co-senior authors.
Congenital Heart Surgeons’ Society

Received 17 May 2007; received in revised form 19 July 2007; accepted 24 July 2007. published online 09 November 2007.

Objective

In critical left ventricular outflow tract obstruction, the common perception that biventricular physiology is superior to univentricular physiology has led to a bias favoring biventricular repair. We hypothesized that pursuit of biventricular repair in borderline candidates increases mortality.

Methods

Between 1994 and 2001, 362 neonates with critical left ventricular outflow tract obstruction were prospectively enrolled by 26 institutions. Initial procedure indicated intended univentricular repair (n = 223; 84 deaths) or biventricular repair (n = 139; 39 deaths). Parametric risk–hazard analysis identified predictors of death for univentricular and for biventricular repair, which allowed prediction of the 5-year univentricular survival advantage for every infant. Survival was scrutinized for children managed discordantly to univentricular survival advantage predictions.

Results

Incremental factors for death after univentricular repair were as follows: tricuspid regurgitation, smaller mitral annulus z-score, smaller indexed dominant ventricular length, and presence of a large ventricular septal defect; risk factors after biventricular repair were as follows: minimum left ventricular outflow tract diameter, endocardial fibroelastosis, left ventricular dysfunction, and smaller mid-aortic arch. These variables formed the univentricular survival advantage tool (all P < .0001, R² = 0.92). Discordant management was more common with biventricular than with univentricular repair (56% vs 21%; P < .01). Discordant pursuit of biventricular repair was associated with significantly more observed versus expected deaths (biventricular repair 30 vs 14; P < .001; univentricular repair 20 vs 13; P = .02). Survival after biventricular repair is sensitive to changes in univentricular survival advantage values, especially in borderline candidates. In contrast, univentricular repair survival is insensitive to changes in univentricular survival advantage values.

Conclusions

Inappropriate pursuit of biventricular repair in borderline candidates is more frequent and more consequential in survival terms than is inappropriate pursuit of univentricular repair. Use of the univentricular survival advantage tool will help identify infants for whom univentricular repair may be a better choice than attempting biventricular repair.

CTSNet classification: 18, 20, 21

Abbreviations and Acronyms: BAV, balloon aortic valvotomy, BVR, biventricular repair, CHSS, Congenital Heart Surgeons’ Society, EFE, endocardial fibroelastosis, LVOT, left ventricular outflow tract, UVR, univentricular repair, UVR-SA, univentricular repair survival advantage, VSD, ventricular septal defect