Durability of Fontan operation studied in modern single ventricle patients
Researchers from The Children’s Hospital of Philadelphia have identified risk factors for early and late mortality in pediatric cardiac patients who underwent a Fontan operation for single-ventricle heart disease.
Tacy E. Downing, MD, a cardiology fellow, and colleagues reviewed 773 patients who underwent Fontan procedures from 1992 to 2009. The primary outcome was a composite of death, transplant or Fontan takedown. The data were presented at Cardiology 2016, the 19th Annual Update on Pediatric and Congenital Cardiovascular Disease.
Of the 773 patients enrolled in the study, 49% had hypoplastic left heart syndrome. Almost half of the patients underwent a lateral tunnel Fontan procedure, while the remainder had an extracardiac Fontan procedure. Downing and colleagues obtained recent vital status for 99.2% of the patients during a median follow-up of 8.9 years. A longer follow-up of more than 15 years was only available for one-third of the patients.
At 20 years post-Fontan surgery, freedom from death, transplant or Fontan takedown was 74%, according to the researchers. Seventy-nine patients died, 25 underwent heart transplants and 10 had Fontan takedown. For those patients who survived to 1 year, the conditional 20-year survival rate was 79%.
Risk factors for early mortality, transplant or loss of Fontan circulation at less than 1 year were early era of Fontan procedure (before 1997), postoperative pleural drainage for more than 14 days, extended stay in the ICU and longer aortic cross-clamp time. Risk factors for late mortality or transplant were mild or greater AV valve regurgitation before Fontan and longer ICU stay.
In a subgroup of patients with pre-Fontan hemodynamic data, those with pulmonary artery pressure greater than 15 mm Hg were more at risk for early, but not late mortality, transplant or Fontan takedown.
“Hypoplastic left heart syndrome, morphology of systemic ventricle and Fontan type were not associated with either early or late events,” the researchers wrote.
Downing told Cardiology Today that what surprised her the most was that despite “significant advances in perioperative survival, true long-term survival for these patients has not improved much over the past 10 years. We know more today than we did a decade ago about how to medically manage Fontan complications, but this has not really impacted mortality.”
According to Downing, “what is needed is an alternative to the Fontan operation. Fontan physiology is inherently flawed and is not sustainable for a lifetime.”
Downing sees “two major areas for game-changing potential innovation.” The first is the “development of a durable Fontan assist device that could permanently improve the physiology of right-sided congestion,” she said. The second is “a major advance in transplant immunology such that heart transplantation could be more durable and more available to highly sensitized patients.” – by Tracey Romero
Downing TE, et al. Abstract 174. Presented at: Cardiology 2016, the 19th Annual Update on Pediatric and Congenital Cardiovascular Disease; Feb. 24-28, 2016; Orlando, Fla.
Disclosure: Downing reports no relevant financial disclosures.