Single-ventricular CHD patients have higher mortality in first year post-transplant vs. biventricular patients, but survival rates are approximately equal at 10 years among those who survive the first post-transplant year

In patients with congenital heart disease (CHD) who undergo heart transplantation, single-ventricle physiology is associated with higher short-term mortality rates, a new study shows.

However, among patients who survive the first year after transplant, biventricular and single-ventricular CHD patients have similar 10-year conditional survival rates. Additionally, 10-year survival rates are better for biventricular CHD patients than for those without CHD who survive the first year after transplant, according to the study.

These data were reported by Syed Shahyan Bakhtiyar, MD, of the David Geffen School of Medicine at UCLA and the University of Colorado Anschutz Medical Center, Aurora, and colleagues, in a manuscript published Monday online and in the Sept. 19 issue of the Journal of the American College of Cardiology.

There is little guiding evidence for patient counseling and management for patients with single-ventricle CHD. With 1.4 million adults in the U.S. living with CHD, and the numbers steadily rising, guidance for management and treatment of CHD is crucial. CHD patients who have single-ventricle physiology are predicted to have the highest risk profiles. Heart transplantation is particularly challenging in this patient group.

This study examined the survival rates after heart transplantation in patients with single and biventricular CHD, comparing CHD and non-CHD recipients of heart transplants, between January 2005 and December 2020. This retrospective, 15-year, outcome-blinded investigator analysis combined the National Inpatient Sample and Organ Procurement and Transplantation Network data sets using probability-linkage.

A total of 382 patients (≥18 years of age) with CHD had heart transplants, and 182 of those patients had single-ventricle physiology. The patients were mostly male (single-ventricle 57%, biventricular 67%), mean age was approximately 37 years, and most patients were white (single-ventricle 74%, biventricular 77%).Single-ventricle CHD patients had significantly lower rates of survival, compared with biventricular CHD patients, at 1 year (91% versus 80%; hazard ratio [HR]=2.50; 95% confidence interval [CI]=1.40-4.49; p=0.002) and 10 years (71% versus 54%; HR=2.10; 95% CI=1.38-3.18; p<0.001).

However, biventricular and single-ventricular patients had similar 10-year survival rates when the single-ventricle patients survived the first post-transplantation year, except in patients with hypoplastic heart syndrome (79% versus 71%; HR=1.58; 95% CI=0.85-2.92; p=0.15). Biventricular CHD transplant patients also had higher 10-year conditional survival rates compared with transplant patients who did not have CHD (79% versus 68%; HR=0.73; 95% CI=0.59-0.90; p=0.003).

The limitations of this study included the lack of transplantation data available in a retrospective study from the two available databases, not all procedures were able to be analyzed due to availability of surgical history, and this study is not generalizable to both pediatric and adult patients.

The investigators concluded that, after surviving the first-year post-transplantation, patients with single-ventricle CHD have similar survival rates to biventricular CHD patients. In addition, patients with biventricular CHD have greater chances of 10-year survival than non-CHD patients who underwent heart transplantation.

In an accompanying editorial, Daphne T. Hsu, MD, of the Albert Einstein College of Medicine, Bronx, New York, and George K. Lui, MD, of Stanford University School of Medicine, Palo Alto, California, described the history of surgical outcomes for CHD and the progress made in treatment methods for the disease.

“The convergence of improved survival after CHD surgery and improved outcomes after transplantation is reflected in the rising proportion of adult patients undergoing cardiac transplantation with the diagnosis of CHD from 2011 to 2021,” the commenters noted.

They pointed out the benefits and future areas for research in this present study and commented on the important of pediatric and adult provider relationships as CHD treatment data continues to unfold.

“The formation of close partnerships between pediatric and adult CHD providers and transplantation specialists offers the potential for improving outcomes in this emerging population. The results of this analysis support the principle that cardiac transplantation should be considered as another stage in the lifelong journey of the patient with complex CHD,” the editorialists concluded.

Sources:

Bakhtiyar SS, Sakowitz S, Ali K, et al. Survival After Cardiac Transplantation in Adults With Single-Ventricle Congenital Heart Disease. J Am Coll Cardiol. 2023;82:1226-1241.

Hsu DT, Lui GK. Transplant in Single Ventricle Physiology: The Forth Stage? J Am Coll Cardiol. 2023;82:1242-1244.

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