Elsevier

JACC: Heart Failure

Volume 8, Issue 7, July 2020, Pages 557-568
JACC: Heart Failure

Mini-Focus Issue: Advanced Heart Failure
Clinical Research
Heart Transplantation: An In-Depth Survival Analysis

https://doi.org/10.1016/j.jchf.2020.03.014Get rights and content
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Abstract

Objectives

This study aims to understand the complex factors affecting heart transplant survival and to determine the importance of possible sex-specific risk factors.

Background

Heart transplant allocation is primarily focused on preventing waitlist mortality. To prevent organ wastage, future allocation must balance risk of waitlist mortality with post-transplantation mortality. However, more information regarding risk factors after heart transplantation is needed.

Methods

We included all adults (30,606) in the Scientific Registry of Transplant Recipients database who underwent isolated heart transplantation from January 1, 2004, to July 1, 2018. Mortality (8,278 deaths) was verified with the complete Social Security Death Index with a median follow-up of 3.9 years. Temporal decomposition was used to identify phases of survival and phase-specific risk factors. The random survival forests method was used to determine importance of mortality risk factors and their interactions.

Results

We identified 3 phases of mortality risk: early post-transplantation, constant, and late. Sex was not a significant risk factor. There were several interactions predicting early mortality such as pretransplantation mechanical ventilation with presence of end-organ function (bilirubin, renal function) and interactions predicting later mortality such as diabetes and older age (donor and recipient). More complex interactions predicting early-, mid-, and late-mortality existed and were identified with machine learning (i.e., elevated bilirubin, mechanical ventilation, and dialysis).

Conclusions

Post–heart transplant mortality risk is complex and dynamic, changing with time and events. Sex is not an important mortality risk factor. To prevent organ wastage, end-organ dysfunction should be resolved before transplantation as much as possible.

Key Words

heart transplantation
mechanical circulatory support
mortality
outcome assessment
sex

Abbreviations and Acronyms

ECMO
extracorporeal membrane oxygenation
IHTSA
International Heart Transplant Survival Algorithm
IMPACT
Index for Mortality Prediction After Cardiac Transplantation
ISHLT
International Society for Heart and Lung Transplantation
OPTN
Organ Procurement and Transplantation Network
RSF
random survival forests
SRTR
Scientific Registry of Transplant Recipients

Cited by (0)

Supported in part by grants HL141892 and GM125072 from the National Institutes of Health (NIH) and support from the Cystic Fibrosis Foundation. The data reported here have been supplied by the Hennepin Healthcare Research Institute (HHRI) as the contractor for the Scientific Registry of Transplant Recipients (SRTR). The interpretation and reporting of these data are the responsibility of the author(s) and in no way should be seen as an official policy of or interpretation by the SRTR or the U.S. Government. The authors have reported that they have no relationships relevant to the contents of this paper to disclose. John Teerlink, MD, was Guest Editor on this paper.

The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Heart Failure author instructions page.