Medical Research: What are the main findings of the study?
Dr. Hsich: Women are dying on the heart transplant waiting list at a faster rate than men for almost a decade (see Figure 1) and few studies have even addressed this problem. The occurrence is largely driven by gender differences in survival at the most urgent status (UNOS Status 1A) but the cause remains unclear. Although data is limited our findings raise concern that women are not successfully bridged to transplantation while they remain at high status and are inactivated due to worsening condition.
Figure 1. Scientific Registry of Transplant Recipients: Mortality on Waiting List For Heart Transplantation
Figure derived from table in Scientific registry of transplant recipients: Heart waiting list by gender 2000-2009. Available at:
accessed january 9, 2014.
Medical Research: Were any of the findings unexpected?
Dr. Hsich: Yes. Initially we were surprised that women had a better survival than men when listed as ambulatory UNOS Status 2 patients. However, the difference in survival is most likely due to premature listing of women based on the results of cardiopulmonary stress testing. Women tend to have a better survival than men with any given peak oxygen consumption value (Am J Cardiol 2007; 100:291-5; J Am Coll Cardiol 2006; 47:2237-42). However, there are no sex specific transplant guidelines and the same peak oxygen consumption value for women and men is often used to determine objectively when an ambulatory patient needs to be considered for transplantation.
Medical Research: What should clinicians and patients take away from your report?
Dr. Hsich: More research needs to be done to further explore gender differences in survival and assess for other disparities to improve our current heart transplant allocation system.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Hsich: Machine learning statistical methods can possibly be used to overcome the limitations with the current national database but ultimately we need to enforce better collection of critical data such as hemodynamics, peak oxygen consumption, and panel of reactive antibodies.