Cardiac Mechanics in Altered Hormonal States as a Surrogate for Understanding the Effects of Transgender Hormone Therapy

Transgender individuals are increasingly seeking the care of physicians to physically transition to their self-identified gender identity. Gender-affirming hormone therapy (GAHT) has significant endocrine effects which may have cardiovascular consequences, and cardiovascular disease in transgender individuals is a growing area of study. The effects of GAHT on cardiac mechanics have yet to be characterized, but there is existing literature regarding changes to cardiac mechanics in similar altered hormonal states. We reviewed this literature, with a focus on echocardiographic findings. We found variable results between studies of different methodologies. These include findings that supraphysiological levels of testosterone may impair cardiac mechanics, whereas estrogen-containing hormonal replacement therapy may improve diastolic echocardiographic parameters. In summary, there are alterations to echocardiographic parameters in altered endocrine states related to exogenous testosterone and estrogen, in a manner that is likely dose-dependent. Encouragingly, the studies we reviewed did not suggest that hormonal changes within physiologic ranges would detrimentally affect echocardiographic parameters of systolic and diastolic function. Future research into the cardiovascular effects of long-term GAHT is warranted to safely guide the longitudinal treatment of transgender individuals.