Cardiac arrhythmias secondary to hormone therapy in trans women

ABSTRACT

Introduction: With greater social acceptance and the evolution of transgender medicine as a specialty, more trans women are seeking hormone therapy (HT). Several studies have identified an increase in cardiovascular disease in trans women, however no studies have investigated the incidence of arrhythmias. Using two cases from the authors’ clinic as examples, we propose that hormone therapy in trans women may increase the risk of cardiac arrhythmias.

Areas covered: A literature search of sex hormones and cardiac arrhythmias was conducted. Using sex hormone studies completed in cis individuals and animal models we identified several similarities to trans women on HT. In cis men, low levels of testosterone are associated with increased rates of atrial fibrillation and right ventricular outflow tract arrhythmias. The role of estradiol remains less clear but there is evidence to suggest that the administration of exogenous estrogen may increase the rates of cardiac arrhythmias in cis women.

Expert opinion: Research in the field of transgender medicine is expanding. As more trans women initiate HT, we will have a larger database from which to collect information regarding the benefits and risks of treatment, including the potential side effect of arrhythmias.

KEYWORDS:

• Arrhythmogenicity
• atrial fibrillation
• estrogen
• hormone therapy
• sex hormones
• testosterone
• transgender

Article highlights

• Hormone therapy prescribed for trans women includes a compound to reduce serum levels of testosterone as well as a formulation of estrogen; in order to correspond with the physiological hormone levels of premenopausal cis women.

• Hormone therapy increases the risk of cardiovascular disease in trans women compared to trans men, cis men and cis women.

• In studies involving cis men with hypogonadism and those undergoing androgen deprivation therapy for prostate cancer, low testosterone has been associated with increased rates of atrial and ventricular arrhythmias.

• In animal models, low testosterone causes calcium mishandling and increased arrhythmogenesis.

• The exogenous administration of estrogen in post-menopausal women has been found to increase the risk of atrial fibrillation.

• Trans women taking hormone therapy may be at an increased risk of atrial and ventricular arrhythmias.

Disclosure statement

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.