Cardiac function and coronary plaque development following masculinizing gender-affirming hormone therapy: A prospective cohort study

Introduction: Myocardial dysfunction and the presence of calcified and non-calcified coronary plaques are predictors of cardiovascular disease. Masculinizing gender-affirming hormone therapy may increase cardiovascular risk, highlighting the need for prospective studies to evaluate cardiovascular outcomes during gender-affirming hormone therapy. Objectives: To evaluate changes in cardiac morphology, systolic and diastolic function, and development of coronary plaques after masculinizing gender-affirming hormone therapy. Methods: Prospective study including 47 transmasculine persons (gender-affirming hormone therapy-naïve, TransM_TN, n = 15 and gender-affirming hormone therapy-ongoing, TransM_TO, n = 32). Included persons were evaluated at study inclusion and after one year of masculinizing gender-affirming hormone therapy. At baseline, the median age of TransM_TN was 22 years (interquartile range 19–28 years) and TransM_TO 26 years (interquartile range 24–37 years) with a median gender-affirming hormone therapy duration of 4 years (interquartile range 2–5 years). Cardiac morphology including left ventricular wall thickness, volume, and mass, as well as left ventricular systolic and diastolic function was evaluated using echocardiography. Coronary artery calcifications and non-calcified coronary plaque were assessed using coronary computed tomography angiography. Paired and unpaired statistical analyses were performed within and between TransM_TN and TransM_TO groups. Results: In TransM_TN, diastolic function decreased during follow-up with decreased septal and lateral left ventricular relaxation (14–11 cm/s, p = 0.04 and 18–15 cm/s, p = 0.02, respectively). No significant changes were observed in cardiac morphology, systolic function, or formation of coronary artery calcifications and non-calcified coronary plaque in TransM_TN or TransM_TO groups. At baseline, left ventricular end-diastolic internal diameter was significantly higher in TransM_TO compared to TransM_TN, 4.6 cm (interquartile range 4.3–5.0 cm) versus 4.4 cm (interquartile range 4.2–4.6 cm), p < 0.05. Other baseline cardiac outcomes were comparable between TransM_TN and TransM_TO. Conclusion: Diastolic function declined after the initiation of masculinizing gender-affirming hormone therapy and individuals on long-term masculinizing gender-affirming hormone therapy had larger left ventricular dimensions compared to individuals before gender-affirming hormone therapy initiation. Cardiac morphology, systolic function, and coronary plaque formation remained stable during masculinizing gender-affirming hormone therapy.