Post-heart Surgery and Levothyroxine Therapy: A Narrative Review

Abstract

Context: Cardiopulmonary bypass (CPB), commonly used in cardiac surgeries, often disrupts thyroid hormone levels, leading to conditions like sick euthyroid syndrome (SES), which can impair myocardial function and delay recovery. Objectives: This narrative review examines the impact of levothyroxine therapy on cardiac performance and survival outcomes in patients undergoing heart surgery, particularly those with thyroid dysfunction. Methods: This narrative review was conducted through a literature search on articles in English with the relevant keywords. Results: The review highlights that levothyroxine, a synthetic thyroid hormone, helps restore normal thyroid function, improving hemodynamic stability and cardiac output, and reducing postoperative complications. Studies suggest that levothyroxine therapy facilitates faster recovery, shorter ICU stays, and potentially lower mortality rates. However, the optimal dosing, timing, and duration of therapy remain unclear. Conclusions: While short-term benefits are evident, further research is needed to evaluate the long-term effects of levothyroxine on cardiac function and survival.