The Impact of Hypothyroidism on Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention

Abstract

Introduction: Hypothyroidism either subclinical (SCH) or overt is independently associated with an increased risk of coronary artery disease (CAD). The combined effects of SCH and overt hypothyroidism on clinical outcomes after percutaneous coronary intervention (PCI) are largely unknown. Aim: The aim of the study is to assess the impact of subclinical and overt hypothyroidism among patients presenting with CAD undergoing PCI. Materials and Methods: A total of 102 patients who were referred to the Madras Medical Mission Hospital for PCI from September 2020 to March 2021 were enrolled in the study. These patients were categorized into three groups. Each group has 34 patients and was followed for one year. Group 1: Patients with normal TSH levels (TSH-0.45 -5mlU/Liter) and euthyroid at T₃, T₄ levels. Group 2: Patients with subclinical hypothyroidism with elevated TSH levels (TSH=5-15mlU/liter) and normal thyroid with T_3, T₄ levels. Group 3: Patients with a family history of overt hypothyroidism or high TSH levels(<15mlU/liter) and low T₃ and T₄ levels ^[16]. Results: We applied ANOVA to find the PCI outcomes. A p-value of <0.05 was accepted as significant. Age (p-0.03), recent myocardial infarction (p-0.04), diabetes mellitus (p<0.001), HbA1C (p-0.012), and systolic blood pressure (p-0.04) were found to be significant. Post-PCI bleeding complications (p<0.001) during one month, six months, and one-year follow-up were the main observation of the study. Conclusion: The prior history of DM and elevated HbA1c levels observed in the overt hypothyroid group indicate that DM was one of the key factors associated with overt hypothyroidism. Despite the fact that PCI was safe for patients with hypothyroidism, the risk of early post-PCI bleeding was of concern.