Subclinical hypothyroidism and clinical outcomes after cardiac surgery: A systematic review and meta-analysis

Area of Science:

• Cardiology
• Endocrinology
• Surgical Outcomes

Background:

• Subclinical hypothyroidism (SCH) is linked to adverse cardiovascular events.
• Existing research on SCH and cardiac surgery outcomes is conflicting.
• Patients with SCH are not routinely treated before cardiac surgery.

Purpose of the Study:

• To analyze the impact of SCH on nonurgent cardiac surgery outcomes.
• To evaluate operative mortality, hospital LOS, and other complications.
• To assess long-term all-cause mortality in SCH patients post-surgery.

Main Methods:

• Study-level meta-analysis of seven observational studies.
• Included 3445 patients undergoing coronary artery bypass grafting, valve, or aortic surgery.
• Primary outcome: operative mortality; Secondary outcomes: LOS, ICU stay, POAF, IABP use, renal complications, long-term mortality.

Main Results:

• SCH patients had higher operative mortality (OR 2.57) and prolonged hospital LOS (SMD 0.32).
• Increased renal complications were observed in SCH patients (OR 2.53).
• No significant differences in ICU stay, POAF, or IABP use; higher long-term mortality (IRR 1.82).

Conclusions:

• SCH is associated with worse outcomes in cardiac surgery, including mortality and renal complications.
• Prolonged hospital LOS is a significant concern for SCH patients.
• Maintaining a euthyroid state may improve postoperative cardiac surgery outcomes.