Poor preoperative left ventricular function is associated with decreased insulin sensitivity during cardiac surgery

Area of Science:

• Cardiology
• Metabolic Medicine
• Surgical Physiology

Background:

• Left ventricular ejection function (LVEF) is a key indicator of cardiac health.
• Insulin sensitivity plays a crucial role in glucose metabolism.
• Cardiac surgery, especially with cardiopulmonary bypass (CPB), can significantly affect metabolic processes.

Purpose of the Study:

• To investigate the association between preoperative left ventricular ejection function (LVEF) and whole-body insulin sensitivity.
• To understand how impaired LVEF influences metabolic status before cardiac surgery.

Main Methods:

• Prospective, non-randomized trial involving 140 non-diabetic patients undergoing elective cardiac surgery.
• Patients were grouped by normal (LVEF ≥55%) or low (LVEF ≤45%) preoperative LVEF.
• Insulin sensitivity was measured using the hyperinsulinemic-normoglycemic clamp technique before and during CPB.

Main Results:

• Patients with normal LVEF exhibited higher preoperative insulin sensitivity compared to those with low LVEF (p=0.04).
• Insulin sensitivity decreased significantly in both groups by the end of CPB (p<0.001).
• Demographics were similar between groups, with LVEF being the primary differentiator (p<0.001).

Conclusions:

• Preoperative left ventricular dysfunction is associated with reduced insulin sensitivity in patients undergoing cardiac surgery.
• This finding highlights a potential metabolic vulnerability in patients with poor LVEF prior to CPB.
• Further research may explore interventions to mitigate this metabolic impact.