CGM-enabled insulin protocol enhances outcomes in cardiac surgery patients

An insulin control protocol utilizing continuous glucose monitoring (CGM) can improve glycemic control and reduce the incidence of heart fibrillation in patients undergoing heart surgery, according to a new study.

A research team led by Professors Moon Sun-joon and Park Cheol-young of the Department of Endocrinology and Professors Kim Min-su and Chung Eui-seok of the Department of Cardiovascular and Thoracic Surgery at Kangbuk Samsung Hospital said Wednesday that it has demonstrated the glycemic control effect in a randomized clinical trial involving 54 patients with type 2 diabetes and prediabetes who underwent heart surgery from 2022 to 2024.

Patients who undergo heart surgery can experience significant fluctuations in blood glucose levels due to systemic inflammatory responses and hormonal changes, which can lead to various complications. Therefore, it is crucial to control blood glucose levels both before and after heart surgery.

However, existing methods of measuring blood glucose have been criticized for their limitations, as they sometimes fail to detect changes in blood glucose levels.

The researchers developed an insulin control protocol using CGM. They compared the results of the CGM-specific insulin control protocol group with those of the conventional glucose measurement-based control group for seven days after surgery.

The analysis showed that the CGM-specific personalized insulin control protocol group had an average of 83.8 percent of the time that blood glucose remained within the ideal range (70-180 mg/dL) compared to the conventional treatment group, which was 8.8 percent higher than the conventional group (75.8 percent). This translates to about two hours of stable blood glucose control on a 24-hour basis.

The CGM-enabled specialized insulin control protocol group also achieved better control in the tighter glycemic target bands of 100-140 mg/dL and 70-140 mg/dL by 11.4 percent and 16.8 percent, respectively.

In particular, the incidence of atrial fibrillation, a common complication after cardiac surgery, was lower in the CGM-specific insulin control protocol group (18.8 percent), less than half that of the conventional group (55.6 percent).

“This is the first study to demonstrate the safety and effectiveness of a specialized insulin control protocol using CGM in cardiac surgery patients,” Professor Moon said. “We will conduct further studies to develop a treatment that can be applied to a wider patient population.”

The findings were published in the latest issue of Cardiovascular Diabetology.