Marlene Busko, for Medscape

May 10, 2023

The study covered in this summary was published on Research Square as a preprint and has not yet been peer reviewed.

Key Takeaways

People with a higher metabolic score for insulin resistance (METS-IR) had a significantly greater rate of major adverse cardiac events (MACE) after they underwent coronary artery bypass graft (CABG) surgery and independent of traditional cardiovascular risk factors in a Chinese study.

Following CABG, patients in the highest quartile for METS-IR had a nearly twofold increased risk of MACE during follow-up compared with patients in the lowest METS-IR quartile after adjusting for potential confounders.

Why This Matters

CABG is standard treatment for people with multivessel and left main coronary artery disease and significantly improves cardiovascular outcomes, but long-term survival after CABG remains poor.

This is the first reported study to examine the relationship between METS-IR and MACE in patients following CABG surgery.

The results suggest that METS-IR is a simple and reliable measure for risk stratification and to guide early interventions for patients who have undergone CABG surgery.

Study Design

The researchers performed a retrospective analysis of 1100 patients who had CABG during 2014 to 2018 at three hospitals in Shandong province, China. The average age of the patients was 63 years.

The authors calculated each patient's METS-IR at baseline using a published formula that takes into account fasting plasma glucose, fasting triglycerides, body mass index, and high-density lipoprotein cholesterol. They called this formula a reliable alternative measure of insulin resistance that has high concordance with the standard measure of insulin resistance obtained by using a hyperinsulinemic-euglycemic clamp.

MACE was a composite of all-cause death, nonfatal myocardial infarction, percutaneous coronary intervention, CABG, or stroke.

The researchers compared the MACE risk during follow-up of patients in the quartile with the highest METS-IR score with those in the quartile with the lowest METS-IR score and adjusted for 20 potential confounders.

Key Results

During a median 70-month follow-up, 243 patients (22%) had a first MACE.

Patients in the highest METS-IR quartile had a significant 97% higher risk of MACE during follow-up compared with those in the lowest METS-IR quartile after adjusting for potential confounders.

Foreach standard deviation increase in METS-IR score the MACE risk increased by a significant 36% after full adjustment.

Adding METS-IR to traditional risk factors for cardiovascular disease significantly improved MACE prediction following CABG surgery, raising the C-statistic for MACE prediction with full adjustment from 0.702 without METS-IR to 0.720 with METS-IR.

Limitations

This was a retrospective study, and hence, the associations found are hypothesis-generating only.

The researchers used telephone follow-up to collect MACE rates, an approach that may have introduced bias from incomplete patient recall.

The researchers did not have information on METS-IR measurements made at times other than at the study's baseline.

Disclosures

The study did not receive commercial funding.

None of the authors had relevant financial disclosures.

This is a summary of a preprint research study, "The metabolic score for insulin resistance in the prediction of major adverse cardiovascular events in patients after coronary artery bypass surgery," written by researchers from Shandong University, China, on Research Square andprovided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on researchsquare.com.

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