Samsung Medical Center study identifies new indicator for heart disease risk

A multicenter study conducted by researchers from Samsung Medical Center and Chonnam National University Hospital has identified Microvascular Resistance Reserve (MRR) as a highly effective indicator for assessing coronary microvascular dysfunction (CMD).

Analyzing 1,003 patients across seven South Korean medical institutions between April 2022 and November 2024, the study found that 33.3% of participants exhibited CMD, defined by an MRR value of 2.5 or lower. Patients with this dysfunction faced a 1.94 times higher risk of major cardiovascular events—including death, myocardial infarction, the need for revascularization, and hospitalization for heart failure—compared to those with preserved microvascular function.

The two-year estimated incidence rate for major cardiovascular events was 18.2% in the CMD group, significantly higher than the 8.6% observed in the group with preserved function. The findings, published in the European Heart Journal, suggest that MRR can serve as a concise and precise tool for diagnosing microvascular issues that are often difficult to detect through standard coronary angiography alone.