BNP Peptide and Blood Glucose Together Help Detect Hidden Coronary Microvascular Disease | Research

The takeaway

BNP (a natriuretic peptide) combined with blood glucose levels showed good diagnostic accuracy (AUC=0.74-0.77) for identifying impaired coronary flow reserve and microvascular dysfunction in patients with metabolic risk factors.

AUC = 0.77
for BNP in detecting structural coronary microvascular disease, suggesting this accessible peptide biomarker could screen for hidden heart damage

What the researchers found

Among 65 patients, 31% had impaired coronary flow reserve (CFR). BNP showed diagnostic accuracy for impaired CFR with AUC=0.74 (95% CI 0.60-0.88), while casual blood glucose had AUC=0.64 (95% CI 0.49-0.80). Combining both markers improved discrimination (p=0.03).

For structural CMD (CFR<2.0 and IMR≥25), elevated BNP (AUC=0.77, 95% CI 0.59-0.95) and higher urine albumin-to-creatinine ratio (AUC=0.71, 95% CI 0.52-0.90) were significantly associated, but casual blood glucose was not. BNP emerged as the most consistent biomarker across both functional and structural CMD definitions.

Why it matters

CMD is underdiagnosed because it requires invasive testing to confirm. Finding that a simple, widely available blood test — BNP — can identify patients with impaired coronary microvascular function could enable earlier detection and treatment. The CKM (cardiovascular-kidney-metabolic) framework links this to the broader understanding that metabolic disease damages small blood vessels throughout the body.

How the study worked

Retrospective analysis of 65 patients who underwent invasive coronary physiological assessment using thermodilution-derived coronary flow reserve and index of microcirculatory resistance. Clinical variables (blood glucose, BNP, urine ACR) and echocardiographic diastolic function indices were correlated with CMD measures. Diagnostic accuracy was assessed using ROC analysis.

What this study cannot tell us

This is a small retrospective study of only 65 patients, limiting statistical power and generalizability. The diagnostic thresholds need validation in larger, prospective cohorts. Casual (non-fasting) blood glucose is inherently variable. The study population underwent invasive testing, so results may not represent the general population with suspected CMD.

How to read the evidence

This is a small retrospective exploratory analysis of 65 patients. While the findings are intriguing and the biomarkers are clinically accessible, the study is hypothesis-generating and needs validation in larger prospective cohorts.

When this study was published

Published in 2026, this study applies the recent CKM syndrome framework to coronary microvascular disease diagnosis using accessible biomarkers.

The bigger picture

This study applies the emerging CKM (cardiovascular-kidney-metabolic) syndrome framework to coronary microvascular disease, showing that metabolic risk factors converge on microvascular damage detectable through accessible biomarkers. As the medical community increasingly recognizes CMD as a distinct clinical entity, having simple screening tools like BNP could transform how these patients are identified and managed.

Questions still open

Would serial BNP measurements track CMD progression or response to treatment?
Could a simple BNP + glucose screening panel replace invasive testing for initial CMD assessment?
Do GLP-1 drugs that lower glucose and improve cardiovascular outcomes also improve coronary microvascular function?

Common questions

What is coronary microvascular dysfunction?

It's a condition where the tiny blood vessels in the heart don't work properly, reducing blood flow to the heart muscle. It can cause chest pain even when major arteries look normal on standard tests. This study found that a simple blood test (BNP) could help identify it without invasive procedures.

What is BNP and why is it useful for detecting heart problems?

BNP (B-type natriuretic peptide) is a hormone released by the heart when it's under stress. Higher BNP levels indicate the heart is working harder than normal. This study found BNP levels can also identify damage to the heart's tiny blood vessels, adding a new use for this commonly ordered blood test.

Read the original research

Integration of BNP and blood glucose for identifying coronary flow reserve impairment: A cardiovascular-kidney-metabolic perspective.

American heart journal plus : cardiology research and practice, 61, 100671

View on PubMed ↗Publisher’s paper ↗

Citation

Matsumoto, Kotaro; Otsuka, Kenichiro; Kagawa, Shunsuke; Yamaura, Hiroki; Miura, Tsubasa; Sugioka, Kazuya; Saitoh, Wataru; Okamoto, Akihiro; Kajio, Go; Fujisawa, Naoki; Yamaguchi, Tomohiro; Shimada, Takenobu; Hayashi, Yusuke; Shibata, Atsushi; Ito, Asahiro; Yamazaki, Takanori; Fukuda, Daiju. (2026). Integration of BNP and blood glucose for identifying coronary flow reserve impairment: A cardiovascular-kidney-metabolic perspective.. American heart journal plus : cardiology research and practice, 61, 100671. https://doi.org/10.1016/j.ahjo.2025.100671