Association Between Non-Obstructive Coronary Atherosclerosis and Myocardial Work in Patients with Type 2 Diabetes Mellitus: A Coronary CT Angiography Study.
In patients with T2DM and preserved LVEF, non-obstructive coronary atherosclerosis was independently associated with impaired myocardial mechanical efficiency, whereas global longitudinal strain did not differ significantly across categories.
Key Findings
Results
Global work efficiency (GWE) declined progressively across increasing CAD-RADS categories in T2DM patients with preserved LVEF.
GWE values were 98.0 ± 0.4% (CAD-RADS 0), 96.2 ± 1.1% (CAD-RADS 1), and 93.0 ± 3.5% (CAD-RADS 2).
The trend across categories was statistically significant (p for trend < 0.001).
Study included 114 patients: CAD-RADS 0 (n = 21), CAD-RADS 1 (n = 46), CAD-RADS 2 (n = 47).
Each one-category increase in CAD-RADS was independently associated with a 2.69 percentage-point lower GWE (95% CI -3.36 to -2.03, p < 0.001).
Results
Global wasted work increased progressively across increasing CAD-RADS categories in T2DM patients.
Global wasted work values were 37 mmHg% (IQR 32–44) for CAD-RADS 0, 67 mmHg% (IQR 61–77) for CAD-RADS 1, and 98 mmHg% (IQR 90–103) for CAD-RADS 2.
The trend across categories was statistically significant (p for trend < 0.001).
Each one-category increase in CAD-RADS was independently associated with a 30.6 mmHg% higher global wasted work (95% CI 28.0 to 33.3, p < 0.001).
Findings were consistent when the Agatston score was used instead of CAD-RADS as the exposure variable.
Results
Global longitudinal strain (GLS) did not differ significantly across CAD-RADS categories.
GLS values were -20.1 ± 2.1% (CAD-RADS 0), -19.7 ± 1.9% (CAD-RADS 1), and -19.3 ± 3.1% (CAD-RADS 2).
The p for trend was 0.239, indicating no statistically significant gradient across categories.
This finding suggests GLS may be less sensitive than myocardial work indices for detecting subclinical dysfunction in this population.
Secondary outcomes were corrected for multiplicity using the Holm procedure.
Results
Left ventricular ejection fraction remained normal across all CAD-RADS categories, though a modest downward trend was present.
LVEF was preserved in every CAD-RADS category (0, 1, and 2).
A modest downward trend in LVEF was statistically significant (p for trend = 0.011), despite all values remaining within normal range.
This indicates that myocardial work impairment occurs before overt systolic dysfunction becomes apparent.
Methods
The association between coronary atherosclerotic burden and impaired myocardial work was independent of multiple cardiovascular and metabolic covariates.
Multivariable linear regression was used with adjustment for body mass index, diabetes duration, smoking, heart rate, and estimated glomerular filtration rate, beyond the original covariate set.
CAD-RADS was modelled both as an ordinal term and categorically, yielding consistent results.
The study was retrospective and cross-sectional, with CCTA and echocardiography performed a median of 41 days apart (IQR 31–57 days).
The authors note the design cannot establish causality or temporal sequence.
Conclusions
Non-obstructive coronary atherosclerosis in T2DM patients is associated with subclinical myocardial mechanical inefficiency detectable before obstructive CAD develops.
The study specifically included only CAD-RADS categories 0–2, representing no to mild (non-obstructive) coronary atherosclerosis.
The predefined primary outcome was GWE, with secondary outcomes corrected for multiplicity.
The authors conclude that 'myocardial work indices may detect subclinical mechanical inefficiency that escapes detection by GLS and LVEF' in this population.
Prospective studies are recommended to determine whether myocardial work adds incremental prognostic value.
What This Means
This research suggests that even mild, non-blocking buildup of plaque in the coronary arteries (non-obstructive atherosclerosis) is associated with subtle but measurable reductions in how efficiently the heart muscle works in people with type 2 diabetes. The study examined 114 diabetic patients using two imaging tools: coronary CT angiography to grade their artery plaque burden, and echocardiography to measure how the heart muscle performs. Patients with greater plaque burden showed progressively worse 'myocardial work efficiency' and more 'wasted work' — energy the heart expends without contributing to useful pumping — even though their overall heart pumping function (ejection fraction) appeared normal and a traditional strain measure (GLS) showed no significant differences.
The practical implication of these findings is that myocardial work indices, derived from echocardiography combined with blood pressure measurements, may pick up on early heart muscle dysfunction in diabetic patients at a stage when standard measures like ejection fraction and global longitudinal strain appear normal. This raises the possibility that these newer measures could identify patients at risk of heart problems earlier than current tools allow, potentially before any symptoms or overt heart disease are present.
However, because this was a cross-sectional study — meaning it captured a single snapshot in time rather than following patients over years — the findings show an association but cannot prove that plaque buildup directly causes the heart muscle changes, or predict whether patients with these early changes will go on to develop heart disease. The authors call for prospective studies to determine whether these myocardial work measurements can meaningfully predict future cardiovascular outcomes in diabetic patients.
Doğan N, Kuzucu &. (2026). Association Between Non-Obstructive Coronary Atherosclerosis and Myocardial Work in Patients with Type 2 Diabetes Mellitus: A Coronary CT Angiography Study.. Echocardiography (Mount Kisco, N.Y.). https://doi.org/10.1111/echo.70631