Strain Imaging Tracks Severe Coronary Disease Better Than Routine Revascularization Candidates
Resting strain and strain rate imaging may be most useful when coronary disease is already advanced enough to leave a clear mechanical footprint on the myocardium. In a prospective study of 510 patients with stable chest pain referred for CT coronary angiography, these echocardiographic measures separated patients who ultimately underwent coronary artery bypass grafting far more convincingly than those treated with percutaneous coronary intervention.
That split is clinically important. It suggests the signal captured by myocardial deformation imaging becomes stronger as ischemic burden rises and coronary anatomy becomes more complex, but weakens when disease is less extensive or more focal.
Diagnostic Performance Rose Sharply in the CABG Group
Investigators performed echocardiography with strain and strain rate imaging in a single-centre cohort at the University Hospital of North Norway in Tromsø between 2016 and 2021. The population represented a real-world stable chest pain referral pathway rather than an enriched laboratory sample, which makes the findings relevant to everyday pre-test decision-making. Echocardiographic findings were compared with CT coronary angiography and coronary angiography, and a new scoring model incorporating strain parameters was developed to test diagnostic accuracy.
The strongest performance came from early diastolic strain rate (SRe), which reached an area under the curve of 0.91 for identifying patients undergoing CABG. Peak longitudinal strain (PLS) followed with an AUC of 0.81, while systolic strain rate (SRs) reached 0.71. Those numbers point to a high degree of discrimination in the subgroup carrying the heaviest revascularization burden.
A single measurement did not drive the finding. Instead, the pattern across multiple deformation markers suggests that both diastolic relaxation abnormalities and systolic contraction impairment contribute to the echo phenotype of advanced coronary disease. When chronic ischemia becomes diffuse enough to affect myocardial energetics and relaxation, strain-based imaging can capture a physiologic consequence that standard wall-motion assessment may miss at rest.
PCI-Level Disease Remained Much Harder to Detect
The picture changed sharply in patients who went on to PCI. In that subgroup, diagnostic accuracy fell into a much narrower range, with AUC values of 0.580 for SRe, 0.539 for SRs, and 0.552 for PLS. Those figures are close to the threshold where a test adds little practical separation between diseased and non-diseased states.
The bedside implication is straightforward. Resting strain imaging may not reliably detect the kind of coronary stenosis that prompts PCI, especially when ischemia is more focal, physiology is less globally disrupted, or lesions have not yet altered resting myocardial mechanics enough to create a strong deformation signature. A lesion can be anatomically significant and still fail to announce itself clearly on a resting echocardiogram.
This is where pathophysiology matters. CABG candidates often carry more extensive multivessel or left main-pattern disease, conditions that can produce broader downstream effects on myocardial function. PCI candidates, by contrast, may have more localized flow limitation that is easier to miss when the heart is examined at rest and before provocation.
What the Study Design Says About Real-World Use
The prospective design strengthens the clinical credibility of the findings. By enrolling patients referred for CCTA because of chest pain, the study reflects the uncertainty clinicians face when deciding who needs additional imaging, invasive angiography, or revascularization planning. The cohort size of 510 patients provides a meaningful base for a diagnostic accuracy analysis, although it remains a single-centre experience.
The study also moved beyond a simple yes-or-no comparison by developing a novel scoring model that incorporated S/SR parameters. That approach matters because coronary disease prediction rarely depends on one isolated measurement. In daily practice, clinicians synthesize symptoms, pre-test probability, imaging findings, and downstream anatomy. A composite deformation score could fit naturally into that workflow if validated more broadly.
Still, the operating characteristics differed by treatment pathway, and the contrast was stark. High AUC values in CABG patients suggest that strain imaging may identify a phenotype of advanced ischemic burden rather than coronary disease in the abstract. Lower AUC values in PCI patients show that not all obstructive CAD is equally visible through resting deformation analysis.
Why Diastolic Strain Rate May Carry the Strongest Signal
Among the tested parameters, SRe performed best in the CABG group. That is biologically plausible. Early diastolic relaxation is tightly linked to myocardial energy state, calcium handling, and the cumulative effects of ischemia on ventricular compliance. When coronary disease becomes extensive, impaired relaxation can emerge before overt systolic failure becomes obvious, making diastolic strain rate a sensitive marker of myocardial compromise.
PLS also performed well, which fits with the idea that longitudinal fibers in the subendocardium are among the first to suffer during ischemia. Because these fibers are especially vulnerable to reduced perfusion, longitudinal deformation can fall before more global echocardiographic abnormalities become obvious. SRs, while still informative, was less discriminating than the other two measures in this cohort.
The hierarchy of performance is useful for clinicians. It suggests that if strain imaging is incorporated into stable chest pain assessment, the most informative signal may come from a combination of deformation markers rather than a single metric interpreted in isolation.
Practical Limits of Resting Deformation Imaging
The study does not support using resting strain imaging as a stand-alone rule-out test for CAD in stable chest pain patients. Its utility appears concentrated in more severe disease, particularly among those whose coronary anatomy and clinical course lead to CABG. In patients headed for PCI, performance was too modest to justify overreliance on the technique.
Single-centre design also limits generalizability. Imaging acquisition, vendor differences, reader expertise, and referral patterns can all influence diagnostic yield. A score that performs well in one hospital may lose precision when deployed in another health system with different patient mix and image quality.
Even so, the study provides a clear clinical signal: resting strain and strain rate imaging can reveal the myocardial consequences of advanced coronary disease, but it is not equally effective across the full spectrum of obstructive CAD. The next step is not more enthusiasm, but validation across broader populations, standardized acquisition methods, and comparison with other diagnostic pathways used in stable chest pain evaluation.