The Value of 2D Global Longitudinal Strain in Predicting the Severity of Coronary Artery Disease in Patients with NSTEMI and Unstable Angina and Regional Strain Value for Predicting the Culprit Artery

Background: Our study aimed to evaluate the predictive ability of resting strain to determine the severity of CAD in the absence of impaired LVEF in patients with NSTEMI and unstable angina. Additionally, the study sought to predict culprit and infracted related artery (IRA) using regional strain (SLR).

Methods: The study was conducted between January 2023 and May 2023 at the cardiology department of Ibn Rochd Hospital, Morocco. We conducted a comparative analysis involving 30 patients, comprising 23 individuals with NSTEMI and 7 with unstable angina. In all cases, we assessed both GLS and RLS before proceeding to coronary angiography. Subsequently, we categorized the patients into two groups: one consisted of 18 individuals with severe coronary lesions, including left main trunk (LM) and three vessels lesions, while the other group, comprising 12 patients, served as the control group and had non-severe coronary lesions

Results: At resting GLS threshold below -16,3 %, despite its subnormal nature, should raise suspicion and suggest severe coronary artery disease. RLS in the "Single-vessel" group was significantly lower in the culprit artery territories, suggesting that RLS may be a better marker for identifying the culprit artery. Both GLS and the visual analysis of segmental kinetics by WMSI (Wall Motion Score Index) at rest, were statistically significant for detecting severe coronary lesions.

Conclusion: GLR and SLR are sensitive markers for early detection of myocardial ischemia and predicting its severity. A resting GLR threshold of less than -16.13% could indicate severe CAD with severe tri-truncular or LMT damage, especially when combined with abnormal WMSI scores. These 2D strain parameter changes precede subjective abnormalities in segmental kinetics, which are often considered normal at rest.