ABSTRACT
BACKGROUND: Coronary slow flow (CSF) often links to inflammation and endothelial function disturbance. While conventional ejection fraction measurements fall short in identifying myocardial dysfunction, left ventricular global longitudinal strain (LV GLS) has shown superior efficacy in this regard. Our study aimed to explore subclinical left ventricular systolic dysfunction by assessing LV GLS in patients diagnosed with coronary slow flow (CSF). METHODS: The study included sixty patients with CSF and sixty control individuals without CSF. Coronary angiography employed the Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) to identify CSF. LV GLS values were evaluated and compared between the two groups. RESULTS: Significantly reduced LV GLS was evident in the CSF group compared to the control group (- 16.18 ± 1.25 vs. - 19.34 ± 1.33, p < 0.001). A notable correlation (r = 0.492, p < 0.001) between LV GLS and TFC was observed in the CSF group. Multivariate logistic regression analysis highlighted reduced LV-GLS (OR 2.2, 95% CI 1.57-3.09, p < 0.001) and smoking (OR 11.55, 95% CI 3.24-41.2, p < 0.001) as significant predictors for CSF presence. The receiver operating characteristic curve established that an LV GLS value of ≥ - 17.8% accurately predicted the presence of CSF (AUC: 0.958, 95% CI: 0.924-0.991, p < 0.001) with 90% specificity and 91.7% sensitivity. CONCLUSION: Our study indicates that reduced LV GLS is associated with CSF presence, offering a valuable means to early detect subclinical left ventricular systolic dysfunction in high-risk patients susceptible to heart failure. TRIAL REGISTRATION: ZU-IRB#7038/12-7-2021 Registered 12 July 2021, email: IRB_123@medicine.zu.edu.eg.
ABSTRACT
This study aimed to investigate the diagnostic performance of non-invasive resting myocardial deformation indices in identifying functional significance of intermediate stenosis of the left anterior descending (LAD) artery. Patients with 50-70% LAD stenosis upon coronary angiography were enrolled and divided into group I with fractional flow reserve (FFR) > 0.8 and group II with FFR ≤ 0.8. Patients were subjected to conventional and speckle tracking echocardiography with measurement of myocardial deformation indices including regional peak longitudinal strain (PLS), global longitudinal strain (GLS), Post-systolic strain index (PSI), and time interval between Aortic valve closure (AVC) and PLS. The current study included 200 patients. Group II patients had significantly lower absolute mean values of regional (PLS) and (GLS) compared to group I (- 14.98 ± 5.05 and - 18.73 ± 3.92 vs. - 17.59 ± 3.62 and - 19.20 ± 2.61, p = 0.001 and 0.02, respectively). The FFR values of LAD correlated significantly and negatively with the time interval between AVC and regional PLS (r = - 0.201, p = 0.004) as well as PSI (r = - 0.257, p < 0.001). For identifying cases with FFR ≤ 0.8, the optimal cut-off value of the time interval between AVC and PLS was 76 ms with 77.8% sensitivity and 93.8% specificity. The best cut-off value of PSI was 13%, yielding 50% sensitivity and 87.5% specificity. In patients with intermediate 50-70% LAD coronary artery stenotic lesions, the PSI and the duration between AVC and regional PLS enabled the identification of functionally significant lesions with reasonable diagnostic accuracy.Trial registration ZU-IRB#3199-20-11-2015 Registered 20 November 2015, IRB_123@medicine.zu.edu.eg.
