Title : Preliminary research of the application of resting myocardial contrast echocardiography multi-indicator combined diagnostic model in coronary heart disease
Abstract:
Objective: This article is in purpose of developing a multi-indicator combined diagnostic model of resting myocardial contrast echocardiography (MCE) to qualify myocardial perfusion dysfunction in coronary heart disease (CHD).
Methods: We performed resting MCE and stress myocardial single-photon emission computed tomography (SPECT) examinations in 113 patients with CHD. Taking the results of myocardial perfusion SPECT as the gold standard, combined with MCE visual analysis, we enrolled 312 myocardial perfusion segments into Q-Lab quantitative analysis (156 each with normal and abnormal segments) and calculated the peak time (TP) of contrast agent microbubble concentration, microbubble duration time (T) and microbubble video peak intensity (PI), myocardial blood flow (Axβ), so as to predict the cut-off value of abnormal myocardial perfusion and the diagnostic sensitivity and specificity. We applied logistic regression and ROC curves to construct multi-indicator diagnostic model of MCE abnormal myocardial perfusion and evaluated model performance.
Results: 1. The abnormal TP and T segments were longer than those of the normal perfusion segment (P <0.05), while PI and AXβ were reduced compared with the normal perfusion segment (P <0.05); 2. The cutoff values, sensitivity and specificity of TP, T, PI and AXβ in predicting myocardial perfusion abnormalities were 6.54 s, 74.3%, 92.8%; 13.36 s, 86.6%, 89.6%; 6.67 dB, 82.4%, 78.4%?9.34 dB2/s?93.0%?87.2%?respectively; 3. The MCE combined diagnostic model is: Logit P?0.769×TP - 0.662×PI -0.301×A×β+ 0.871×T - 8.464. The area under the curve (AUC) underneath the ROC curve is 0.993. The sensitivity and specificity for diagnosing abnormal myocardial perfusion are 97.9% vs 96.8%.
Discussion: The performance of the resting MCE combined diagnosis model for qualitative myocardial perfusion dysfunction is equivalent to that of stress SPECT. It enables the preliminary CHD screening, PCI efficacy evaluation and prognosis assessment in patients with chest pain. Increased microvascular resistance and the adhesion effect of inflammatory vascular endothelial factors onto contrast agent microbubble may probably co-contribute to the significantly prolonged TP and T components in the abnormal myocardial perfusion segments (P < 0.05), therefore it is presumed that the resting MCE diagnostic model is more advantageous in detecting microvascular angina than SPECT, which lacks temporal resolution.
Conclusion: The resting MCE multi-indicator combined model has high efficiency in qualitative diagnosis of myocardial microcirculatory perfusion dysfunction.
Key words: Resting Myocardial Contrast Echocardiography; Coronary Heart Disease; Diagnostic Model
Audience Take Away
- Resting MCE model is superior to ECG in prognosis assessment in patients with chest pain. Patients with negative MCE results can avoid emergency CAG. It enables the CHD screening and PCI efficacy evaluation.
- Resting MCE diagnostic model is an effective and noninvasive method for detecting of coronary microcirculation dysfunction, which makes it easy for using as an routine examination.
- Resting MCE diagnostic model is more advantageous in detecting microvascular angina than SPECT, which lacks temporal resolution.
