Correlation between Left Ventricular Pressure–Strain Loop and Severity in Patients with Non-ST-Segment Elevation Acute Coronary Syndrome and Its Application Value in Short-Term Prognosis Evaluation

Purpose To investigate the diagnostic value of nonintrusive left ventricular pressure–strain loop (LV-PSL) for assessing overall myocardial function in sufferers with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) with or without coronary stenosis. The results of this research might provide insights into the diagnosis and management of NSTE-ACS. Methods All 268 sufferers with NSTE-ACS who were received by the First Affiliated Hospital of Nanchang University between June 2019 and June 2021 were enrolled. Sufferers with single or multiple extramural coronary diameter stenosis ≥70% on coronary angiography were defined as the stenosis group. All sufferers underwent noninvasive LV-PSL construction by using cuff blood pressure as the left ventricular pressure before coronary angiography, and the resulting images were imported and analysed with offline analysis software to obtain global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE). The correlation between severity Gensini score and myocardial work (MW) parameters was identified through Spearman analysis. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut-off values for predicting coronary stenosis, and logistic regression analysis was used to identify independent factors affecting left ventricular myocardial function in sufferers of NSTE-ACS. The occurrence of adverse cardiac events during the follow-up period was recorded. Results Through the comparative analysis of general clinical data, significant differences were found between the stenosis and nonstenosis groups in terms of gender, hyperlipidaemia, hypertension and smoking. However, statistical difference was observed only for hypertension (stenosis group 54.2%; p < 0.05) and hypercholesterolaemia (stenosis group 53.5%; p < 0.05). GLS (tz value 3.063), GCW (tz value 11.494), GWI (tz value 9.627) and GWE (tz value 12.780) reduced and GWW (tz value 11.504) increased in the stenosis group compared with those in the nonstenosis group. All differences were statistically significant (all p < 0.05). Severity Gensini scores were negatively correlated with GLS, GCW, GWI and GWE but positively correlated with GWW (p < 0.001). The ROC curve and univariate and multivariate logistic regression analyses revealed that GWE (odds ratio (OR) 2.881; 95% confidence internal (95% CI) 2.176–3.816; p < 0.001) had the largest area under the curve and greatest sensitivity for coronary stenosis diagnosis. GWE was (OR 2.875; 95% CI 2.217–3.727; p < 0.001) and (OR 2.881; 95% CI 2.176–3.816; p < 0.001). During an average follow-up period of 26.7 months, 19 sufferers experienced adverse cardiac events. GWE exhibited high predictive ability for identifying such events. Conclusions Noninvasive LV-PSL can identify whether sufferers of NSTE-ACS have acute coronary stenosis regardless of the location or size of the stenosis and can detect varying degrees of left ventricular dysfunction in such sufferers. Amongst indices, GWE had the highest diagnostic efficiency for diagnosing sufferers of NSTE-ACS with coronary stenosis and highest predictive ability for adverse cardiac events.