Evaluation Of Alterations Of Left Heart Function In Patients With Unstable Angina After PCI Using Tissue Doppler Imaging

BackgroundFor decades coronary atherosclerosis has been considered the principal reason of coronary heart disease, with most of our effort dedicated to identifying and removal of coronary stenosis. Percutaneous coronary intervention (PCI) has been used increasingly for recovery reperfusion of ischemic myocardium.With the emergence of microcirculation dysfunction and reperfusion injury, the open artery theory has been to some extent questioned. The research of improvement of cardiac function before and after PCI is mostly concentrated in patients with acute myocardial infarction, and the results are controversial,while less such research is on patients with unstable angina; especially studies in patients with multi-vessel coronary artery disease were focused on the choice of revascularization strategy with the application of survival analysis methods, comprehensive quantitative assessment of the changes of heart function before and after PCI with ultrasonic indicators has not been reported.ObjectiveWe used TDI imaging combined with the SYNTAX score and residual SYNTAX score to explore short-term benefit of PCI for patients with multivessel disease in such clinical settings as different severity and different degree of revascularization, then to further discuss the revascularization strategy of multi-vessel coronary disease and the prognosis.MethodsEighty consecutive patients with UA refered to Shandong University Qilu hospital for elective PCI were included, among which62were with multi-vessle disease. Echocardiography was performed24hrs before,24hrs after and1month after stenting respectively for every one using a vivid7ultrasound machine (GE company) with a2-4MHz tranducer. Another20healthy individuals were examined as control. The patients were then divided into three subgroups according to the SYNTAX score during the procedure of elective PCI, mild lesion group (0～17),middle lesion group (17～27.5) and severe lesion group (≥27.5). According to the revasculation settings, patients were further divided into two subgroups, i.e.complete revascularization group (rss=0) and incomplete revascularization group (rss>0). The echocardiographic parameters include:①LVEF measured by Simpson’s method.②peak early diastolic velocity (E), peak late diastolic velocity (A), E/A ratio.③early diastolic velocities (Ea), and late diastolic velocities (Aa), peak systolic mitral annular velocity (Sa), E/Ea, E/Ea×Sa④ei index measured by tissue Doppler imaging.Results1. There were significant differerces in TG、TC and LDL-C between CAD patients and healthy individuals(all P＜0.05), but no difference was shown in clinical data. Comparison of echocardiographic parameters between healthy individuals and CAD patients showed that differences in echocardiographic parameters LVEF^E/A、E/Ea、Tei index and E/Ea×Sa were significant(all P<0.05)2. The improvement of LVEF was not remarkable24hrs after PCI (P>0.05),while other echocardiographic parameters E/A、E/Ea、Tei index and E/EaxSa changed significantly compared with preinterventional values (all P<0.05).There were significant differences in LVEF、E/A、E/Ea、Tei-index and E/EaxSa between1month after and24hrs before PCI(all P<0.05).3. The value of Tei index and E/EaxSa, from mild to severe lesion group, increased gradually. Compared with preinterventional values, echocardiographic parameters Tei index and E/Ea×Sa improved significantly24hrs and1month after PCI in all the3subgroups(all P<0.05). Patients with severe coronary artery disease seemed to have a lower rate of change of both24hrs and1month after stenting in the same echocardiographic parameters than mild and middle lesion groups(all P <0.05).4. The SYNTAX score was lower in the CR group than that in the IR group (15.94±5.6vs.25.36±9.5, P＜0.01). The differences in echocardiography parameters, i.e. Tei index and E/EaxSa were significant among1month after、24hrs after and24hrs before PCI in both CR and IR group(all P<0.05), whereas patients unergoing CR seemed to have a higher rate of change1month after PCI in the same echocardiographic parameters than IR group.5. The SYNTAX score was positively correlated to E/Ea(r=0.668, P<0.05)、Tei index(r=0.777, P<0.05)、E/EaxSa (r=0.724, P<0.05),and negatively toLVEF(r=-0.592, P<0.05)、E/A(r=-0.561, P<0.05).Conclusion1. Lipid abnormalities associated with atherosclerosis are very common in patients with unstable angina, the cardiac function of which can be significantly improved after stent implantation, supporting a functional impact of successful PCI. Moreover, improvement in left ventricular diastolic function may proceed left ventricular systolic function.2. There is strong correlation between DTI-Tei and E/EaxSa with the severity of coronary atherosclerosis, and DTI-Tei and E/EaxSa may be helpful to predict the extent of coronary atherosclerosis.3. In patients with MVD, no matter how severity the coronary lesions are, and either complete revascularization treatment or incomplete revascularization treatment, cardiac function could be remarkably improved in the short term. The short-term outcomes of patients with mild and middle coronary lesion are much better than those with severity lesion. CR strategy using drug-eluting stents could improve the cardiac function more significantly compared with IR strategy.