Objective To investigate the value of tissue-tracking mitral annular displacement (TMAD) in evaluating left ventricular longitudinal motor function and prognosis in asymptomatic severe aortic stenosis (SAS) patients with preserved ejection fraction.
Methods A total of 60 patients with asymptomatic SAS with preserved ejection fraction were selected and divided into two groups, including group A (21 cases) with cardiovascular related events and group B (39 cases) with no cardiovascular related events according to the follow-up results. The clinical data of the subjects were collected. All patients were followed up for 24 months after examination. The dynamic images of apical four chamber, three chamber and two chamber sections were collected for 4 consecutive cardiac cycles, and the left ventricular ejection fraction (LVEF) was measured by biplane Simpson method. The left ventricular global longitudinal strain (LVGLS) was obtained by two-dimensional speckle tracking echocardiography, and the longitudinal mean displacement of the midpoint between the septum and the lateral valve ring (TMAD Midpt) was obtained by four-chamber heart. The percentage of TMAD in the end diastolic left ventricular length diameter (TMAD Midpt%) was automatically obtained by equipment. The differences of the above parameters between two groups were compared, and the value of TMAD Midpt% in predicting cardial related events in SAS patients was analyzed.
Results TMAD Midpt% and LVGLS in the group A were significantly lower than those in the group B (P < 0.01), and there was no significant difference in LVEF between the two groups (P > 0.05). The myocardial mass index (MI) and B-type brain natriuretic peptide (BNP) in the group A were significantly higher than those in the group B (P < 0.01), but there was no significant difference in other clinical data and echocardiographic parameters (P > 0.05). TMAD Midpt% decreased with the decrease of LVGLS in 60 patients, and there was a significant positive correlation between them (r=0.696, P < 0.01). The ROC curve analysis showed that TMAD Midpt% had equal value in predicting cardiac events and LNGLS. The areas under the curve were 0.897 and 0.901, respectively (P < 0.01).
Conclusions TMAD Midpt% has the same value as LVGLS in predicting the occurrence of cardiac events, and the technology is simple, which can quickly evaluate the left ventricular function impairment and predict the occurrence of cardiac events in asymptomatic SAS patients with preserved left ventricular ejection fraction, and is worthy of clinical application.
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