Evaluation of regional myocardial strains in patients with left anterior descending artery stenosis by three-dimensional speckle tracking imaging

Abstract

Objective To determine the value of three-dimensional speckle tracking imaging (3D-STI) in diagnosis of coronary artery diseases in patients with stenosis of left anterior descending artery (LAD). Methods Sixty patients with clinical possible diagnosis of coronary heart disease (CHD) in Beijing Army General Hospital from December 2013 to May 2014 were enrolled in the study. According to the results of coronary angiography, the patients were divided into four groups: the control group with 18 cases without LAD stenosis, the mild stenosis group (luminal stenosis rate≤50%) with 10 cases, the moderate stenosis group (50% 75%) with 22 cases. The echocardiographic parameter included long axis strain (LS), radial strain (RS), circumferential strain (CS) and area strain (AS) acquired by 3D-STI in 7 myocardial segments [basis anterior (BA), basis anterior septal (BAS), middle anterior (MA), middle anterior septal (MAS), apex anterior (AA), apex septal (AS), apex (A)] of left ventricle supplied by LAD. The differences of these parameters between the different groups were compared. Results (1) Results of LS: the mild stenosis group had no significant difference were observed compared with the control group. LS of moderate stenosis group was significantly lower than that of control group (t=-7.58, -4.76, -4.38, -4.64, -7.37, -5.00 and -7.24, all P<0.05), and part of the segments (AS) LS was significantly lower than that of mild stenosis group (t=-3.73, P<0.05). The other segments LS of moderate stenosis group had no significant difference were observed compared with that of the mild stenosis group. Each segment LS of severe stenosis group was significantly lower than that of control group, the mild stenosis group and moderate stenosis group (severe stenosis group compared with control group, t=-10.80, -13.96, -13.65, -15.25, -11.11, -11.66 and -10.77, all P<0.05; severe stenosis group compared with mild group, t=-6.76, -9.96, -9.27, -10.60, -7.45, -8.59 and -6.88, all P<0.05; severe stenosis group compared with moderate group, t=-5.23, -8.02, -7.89, -9.01, -6.08, -6.16 and -5.49, all P<0.05). (2) Results of RS: the mild stenosis group had no significant difference were observed compared with the control group. BA segment RS of moderate stenosis group has no significant difference were observed compared with that of the control group; the other segments RS was significantly lower than that of control group (t=1.16, 2.78, 3.28, 4.86, 2.11 and 4.03, all P<0.05). RS of moderate stenosis group has no statistical significance difference compared with that of mild stenosis group. Each segment RS of severe stenosis group was significantly lower than that of control group and mild stenosis group (severe stenosis group compared with control group, t=4.02, 3.26, 5.91, 5.74, 5.92, 5.67 and 5.11, all P<0.05; severe stenosis group compared with mild group, t=3.60, 2.83, 3.96, 3.55, 3.21, 3.31 and 2.85, all P<0.05), but the difference compared with moderate stenosis group had no statistical significance. (3) Results of CS: the mild stenosis group had no significant difference were observed compared with the control group. BA and MA segments circumferential strain of moderate stenosis group had no significant difference were observed compared with those of the control group; the other segments CS was significantly lower than that of control group (t=-6.28, -5.56, -7.37, -4.58 and -3.56, all P<0.05), each segment CS in moderate stenosis group has no statistical significance difference compared with that of mild stenosis group. Each segment CS of severe stenosis group was significantly lower than that of control group, the mild stenosis group and moderate stenosis group (severe stenosis group compared with control group, t=-16.54, -7.58, -12.87, -14.15, -15.93, -14.79 and -13.38, all P<0.05; severe stenosis group compared with mild group, t=-10.19, -6.28, -6.94, -8.19, -9.59, -9.30 and -9.15, all P<0.05; severe stenosis group compared with moderate group, t=-6.20, -3.92, -7.62, -5.21, -6.47, -7.90 and -7.56, all P<0.05). (4) Results of AS: BA segment AS of mild stenosis group had no significant difference were observed compared with that of the control group; the other segments AS was significantly lower than that of control group (t=-4.97, -3.16, -3.52, -4.92, -4.55 and -7.32, all P<0.05). Each segmental AS of moderate stenosis group was significantly lower than that of control group (t=-4.69, -7.00, -4.47, -4.00, -6.60, -4.90 and -7.78, all P<0.05), and part of the segments (BA and BAS) was significantly lower than that of mild stenosis group (t=-1.87 and -2.30, both P<0.05), the other segments AS had no significant difference were observed compared with that of the mild stenosis group. The strain of severe stenosis group was significantly lower than that of control group, mild stenosis, and moderate stenosis group (severe stenosis group compared with control group, t=-9.19, -14.33, -9.54, -9.41, -11.39, -10.35 and -14.19, all P<0.05; severe stenosis group compared with mild group, t=-4.51, -7.68, -4.13, -5.19, -3.55, -5.50 and -3.62, all P<0.05; severe stenosis group compared with moderate group, t=-2.15, -4.86, -4.55, -4.26, -3.86, -3.71 and -3.39, all P<0.05). Conclusion 3D-STI can be used for evaluation of segmental myocardial strains in patients with different stenosis of LAD and AS is a more sensitive parameter for detecting myocardial strain change in mild coronary stenosis. Key words: Three-dimensional speckle tracking imaging; Coronary stenosis; Myocardial strain