Influence of granulocyte colony-stimulating factor on cardiac function in patients with acute myocardial infarction and leukopenia after revascularization / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Granulocyte colony-stimulating factor (G-CSF) seems to improve cardiac function and perfusion when used systemically through mobilization of stem cells into peripheral blood, but results of previous clinical trials remain controversial. This study was designed to investigate safety and efficacy of subcutaneous injection of G-CSF on left ventricular function in patients with impaired left ventricular function after ST-segment elevation myocardial infarction (STEMI).</p><p><b>METHODS</b>Thirty-three patients (22 men; age, (68.5 +/- 6.1) years) with STEMI and with comorbidity of leukopenia were included after successful primary percutaneous coronary intervention within 12 hours after symptom onset. Patients were randomized into G-CSF group who received G-CSF (10 microg/kg of body weight, daily) for continuous 7 days and control group. Results of blood analyses, echocardiography and angiography were documented as well as possibly occurred adverse events.</p><p><b>RESULTS</b>No severe adverse events occurred in both groups. Mean segmental wall thickening in infract segments increased significantly at 6-month follow up compared with baseline in both groups, but the longitudinal variation between two groups had no significant difference (P > 0.05). The same change could also be found in longitudinal variation of wall motion score index of infarct segments (P > 0.05). At 6-month follow-up, left ventricular end-diastolic volume of both groups increased to a greater extent, but there were no significant differences between the two groups when comparing the longitudinal variations (P > 0.05). In both groups, left ventricular ejection fraction measured by echocardiography ameliorated significantly at 6-month follow-up (P < 0.05), but difference of the longitudinal variation between two groups was not significant (P > 0.05). When pay attention to left ventricular ejection fraction measured by angiocardiography, difference of the longitudinal variation between groups was significant (P = 0.046). Early diastolic mitral flow velocity deceleration time changed significantly at 6- month follow-up in both groups (P = 0.05).</p><p><b>CONCLUSIONS</b>Mobilization of stem cells by G-CSF after reperfusion of infarct myocardium is safe and seems to offer a pragmatic strategy for recovery of myocardial global function.</p>

Real-time myocardial contrast echocardiography can predict functional recovery and left ventricular remodeling after revascularization in patients with ischemic heart disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies showed that preservation of microvascular integrity after myocardial ischemia was associated with myocardial viability. Real-time myocardial contrast echocardiography (RT-MCE) is a promising modality for non-invasive evaluation of microcirculation perfusion. Thus, it provides a unique tool to detect myocardial viability. We sought in this study to investigate the role of RT-MCE in predicting left ventricular (LV) functional recovery and remodeling after revascularization in patients with ischemic heart disease.</p><p><b>METHODS</b>Thirty-one patients with ischemic heart disease and resting regional LV dysfunction were included. LV volume, global and regional function were evaluated by echocardiography before and 6 - 9 months after revascularization. RT-MCE was performed before revascularization using low mechanical index power modulation imaging. Myocardial contrast opacification of dysfunctional segments was scored on a 3-point scale and mean contrast score in dysfunctional segments was calculated. Patients were divided into 2 groups according to mean contrast score in dysfunctional segments: group A, patients with mean contrast score = 0.5 (n = 19); group B, patients with mean contrast score < 0.5 (n = 12).</p><p><b>RESULTS</b>Wall motion improvement was found to be 94.5%, 45.5% and 16.1% respectively (P < 0.01) in homogenous, patchy and absent contrast opacification segments. At baseline, there was no significant difference in LV volume and global function between the two groups. After revascularization, group B had significantly larger LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV), lower LV ejection fraction (LVEF) and higher wall motion score index (WMSI) than those of group A (all P < 0.05). Revascularization was followed by significant improvement of LV volume and recovery of global LV function in group A (all P < 0.01); however, in group B, after revascularization, deterioration of LVEDV (P < 0.05) was observed, moreover LVESV, WMSI and LVEF did not change significantly.</p><p><b>CONCLUSIONS</b>The maintenance of myocardial microcirculation detected by RT-MCE can predict functional recovery and LV remodeling after revascularization in patients with ischemic heart disease, which might be helpful in clinical decision-making and risk stratification.</p>

Usefulness of dobutamine stress myocardial contrast echocardiography for assessing coronary artery disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Quantitatively assessing myocardial perfusion and its reserve is of great importance for the diagnosis and stratification of patients with coronary artery disease (CAD), and represents an important goal of myocardial contrast echocardiography. In this study we sought to test the usefulness of low dose dobutamine stress real-time myocardial contrast echocardiography (RT-MCE) in the assessment of CAD, and to explore the relationship between perfusion reserve and contractile reserve.</p><p><b>METHODS</b>Twenty-six patients with suspected or clinical diagnosed CAD were enrolled and underwent RT-MCE at baseline and under low dose dobutamine stress, and subsequent coronary angiography. RT-MCE images were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve.</p><p><b>RESULTS</b>At baseline, significant differences in beta (0.28 +/- 0.12, 0.25 +/- 0.09, 0.22 +/- 0.06, 0.20 +/- 0.07 respectively, P < 0.01) and A x beta (1.37 +/- 0.46, 1.28 +/- 0.47, 1.13 +/- 0.37, 0.91 +/- 0.32, respectively, P < 0.01) were observed among four segment groups with graded coronary artery stenosis severity (normal; 30% - 69% stenosis; 70% - 90% stenosis; and beyond 90% stenosis), but not observed in parameter A. When under stress, significant differences in A (5.73 +/- 1.28, 5.63 +/- 1.01, 4.96 +/- 0.81, 4.57 +/- 0.62, respectively, P < 0.01), beta (0.67 +/- 0.17, 0.55 +/- 0.19, 0.32 +/- 0.13, 0.25 +/- 0.08, respectively, P < 0.01) and A x beta (3.81 +/- 1.20, 3.11 +/- 1.17, 1.59 +/- 0.82, 1.12 +/- 0.37, respectively, P < 0.01) were observed among the formerly mentioned groups. Graded decreases in A reserve (1.20 +/- 0.53, 1.11 +/- 0.16, 0.98 +/- 0.12, 0.99 +/- 0.13, respectively, P < 0.01), beta reserve (2.65 +/- 1.07, 2.32 +/- 0.82, 1.44 +/- 0.40, 1.29 +/- 0.34, respectively, P < 0.01) and A x beta reserve (3.05 +/- 1.63, 2.59 +/- 1.01, 1.42 +/- 0.44, 1.27 +/- 0.34, respectively, P < 0.01) could also be observed with increasing coronary stenosis severity. In five segments groups scored by WMS (1 - 5), concordance between contractile function and myocardial perfusion could be found both at rest (beta: 0.28 +/- 0.11, 0.22 +/- 0.08, 0.21 +/- 0.05, 0.17 +/- 0.05, 0.19 +/- 0.06, respectively, P < 0.01; A x beta: 1.29 +/- 0.48, 0.98 +/- 0.45, 0.94 +/- 0.29, 0.76 +/- 0.30, 0.92 +/- 0.32, respectively, P < 0.01) and under stress (beta: 0.59 +/- 0.20, 0.35 +/- 0.15, 0.27 +/- 0.08, 0.17 +/- 0.05, 0.20 +/- 0.05, respectively, P < 0.01; A x beta: 3.07 +/- 1.38, 1.62 +/- 0.82, 1.28 +/- 0.40, 0.78 +/- 0.24, 0.93 +/- 0.22, respectively, P < 0.01). This concordance is also valid in terms of the reserves, and the MCE parameters in segments with ameliorated contractile function are significantly higher than in those without.</p><p><b>CONCLUSIONS</b>Quantitative RT-MCE in conjunction with dobutamine stress shows promise in identifying and stratifying CAD and in exploring the perfusion-contractile correlation.</p>

Value of low dose dobutamine real-time myocardial contrast echocardiography in the assessment of coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the value of quantitative real-time myocardial contrast echocardiography (RT-MCE) combined with low dose dobutamine stress test in the detection of coronary artery disease (CAD), and to assess the contribution of collateral blood flow (CBF) to myocardial perfusion.</p><p><b>METHODS</b>Twenty-six hospitalized patients referred for coronary angiography and subsequent revascularization underwent routine echocardiography, RT-MCE at baseline and after low dose dobutamine administration. The images of RT-MCE were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve by using the QLab software.</p><p><b>RESULTS</b>At baseline, both beta and A x beta (but not A) were decreased with the increase of severity of coronary stenosis (P < 0.01). Under dobutamine stress, A, beta and A x beta values were decreased with the increase of severity of coronary stenosis (P < 0.01), Graded decreasing in the reserves of A, beta and A x beta were observed with increasing coronary stenosis severity (P < 0.01). Furthermore, significant differences in beta, A x beta, and WMS were observed between segments with CBF and those without.</p><p><b>CONCLUSION</b>Quantitative RT-MCE in conjunction with dobutamine stress can be used as a sensitive measure to identify and stratify CAD as well as to assess the contribution of collateral blood flow.</p>