Does left ventricular dyssynchrony immediately after acute myocardial infarction result in left ventricular dilatation?

BACKGROUND: Reverse remodeling of the left ventricle (LV) is one of the advantageous mechanisms of cardiac resynchronization therapy (CRT). Substantial LV dyssynchrony seems mandatory for echocardiographic response to CRT. Conversely, LV dyssynchrony early after acute myocardial infarction may result in LV dilatation during follow-up. OBJECTIVE: The purpose of this study was to evaluate the relation between LV dyssynchrony early after acute myocardial infarction and the occurrence of long-term LV dilatation. METHODS: A total of 124 consecutive patients presenting with acute myocardial infarction who underwent primary percutaneous coronary intervention were included. Within 48 hours of intervention, two-dimensional echocardiography was performed to assess LV volumes, LV ejection fraction (LVEF), and wall motion score index (WMSI). LV dyssynchrony was quantified using color-coded tissue Doppler imaging (TDI). At 6-month follow-up, LV volumes and LVEF were reassessed. RESULTS: Patients with substantial LV dyssynchrony (> or =65 ms) at baseline (18%) had comparable baseline characteristics to patients without substantial LV dyssynchrony (82%), except for a higher prevalence of multivessel coronary artery disease (P = .019), higher WMSI (P = .042), and higher peak levels of creatine phosphokinase (P = .021). During 6 months of follow-up, 91% of the patients with substantial LV dyssynchrony at baseline developed LV remodeling, compared with 2% in the patients without substantial LV dyssynchrony. LV dyssynchrony at baseline was strongly related to the extent of long-term LV dilatation at 6 months of follow-up. CONCLUSION: Most patients with substantial LV dyssynchrony immediately after acute myocardial infarction develop LV dilatation during 6 months of follow-up.     

Left ventricular systolic dyssynchrony index by three-dimensional echocardiography in patients with decreased left ventricular function: comparison with tissue Doppler echocardiography

Background: Three‐dimensional echocardiography (3DE) can simultaneously assess left ventricular (LV) regional systolic motion and global LV mechanical dyssynchrony. Methods: We used 3DE to measure systolic dyssynchrony index (SDI) (standard deviation of the time from cardiac cycle onset to minimum systolic volume in 17 LV segments) in 100 patients and analyzed the association of SDI with other parameters for LV systolic function or dyssynchrony. Eighteen patients who underwent cardiac resynchronization therapy (CRT) were also evaluated at 6 months after CRT, and the association of baseline SDI and tissue Doppler imaging (TDI) dyssynchrony index (Ts‐SD) with the change of LV end‐systolic volume (ESV) analyzed. Ts‐SD was calculated using the standard deviation of the time from the QRS complex to peak systolic velocity. Results: There was a significant inverse correlation between LVEF and SDI (r =?0.686, P < 0.0001). QRS duration was also significantly correlated to SDI (r = 0.407, P < 0.0001). There was a significant positive correlation between baseline SDI and the decrease in LVESV after CRT (r = 0.42). Baseline SDI was significantly greater in responders (10 patients) than in nonresponders (16.4 ± 5.1 vs. 7.9 ± 2.4%, P < 0.01), but there was no significant difference in Ts‐SD. SDI > 11.9% predicted CRT response with a sensitivity of 90% and a specificity of 75%. Conclusions: SDI derived from 3DE is a useful parameter to assess global LV systolic dyssynchrony and predict responses to CRT. (Echocardiography 2012;29:346‐352)     

Comparison between Tissue Doppler Imaging (TDI) and Tissue Synchronization Imaging (TSI) in Evaluation of Left Ventricular Dyssynchrony in Patients with Advanced Heart Failure

Background: Assessment of left ventricular (LV) dyssynchrony has an important role in optimizing the selection of cardiac resynchronization therapy (CRT) candidates. We compared a new semiautomatic echocardiographic modality, tissue synchronization imaging (TSI) with a manual method, color-coded tissue Doppler imaging (TDI), in the assessment of LV dyssynchrony in patients with heart failure (HF). Methods: Ninety-five patients (age = 54.5 ± 17.1 years, 66.3% male) with advanced HF (NYHA functional class ≥III and ejection-fraction ≤35%) were included in the study and evaluated echocardiographically. The time to regional peak systolic velocity (Ts) in six basal and six middle segments of the LV was measured manually using velocity curves from TDI and semiautomatically using TSI and seven parameters of systolic dyssynchrony were computed. Results: Overall, a moderate-to-good association was found between Ts derived by these two modalities, whereas the mean of Ts via TSI was significantly lower than that measured by TDI in many LV segments. The agreement between these two modalities in identifying LV dyssynchrony varied from weak to moderate according to various dyssynchrony indices. In comparison to the TDI-derived dyssynchrony indices, TSI showed a high sensitivity of more than 90% using Ts delay at the basal/all LV segments and the indices for their standard deviations (SD) for identifying LV dyssynchrony, whereas the highest specificity of 80% was achieved using the septal-lateral dyssynchrony index in the prediction of LV dyssynchrony. Conclusion: With the aid of selected LV dyssynchrony indices, the TSI method may confer enough sensitivity for a speedy evaluation and initial screening of LV dyssynchrony in HF patients; however, the current technology of TSI does not seem specific enough to replace TDI in the evaluation of dyssynchrony. (Echocardiography 2012;29:7-12).     

Circulating level of gelatinase activity predicts ventricular remodeling in patients with acute myocardial infarction

BACKGROUND: Matrix metalloproteinase (MMP) plays an important role in the development of ventricular remodeling in an animal model of acute myocardial infarction (AMI). We examined whether circulating MMP activity can predict left ventricular (LV) remodeling after AMI in humans. METHODS: We measured the circulating level of MMP-2 and MMP-9 activities (gelatinase activity) at 14 days after the onset of AMI by gelatin zymography in 52 consecutive patients (age 62+/-2). All patients underwent direct PTCA and stenting at an acute stage, and were treated subsequently with losartan or enalapril. Biplane left ventriculography was performed at admission, and 2 weeks and 6 months after the onset of AMI. RESULTS: We expressed gelatinolysis activity as the ratio to MMP-2 standard. Mean gelatinase activity was 0.721+/-0.013. We divided patients into two groups, groups with gelatinolysis activity <0.72 (low group, n=27) and >0.72 (high group, n=25). Either change in LV end-diastolic volume index (LVEDVI, ml/m(2)) or end-systolic volume index (LVESVI, ml/m(2)) from admission to 2 weeks was not different between the two groups. Changes in both LVEDVI and LVESVI from 2 weeks to 6 months were greater in high gelatinolysis activity group than those in low activity group. Moreover, circulating level of gelatinolysis activity was positively correlated with changes in LVEDVI and LVESVI from 2 weeks to 6 months. CONCLUSION: These results demonstrate that circulating level of gelatinase activity can predict LV remodeling after AMI. Inhibition of gelatinase activity at the acute phase may be a therapeutic strategy for the prevention of remodeling after AMI.     

Speckle tracking imaging as a predictor of left ventricular remodeling 6 months after first anterior ST elevation myocardial infarction in patients managed by primary percutaneous coronary intervention

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. LV remodeling is an important factor in the pathophysiology of advancing heart failure (HF).

Does Longitudinal Strain Predict Left Ventricular Remodeling after Myocardial Infarction?

Background: One of the most prognostically significant consequences of acute myocardial infarction (AMI) is the development of an adverse left ventricular (LV) remodeling. Objectives: The purpose of our study was to evaluate a feasibility of speckle tracking imaging (STI), in particular, global longitudinal strain (Ls) in predicting LV remodeling after AMI. Methods: A total of 82 AMI patients (mean age 57.6 ± 9.4) were included in the study. Within 48–72 hours of the onset of AMI and at a 4‐month follow‐up, two‐dimensional echocardiography was performed. The apical two‐ and four‐chamber views of the heart were analyzed offline using Echo Pac software for the assessment of strain by the STI method. LV remodeling was defined as a 15% increase from the baseline in LV end‐diastolic volume. Results: Twenty‐eight patients (34.1%) with LV remodeling at 4‐month follow‐up had comparable baseline clinical and echocardiographic characteristics with 54 patients (without LV remodeling), except for a predominance of the anterior wall MI (P < 0.01), higher leukocyte count value at admission (P < 0.01), lower ejection fraction (P < 0.05), increased end‐systolic volume (P < 0.05), and reduced global systolic Ls (P < 0.05). Multivariable logistic regression analysis revealed the systolic Ls as an independent determinant of LV remodeling after AMI. A receiver operating characteristic curve analysis showed that a cutoff value of ?11.6% for the systolic Ls yielded a 78% sensitivity and a 73% specificity to predict LV remodeling in 4 months. Conclusions. Our study has shown that LV longitudinal strain assessed by STI is an independent predictor of LV remodeling after AMI. (Echocardiography 2012;29:419‐427)     

Left ventricular dyssynchrony acutely after myocardial infarction predicts left ventricular remodeling.

OBJECTIVES: We sought to identify predictors of left ventricular (LV) remodeling after acute myocardial infarction. BACKGROUND: Left ventricular remodeling after myocardial infarction is associated with an adverse long-term prognosis. Early identification of patients prone to LV remodeling is needed to optimize therapeutic management. METHODS: A total of 178 consecutive patients presenting with acute myocardial infarction who underwent primary percutaneous coronary intervention were included. Within 48 h of intervention, 2-dimensional echocardiography was performed to assess LV volumes, LV ejection fraction (LVEF), wall motion score index, left atrial dimension, E/E' ratio, and severity of mitral regurgitation. Left ventricular dyssynchrony was determined using speckle-tracking radial strain analysis. At 6-month follow-up, LV volumes, LVEF, and severity of mitral regurgitation were reassessed. RESULTS: Patients showing LV remodeling at 6-month follow-up (20%) had comparable baseline characteristics to patients without LV remodeling (80%), except for higher peak troponin T levels (p < 0.001), peak creatine phosphokinase levels (p < 0.001), wall motion score index (p < 0.05), E/E' ratio (p < 0.05), and a larger extent of LV dyssynchrony (p < 0.001). Multivariable analysis demonstrated that LV dyssynchrony was superior in predicting LV remodeling. Receiver-operating characteristic curve analysis demonstrated that a cutoff value of 130 ms for LV dyssynchrony yields a sensitivity of 82% and a specificity of 95% to predict LV remodeling at 6-month follow-up. CONCLUSIONS: Left ventricular dyssynchrony immediately after acute myocardial infarction predicts LV remodeling at 6-month follow-up.     

厄贝沙坦合用培哚普利对急性心肌梗死后左室重塑的影响

目的观察厄贝沙坦合用培哚普利对急性心肌梗死(AM I)患者左室重塑的影响。方法50例AM I患者随机分为治疗组(26例)和对照组(24例),治疗组在常规治疗基础上加厄贝沙坦及培哚普利,对照组仅加用培哚普利,在第3、6个月时分别采用超声观察左室舒张末期容积指数(LVEDVI)、收缩末期容积指数(LVESVI)、室壁运动指数(WMSI)、射血分数(LVEF)变化。结果2组治疗后,LVESVI、WMSI均减少,LVEF增加,与治疗前相比差异有显著性意义(P<0.05);治疗后治疗组与对照组间比较差异有显著性意义(P<0.05)。结论应用厄贝沙坦合用培哚普利能更有效地防治急性心肌梗死后的左室重塑。     

Tissue Doppler derived mechanical dyssynchrony does not change after cardiac resynchronization therapy

Background: Mechanical left ventricular (LV) dyssynchrony, as determined by tissue Doppler imaging (TDI), predicts response to cardiac resynchronization therapy (CRT). However, changes in TDI mechanical dyssynchrony after CRT implantation have only limited investigation. Our objective was to detect changes in the extent and location of TDI mechanical dyssynchrony pre‐ and post‐CRT, and to explore their relationship in response to CRT. Methods: Thirty‐nine consecutive patients undergoing CRT implantation for chronic heart failure underwent TDI analysis pre‐CRT and up to 12 months post‐CRT. Regional dyssynchrony was determined by the time to systolic peak velocity of opposing LV walls. Dyssynchrony was defined as a difference in time to peak contraction of >105 msec. Two patients were excluded, as suitable coronary venous access was not available. Results: Of the 37 patients, 28 (76%) had significant mechanical dyssynchrony pre‐CRT. Of those with dyssynchrony, 18 (64%) had septal delay and 10 (36%) had LV free wall delay. Post‐CRT, 29 (78%) patients had significant mechanical dyssynchrony, 17 (59%) with septal delay, and 12 (41%) with LV free wall delay. There was no difference in both the amount of dyssynchrony (P = 0.8) or the location of the dyssynchrony (P = 0.5), before and after CRT, even though 28 (76%) were considered responders based on symptomatic and echocardiographic parameters. Conclusion: The TDI‐derived dyssynchrony does not change with CRT despite significant symptomatic and echocardiographic improvement in cardiac function. The TDI is of limited utility for monitoring response to CRT. (Echocardiography 2011;28:961‐967)     

New equation for prediction of reverse remodeling after cardiac resynchronization therapy

Objectives: To integrate data from two‐dimensional echocardiography (2D ECHO), three‐dimensional echocardiography (3D ECHO), and tissue Doppler imaging (TDI) for prediction of left ventricular (LV) reverse remodeling (LVRR) after cardiac resynchronization therapy (CRT). It was also compared the evaluation of cardiac dyssynchrony by TDI and 3D ECHO. Methods: Twenty‐four consecutive patients with heart failure, sinus rhythm, QRS ≥ 120 msec, functional class III or IV and LV ejection fraction (LVEF) ≤ 0.35 underwent CRT. 2D ECHO, 3D ECHO with systolic dyssynchrony index (SDI) analysis, and TDI were performed before, 3 and 6 months after CRT. Cardiac dyssynchrony analyses by TDI and SDI were compared with the Pearson's correlation test. Before CRT, a univariate analysis of baseline characteristics was performed for the construction of a logistic regression model to identify the best predictors of LVRR. Results: After 3 months of CRT, there was a moderate correlation between TDI and SDI (r = 0.52). At other time points, there was no strong correlation. Nine of twenty‐four (38%) patients presented with LVRR 6 months after CRT. After logistic regression analysis, SDI (SDI > 11%) was the only independent factor in the prediction of LVRR 6 months of CRT (sensitivity = 0.89 and specificity = 0.73). After construction of receiver operator characteristic (ROC) curves, an equation was established to predict LVRR: LVRR =?0.4LVDD (mm) + 0.5LVEF (%) + 1.1SDI (%), with responders presenting values >0 (sensitivity = 0.67 and specificity = 0.87). Conclusions: In this study, there was no strong correlation between TDI and SDI. An equation is proposed for the prediction of LVRR after CRT. Although larger trials are needed to validate these findings, this equation may be useful to candidates for CRT. (Echocardiography 2012;29:678‐687)     

Has Mechanical Dyssynchrony Still a Role in Predicting Cardiac Resynchronization Therapy Response?

Current guidelines for cardiac resynchronization therapy (CRT) include electrical but not mechanical dyssynchrony assessment. Our study aims to investigate the effects of isolated or combined mechanical and electrical dyssynchrony, according, respectively, to a standard deviation of tissue Doppler imaging (TDI) derived time to systolic peak ≥32.6 ms and to a QRS duration ≥120 ms, in predicting CRT reverse remodeling. Method: One hundred ninety‐two CRT patients were studied. All patients underwent a complete standard and TDI echocardiography examination before and 6 months after CRT. According to baseline evaluation patients were divided into Group 1, patients with isolated electrical dyssynchrony (QRS ≥ 120 ms, TS‐SD < 32.6), Group 2, patients with isolated mechanical dyssynchrony (QRS < 120 ms, TS‐SD ≥ 32.6) and Group 3, patients with combined electrical and mechanical dyssynchrony (QRS ≥ 120 ms, TS‐SD ≥ 32.6). Patients were considered CRT responders according to ≥15 left ventricular end‐systolic volume (LVESV) reduction at follow‐up (FU). Result: At FU, 86 (45%) patients were responders. The highest CRT response rate was observed in Group 3 (62/119, 52%, P < 0.001 vs. Group 1). No significant differences in response rate were observed between Group 1 (13/47, 27%) and Group 2 (11/26, 42%). In Group1, CRT did not induce any significant change in LV end‐diastolic volume (LVEDV), LVESV, LV ejection fraction (LVEF), myocardial performance index (MPI), while in Group 2, LVEF (P < 0.001) and MPI (P < 0.05) were improved. In Group 3, LVEDV, LVESV, LVEF, MPI were significantly improved (P < 0.0001 for all). Conclusion: Our data demonstrate that the highest CRT response rate can be achieved by combining traditional QRS criterion and a currently used echocardiographic dyssynchrony parameter. (Echocardiography, 2010;27:831‐838)     

Tissue Doppler imaging a new prognosticator for cardiovascular diseases.

Tissue Doppler imaging (TDI) is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular (LV) systolic and diastolic function. Recent studies have explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as heart failure, acute myocardial infarction, and hypertension. In these conditions, myocardial mitral annular or basal segmental (Sm) systolic and early diastolic (Ea or Em) velocities have been shown to predict mortality or cardiovascular events. In particular, those with reduced Sm or Em values of <3 cm/s have a very poor prognosis. In heart failure and after myocardial infarction, noninvasive assessment of LV diastolic pressure by transmitral to mitral annular early diastolic velocity ratio (E/Ea or E/Em) is a strong prognosticator, especially when E/Ea is > or =15. In addition, systolic intraventricular dyssynchrony measured by segmental analysis of myocardial velocities is another independent predictor of adverse clinical outcome in heart failure subjects, even when the QRS duration is normal. In heart failure patients who received cardiac resynchronization therapy, the presence of systolic dyssynchrony at baseline is associated with favorable LV remodeling, which in turn predicts a favorable long-term clinical outcome. Finally, TDI and derived deformation parameters improve prognostic assessment during dobutamine stress echocardiography. A high mean Sm value in the basal segments of patients with suspected coronary artery disease is associated with lower mortality rate or myocardial infarction and is superior to the wall motion score.     

Tissue Doppler imaging a new prognosticator for cardiovascular diseases

Tissue Doppler imaging (TDI) is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular (LV) systolic and diastolic function. Recent studies have explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as heart failure, acute myocardial infarction, and hypertension. In these conditions, myocardial mitral annular or basal segmental (Sm) systolic and early diastolic (Ea or Em) velocities have been shown to predict mortality or cardiovascular events. In particular, those with reduced Sm or Em values of <3 cm/s have a very poor prognosis. In heart failure and after myocardial infarction, noninvasive assessment of LV diastolic pressure by transmitral to mitral annular early diastolic velocity ratio (E/Ea or E/Em) is a strong prognosticator, especially when E/Ea is > or =15. In addition, systolic intraventricular dyssynchrony measured by segmental analysis of myocardial velocities is another independent predictor of adverse clinical outcome in heart failure subjects, even when the QRS duration is normal. In heart failure patients who received cardiac resynchronization therapy, the presence of systolic dyssynchrony at baseline is associated with favorable LV remodeling, which in turn predicts a favorable long-term clinical outcome. Finally, TDI and derived deformation parameters improve prognostic assessment during dobutamine stress echocardiography. A high mean Sm value in the basal segments of patients with suspected coronary artery disease is associated with lower mortality rate or myocardial infarction and is superior to the wall motion score.     

Effect of bivalirudin compared with unfractionated heparin plus abciximab on infarct size and myocardial recovery after primary percutaneous coronary intervention: the horizons-AMI CMRI substudy

Background : Myocardial infarct size is a strong independent predictor of mortality in patients with ST‐elevation myocardial infarction (STEMI). In the Harmonizing Outcomes with RevasculariZatiON and Stents in Acute Myocardial Infarction (HORIZONS‐AMI) trial, bivalirudin compared with unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor reduced cardiac mortality in STEMI patients, which was attributed to reduced major bleeding. Whether a possible reduction in infarct size with bivalirudin may have contributed to the enhanced survival with this agent is unknown. Methods : Cardiac magnetic resonance imaging was performed within 7 days and after 6 months in 51 randomized patients from a single center in HORIZONS‐AMI trial (N = 28 bivalirudin, N = 23 heparin plus abciximab). Infarct size, microvascular obstruction (MVO), left ventricular ejection fraction (LVEF), and LV end‐diastolic and end‐systolic volume indices were evaluated. Results : Infarct size was not significantly different after treatment with bivalirudin compared with heparin plus abciximab either within 7 days (median 9.3% [interquartile range 4.9%, 26.6%] vs. 20.0% [5.9%, 28.2%], P = 0.28) or at 6 months 6.7% [3.8%, 20.0%] vs. 8.2% [1.8%, 16.5%], P = 0.73). MVO was present in 28.6% versus 34.8% of patients respectively (P = 0.63). LVEF and LV volume indices also did not significantly differ between the two groups at either time period, nor were differences in myocardial recovery evident. Conclusions : In conclusion, in the HORIZONS‐AMI Cardiac magnetic resonance imaging (CMRI) substudy, cardiac magnetic resonance imaging within 7 days and at 6 months after primary percutaneous coronary intervention (PCI) did not demonstrate significant differences in infarct size, MVO, LVEF, or LV volume indices in patients treated with bivalirudin compared with unfractionated heparin plus abciximab. © 2011 Wiley Periodicals, Inc.     

Comparison of the angiographic myocardial blush grade with delayed‐enhanced cardiac magnetic resonance for the assessment of microvascular obstruction in acute myocardial infarctions

Background: Both myocardial blush grade (MBG) and cardiac magnetic resonance (CMR) are imaging tools that can assess myocardial reperfusion after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). Objectives: We studied the relation between MBG and gadolinium‐enhanced CMR for the assessment of microvascular obstruction (MVO) in patients with acute ST‐elevated myocardial infarction (STEMI) treated by primary PCI. Material and Methods: MBG was assessed in 39 patients with initial TIMI 0 STEMI successfully treated by PCI, resulting in TIMI 3 flow grade and complete ST‐segment resolution. These MBG values were related to MVO determined by CMR, performed between 2 and 7 days after PCI. Left ventricular (LV) volumes were determined at baseline and at 6‐month follow‐up. Results: No statistical relation was found between MBG and MVO extent at CMR (P = 0.63). Regarding MBG 0 and 1 as a sign of MVO, the sensitivity and specificity of these scores were 53.8 and 75%, respectively. In this study, CMR determined MVO was the only significant LV remodeling predicting factor (β = 31.8; P = 0.002), whatever the MBG status was. Conclusion: MBG underestimates MVO after an optimal revascularization in AMI compared with CMR. This study suggests the superior accuracy of delayed‐enhanced magnetic resonance over MBG for the assessment of myocardial reperfusion injury that is needed in clinical trials, where the principal endpoint is the reduction of infarct size and MVO. © 2009 Wiley‐Liss, Inc.     

Prevalence of dyssynchrony and relation with long-term outcome in patients after acute myocardial infarction

The impact of left ventricular (LV) dyssynchrony on the long-term outcomes of patients with acute myocardial infarction (AMI) remains unknown. The purpose of the present study was to evaluate the prevalence of LV dyssynchrony after AMI and the potential relation with adverse events. A total of 976 consecutive patients admitted with AMI treated with primary percutaneous coronary intervention were evaluated. Two-dimensional echocardiography was performed <48 hours after admission. LV dyssynchrony was assessed with speckle-tracking imaging and calculated as the time difference between the earliest and latest activated segments. Patients were followed up for the occurrence of all-cause mortality (the primary end point) or the composite secondary end point (heart failure hospitalization and all-cause mortality). Within 48 hours of admission for the index infarction, mean LV dyssynchrony was 61 ± 79 ms, and 14% of the patients demonstrated a ≥130-ms time difference, defined as significant LV dyssynchrony. During a mean follow-up period of 40 ± 17 months, 82 patients (8%) reached the primary end point. In addition, 36 patients (4%) were hospitalized for heart failure. The presence of LV dyssynchrony was associated with an increased risk for all-cause mortality and hospitalization for heart failure during long-term follow-up (adjusted hazard ratio 1.06, 95% confidence interval 1.05 to 1.08, p <0.001, per 10-ms increase). Moreover, LV dyssynchrony provided incremental value over known clinical and echocardiographic risk factors for the prediction of adverse outcomes. In conclusion, LV dyssynchrony is a strong predictor of long-term mortality and hospitalization for heart failure in a population of patients admitted with ST-segment elevation AMI treated with primary percutaneous coronary intervention.     

Losartan improves regional left ventricular systolic and diastolic function in patients with hypertension: accurate evaluation using a newly developed color-coded tissue doppler imaging technique

BACKGROUND: Angiotensin II receptor antagonists have recently been accepted as antihypertensive therapy. Tissue Doppler imaging (TDI) has been developed as a noninvasive tool to assess quantitatively regional myocardial motion abnormalities. This study was designed to determine whether our newly developed technique of color-coded TDI may be a useful means of quantifying the improvement in regional left ventricular (LV) myocardial contractility and relaxation after treatment with losartan in patients with hypertension. METHODS AND RESULTS: Losartan (50 to 100 mg) was administered for 6 months to 37 previously untreated patients with essential hypertension. Averaged myocardial velocity profiles (MVPs) for color-coded TDI were recorded in the ventricular septum and LV posterior wall before and after treatment. Peak myocardial velocities and peak myocardial velocity gradients (MVGs) in the LV walls were determined during systole and early diastole. The plasma concentration of transforming growth factor (TGF)-beta1 also was measured in all patients. Blood pressure and plasma TGF-beta1 level decreased after initiation of losartan therapy. The LV mass index and LV meridional end-systolic wall stress also decreased after treatment with losartan. LV geometry changed from a pattern consistent with concentric hypertrophy to normal geometry in 10 patients and to a pattern consistent with concentric remodeling in 5 patients, and from concentric remodeling to normal geometry in 5 patients after treatment with losartan. The ratio of early to late diastolic filling for the transmitral flow velocity increased after losartan treatment. The peak systolic and early diastolic myocardial velocities and MVGs in the ventricular septum and LV posterior wall increased after treatment with losartan, although the values 6 months after treatment with losartan were still lower than those in normal individuals. There were good correlations between changes in plasma TGF-beta1 level and changes in systolic and early diastolic MVGs 6 months after losartan. However, there were no significant correlations between changes in the systolic blood pressure and LV end-systolic wall stress and changes in the TDI parameters. CONCLUSION: Losartan improves regional LV function in patients with hypertension. Our newly developed averaged MVP and MVG measurements may be useful for accurately evaluating regional LV myocardial contractility and relaxation in these patients.     

急性心肌梗死后存活心肌对梗死相关血管晚期血运重建术后左室功能的影响

目的探讨存活心肌对急性心肌梗死(AMI)后梗死相关血管(IRA)晚期血运重建术后远期左室功能以及左室重构的影响.方法69例AMI未接受早期再灌注治疗者,于发病10～21 d行IRA经皮冠状动脉血运重建(PCI)术,术前于AMI发病后5～10 d应用小剂量多巴酚丁胺(5和10μg·min-1·kg-1)超声心动图负荷试验检测存活心肌,并分别测定和计算给药前后左室腔大小、左室射血分数(LVEF)以及室壁运动积分(WMS).按有无存活心肌分为存活心肌组和无存活心肌组,超声心动图随访术后6个月时两组左室腔大小、LVEF和WMS的变化.结果157个运动异常节段中89个节段(57%)有存活心肌,有存活心肌组26例(占38%),无存活心肌组43例(占62%).存活心肌组术后6个月LVEF较术前明显提高(P＜0.05),收缩末期容积指数(LVESVI)和WMS明显降低(P＜0.05和P＜0.01);而无存活心肌组LVEF较术前明显降低(P＜0.01),LVESVI和左室舒张末期容积指数(LVEDVI)较术前明显增加(P＜0.05),WMS无明显变化.存活心肌组多巴酚丁胺负荷时的LVEF和WMS明显改善,且与6个月时的测定值相近;而无存活心肌组PCI前应用多巴酚丁胺LVEF和WMS均无明显变化.结论AMI后有存活心肌者晚期血运重建有利于改善远期左室功能和减少左室重构.心肌梗死后早期小剂量多巴酚丁胺负荷状态下左室收缩功能的提高预示晚期血运重建术后心功能改善.     

急诊和择期冠状动脉介入治疗对急性心肌梗死左心室重构和功能的影响

目的评价急性心肌梗死(AMI)患者接受急诊和择期经皮冠状动脉介入(PCI)治疗对左心室重构和收缩功能的影响。方法对48例初次发病,发病时间在12h以内或12～24h之间的AMI患者行急诊PCI术;对27例AMI患者行择期PCI术。于术后2周、3个月和6个月行二维超声心动图测量左心室收缩末容积指数(LVESVI)、左心室舒张末容积指数(LVEDVI)、左心室射血分数(LVEF)和梗死区室壁运动指数(RWMI),并进行对比。结果术后2周、3个月急诊PCI组LVESVI、LVEDVI、LVEF和RWMI均显著优于择期PCI组。两组3个月和6个月时LVESVI、LVEDVI、LVEF及RWMI与2周时比较均有显著改善。至6个月时,两组间LVEDVI、LVEF和RWMI比较差异无统计学意义(P>0.05),而LVESVI差异有统计学意义(P<0.05)。两组间GWMI在各时间点统计差异无统计学意义。结论急诊PCI及择期PCI均可有效抑制左心室重构和改善左心室功能,急诊PCI更优于择期PCI。     

Effects of early abciximab administration before primary percutaneous coronary intervention on left ventricular function assessed by cardiac magnetic resonance

BACKGROUND: It has been shown that early abciximab administration before primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI) improves efficacy of treatment. However, there are no data on the impact of this strategy on left ventricular (LV) function during long-term follow-up. AIM: To analyse the effects of early abciximab administration in patients with first anterior STEMI treated with pPCI on infarct size and LV function assessed by cardiac magnetic resonance. METHODS: A total of 59 patients with STEMI, <12 hours from the chest pain onset, without cardiogenic shock, admitted to local hospitals without interventional facilities, with anticipated delay to pPCI <90 min were randomly assigned to two study groups: 27 patients received abciximab before transfer to the catheterisation laboratory (early abciximab group), and 32 patients received abciximab in the catheterisation laboratory just before pPCI (late abciximab group). All patients received aspirin and heparin (70 U/kg) before transfer to the cath lab. Clopidogrel loading dose was administered in the cath lab before angiography. RESULTS: Cardiac magnetic resonance was performed in 14 patients from each study group 1 year after pPCI and revealed a significantly lower LV end-systolic volume index (p=0.003), end-diastolic volume index (p=0.009) and better ejection fraction (p <0.05) in patients who received abciximab early. CONCLUSIONS: Early abciximab administration prior to transfer for pPCI in patients with first anterior STEMI results in a lower degree of LV remodelling and better LV ejection fraction at 1-year follow-up compared to late abciximab administration in the cath lab during pPCI.