Predictive value of markers of myocardial reperfusion in acute myocardial infarction for follow-up left ventricular function

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R² = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of ≥50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive.     

Effects of abciximab on microvascular integrity and left ventricular functional recovery in patients with acute infarction treated by primary coronary angioplasty.

AIM: To investigate the effect of abciximab on microvascular integrity and left ventricular (LV) functional recovery in patients with acute myocardial infarction (MI) treated by primary coronary angioplasty (PTCA). METHODS AND RESULTS: Thirty-one patients (27 males; age 39-76 years) with first, acute MI (<6 h after onset) were randomized to receive either abciximab+primary PTCA (n=17) or primary PTCA alone (n=14). Baseline characteristics of the two groups were similar. Myocardial reperfusion was studied shortly after PTCA by corrected TIMI frame count (cTFC) and intracoronary myocardial contrast echocardiography (MCE), after 48 h by intravenous MCE using intermittent, harmonic power Doppler, and after 1 month by intravenous MCE and 99 mTc-tetrofosmin SPECT. The patients treated with abciximab showed a shorter cTFC (23+/-4 vs 30+/-9 frames; P<0.05), a more preserved microvascular integrity shortly after PTCA (77% vs 55%; P<0.01), after 48 h (86% vs 50%; P<0.005) and at 1-month follow-up (86% vs 54% by MCE, P<0.001, and 68% vs 60% by SPECT, P<0.005) than patients treated with PTCA alone. Abciximab patients also showed a better recovery of LV function, as demonstrated by greater reduction in wall motion score index (1.4+/-0.3 vs 1.5+/-0.2; P<0.05) and increase in LV ejection fraction (53+/-7% vs 48+/-5%; P<0.001). CONCLUSIONS: Abciximab improves microvascular perfusion and LV functional recovery in primary PTCA.     

Evaluation of transmural myocardial perfusion by ultra-harmonic myocardial contrast echocardiography in reperfused acute myocardial infarction.

BACKGROUND: The transmural distribution of myocardial perfusion is important for predicting the contractile reverse of an infarcted wall in reperfused acute myocardial infarction (AMI). Evaluating transmural myocardial perfusion by myocardial contrast echocardiography (MCE) could predict the long-term recovery of left ventricular (LV) function. METHODS AND RESULTS: The study group comprised 20 consecutive patients with a first-episode anterior AMI with total occlusion of the proximal left anterior descending artery, who underwent successful percutaneous coronary intervention within 24 h of onset. MCE was performed on the 15th day after the onset, using ultraharmonic gray-scale imaging with intermittent end-systolic triggering every 4 beats or every 6 beats. Regions of interest were placed over both the endocardial and epicardial region at the mid-septal level. Regional wall motion (RWM) of the infarcted anterior wall and global LV function were assessed by 2-dimensional echocardiography and left ventriculography in both the acute and chronic phase. The transmural distribution of myocardial perfusion by MCE demonstrated a significant relation with RWM score index (r = 0.75, p = 0.0004). Recovery of RWM and LV ejection fraction (LVEF) at 6 months after reperfusion was significantly greater in the group with good perfusion of the epicardium according to MCE than in the poor perfusion group [RWM (SD/cord); -1.23+/-0.91 vs -3.51+/-0.84, p = 0.001, LVEF (%); 63.8+/-10.4 vs 47.0+/-3.4, p = 0.04]. CONCLUSIONS: Assessing the transmural distribution of myocardial perfusion by MCE can predict the long-term recovery of LV function after a reperfused AMI.     

Serial evaluation of perfusion defects in patients with a first acute myocardial infarction referred for primary PTCA using intravenous myocardial contrast echocardiography.

AIMS: To investigate whether myocardial contrast echocardiography using Sonazoid could be used for the serial evaluation of the presence and extent of myocardial perfusion defects in patients with a first acute myocardial infarction treated with primary PTCA, and specifically, (1) to evaluate safety and efficacy of myocardial contrast echocardiography to detect TIMI flow grade 0--2, (2) to evaluate the success of reperfusion and (3) to predict left ventricular recovery after 4 weeks follow-up. METHODS AND RESULTS: Fifty-nine patients underwent serial myocardial contrast echocardiography, immediately before primary PTCA (MCE1), 1 h (MCE2) and 12--24 h after PTCA (MCE3). A perfusion defect was observed in 21 of 24 patients (88%) with anterior acute myocardial infarction. All but one had TIMI flow grade 0--2 prior to PTCA. Nine of 31 patients (29%) with inferior acute myocardial infarction showed a perfusion defect and all had TIMI flow grade 0-2 prior to PTCA. Restoration of TIMI flow grade 3 was achieved in 73% of the patients by primary PTCA. A reduction in size of the initial perfusion defect of at least one segment (16 segment model) or no defect vs persistent defect in patients with anterior acute myocardial infarction was associated with improved global left ventricular function at 4 weeks; mean global wall motion score index 1.29+/-0.21 vs 1.66+/-0.31 (P=0.009). Multiple regression analysis in patients with an anterior acute myocardial infarction revealed that the extent of the perfusion defect at MCE3 was a significant (P=0.0005) independent predictor for left ventricular recovery at 4 weeks follow-up. The only other independent predictor was TIMI flow grade 3 post PTCA (P=0.007). CONCLUSION: Intravenous myocardial contrast echocardiography immediately prior to primary PTCA seems safe and is capable of detecting the presence of a perfusion defect and its subsequent dynamic changes, particularly in patients with a first anterior acute myocardial infarction. A significant reduction in size of the initial perfusion defect using serial myocardial contrast echocardiography predicts functional recovery after 4 weeks and these findings underscore the potential diagnostic value of intravenous myocardial contrast echocardiography.     

Intravenous nicorandil can reduce the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in acute myocardial infarction

BACKGROUND: Because nicorandil, a potassium channel opener, has a cardioprotective effect and attenuates reperfusion injury in patients with acute myocardial infarction (AMI), intravenous nicorandil should reduce arrhythmic mortality and QT dispersion in patients with AMI. OBJECTIVES: The purpose of this study was to evaluate whether intravenous nicorandil reduces the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in AMI. METHODS: A historical cohort study on the effect of nicorandil on ventricular fibrillation and QT dispersion was conducted. Eighty-three patients with AMI who underwent successful percutaneous transluminal coronary angioplasty (PTCA) were enrolled. The patients were divided into two groups: nicorandil (n=46) and control group (n=37). Nicorandil was injected at 4 mg/h continuously from admission to 48 h after PTCA in the nicorandil group. QT dispersion was measured before, immediately after, 24 h after and 48 h after PTCA. RESULTS: Ventricular fibrillation was observed in three patients in the control group, but none was observed in the nicorandil group. QT dispersion in the nicorandil group was shorter than that in the control group 48 h after PTCA (QT dispersion was 23.2+/-16.1 ms and 33.4+/-24.0 ms, respectively, P<0.05). There was a significant difference between the two groups in time course after the onset of AMI (P<0.05). CONCLUSIONS: Because intravenous nicorandil reduces the occurrence of ventricular fibrillation and QT dispersion in patients with successful coronary angioplasty in AMI, it would prevent the occurrence of cardiac events after successful PTCA for AMI.     

Coronary flow velocity immediately after primary coronary stenting as a predictor of ventricular wall motion recovery in acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity immediately after successful primary stenting and the recovery of left ventricular (LV) wall motion in patients with acute myocardial infarction (AMI).

BACKGROUND

It is difficult to predict the recovery of LV wall motion immediately after direct angioplasty in AMI. Recent reports indicate that dysfunctional coronary microcirculation is an important determinant of prognosis for AMI patients after successful reperfusion.

METHODS

We measured left anterior descending coronary flow velocity variables using a Doppler guide wire immediately after successful primary stenting in 31 patients with their first anterior AMI. The patients were divided into two groups: those with and those without early systolic reverse flow (ESRF). Changes in LV regional wall motion (RWM) and ejection fraction (EF) at admission and at discharge were compared between the two groups. Coronary flow velocity variables immediately after primary stenting were compared with changes in left ventriculographic indexes.

RESULTS

The change in RWM was significantly greater in the non-ESRF group than it was in the ESRF group (0.9 ± 0.7 vs. −0.1 ± 0.3 standard deviation/chord, respectively, p < 0.001). The change in EF was also significantly greater in the non-ESRF group than it was in the ESRF group (10 ± 10 vs. 1 ± 6%, respectively, p < 0.05). In the non-ESRF group (diastolic to systolic velocity ratio [DSVR] <3.0), the DSVR correlated positively with the change in RWM (r = 0.60, p < 0.005, n = 24) and the change in EF (r = 0.52, p < 0.01).

CONCLUSIONS

The coronary flow velocity pattern measured immediately after successful primary stenting is predictive of the recovery of regional and global LV function in patients with AMI.     

The effect of intra-aortic balloon counterpulsation on left ventricular functional recovery early after acute myocardial infarction: a randomized experimental magnetic resonance imaging study.

AIMS: We sought to determine whether intra-aortic balloon pump (IABP) counterpulsation improves the recovery of left ventricular (LV) systolic function after reperfused acute myocardial infarction (AMI). METHODS AND RESULTS: Fourteen dogs underwent 90-min coronary artery occlusion followed by reperfusion. Seven animals were randomized to IABP counterpulsation immediately after reperfusion. Tagged, cine, and contrast-enhanced magnetic resonance imaging were used for regional and global LV functional assessment and MI characterization, respectively. Image acquisition was performed at 1 h, 6 h, and 24 h after reperfusion, during which the IABP device was paused. Animals randomized to IABP demonstrated an earlier improvement of LV ejection fraction when compared with controls (25+/-3 vs. 25+/-2% at 1 h, P=0.91; 36+/-3 vs. 26+/-2% at 6 h, P=0.015; and 38+/-3 vs. 35+/-1% at 24 h, P=0.34). Regional functional analyses revealed the same behaviour among non-infarcted risk regions, i.e., earlier circumferential systolic strain improvement in the IABP group than in controls (-5.4+/-0.4 vs. -5.3+/-0.5% at 1 h, P=0.86; -12.1+/-1.0 vs. -6.0+/-0.4% at 6 h, P<0.001; and -13.9+/-1.1% vs. -12.8+/-0.6% at 24 h, P=0.40). Importantly, however, the degree of LV functional recovery 24 h after reperfusion was similar whether IABP counterpulsation was used or not. CONCLUSION: IABP counterpulsation accelerates but does not significantly improve the recovery of LV systolic function after reperfused AMI.     

QT dispersion and left ventricular function after stent placement in acute myocardial infarction

BACKGROUND: QT dispersion is increased in acute myocardial infarction (AMI), but the relation of QT dispersion to left ventricular (LV) function has not yet been fully elucidated. The purpose of this study was to evaluate the relationship between QT dispersion and LV function in patients with successful coronary stenting in AMI. METHODS: Seventy five patients with AMI who underwent percutaneous transluminal coronary angioplasty (PTCA) were enrolled in this study. Corrected QT dispersion was measured before, immediately after, 24 h after, 48 h after, and 6 months after PTCA. Left ventricular ejection fraction (LVEF) was evaluated by left ventriculography at 6 months after PTCA. RESULTS: Corrected QT dispersion at 24 h after and 48 h after PTCA were significantly related to LVEF by univariate analysis (r=-0.282, p<0.05 and r=-0.326, p<0.01, respectively). In multiple regression model, corrected QT dispersion at 24 h after and 48 h after PTCA revealed significant associations with LVEF (R(2)=0.441, coefficient=-0.283, p=0.006 and R(2)=0.411, coefficient=-0.225, p=0.039, respectively), but corrected QT dispersion before, immediately after, and 6 months after PTCA were not associated with LVEF. CONCLUSIONS: Corrected QT dispersion at 24 h after and 48 h after PTCA in AMI correlate with LVEF at 6 months after PTCA.     

Assessing myocardial perfusion with the transthoracic Doppler technique in patients with reperfused anterior myocardial infarction: comparison with angiographic, enzymatic and electrocardiographic indices.

AIMS: Doppler guidewire studies demonstrated that the no-reflow phenomenon in acute myocardial infarction is associated with characteristic coronary blood flow pattern. We investigated the potential of coronary flow measurement with transthoracic Doppler technique to detect the no-flow in the patients with reperfused infarction, and compared it to that of other modalities. METHODS AND RESULTS: We performed intracoronary myocardial contrast echocardiography after successful primary coronary intervention in the 94 patients with first, anterior wall infarction. Coronary blood flow in the left anterior descending artery was detected with transthoracic Doppler echocardiography within 24 h after reperfusion in 83 patients (88.3%). Twenty-two patients with the no-reflow had significantly lower systolic peak velocity (5.1 +/- 4.2 vs. 8.1 +/- 6.2 cm/s, p = 0.04), higher diastolic peak velocity (38.2 +/- 10.3 vs. 30.8 +/- 15.7 cm/s; p = 0.04), and shorter diastolic deceleration time (134 +/- 41 vs. 424 +/- 202 ms; p < 0.0001) than those with good-reflow. Systolic flow reversal was more frequently observed in those with no-reflow (18.2% vs. 3.3%, p = 0 .02). Diastolic deceleration time < 185 ms detected the no-reflow with far higher sensitivity/specificity (95.5%/95.1%) than TIMI frame count (45.5%/91.8%), ST resolution (54.5%/73.8%) and creatinine kinase-MB (54.5%/88.5%). CONCLUSION: Analysing coronary blood flow pattern can detect the no-reflow after anterior infarction better than other angiographic, electrocardiographic and enzymatic modalities.     

Comparison of real-time contrast echocardiography and low-dose dobutamine stress echocardiography in predicting the left ventricular functional recovery in patients after acute myocardial infarction under different therapeutic intervention

BACKGROUND: Early prediction of left ventricular (LV) functional recovery after acute myocardial infarction (AMI) remains challenging. This prospective study aims to compare real-time myocardial contrast echocardiography (MCE) with low-dose dobutamine stress echocardiography (LDDSE) in predicting the LV functional recovery in patients after AMI who underwent different therapeutic interventions. METHODS: Ninety-two patients with AMI were divided into 3 groups: primary coronary intervention group (n=34), thrombolysis group (n=30) and conservative therapy group (n=28). MCE was performed 2.3+/-0.7 days after chest pain onset. LDDSE was done within 2 days of MCE study. Follow-up echocardiography was performed 4 months later. RESULTS: Patients treated by primary coronary intervention or thrombolysis had significantly lower regional perfusion score (0.65+/-0.53 vs. 1.01+/-0.49, p=0.008; 0.78+/-0.55 vs. 1.01+/-0.49, p=0.03), better contractile reserve (regional dobutamine Deltawall motion score -1.12+/-0.39 vs. -0.80+/-0.43, p=0.01; -0.99+/-0.50 vs. -0.80+/-0.43, p=0.08) and LV function recovery (regional Deltawall motion score -1.67+/-0.53 vs. -1.02+/-0.46, p=0.003; -1.42+/-0.58 vs. -1.02+/-0.46, p=0.03) than those of conservative therapy group. MCE and LDDSE showed good concordance for predicting LV functional recovery (kappa=0.63, p<0.001). Perfusion score index had a good correlation with LV functional recovery (r=-0.75, p<0.001). CONCLUSIONS: This study demonstrates that perfusion score index obtained from real-time MCE is comparable to LDDSE in predicting the LV functional recovery even under different therapeutic interventions. Revascularization results in better preservation of myocardial microvascular integrity, regional contractile reserve and LV functional recovery.     

Initial experience with hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction: results of a pilot study utilizing intracoronary aqueous oxygen therapy

OBJECTIVES: The purpose of this study was to evaluate the feasibility and safety of intracoronary hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction (MI). BACKGROUND: Hyperoxemic therapy with aqueous oxygen (AO) attenuates reperfusion injury and preserves left ventricular (LV) function in experimental models of MI. METHODS: In a multi-center study of patients with acute MI undergoing primary angioplasty (PTCA), hyperoxemic blood (pO(2): 600 to 800 mm Hg) was infused into the infarct-related artery for 60 to 90 min after intervention. The primary end points were clinical, electrical and hemodynamic stability during hyperoxemic reperfusion and in-hospital major adverse cardiac events. Global and regional LV function was evaluated by serial echocardiography after PTCA, after AO infusion, at 24 h and at one and three months. RESULTS: Twenty-nine patients were enrolled (mean age: 58.9+/-12.6 years). Hyperoxemic reperfusion was performed successfully in all cases (mean infusion time: 80.8+/-18.2 min; mean coronary perfusate pO(2): 631+/-235 mm Hg). There were no adverse events during hyperoxemic reperfusion or the in-hospital period. Compared with baseline, a significant improvement in global wall motion score index was observed at 24 h (1.68+/-0.24 vs. 1.48+/-0.24, p < 0.001) with a trend toward an increase in ejection fraction (48.6+/-7.3% vs. 51.8+/-6.8%, p = 0.08). Progressive improvement in LV function was observed at one and three months, primarily due to recovery of infarct zone function. CONCLUSIONS: Intracoronary hyperoxemic reperfusion is safe and well tolerated after primary PTCA. These preliminary data support the need for a randomized controlled trial to determine if hyperoxemic reperfusion enhances myocardial salvage or improves long-term outcome.     

Course and prognostic implications of QT interval and QT interval variability after primary coronary angioplasty in acute myocardial infarction

OBJECTIVES: The aim of this study was to determine the influence of early reperfusion on the course of QT interval and QT interval variability in patients undergoing primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) and its prognostic implications on major arrhythmic events during one-year follow-up. BACKGROUND: Although early coronary artery recanalization by primary angioplasty is an established therapy in AMI, a substantial number of patients is still threatened by malignant arrhythmias even after early successful reperfusion, which may be caused by an inhomogeneity of ventricular repolarization despite reperfusion. METHOD: Temporal fluctuations of ventricular repolarization were studied prospectively in 97 consecutive patients with a first AMI by measurements of QT interval and QT interval variability during and after successful PTCA (Thrombolysis in Myocardial Infarction flow grades 2 and 3). Continuous beat-to-beat QT interval measurement was performed from 24-h Holter monitoring, which was initiated at admission before PTCA. RESULTS: Reperfusion caused a significant continuous increase of mean RR interval (738 +/- 98 to 808.5 +/- 121 ms; p < 0.001) and a significant decrease of parameters of QT interval (QTc: 440 +/- 32 to 416.5 +/- 37ms; p < 0.001) and QT interval variability (QTcSD: 27.5 +/- 3 to 24.9 +/- 6 ms; p < 0.001) in the majority of patients. However, in patients with major arrhythmic events at the one-year follow-up (sudden cardiac death, ventricular fibrillation or sustained ventricular tachycardia, n = 15), parameters of QT interval remained unaltered after successful reperfusion (QTc: 447.3 +/- 41 to 432.9 +/- 45 ms, p = NS; QTcSD: 35.1 +/- 13.4 to 29.0 +/- 9.1 ms, p = NS). CONCLUSIONS: Reduction of QT interval and QT interval variability after timely reperfusion of the infarct-related artery may be a previously unreported beneficial mechanism of primary PTCA in AMI, indicating successful reperfusion.     

Increased Tei index suggests absence of adequate coronary reperfusion in patients with first anteroseptal acute myocardial infarction.

BACKGROUND: The estimation of coronary reperfusion in acute myocardial infarction (AMI) is important. The left ventricular (LV) Tei index is a noninvasive and sensitive parameter expressing overall LV function. We hypothesized that patients without good coronary reperfusion have worse LV function with a higher or worse Tei index compared to those with good reperfusion. METHODS AND RESULTS: In 85 patients with first anteroseptal AMI, without other cardiac lesions such as prior myocardial infarction, LV hypertrophy or valvular disease, the Tei index was measured using Doppler echocardiography immediately after patients' arrival to the hospital, and the Thrombolysis in Myocardial Infarction (TIMI) grade was evaluated through subsequent coronary angiography. The Tei index was significantly greater in patients who did not have TIMI score of 3 compared to those with a TIMI of 3 (0.60+/-0.13 vs 0.46+/-0.06, p<0.0001). A Tei index >0.50 as the criteria for the absence of TIMI 3 had the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 75, 86, 94, 54 and 78%, respectively. CONCLUSION: An increased Tei index suggests the absence of adequate coronary reperfusion in patients with first anterior AMI without other lesion.     

直接经皮腔内冠状动脉成形术对急性心肌梗塞QT离散度的影响

目的　研究急性心肌梗塞 (AMI)患者应用直接经皮腔内冠状动脉成形术 (PTCA)对 QT离散度(QTd)的影响。方法　回顾 95例 AMI患者 ,通过测量入院时及入院后不同时间心电图 ,计算校正 QTd(QTcd)。对比分析其中 68例 PTCA再通患者 (PTCA组 )与 2 7例未行 PTCA或溶栓患者 (对照组 )不同时间 QTd与 QTcd的变化。结果　 PTCA组再通即刻 QTd、QTcd较再通前明显延长 (P<0 .0 1 ) ,2小时后恢复到入院时水平 ,4小时后较入院时明显缩短 (P<0 .0 1 ) ,以后 2 4小时内相对稳定。对照组入院后 2 4小时内 QTd、 QTcd变化不大 (P>0 .0 5 )。结论　 AMI患者应用成功的 PTCA治疗可以缩短心室复极的 QTd,但再灌注即刻可加重心室复极的 QTd     

Effects of reperfusion on left ventricular ejection fraction and volume after acute myocardial infarction.

The effects of reperfusion on left ventricular (LV) function and volume were studied in patients with evolving acute myocardial infarction (AMI). We analyzed the LV ejection fraction and volume in patients who had been admitted within 24 h of the onset of their first AMI with culprit lesion of #6, #7 and #1 (American Heart Association classification). Sixty-five patients (Re group) received successful reperfusion therapy within 6 h after the AMI. The other 60 patients (Oc group), who were admitted from 6 to 24 h after the AMI, received conservative therapy. Patients with re-obstruction of the culprit lesion after reperfusion therapy were excluded from the Re group. Patients with spontaneous recanalization following conservative therapy were excluded from the Oc group. The LV ejection fraction (LVEF), LV end-systolic volume index (LVESVI), and LV end-diastolic volume index (LVEDVI) were measured using a modified Dodge's formula by left ventriculography performed 4 weeks after the AMI. LVEF in the Re group was significantly greater than in the Oc group (57 +/- 12 vs 49 +/- 11%) (mean +/- SD, p less than 0.01). LVESVI in the Re group was significantly smaller than in the Oc group (30 +/- 13 vs 38 +/- 16 ml/m2, p less than 0.01). Although LVEDVI was not significantly different between the 2 groups, in patients with a responsible coronary lesion of segment #6, LVEDVI in the Re group was significantly smaller than in the Oc group (67 +/- 14 vs 77 +/- 18 ml/m2, p less than 0.05). Although LVEF and LV volume correlated in both groups, the correlation was weak (r = 0.40-0.42), suggesting that LV volume was not dependent solely on LV functional recovery. The incidence of ventricular aneurysm in the Re group was significantly lower than in the Oc group (15.4 vs 45.0%, p less than 0.01). Multivariate analysis selected reperfusion of the responsible coronary artery as one of the factors significantly associated with a reduction of LVEDVI, LVESVI, an improvement of LVEF, and a decrease in the rate of aneurysm formation. In summary, our results indicated that reperfusion improved EF, reduced LV volume, and decreased the rate of aneurysm formation as compared to non-reperfusion, which suggests that reperfusion therapy is beneficial for both functional recovery and ventricular remodeling.     

Myocardial perfusion grade and survival after percutaneous transluminal coronary angioplasty in patients with cardiogenic shock

We sought to evaluate myocardial reperfusion and its prognostic value after percutaneous transluminal coronary angioplasty (PTCA) in patients admitted for cardiogenic shock. Lack of myocardial reperfusion despite restored coronary flow affects the survival of patients with acute myocardial infarction (AMI). Myocardial blush grade (MBG) is an angiographic measure of myocardial perfusion. We assessed MBG in 41 consecutive patients admitted to our department within 12 hours from the onset of AMI and in cardiogenic shock. PTCA was successful in 83% of patients. Thrombolysis In Mycardial Infarction (TIMI) grade 3 flow was demonstrated in 22 patients (53%). MBG 2/3 was found in 14 patients (34%); among them, 12 had TIMI 3 flow. Compared with patients with MBG 2/3, those with MBG 0/1 were older (71 +/- 11 vs 57 +/- 13 years, p = 0.001), had a higher prevalence of diabetes (48% vs 14%, p = 0.04) and hypertension (63% vs 29%, p = 0.04), showed a trend toward longer ischemic time (6.1 +/- 2.4 vs 4.9 +/- 1.1), and had larger enzymatic infarct size (peak creatine kinase 7,690 +/- 3,516 vs 5,500 +/- 2,977 IU/L). Mortality was higher in patients with MBG 0/1 both in the hospital (81% vs 14%, p <0.001) and at follow-up (81% vs 29%, p = 0.001). After adjustment by multivariate analysis, MBG 0/1 (odds ratio 16, p = 0.01) and age (odds ratio 3.8/10 years, p = 0.04) were correlated with in-hospital mortality. MBG 2/3 was achieved in a few patients in cardiogenic shock after AMI who were treated with PTCA; this was a strong predictor of in-hospital survival. Also, risk stratification after mechanical revascularization should include assessment of restoration of myocardial reperfusion.     

Cardioprotective effects of magnesium sulfate in patients undergoing primary coronary angioplasty for acute myocardial infarction.

BACKGROUND: Experimental evidence indicates that magnesium sulfate may have potential cardioprotective properties as an adjunct to coronary reperfusion. The present study was designed to examine the hypothesis that magnesium might have beneficial effects on left ventricular (LV) function and coronary microvascular function in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: The study population of 180 consecutive patients with a first AMI (anterior or inferior) underwent successful primary coronary intervention. Patients were randomized to treatment with either intravenous magnesium (magnesium group, n=89) or normal saline (control group, n=91). Pre-discharge left ventriculograms were used to assess LV ejection fraction (LVEF), regional wall motion (RWM) within the infarct-zone and LV end-diastolic volume index. The Doppler guidewire was used to assess coronary flow velocity reserve (CFVR) as an index of coronary microvascular function. Magnesium group subjects showed significantly better LV systolic function (LVEF 63+/-9% vs 55+/-13%, p<0.001; RWM: -1.01+/-1.29 SD/chord vs -1.65+/-1.11 SD/chord, p=0.004), significantly smaller LV end-diastolic volume index (63+/-17 ml/m(2) vs 76+/-20 ml/m(2), p<0.001), and significantly higher CFVR (2.95+/-0.76 vs 2.50+/-0.99, p=0.023) than controls. CONCLUSION: Magnesium sulfate as an adjunct to primary coronary intervention shows favorable functional outcomes in patients with AMI.     

Impact of spontaneous anterograde flow of the infarct artery on left ventricular function in patients with a first anterior wall acute myocardial infarction

To assess the impact of spontaneous anterograde flow of the infarct artery on outcomes in patients with acute myocardial infarction (AMI), we studied 478 patients with a first anterior wall AMI who underwent coronary angiography within 12 hours after the onset of chest pain; Thrombolysis In Myocardial Infarction (TIMI) 3 flow was obtained after reperfusion therapy. Patients were divided into 3 groups: 119 patients with spontaneous anterograde flow (initial TIMI 2 or 3 flow) of the infarct artery, 118 patients with an initially occluded artery (TIMI 0 or 1 flow) and time to angiography or=55% (odds ratio 7.13, 95% confidence interval 3.10 to 16.4, p <0.001). In conclusion, although very early reperfusion improved LV function more than late reperfusion, spontaneous anterograde flow was associated with better acute and predischarge LV function after AMI compared with very early reperfusion of an initially occluded artery.     

Left ventricular function after successful percutaneous transluminal coronary angioplasty for postinfarction angina pectoris

The purpose of this study was to determine if coronary revascularization by balloon angioplasty (PTCA) in patients with postinfarction angina can elicit an improvement of global systolic left ventricular (LV) function. LV function was evaluated in 18 patients with postinfarction angina based on peak aortic blood acceleration measured noninvasively with a continuous wave Doppler velocimeter. Initial Doppler measurements were made 4 +/- 1 days after infarction and just before PTCA and were repeated 24 to 48 hours after PTCA. Patients were divided into 2 groups. Group I (n = 10) had successful PTCA (reperfusion). Group II (n = 8) either had an unsuccessful PTCA or did not undergo PTCA or thrombolytic therapy (no reperfusion). In group I patients, peak acceleration increased from 16 +/- 1 m/s/s just before PTCA to 24 +/- 2 m/s/s 24 to 48 hours after successful PTCA (p less than 0.001). In group II patients, peak acceleration was 17 +/- 2 m/s/s just before PTCA and remained relatively unchanged (18 +/- 2 m/s/s) 24 to 48 hours later. These data indicate that revascularization of coronary arteries in patients with postinfarction angina can elicit considerable improvement of global LV systolic function.     

Usefulness of impairment of coronary microcirculation in predicting left ventricular dilation after acute myocardial infarction

The goals of this study were to assess the serial change in coronary blood flow velocity (CBFV) patterns with transthoracic Doppler echocardiography and to decide optimal timing to predict left ventricular (LV) remodeling in patients with anterior acute myocardial infarction. We recorded CBFV of the left anterior descending (LAD) coronary artery with transthoracic Doppler echocardiography and measured diastolic deceleration time (DDT, measured in milliseconds) on days 2, 7, and 21 in 52 patients with anterior acute myocardial infarction treated with primary coronary angioplasty. On day 2, DDT was >/=600 ms in 21 patients (group A) and <600 ms in the other 31 patients (group B). In group B, DDT increased to >/=600 ms in 12 patients on day 7 (group B1), and DDT was still <600 ms in the other 19 patients (group B2). However, DDT became comparable among 3 groups on day 21. Group B2 patients had significant chronic LV dilation (LV end-diastolic volume index in groups A, B1, and B2 at 6 months: 74 +/- 16 vs 81 +/- 17 vs 100 +/- 22. ml/m(2), respectively; p <0.05 vs other groups). Multivariate analysis revealed that DDT <600 ms on day 7 was the only independent variable related to LV remodeling. In conclusion, the CBFV pattern changed toward normalization with time in patients with acute myocardial infarction. Time taken for normalization varied among patients. Persistence of microvascular dysfunction up to 7 days after reperfusion predicted LV remodeling.