Long-term prognosis of late spontaneous reperfusion after failed thrombolysis for acute myocardial infarction

BACKGROUND: Early reperfusion improves left ventricular (LV) function and survival after acute myocardial infarction (MI). Thrombolytic therapy achieves early patency of the infarct artery in about two-thirds of patients. In nearly half of the remaining patients, in whom early reperfusion was not achieved with thrombolytic therapy, the infarct artery might reopen by the time of predischarge angiography. However, the impact of such late spontaneous reperfusion after failed thrombolytic therapy on LV function and long-term survival remained unclear. HYPOTHESIS: This study was undertaken to assess implication of late spontaneous reperfusion after failed thrombolytic therapy on LV function and long-term survival after acute MI. METHODS: The study consisted of 198 patients with anterior acute MI who underwent thrombolytic therapy and predischarge angiography: 160 patients with infarct artery patent early and late after therapy (persistent patency), 17 patients with infarct artery occluded early after therapy but patent at predischarge angiography (late spontaneous reperfusion), and 21 patients with infarct artery occluded early and late after therapy (persistent occlusion). RESULTS: Persistent patency was associated with enhanced improvement in LV ejection fraction (7.7 +/- 11.8%) compared with late spontaneous reperfusion (0.0 +/- 9.6%, p = 0.03) and persistent occlusion (-1.4 +/- 9.7%, p = 0.003). Persistent patency was associated with better long-term survival than with late spontaneous reperfusion (p < 0.001) and persistent occlusion (p < 0.001). Multivariate analysis comparing persistent patency and late spontaneous reperfusion showed that early reperfusion was an independent predictor of long-term survival. CONCLUSION: Late spontaneous reperfusion after failed thrombolytic therapy was associated with poor LV function and long-term survival, emphasizing the importance of early reperfusion.     

Impact of prodromal angina pectoris and white blood cell count on outcome of patients with acute myocardial infarction

BACKGROUND: Elevation of white blood cell (WBC) count at admission is associated with adverse outcome after acute myocardial infarction (AMI). Prodromal angina, by the mechanism of ischemic preconditioning, improves left ventricular (LV) function and survival after reperfusion therapy in patients with AMI. Recent experimental studies have reported that preconditioning has anti-inflammatory effect. METHODS: This study consisted of 598 patients with first anterior wall AMI who underwent coronary angiography within 12 h after symptom onset. WBC count was measured at the time of hospital admission. Prodromal angina was defined as angina occurring within 24 h before the onset of AMI. Serial measurements of LV ejection fraction (EF) were obtained before reperfusion therapy and before discharge in 421 patients (71%). RESULTS: High WBC count (>10.2 x 103/mm3, n=297) was associated with higher 30-day mortality (8% vs. 4%, p=0.02) and lower predischarge LVEF (51+/-15% vs. 57+/-14%, p<0.001), although there was no significant difference in acute LVEF (47+/-10% vs. 49+/-11%, p=0.07). High WBC count was an independent predictor of 30-day mortality (p=0.009) and predischarge LVEF (p=0.002). Prodromal angina was associated with lower 30-day mortality (3% vs. 7%, p=0.02) and preserved predischarge LVEF (57+/-15% vs. 53+/-14%, p=0.006). Patients with prodromal angina had lower WBC count (10.0+/-3.3 x 10(3)/mm3 vs. 11.0+/-3.9 x 10(3)/mm3, p=0.001) and prodromal angina was an independent predictor of WBC count (p<0.001). CONCLUSIONS: Elevation of WBC count and lack of prodromal angina were associated with impaired LV function and mortality after reperfusion in patients with AMI. Prodromal angina might have contributed to favorable outcome after AMI through its anti-inflammatory effect.     

Impact of the magnitude of the initial ST-segment elevation on left ventricular function in patients with anterior acute myocardial infarction.

BACKGROUND: In the percutaneous coronary intervention (PCI) era, the impact of initial ST-segment elevation magnitude on left ventricular (LV) function in patients with acute myocardial infarction (AMI) remains unclear. METHODS AND RESULTS: In the present study, 239 patients with total occlusion and 81 patients with spontaneous reperfusion within 12 h of their first anterior AMI were evaluated. The sum of ST-segment elevation (SigmaST) was measured in leads I, aV(L) and V(1-6) shortly before angiography. Predischarge LV ejection fraction (LVEF) was obtained at 15+/-5 days. In total occlusion, the predischarge LVEF was significantly lower in patients with SigmaST >/=10 mm than in those with SigmaST <10 mm (51+/-14% vs 57+/-14%, p<0.01). However, in spontaneous reperfusion, there was no significant difference between patients with ST >/=10 mm and those with SigmaST <10 mm (61+/-13 vs 62+/-14 %, p=NS). Predischarge LVEF significantly correlated with SigmaST in total occlusion (r=-0.25, p<0.01), but not in spontaneous reperfusion (r=0.03, p=NS). CONCLUSION: The results suggest that initial SigmaST is an important predictor of LV function in patients with total occlusion, but not in those with spontaneous reperfusion.     

Prediction of remote left ventricular volumes and functions after acute myocardial infarction with successful coronary intervention.

BACKGROUND: The scintigraphic perfusion defect size (DS) at 1 week after acute myocardial infarction (AMI) predicts remote left ventricular (LV) volumes and LV ejection fraction (LVEF). The present study examined whether LV volumes and LVEF 6 months after AMI may be better predicted by the combination of LV volumes and LVEF just after reperfusion, and DS at 1 week, after AMI in patients with Thrombolysis In Myocardial Infarction (TIMI) grade III reperfusion by percutaneous coronary intervention. METHODS AND RESULTS: In 48 patients with AMI and TIMI grade III reperfusion, quantitative gated SPECT (QGS) was performed just after reperfusion, and at 1 week and 6 months after AMI. LV end-diastolic volume index decreased (108+/-8 to 93+/-6 ml/m(2), p<0.05) and LVEF increased (44+/-3 to 50+/-2%, p<0.05) 6 months after AMI. In addition, they were better predicted by a combination of LV volumes and LVEF just after reperfusion and DS at 1 week after AMI. CONCLUSIONS: In AMI with TIMI grade III reperfusion, LV volumes and LVEF at 6 months after MI correlate with the values obtained just after reperfusion. Myocardial perfusion imaging combined with QGS at reperfusion may predict these late-phase parameters.     

Reperfusion arrhythmias: are they only a marker of epicardial reperfusion or continuing myocardial ischemia after acute myocardial infarction?

Reperfusion arrhythmias are associated with epicardial reperfusion but may also be a sign of vascular reperfusion injury which can be seen as no-reflow phenomenon on coronary angiography and predicts in-hospital complications and recovery of left ventricular (LV) function. No-reflow phenomenon (thrombolysis in myocardial infarction [TIMI] 相似文献   

Contrast echocardiography accurately predicts myocardial perfusion before angiography during acute myocardial infarction

OBJECTIVES: To determine whether myocardial contrast echocardiography (MCE) can quickly and accurately assess myocardial perfusion and infarct-related artery (IRA) patency before emergency angiography during acute myocardial infarction (AMI). BACKGROUND: Despite encouraging experimental and clinical studies, the reliability and practicality of MCE in predicting IRA patency during AMI before angiography has not been proven. METHODS: Two-dimensional echocardiography and MCE were performed in 51 patients with AMI just before emergency angiography. With knowledge of the electrocardiogram findings and regional wall motion, myocardial perfusion was assessed to predict IRA patency. RESULTS: Myocardial perfusion studies were adequate for interpretation in 40 patients. An occluded IRA was predicted in 28 patients; the artery was occluded in 22 patients, and six patients had Thrombolysis In Myocardial Infarction (TIMI) grade 2 flow or less. A patent IRA was predicted in 12 patients; eight patients had TIMI grade 3 flow, one patient had TIMI grade 2 flow and the IRA was occluded in three patients. In one of the three patients, the appropriate view was not obtained. In another patient, collateral flow was adequate for near-normal regional wall motion, and in the last, the findings suggested reperfusion of the proximal artery with distal embolic occlusion. Taken together, MCE accurately predicted either TIMI grade 2 flow or less, or TIMI grade 3 flow in 36 of 40 patients. Sensitivity was 87.5%, specificity and positive predictive value were 100% and negative predictive power was 66.7% (P<0.001). CONCLUSIONS: MCE, together with the electrocardiogram and regional wall motion, can be used to quickly and reliably predict IRA patency early during AMI and may be useful to facilitate a management strategy.     

Randomized early versus late abciximab in acute myocardial infarction treated with primary coronary intervention (RELAx-AMI Trial).

OBJECTIVES: This prospective randomized trial evaluates the impact of early abciximab administration on angiographic and left ventricular function parameters. BACKGROUND: Glycoprotein IIb/IIIa inhibitors improve myocardial reperfusion in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI), but optimal timing of administration remains unclear. METHODS: Two-hundred ten consecutive patients with first AMI undergoing primary PCI were randomized to abciximab administration either in the emergency room (early group: 105 patients) or in the catheterization laboratory, after coronary angiography (late group: 105 patients). Primary end points were initial Thrombolysis In Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count (cTFC), and myocardial blush grade (MBG), as well as left ventricular function recovery as assessed by serial echocardiographic evaluations. RESULTS: Angiographic pre-PCI analysis showed a significantly better initial TIMI flow grade 3 (24% vs. 10%; p = 0.01), cTFC (78 +/- 30 frames vs. 92 +/- 21 frames; p = 0.001), and MBG 2 or 3 (15% vs. 6%; p = 0.02) favoring the early group. Consistently, post-PCI tissue perfusion parameters were significantly improved in the early group, as assessed by 60-min ST-segment reduction > or =70% (50% vs. 35%; p = 0.03) and MBG 2 or 3 (79% vs. 58%; p = 0.001). Left ventricular function recovery at 1 month was significantly greater in the early group (mean gain ejection fraction 8 +/- 7% vs. 6 +/- 7%, p = 0.02; mean gain wall motion score index 0.4 +/- 0.3 vs. 0.3 +/- 0.3, p = 0.03). CONCLUSIONS: In patients with AMI treated with primary PCI, early abciximab administration improves pre-PCI angiographic findings, post-PCI tissue perfusion, and 1-month left ventricular function recovery, possibly by starting early recanalization of the infarct-related artery.     

Effect of prodromal angina pectoris on altering the relation between time to reperfusion and outcomes after a first anterior wall acute myocardial infarction

To test the hypothesis that prodromal angina may favorably alter the relation between time to reperfusion and outcomes after acute myocardial infarction (AMI), we studied 658 patients with a first anterior AMI: 200 patients with early reperfusion (time to reperfusion 相似文献   

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.     

Spontaneous anterograde flow of the infarct artery preserves myocardial perfusion and fatty acid metabolism in patients with anterior acute myocardial infarction.

BACKGROUND: It remains unclear whether spontaneous anterograde flow preserves myocardial fatty acid metabolism in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: The present study comprised 129 patients with a first anterior AMI in whom Thrombolysis in Myocardial Infarction (TIMI) 3 flow was obtained on the final angiogram: 28 patients with spontaneous anterograde flow and 101 patients with total occlusion on the initial angiogram. Thallium-201 (201Tl) and iodine-123-beta-methyl-p-iodophenyl penta-decanoic acid (123I-BMIPP) dual-isotope myocardial single-photon emission computed tomography (SPECT) was performed at 6.5+/-4.2 days after onset. The SPECT image was divided into 17 segments, and each segment was graded with scores between 0 and 4 (0, normal uptake; 4, defective). The sum of each score was defined as the total defect score (TDS). TDS values for 201Tl (9.0 +/-7.4 vs 16.8+/-12.2, p < 0.01) and 123I-BMIPP (19.3+/-11.6 vs 24.1 +/-10.4, p < 0.05) were significantly lower in patients with spontaneous anterograde flow than in those with total occlusion. CONCLUSIONS: These results suggest that spontaneous anterograde flow of the infarct artery preserves not only myocardial perfusion but also fatty acid metabolism in patients with AMI. 123I-BMIPP SPECT image may underestimate the area at risk especially in patients with spontaneous anterograde flow.     

Early positive technetium-99m stannous pyrophosphate images as a marker of reperfusion after thrombolytic therapy for acute myocardial infarction

Fourteen patients with transmural acute myocardial infarction (AMI) were treated with intravenous streptokinase a mean of 4 +/- 1 hours after chest pain and underwent technetium-99m stannous pyrophosphate (Tc-99m-PPi) imaging 7 +/- 2 hours after the onset of chest pain. The early Tc-99m-PPi images were obtained to test the hypothesis that an early, strongly abnormal Tc-99m-PPi image suggests reperfusion. Eleven of 14 patients had early peaking (within 16 hours) serum creatine kinase isoenzyme levels (CK-B) at a mean of 11 +/- 3 hours. Ten of 14 patients had 3+ or 4+ acute Tc-99m-PPi images. Eight of 11 patients had patent infarct-related vessels at cardiac catheterization 15 days after AMI. One patient who had both an early positive Tc-99m-PPi image and CK-B peak level had an occluded infarct-related artery at catheterization. Acute left ventricular (LV) ejection fraction (EF) by radionuclide ventriculography was compared with LVEF on day 15, and improved from 0.37 +/- 0.13 to 0.50 +/- 0.16 (p = 0.004) in the 10 patients with strongly positive acute Tc-99m-PPi images. LVEF also improved from 0.37 +/- 0.12 to 0.49 +/- 0.15 (p = 0.003) in the 11 patients with early peaking serum CK-B values. Three patients without evidence of reperfusion failed to improve the LVEF from the initial value to the one obtained at hospital discharge. Six control patients had acute Tc-99m-PPi images 10 +/- 2 hours after chest pain; none had strongly positive acute Tc-99m-PPi images, and the mean time to peak CK-B was 19 +/- 5 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Predischarge low-dose dobutamine test and prediction of left ventricular function at 1 year in patients with a first anterior myocardial infarction

BACKGROUND: It is unclear whether spontaneous improvement in contractility following acute myocardial infarction (AMI) is related to severity of predischarge systolic dysfunction and can be predicted by isotopic ventriculography with a low-dose dobutamine test (DBT). HYPOTHESIS: Spontaneous improvement in contractility would be similar in patients with more preserved and those with depressed ventricular function, and a DBT test could predict it. METHODS: Left ventricular ejection fraction (LVEF), regional contractility score (RCS), and left ventricular end-diastolic volume index (EDVI) at predischarge, during DBT, and at 1 year were analyzed in 43 patients with a first anterior ST-elevation AMI. RESULTS: Changes produced by DBT in patients with LVEF < 40%, RCS > or = 3, or EDVI > or = 70 ml/m2 were smaller than in those observed at 1 year (LVEF: 30 +/- 5-35 +/- 7%, p < 0.001, vs. 39 +/- 10%, p = 0.005; RCS: 4.9 +/- 1.4-4.6 +/- 2.0, NS, vs. 3.4 +/- 2.0, p < 0.02; EDVI: 92 +/- 14-86 +/- 22, NS, vs. 78 +/- 23 ml/m2, p < 0.03). In contrast, in patients with EF > or = 40%, RCS < 3 or EDVI < 70 ml/m2, changes with DBT tended to be greater than those observed at 1 year (LVEF: 52 +/- 8-57 +/- 11%, p < 0.004 vs. 55 +/- 11%, p < 0.04); RCS: 1.1 +/- 0.9-0.8 +/- 0.8, NS, vs. 1.1 +/- 1.1, NS; and EDVI: 51 +/- 9-47 +/- 11, p < 0.005, vs. 54 +/- 13 ml/m2, NS). CONCLUSIONS: Among patients with a first anterior AMI, spontaneous improvement in contractility at 1 year was greatest in those with a more depressed ventricular function or a dilated ventricle, but its magnitude was underestimated by a predischarge DBT test.     

Late intervention after anterior myocardial infarction: effects on left ventricular size,function, quality of life,and exercise tolerance: results of the Open Artery Trial (TOAT Study)

OBJECTIVE: We sought to conduct a randomized trial comparing late revascularization with conservative therapy in symptom-free patients after acute myocardial infarction (AMI). BACKGROUND: In the absence of ischemia, the benefits of reperfusion late after AMI remain controversial. However, the possibility exists that an open infarct related artery benefits healing post AMI. METHODS: Of 223 patients enrolled with Q-wave anterior AMI, 66 with isolated persistent occlusion of the left anterior descending coronary artery (LAD) were randomized to the following treatments: 1) medical therapy (closed artery group; n = 34) or 2) late intervention and stent to the LAD + medical therapy (open artery group; n = 32). The study was powered to compare left ventricular (LV) end-systolic volume between the two groups 12 months post AMI. RESULTS: Late intervention 26 +/- 18 days post AMI resulted in significantly greater LV end-systolic and end-diastolic volumes at 12 months than medical therapy alone (106.6 +/- 37.5 ml vs. 79.7 +/- 34.4 ml, p < 0.01 and 162.0 +/- 51.4 ml vs. 130.1 +/- 46.1 ml, p < 0.01, respectively). Exercise duration and peak workload significantly increased in both groups from 6 weeks to 12 months post AMI, although absolute values were greater in the open artery group. Quality of life scores tended to deteriorate during this time interval in the closed artery patients but remained unchanged in the open artery patients. Coronary angiography at 1 year documented a low incidence of intergroup cross-over (spontaneous recanalization in 19% and closure in 11%). CONCLUSIONS: In the present study, recanalization of occluded infarct-related arteries in symptom-free patients approximately 1 month post AMI had an adverse effect on remodeling but tended to increase exercise tolerance and improve quality of life.     

Impact of late coronary artery reperfusion on left ventricular function one month after acute myocardial infarction (results from the ISAM study)

To evaluate the impact of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction, findings from 368 patients in the Intravenous Streptokinase in Myocardial Infarction study are presented. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Contrast angiography was performed 1 month after the acute event. The infarct-related coronary artery was patent in 74 of 116 (64%) streptokinase-treated patients and 141 of 252 (56%) patients treated with anticoagulant therapy (placebo group). In all baseline variables, including the actually developed enzymatic and electrocardiographic infarct sizes, there were no differences between the patent- or occluded-artery groups. A patent infarct artery 1 month after infarction was associated with significantly better LV function regardless of the vessel involved and whether or not patients had been treated with streptokinase. Ejection fraction in patients with patent versus occluded artery was 56 +/- 13 versus 50 +/- 14 (p less than 0.0005). Most benefit was noted in patients in whom the proximal left anterior descending coronary artery was affected: ejection fraction was 52 +/- 14 versus 36 +/- 12% (p less than 0.0005). Our data confirm that restoration of adequate flow through an infarct-related coronary artery beyond the time window for actual salvage of ischemic myocardium has a definite beneficial effect on LV function.     

Correlation between distal left anterior descending artery flow velocity by transthoracic Doppler echocardiography and corrected TIMI frame count before mechanical reperfusion in patients with anterior acute myocardial infarction.

BACKGROUND: This study was designed to determine the utility of transthoracic Doppler echocardiography (TTDE) in evaluating angiographic Thrombolysis in Myocardial Infarction (TIMI) frame count as a quantitative index of coronary reperfusion in patients with anterior acute myocardial infarction (AMI) before mechanical reperfusion. METHODS AND RESULTS: Color and pulsed TTDE was performed to evaluate distal left anterior descending coronary artery (LAD) reperfusion in 56 consecutive patients with a first anterior AMI before coronary intervention, and these findings were compared with the corrected TIMI frame count (cTFC) by subsequent angiography. Twenty-four of the 56 patients had LAD reperfusion (TIMI 2 or 3) by angiography. Visual antegrade distal LAD flow by color TTDE was detected in 21 of these 24 patients. In the 21 patients, diastolic peak velocity of the distal LAD flow by pulsed TTDE showed a significant correlation with cTFC by angiography (r = -0.74, p < 0.001). The diagnosis of high risk with angiographic cTFC >40 by distal LAD peak velocity <21 cm/s using TTDE had a sensitivity, specificity, and accuracy of 82%, 93%, and 91%, respectively. CONCLUSION: TTDE enables noninvasive and quantitative evaluation of distal LAD reperfusion in patients with anterior AMI in the acute phase before mechanical reperfusion.     

Collateral flow in patients with acute myocardial infarction

To assess the change in angiographically visualized collaterals in evolving acute myocardial infarction (AMI), coronary arteriograms from 53 patients obtained 6.2 +/- 0.2 hours after onset of AMI symptoms were compared with follow-up angiograms obtained 14 +/- 1 days later. Collaterals were graded according to intensity score and percent of distal infarct-related artery visualized. Collateral intensity score and the percent of distal infarct vessel visualized by collaterals at baseline were low, and there was a significant increase in both values at follow-up angiography. The group of 20 patients with occluded infarct vessels at follow-up study accounted for these increases. In 33 patients with patent infarct vessels at repeat angiography, collateral intensity score and percent of segment visualized were unchanged. Among the patients with occluded infarct vessels at baseline and subsequent improvement in left ventricular (LV) ejection fraction (EF), baseline collateral score and percent of segment visualized were significantly greater than in patients in whom LVEF did not improve. Thus, in patients with evolving AMI, (1) angiographically visible collaterals are not extensive within the early hours of AMI, (2) the extent of collaterals on follow-up angiography may not be representative of that on the day of AMI, (3) collaterals are considerably more common 2 weeks after AMI, especially in patients with occluded infarct arteries during follow-up, and (4) collaterals present at the time of AMI are associated with improved LVEF at 2 weeks.     

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.     

Evolution of left ventricular ejection fraction and its relationship to infarct size after acute myocardial infarction.

OBJECTIVES: The aim of this study was to investigate the evolution of left ventricular (LV) function and infarct size in patients with acute myocardial infarction (MI) treated with primary coronary stenting. BACKGROUND: Little evidence exists on the relationship between LV function and evolution of infarct size after MI. METHODS: This study included 626 patients with first acute MI who underwent 2 angiographic and 3 scintigraphic examinations within 6 months after the acute event. Angiographic left ventricular ejection fraction (LVEF) at baseline and at 6-month angiography, and perfusion defects before intervention and at 7- to 14-day and 6-month scintigraphy after intervention were measured. An analysis of 3-year follow-up was performed. RESULTS: Scintigraphic perfusion defect (median [25th, 75th percentiles]) was 24.6% [14.0%, 41.0%] of LV before intervention; it was reduced to 11.0% [5.0%, 24.0%] of LV at 7 to 14 days and further to 8.0% [2.0%, 19.0%] of LV at 6 months (p < 0.001). The LVEF was 51.6 +/- 12.0% before intervention and increased to 57.4 +/- 12.8% at 6 months (p > 0.001). Independent predictors of LVEF change were baseline LVEF (p < 0.001), initial perfusion defect (p < 0.001), early reduction in perfusion defect (p < 0.001), late reduction in perfusion defect (p < 0.001), peak creatine kinase-MB (p < 0.001), and smoking (p = 0.05). Three-year mortality was 1.2% in patients with improved LF function versus 5.6% in patients with worsened LV function (relative risk 0.29, 95% confidence interval 0.09 to 0.90; p = 0.03). CONCLUSION: Patients with acute MI show an improvement in LV function and a reduction in infarct size within 6 months after coronary reperfusion. This improvement is associated with better long-term survival.     

Importance of early and complete reperfusion to achieve myocardial salvage after thrombolysis in acute myocardial infarction.

The importance of the timing and completeness of coronary artery reperfusion for limitation of acute myocardial infarction (AMI) size after intravenous thrombolytic therapy was studied in 39 patients. All had electrocardiographic epicardial injury and acute coronary angiography performed < 8 hours after symptom onset. Acutely jeopardized myocardium was estimated at baseline, and before and after angiography by quantitative ST-segment analysis. The AMI size was estimated on the final electrocardiogram by the Selvester QRS score. Left ventricular ejection fraction was measured at the time of acute angiography and before discharge in 31 of these patients. In the 21 patients with normal flow (Thrombolysis in Myocardial Infarction [TIMI] trial grade 3) in the infarct-related artery, the amount of jeopardized myocardium decreased from baseline to that before and after angiography (17 to 11 and 11%, respectively; p < 0.00005), and the median final AMI size was reduced (17 to 9%; p = 0.0004). In 6 patients with suboptimal flow (TIMI grade 2), the median amount of jeopardized myocardium decreased slightly from baseline to that before to after angiography (15 to 12%); however, the median final AMI size was not reduced (17%). In 12 patients with no reperfusion (TIMI 0 to 1) flow, the median amount of jeopardized myocardium remained unchanged from baseline to that before angiography (21%), and the final AMI size was not significantly reduced. There was a significant inverse correlation between the change in global left ventricular function and the difference between electrocardiographic estimated jeopardized and final AMI size (rs = -0.53; p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)     

Persistent ST-segment elevation after primary stenting for acute myocardial infarction: its relation to left ventricular recovery

BACKGROUND: Early restoration of coronary artery patency in acute myocardial infarction (AMI) has been linked to improvement in survival. However, early recanalization of an occluded epicardial coronary artery by either thrombolytic agents or percutaneous transluminal coronary angioplasty (PTCA) does not necessarily lead to left ventricular (LV) function recovery. HYPOTHESIS: The aim of this study was to evaluate the relation between persistent ST elevation shortly after primary stenting for acute myocardial infarction (AMI) and LV recovery. METHODS: Thirty-one patients with primary stenting for AMI were prospectively enrolled. To evaluate the extent of microvascular injury, serial ST-segment analysis on a 12-lead electrocardiogram recording just before and at the end of the coronary intervention was performed. Persistent ST-segment elevation (Persistent Group, n = 11) was defined as > or = 50% of peak ST elevation and resolution (Resolution Group, n = 20) was defined as < 50% of peak ST elevation. Echocardiography was performed on Day 1 and 3 months after primary stenting. RESULTS: At 3 months, infarct zone wall-motion score index (WMSI, 2.1 +/- 0.6 vs. 2.7 +/- 0.3, p < 0.05) was smaller in the Resolution Group than in the Persistent Group, whereas wall motion recovery index (RI, 0.4 +/- 0.3 vs. 0.1 +/- 0.2, p < 0.05) and ejection fraction (58 +/- 5 vs. 43 +/- 10%, p < 0.05) were larger in the Resolution Group than in the Persistent Group. The extent of persistent ST elevation (% ST) shortly after successful recanalization of the infarct-related artery was significantly related to RI at 3 months (r = -0.4, p < 0.05). However, time to reperfusion was not related to RI at 3 months. There was also significant correlation between corrected TIMI frame count and %ST (r = 0.4, p < 0.05). CONCLUSIONS: Persistent ST-segment elevation shortly after successful recanalization (> or = 50% of the peak value), as a marker of impaired microvascular reperfusion, predicts poor LV recovery 3 months after primary stenting for AMI.