Impact of myocardial perfusion on left atrial remodeling following primary angioplasty for acute myocardial infarction

OBJECTIVES: To investigate the impact of myocardial perfusion on left atrial remodeling and its determinants after primary percutaneous coronary intervention for acute myocardial infarction. BACKGROUND: Left atrial volume is an important predictor of morbidity and mortality in acute myocardial infarction, while thrombolysis in myocardial infarction (TIMI) myocardial perfusion (TMP) grade is an angiographic index associated with infarct size and mortality. As yet, however, the relationship between TMP grade and left atrial remodeling has not been investigated. METHODS: Conventional transthoracic echocardiography was performed in 105 patients (55+/-13 years old, 92 men) with acute myocardial infarction within 24 h and after 6 months (mean 9+/-4, range 6-29 months) following successful primary percutaneous coronary intervention. Absolute left atrial volume was calculated using an elliptical model. Myocardial perfusion was evaluated, using TMP grade, by visual assessment on the coronary angiogram. Patients were divided into three groups on the basis of myocardial perfusion status, as TMP 0/1 (n=36), TMP 2 (n=36) and TMP 3 (n=33). RESULTS: No difference was observed between baseline and follow-up left atrial volumes in the overall study population (42.5+/-16.1 vs. 43.5+/-17.4 ml, P=0.519). As regards TMP grade, follow-up left atrial volume significantly increased in the TMP 0/1 group (43+/-17 vs. 54.6+/-1.1 ml, P<0.001) and significantly decreased in the TMP 3 group (42.9+/-15.7 vs. 35.5+/-12.2 ml, P=0.001) compared with initial values. No change was observed in left atrial volume in the TMP 2 group. Multivariate analysis showed that TMP grade (P<0.001) and anterior location of myocardial infarction (P<0.001) were independent determinants of left atrial remodeling. CONCLUSIONS: These results suggest that poor myocardial perfusion and anterior location of myocardial infarction can affect left atrial remodeling in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention. It appears that adequate myocardial perfusion is crucial to prevent left atrial remodeling, a poor prognostic factor in acute myocardial infarction.     

Significance of total and differential leucocyte count in patients with acute myocardial infarction treated with primary coronary angioplasty.

AIMS: The aim of this study was to correlate total and differential leucocyte (WBC) count with myocardial blush, peak CK levels, and left ventricular (LV) functional recovery at 6 months in 238 consecutive acute myocardial infarction (MI) patients treated with successful primary coronary angioplasty (PCI). METHODS AND RESULTS: Total and differential WBC counts were measured on admission and every 24 h for at least 4 days after PCI. ST-segment resolution and myocardial blush were evaluated immediately after successful primary PCI. LV functional recovery (defined as improvement involving at least two segments, or at least one segment, when only two were asynergic on the basal examination) was obtained through echocardiographic evaluation of LV wall motion at the baseline and at 6 months. Basal CK (P<0.001) and increased neutrophil levels (P<0.001) were the only independent factors related to peak CK, whereas neutrophils and monocytes peaks were related to ST-segment resolution as well as to myocardial blush grade (MBG) 2-3. MBG 2-3 and monocytes number (both as continuous values as well as percentile values) were the only variables independently associated with 6-month LV functional recovery. CONCLUSION: The present study shows that neutrophils and monocytes counts on the first days after acute MI treated with primary PCI are related to markers of effective myocardial reperfusion such as MBG 2-3 and ST-segment resolution. However, only monocytes and MBG are significantly and independently associated with contractile recovery of the infarcted area at 6 months.     

Relation between coronary thrombus and angiographic no-flow during primary angioplasty in patients with acute myocardial infarction

No flow is an unsolved issue in primary percutaneous transluminal coronary angioplasty (PTCA) for patients with acute myocardial infarction (AMI), and the pathophysiology of no-flow is undetermined. To evaluate the potential participation of coronary thromboembolism in no-flow during primary PTCA, the present study reviewed cinefilms of 256 consecutive patients who underwent primary PTCA for AMI within 24h after the onset of chest pain between January 1992 and June 1998, focusing on the thrombus size. Angiographic no-flow was defined as the cessation of flow into the distal coronary circulation of the treated vessel with a to-and-fro contrast movement, not attributable to high-grade stenosis or spasm of the original target lesion. The coronary thrombus size was determined by using the 2-cm balloon catheter as a reference after crossing the infarct-related occluded artery with a guide wire. Angiographic no-flow was observed in 37 patients (37/256, 14%): 14 of 29 cases (48%) with a large thrombus (> or =2cm) versus 23 of 227 cases (9%) with a small thrombus (<2cm, 14/29 vs 23/227, p<0.01). Among 37 patients who experienced angiographic no-flow, overt distal emboli were observed in 14 patients. A thrombolytic agent was used through a guiding catheter in 102 cases prior to or after balloon dilatation to prevent or attenuate distal embolism, particularly in all those cases with a large thrombus (29/29 100%), and angiographic no-flow was seen in 27 cases of this subgroup (27/102, 26%). It is suggested that distal thromboembolism plays an important role in the mechanism of angiographic no-flow during primary PTCA performed for AMI.     

Relation between preintervention angiographic evidence of coronary collateral circulation and clinical and angiographic outcomes after primary angioplasty or stenting for acute myocardial infarction.

It is unknown if collateral circulation (CC) has a beneficial effect on outcomes of patients who undergo mechanical intervention in the first hours after onset of acute myocardial infarction (AMI). This study analyzes the relation between CC and outcome in patients with AMI who underwent primary angioplasty or stenting within 6 hours of symptom onset. The analysis was performed in a series of 1,164 consecutive patients. The contribution of clinical, angiographic, and procedural variables to the angiographic and clinical outcomes was evaluated by multivariate logistic regression analysis and the Cox proportional hazard model, respectively. Of 1,164 patients, 264 (23%) had angiographic evidence of CC. Patients with CC had a lower incidence of diabetes (11% vs 16%, p = 0.033), anterior AMI (41% vs 55%, p <0.001), cardiogenic shock (9% vs 14%, p = 0.029), anterograde TIMI grade flow >1 (10% vs 21%, p <0.001), and a greater incidence of preinfarction angina (43% vs 32%, p = 0.001), multivessel disease (59% vs 47%, p = 0.001), and total chronic occlusion (20% vs 10%, p <0.001). At 6 months, the mortality rate was lower in patients with CC compared with patients without CC (4% vs 9%, p = 0.011), whereas there were no differences in the incidence of reinfarction, target vessel revascularization, and angiographic restenosis. After multivariate analysis, CC did not emerge as a significant variable in relation to 6-month clinical and angiographic outcomes. CC does not exert a protective effect in patients who undergo mechanical intervention in the first 6 hours of AMI onset.     

Ageing, impaired myocardial perfusion, and mortality in patients with ST-segment elevation myocardial infarction treated by primary angioplasty.

AIMS: It is still unknown whether impaired myocardial perfusion helps to explain the higher mortality observed with ageing in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary angioplasty. METHODS AND RESULTS: In 1548 consecutive patients with STEMI treated with primary angioplasty, myocardial perfusion was evaluated by myocardial blush grade (MBG) and ST-segment resolution. All clinical and follow-up data were prospectively collected. Advanced age was associated with a significantly higher clinical and angiographic risk profile. We found a linear relationship between increasing age, decreased myocardial perfusion, and higher 1-year mortality. After adjustment for baseline potential confounding variables, increased age was still significantly associated with impaired myocardial blush (MBG 0-1) (P=0.028), and ST-segment resolution (<50%) (P=0.007). At multivariable analysis both age (P<0.0001) and poor myocardial perfusion (P<0.0001) were independent predictors of 1-year mortality. CONCLUSION: This study shows that impaired reperfusion is an additional determinant of the poor outcome observed with advanced age in patients with STEMI undergoing mechanical revascularization.     

急性冠状动脉支架成形术后心肌组织灌注的临床研究

目的 观察急性心肌梗死患者冠状动脉介入(PCI)治疗成功后,校正的TIMI帧数(CTFC)与心电图ST段回落联合评价心肌组织水平灌注的可行性。方法 测定PCI治疗后血流达。TIMI3级患者的CTFC,并在术前及术后1个月分别测定室壁运动记分(WMSI)。观察CTFC与WMSI之间的相关性,同时检查术前及术后1小时心电图ST段回落情况。结果 按照CTFC将,TIMI血流3级者分为快、慢两组,快CTFC组患者ST段回落程度明显优于慢CTFC组;1个月后快CTFC组患者的室壁运动记分改善程度明显优于慢CTFC组,CTFC与术前、术后WMSI的差值有明显的负相关;快CTFC组患者从发病到接受PCI治疗的时间明显短于慢CTFC组。结论 CTFC作为一种定量、客观、简单、经济、重复性好的方法评价心肌微循环灌注情况,较低的CTFC及心电图ST段回落完全预示着良好的心功能恢复,可为临床提供是否需要进一步辅助治疗的证据。     

Relation of myocardial perfusion to mortality after primary percutaneous coronary intervention

In patients who undergo primary percutaneous coronary intervention (PCI), poor post-PCI myocardial blush is associated with increased mortality, even when epicardial perfusion is adequate. This observation has important implications for the methods of evaluating primary PCI results and the strategies used to improve myocardial reperfusion.     

The incidence, predictors, and outcomes of early reinfarction after primary angioplasty for acute myocardial infarction

OBJECTIVES: We sought to identify the incidence, predictors, and clinical consequences of one-month reinfarction (RE-MI) in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: One-month reinfarction after AMI significantly increases long-term mortality; however, little is known about the incidence and predictors of RE-MI in patients undergoing primary angioplasty. METHODS: We analyzed data from 3,646 patients who underwent primary PCI in the Primary Angioplasty in Acute Myocardial Infarction (PAMI) studies. We studied the incidence, correlates, and clinical outcomes of 30-day RE-MI. RESULTS: Reinfarction within one month of index hospitalization occurred in 77 (2.1%) of patients. In multivariate analysis, admission Killip class >1 (odds ratio [OR] 2.02, 95% confidence interval [CI] 1.09 to 3.76), left ventricular ejection fraction <50% (OR 2.49, 95% CI 1.30 to 4.74), final coronary stenosis >30% (OR 2.57, 95% CI 1.28 to 5.15), and presence of coronary dissection (OR 2.40, 95% CI 1.36 to 4.24) and thrombus (OR 2.36, 95% CI 1.23 to 4.53) on the final angiogram were independent correlates of RE-MI. One-month reinfarction was independently associated with death (OR 7.14, 95% CI 3.28 to 15.5) and ischemic target vessel revascularization (I-TVR) (OR 15.0, 95% CI 8.68 to 26.0) at six months. CONCLUSIONS: We conclude that, although early RE-MI is uncommon in patients treated by primary PCI, it is a significant independent predictor of death and I-TVR at six months. Admission Killip class >1 and left ventricular systolic dysfunction were associated with higher incidence of RE-MI. Our results suggest that optimal revascularization during primary PCI may decrease RE-MI rates.     

Association between white blood cell count, epicardial blood flow, myocardial perfusion, and clinical outcomes in the setting of acute myocardial infarction: a thrombolysis in myocardial infarction 10 substudy

BACKGROUND: Elevation of the white blood cell (WBC) count during acute myocardial infarction (AMI) is associated with adverse outcomes. We examined the relationship between the WBC count and angiographic findings to gain insight into this relationship. Results and Methods-We evaluated data from 975 patients in the Thrombolysis In Myocardial Infarction (TIMI) 10A and 10B trials. Patients with a closed artery at 60 and 90 minutes had higher a WBC count than patients with an open artery (P:=0.02). Likewise, the presence of angiographically apparent thrombus was associated with a higher WBC count (11.5+/-5.2x10(9)/L, n=290, versus 10.7+/-3. 5x10(9)/L, n=648; P=0.008). In addition, a higher WBC count was associated with poorer TIMI myocardial perfusion grades (4-way P=0.04). Mortality rates were higher in patients with a higher WBC count (0% for WBC count 0 to 5x10(9)/L, 4.9% for WBC count 5 to 10x10(9)/L, 3.8% for WBC count 10 to 15x10(9)/L, 10.4% for WBC count >15x10(9)/L; P=0.03). The development of new congestive heart failure or shock was also associated with a higher WBC count (0% for WBC count 0 to 5x10(9)/L, 5.2% for WBC count 5 to 10x10(9)/L, 6.1% for WBC count 10 to 15x10(9)/L, 17.1% for WBC count >15x10(9)/L; P<0.001), an observation that remained significant in a multivariable model that adjusted for potential confounding variables (odds ratio 1.21, P=0.002). CONCLUSIONS: Elevation in WBC count was associated with reduced epicardial blood flow and myocardial perfusion, thromboresistance (arteries open later and have a greater thrombus burden), and a higher incidence of new congestive heart failure and death. These observations provide a potential explanation for the higher mortality rate observed among AMI patients with elevated WBC counts and helps explain the growing body of literature that links inflammation and cardiovascular disease.     

Impact of diabetes mellitus on myocardial perfusion after primary angioplasty in patients with acute myocardial infarction

OBJECTIVES: We investigated the impact of diabetes mellitus on myocardial perfusion after primary percutaneous coronary intervention (PCI) utilizing myocardial blush grade (MBG) and ST-segment elevation resolution (STR). BACKGROUND: Diabetes is an independent predictor of outcomes after primary PCI for acute myocardial infarction (AMI). Whether the poor prognosis is due to lower rates of myocardial reperfusion is unknown. METHODS: Reperfusion success in those with and without diabetes mellitus was determined by measuring MBG (n = 1,301) and STR analysis (n = 700) in two substudies of the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial among patients undergoing primary PCI for AMI. RESULTS: There were no differences between those with or without diabetes with regard to postprocedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 (>95%), distribution of infarct-related artery, and the frequency of stent deployment or abciximab administration. Patients with diabetes mellitus were more likely to have absent myocardial perfusion (MBG 0/1, 56.0% vs. 47.1%, p = 0.01) and absent STR (20.3% vs. 8.1%, p = 0.002). Diabetes mellitus (hazard ratio [HR] 1.63 [95% confidence interval (CI) 1.17 to 2.28], p = 0.004) was an independent predictor of absent myocardial perfusion (MBG 0/1) and absent STR (HR 2.94 [95% CI 1.64 to 5.37], p = 0.005) by multivariate modeling. CONCLUSIONS: Despite similar high rates of TIMI flow grade 3 after primary PCI in patients with and without diabetes, patients with diabetes are more likely to have abnormal myocardial perfusion as assessed by both incomplete STR and reduced MBG. Diminished microvascular perfusion in diabetics after primary PCI may contribute to adverse outcomes.     

Synergy between intracoronary stenting and abciximab in improving angiographic and clinical outcomes of primary angioplasty in acute myocardial infarction

This study examined 650 consecutive patients who presented with an acute myocardial infarction and were treated with primary angioplasty within 12 hours of symptom onset between August 1995 and December 1998. Patients were placed into 4 treatment groups depending on the adjunctive therapy they received: group 1, percutaneous transluminal coronary angioplasty (PTCA) ("balloon PTCA alone"; n = 220); group 2, PTCA plus intracoronary stent placement ("stent"; n = 128); group 3, PTCA plus abciximab therapy ("abciximab"; n = 104); and group 4, PTCA plus intracoronary stent placement plus abciximab therapy ("stent/abciximab"; n = 198). The patients' clinical characteristics, severity of disease, and total ischemia time on presentation were similar. At baseline, abciximab and stent/abciximab groups had a higher incidence of thrombus on coronary angiography. Postprocedural quantitative coronary analysis showed a significantly larger minimum luminal diameter in the stent and stent/abciximab groups than PTCA alone. Overall, stents were most efficacious in reducing target vessel revascularization rate, whereas abciximab was associated with a higher postprocedural Thrombolysis In Myocardial Infarction-3 trial flow and less "no reflow." The best angiographic result was achieved in the stent/abciximab group. Similarly, the primary combined end point of death, myocardial infarction, and target vessel revascularization at 30 days was the lowest (6.1%) in the stent/abciximab group. The combination of abciximab and stenting in primary angioplasty for acute myocardial infarction is thus synergistic and is associated with improved angiographic and clinical results at 30-day follow-up.     

Abciximab in primary coronary angioplasty for acute myocardial infarction improves short- and medium-term outcomes

Objectives. The purpose of this study was to compare the outcome of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (MI) when performed with or without the platelet glycoprotein IIb/IIIa antibody, abciximab.

Background. Abciximab improves the outcome of angioplasty but the effect of abciximab in primary angioplasty has not been investigated.

Methods. Data were collected from a computerized database. Follow-up was by telephone or review of outpatient or hospital readmission records.

Results. A total of 182 consecutive patients were included; 103 received abciximab and 79 did not. The procedural success rate was 95% in the two groups. At 30-day follow-up, the composite event rate of unstable angina, reinfarction, target vessel revascularization and death from all causes was 13.5% in the group of patients who did not receive abciximab, 4% (p < 0.05) in the abciximab group and 2.4% (p < 0.05) in the subgroup of patients (n = 87) who completed the 12-h abciximab infusion. At the end of follow-up (mean 7 ± 4 months), the composite event rate was 32.4%, 17% (p < 0.05) and 13.1% (p < 0.01) in these three categories respectively. Abciximab bolus followed by a 12-h infusion was an independent predictor of event-free survival, in a Cox proportional hazards model (relative risk 0.49; 95% confidence interval 0.24 to 0.99; p < 0.05).

Conclusions. Abciximab given at the time of primary angioplasty may improve the short- and medium-term outcome of patients with acute MI, especially when a 12-h infusion is completed.     

Evaluation of myocardial perfusion and deformation in patients with acute myocardial infarction treated with primary angioplasty and stent placement

PURPOSE: To prospectively compare the usefulness of myocardial perfusion and deformation imaging for the prediction of functional recovery and left ventricular (LV) remodeling in patients with ST-elevation myocardial infarction (STEMI). METHODS: We prospectively examined 36 patients with reperfused STEMI, 12+ or -9 h after primary angioplasty and stent placement. LV function was reevaluated at 4-6 months of follow-up, to assess relative improvement of LV-ejection fraction (DeltaEF%) and increase in end-diastolic volume (DeltaEDV). RESULTS: During the follow-up period, 19 of 36 patients showed LV function improvement (DeltaEF%> or =10%), whereas 10 patients had LV remodeling (DeltaEDV> or =20%). Peak negative strain (epislon (peak)), peak negative strain rate (SRpeak), and myocardial blood flow (Axbeta) correlated with DeltaEF% (r=-0.55, -0.57, and 0.46, respectively, P<0.01 for all), and allowed for prediction of LV remodeling on an individual level (area under the curve of 0.85 for strain rate, 0.95 for strain, and 0.90 for regional blood flow, P<0.001 for all). The combined assessment of myocardial perfusion and deformation correctly predicted LV remodeling in four additional patients, compared with each technique separately. CONCLUSION: Contrast echocardiography, strain Doppler imaging, and possibly the combination of both are useful for the prediction of adverse LV remodeling and for the early risk stratification of patients with STEMI.     

Comparison of in-hospital outcomes following early or delayed angioplasty for acute myocardial infarction

BACKGROUND: Studies of primary angioplasty for treatment of acute myocardial infarction (AMI) have not appeared to demonstrate a reduction in efficacy as a function of time to treatment. We sought to compare the outcomes of patients treated in New York State with primary angioplasty within 6 hours of symptom onset to those treated between 6 and 23 hours after the onset of AMI. METHODS: We used data from the 1995 Coronary Angioplasty Reporting System of the New York State Department of Health to compare the in-hospital outcomes of patients treated with early (within 6 hours) or delayed angioplasty (6 23 hours) for AMI. RESULTS: Early angioplasty (within 6 hours after onset of chest pain) was attempted in 957 patients (71.3%), while 385 patients (28.7%) had a delayed procedure (6 23 hours after the onset of chest pain). Patients who underwent delayed angioplasty were older (mean age, 62.6 years versus 60.4 years in the early group; p < 0.01) and more often female (36% vs. 28% in the early treatment group; p < 0.001). Patients treated early more frequently demonstrated hemodynamic instability (13.6% versus 9.1% in the late treatment group; p = 0.02), malignant ventricular arrhythmia (8.5% versus 2.9% in the late treatment group; p < 0.001) and cardiogenic shock (6.6% versus 1.8% in the late treatment group; p < 0.001). Overall in-hospital mortality was 63/1,342 (4.7%) with no difference based on early or delayed angioplasty (5.2% versus 3.4%, respectively; p = NS). The composite of the major adverse cardiac events including in-hospital death, reinfarction and emergency bypass surgery did not differ significantly between the early and delayed groups (7.7% versus 5.5%, respectively; p = NS). In multivariable models, delayed angioplasty was not an independent predictor of either in-hospital mortality or major adverse cardiac events. CONCLUSION: Delayed reperfusion does not influence in-hospital clinical outcomes following PTCA for acute myocardial infarction.     

Gender-age interaction in early mortality following primary angioplasty for acute myocardial infarction

Previous studies have demonstrated a significant interaction between gender and age after medically treated acute myocardial infarction (AMI), when younger women were found to have a higher mortality rate than younger men, but the mortality rate for older men and women was similar. The study objective was to determine whether a gender-age interaction exists for AMI treated exclusively with primary angioplasty. This analysis was a retrospective cohort study of 9,015 consecutive patients who underwent primary angioplasty for AMI in New York State from 1997 to 1999. The primary end point of interest was in-hospital mortality. A logistic regression model was constructed to determine the relation between gender and mortality among patients with AMI treated with angioplasty. Additional analyses were performed to test whether a mortality difference existed according to age. In-hospital mortality rate was twofold higher in women than in men (6.7% vs 3.4%, p <0.001). After adjusting for age, co-morbid conditions, and hemodynamic status by multivariable logistic regression analysis, the odds ratio for in-hospital death for women was no longer significant (odds ratio 1.21, 95% confidence interval 0.69 to 2.10, p = 0.51). Among patients <75 years of age, women had a 37% increased risk of in-hospital mortality (adjusted odds ratio 1.37, 95% confidence interval 1.01 to 1.98, p = 0.04), whereas there was no significant difference in mortality between men and women who were >or=75 years of age. In conclusion, female gender was found to be an independent predictor of in-hospital mortality in patients <75 years of age after primary angioplasty for AMI.