Frequency,determinants, and clinical implications of residual intracoronary thrombus following primary angioplasty for acute myocardial infarction

The presence of intracoronary thrombus after percutaneous coronary intervention (PCI) worsens clinical outcomes. We performed this study to assess the incidence of intracoronary thrombus after primary angioplasty for acute myocardial infarction (AMI) and the clinical impact of nonocclusive thrombus. In 2,148 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI)-2, Stent PAMI, and PAMI No-Surgery-On-Site trials, we compared clinical and angiographic characteristics of 131 patients (6%) who had angiographically visible thrombus after PCI with those who did not (n = 2,017). In the subset of 2,115 patients with post-PCI Thrombolysis In Myocardial Infarction (TIMI) 2 or 3 flow, we assessed the impact of post-PCI thrombus (n = 110) on in-hospital, 1-month, and 1-year outcomes (reinfarction, ischemic target vessel revascularization [I-TVR], death, and major adverse cardiovascular events [MACEs] [i.e., death, reinfarction, or I-TVR]). Lack of stent use, presence of thrombus before PCI, and no history of PCI were independent correlates of post-PCI thrombus. Patients with nonocclusive thrombus after PCI had more reinfarctions during the index hospitalization (5.5% vs 2.0%, p = 0.03) and at 1 month (6.8% vs 2.3%, p = 0.01) and had nonsignificantly higher I-TVR (during hospitalization 5.5% vs 2.8%, p = 0.13; at 1 month 5.9% vs 3.4%, p = 0.17), but similar mortality and MACE rates as those without post-PCI thrombus. In multivariate analysis, post-PCI thrombus was not a significant predictor of in-hospital or 1-month reinfarction. At 1 year, clinical outcomes were similar between patient groups (reinfarction 8.3% vs 4.7%, p = 0.14; I-TVR 12.5% vs 12.1%, p = 0.91; death 5.9% vs 5.0%, p = 0.68; and MACEs 21% vs 18%, p = 0.54). We conclude that residual intracoronary thrombus after primary angioplasty is relatively uncommon. In patients who achieve TIMI 2 or 3 flow after PCI, intracoronary thrombus is associated with worse cardiovascular outcomes. However, differences in outcomes between patients with and without residual thombus are related to baseline clinical differences rather than thrombus per se.     

Evaluation of the association of proximal coronary culprit artery lesion location with clinical outcomes in acute myocardial infarction

Impaired coronary artery blood flow and left anterior descending (LAD) artery culprit location are angiographic variables that have been associated with poorer outcomes after fibrinolytic administration in patients with acute myocardial infarction (AMI). We hypothesized that culprit lesion location in the proximal portion of the culprit artery would also be associated with poorer clinical outcomes compared with a mid or distal location. Lesion location and clinical outcomes were evaluated in 2,488 patients from the Thrombolysis In Myocardial Infarction (TIMI) 4, 10A, 10B, and 14 trials. Proximal lesions were located before or at the first major branch of the parent artery, mid lesions were between the first and the second major branches, and all other lesions were classified as distal. Proximal lesions were associated with a higher incidence of in-hospital death or recurrent AMI compared with mid or distal lesions (10.5% [n = 478] vs 6.1% [n = 1,498] vs 3.7% [n = 511], p <0.001), and they were associated with a higher rate of in-hospital death (6.7% [n = 478] vs 3.2% [n = 1,498] vs 2.5% [n = 511], p = 0.001). In a multiple logistic regression model adjusting for TIMI flow grade, age, gender, and pulse, the planimetered distance from the ostium to the LAD culprit lesion was associated with 30-day death or recurrent AMI (odds ratio 0.79 per centimeter increase in distance down the artery, p = 0.01). Proximal culprit lesion location is associated with an increased risk of adverse outcomes after fibrinolytic administration, which is likely due to a larger area of subtended myocardium. In patients with a LAD culprit lesion, proximal lesion location is a multivariate correlate of adverse outcomes even after adjustment for coronary blood flow and other covariates.     

Impact of thrombus aspiration on angiographic and clinical outcomes in patients with ST-elevation myocardial infarction

BackgroundPrimary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) may be limited by thrombus embolization. Export aspiration catheter (EAC) is a thrombectomy device which may enhance angiographic results, but its impact on clinical outcomes is unclear. This trial objective was to assess the impact of EAC on angiographic and clinical outcomes in patients with STEMI.MethodsAll STEMI patients undergoing primary or rescue PCI in a tertiary care center were included. Patients were divided in two groups according to the use of the EAC. Patients were followed up prospectively for death, reinfarction, revascularization, or stroke. Thrombolysis In Myocardial Infarction (TIMI) flow in the culprit vessel was assessed before and after PCI.ResultsIncluded in the analysis were 535 patients. EAC was used in 165 patients before angioplasty (Group 1) and 370 patients underwent PCI without thrombus aspiration (Group 2). More patients in Group 1 had initial TIMI flow 0–1 compared to Group 2 (88% vs. 62%, P<.001). Proportion of patients with a final TIMI flow 3 was the same in both groups (89.1% vs. 87.6% for Groups 1 and 2, respectively; P=.67). An analysis restricted to patients with initial TIMI flow 0–1 yielded similar results. No difference in clinical outcomes was observed between the two groups (P=.70).ConclusionsSelective use of the EAC based on the judgment of operators results in excellent angiographic and clinical results. Further clinical investigation is needed to definitely answer whether thromboaspiration needs to be performed in all STEMI patients undergoing primary PCI.     

Clinical and angiographic correlates and outcomes of suboptimal coronary flow inpatients with acute myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVES: The purpose of this study was to determine the clinical and angiographic correlates and outcomes of patients with suboptimal coronary flow after primary percutaneous coronary interventions (PCI). BACKGROUND: The clinical and angiographic correlates and outcomes of Thrombolysis in Myocardial Infarction (TIMI) < or =2 flow in patients treated with primary PCI are not known. METHODS: We evaluated 3,362 patients with ST elevation myocardial infarction enrolled in various Primary Angioplasty in Myocardial Infarction trials, who underwent primary PCI. RESULTS: Post-procedural final TIMI < or =2 flow occurred in 232 (6.9%) patients. Multivariate analysis identified age > or =70 years (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1 to 2.2), diabetes (OR 1.9; 95% CI, 1.3 to 2.7), symptom onset to emergency room presentation (OR 1.1; 95% CI, 1.1 to 1.2); initial TIMI < or =1 flow (OR 3.2; 95% CI, 1.9 to 5.5), and left ventricular ejection fraction <50% (OR 1.7; 95% CI, 1.2 to 2.4) as independent correlates of final TIMI < or =2 flow. In-hospital (composite of reinfarction, ischemic target vessel revascularization, or death, as well as these events individually) and one-year (reinfarction and/or death) events occurred more frequently in patients with TIMI < or =2 flow. The Cox proportional hazards model identified TIMI < or =2 flow to be independently associated with one-year mortality (hazard ratio 3.8, 95% CI, 2.5 to 5.7). CONCLUSIONS: Final TIMI < or =2 flow, although uncommon after primary PCI, was strongly associated with hospital and one-year adverse events. The clustering of final TIMI < or =2 flow in high-risk groups may partially explain the poor prognosis of these patients. Awareness of these risk factors may be useful to clinicians to triage and treat patients undergoing primary PCI.     

Comparison of outcomes of diabetic and nondiabetic patients undergoing primary angioplasty for acute myocardial infarction

We sought to determine whether diabetes mellitus independently conferred poor prognosis in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). In 3,742 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI) studies with the intention of undergoing primary PCI, we compared in-hospital mortality, 6-month mortality, and 6-month major adverse cardiovascular events (MACEs), i.e., composite of death, reinfarction, or ischemic target vessel revascularization (TVR), between diabetics (n = 626, 17%) and nondiabetics (n = 3,116, 83%). We evaluated the independent impact of diabetes on outcomes after adjustment for baseline clinical and angiographic differences. Diabetics had worse baseline clinical characteristics, longer pain onset-to-hospital arrival time, and longer door-to-balloon time. They had more multivessel coronary disease and lower left ventricular ejection fractions, but better baseline Thrombolysis In Myocardial Infarction (TIMI) flow. Diabetics underwent primary PCI less often (88% vs 91%, p = 0.01). During the index hospitalization, diabetics were more likely to die (4.6% vs 2.6%, p = 0.005). During 6-month follow-up, diabetics had higher incidences of death (8.1% vs 4.2%, p <0.0001) and MACEs (18% vs 14%, p = 0.036). In multivariate analysis, diabetes was independently associated with 6-month mortality (hazard ratio 1.53, 95% confidence interval 1.03 to 2.26, p = 0.03), but not with in-hospital mortality or 6-month MACEs. We conclude that diabetics with AMI have less favorable baseline characteristics and are less likely to undergo primary PCI than nondiabetics. Despite excellent angiographic results, diabetics had significantly worse 6-month mortality.     

Facilitation of early percutaneous coronary intervention after reteplase with or without abciximab in acute myocardial infarction: results from the SPEED (GUSTO-4 Pilot) Trial.

OBJECTIVES: We examined the utility of early percutaneous coronary intervention (PCI) in a trial that encouraged its use after thrombolysis and glycoprotein IIb/IIIa inhibition for acute myocardial infarction (MI). BACKGROUND: Early PCI has shown no benefit when performed early after thrombolysis alone. METHODS: We studied 323 patients (61%) who underwent PCI with planned initial angiography, at a median 63 min after reperfusion therapy began. A blinded core laboratory reviewed cineangiograms. Ischemic events, bleeding, angiographic results, and clinical outcomes were compared between early PCI and no-PCI patients (n = 162), between patients with Thrombolysis in Myocardial Infarction (TIMI) flow grade 0 or 1 before PCI versus flow grade 2 or 3, and among three treatment regimens. RESULTS: Early PCI patients showed a procedural success (<50% residual stenosis and TIMI flow grade 3) rate of 88% and a 30-day composite incidence of death, reinfarction, or urgent revascularization of 5.6%. These patients had fewer ischemic events and bleeding complications (15%) than did patients not undergoing early PCI (30%, p = 0.001). Early PCI was used more often in patients with initial TIMI flow grade 0 or 1 versus flow grade 2 or 3 (83% vs. 60%, p < 0.0001). Patients receiving abciximab with reduced-dose reteplase (5 U double bolus) showed an 86% incidence of TIMI grade 3 flow at approximately 90 min and a trend toward improved outcomes. CONCLUSIONS: In this analysis, early PCI facilitated by a combination of abciximab and reduced-dose reteplase was safe and effective. This approach has several advantages for acute MI patients, which should be confirmed in a dedicated, randomized trial.     

Early coronary intervention following pharmacologic therapy for acute myocardial infarction (the combined TIMI 10B-TIMI 14 experience).

Earlier studies have suggested that immediate percutaneous coronary intervention (PCI) following thrombolytic therapy for acute myocardial infarction (AMI) is associated with an increase in adverse events and that routine PCI in this setting has offered no advantage over a conservative strategy. To reassess this issue in a more recent era, we evaluated 1,938 patients from the Thrombolysis in Myocardial Infarction (TIMI) 10B and 14 trials of AMI. Patients in TIMI 10B were randomized to receive tissue plasminogen activator or TNK tissue plasminogen activator, whereas patients in TIMI 14B trial were randomized to receive thrombolytic therapy with or without abciximab. All patients underwent angiography 90 minutes after receiving pharmacologic therapy. Patients who underwent PCI were classified as having undergone a rescue procedure (TIMI 0 or 1 flow at 90 minutes), an adjunctive procedure (TIMI 2 or 3 flow at 90 minutes), or a delayed procedure (performed >150 minutes after symptom onset, median of 2.75 days). Among patients with TIMI 0 or 1 flow, there was a trend for lower 30-day mortality among patients who underwent rescue PCI than among those who did not (6% vs 17%, p = 0.01, adjusted p = 0.28). Patients who underwent adjunctive PCI had similar 30-day mortality and/or reinfarction as those who underwent delayed PCI. In a multivariate model both had lower 30-day mortality and/or reinfarction than patients with "successful thrombolysis" (i.e., TIMI 3 flow at 90 minutes) who did not undergo revascularization (p = 0.02). Thus, early PCI following AMI is associated with excellent outcomes. Randomized trials of an early invasive strategy following thrombolysis are warranted.     

Protection of Distal Embolization in High-Risk Patients with Acute ST-Segment Elevation Myocardial Infarction (PREMIAR)

Distal embolization may decrease myocardial reperfusion after primary percutaneous coronary intervention (PCI). Nonetheless, results of previous trials assessing the role of distal protection during primary PCI have been controversial. The Protection of Distal Embolization in High-Risk Patients with Acute ST-Segment Elevation Myocardial Infarction Trial (PREMIAR) was a prospective, randomized, controlled study designed to evaluate the role of filter-based distal protection during PCI in patients with acute ST-segment elevation myocardial infarction at high risk of embolic events (including only baseline Thrombolysis In Myocardial Infarction grade 0 to 2 flow). The primary end point was continuous monitoring of ST-segment resolution. Secondary end points included core laboratory analysis of angiographic myocardial blush, ejection fraction measured by cardiac ultrasound, and adverse cardiac events at 6 months. From a total of 194 enrolled patients, 140 subjects were randomized to PCI with or without embolic protection, and 54 were included in a registry arm due to the presence of angiographic exclusion criteria. Baseline characteristics were comparable between arms. The rate of complete ST-segment resolution (>or=70%) at 60 minutes was similar in patients treated with or without distal protection (61.2% vs 60.3%, respectively, p = 0.85). Angiographic myocardial blush (67% vs 70.7%, p = 0.73), in-hospital ejection fraction (47.4 +/- 9.9% vs 45.3 +/- 7.3%, p = 0.29), and combined end point of death, heart failure, or reinfarction at 6 months (14.3% vs 15.7%, p = 0.81) were consistently achieved in a similar proportion in the 2 groups. In conclusion, the use of filter-based distal protection is safe and effectively retrieves debris; however, such use does not translate into an improvement of myocardial reperfusion, left ventricular performance, or clinical outcomes.     

Relation of impaired Thrombolysis In Myocardial Infarction myocardial perfusion grades to residual thrombus following the restoration of epicardial patency in ST-elevation myocardial infarction

Clinical and angiographic data were analyzed from 929 patients who had ST-elevation myocardial infarction and open epicardial arteries after fibrinolytic therapy. Residual angiographically evident thrombus was associated with more frequent Thrombolysis In Myocardial Infarction (TIMI) grade 2 flow (33.6% vs 26.8%, p = 0.03), higher corrected TIMI frame counts (34 vs 31 frames, p = 0.0003), and lower TIMI myocardial perfusion grades (43.0% vs 32.0% TIMI myocardial perfusion grades 0/1, p = 0.001) among all patients and among patients who had TIMI grade 3 flow (33.5% vs 26.0% TIMI myocardial perfusion grades 0/1, p = 0.043). In multivariate analyses, angiographically evident thrombus was associated with higher corrected TIMI frame counts and worsened myocardial perfusion independent of clinical and angiographic covariates, including TIMI grade 3 flow.     

Association of peripheral neutrophilia with adverse angiographic outcomes in ST-elevation myocardial infarction

We hypothesized that absolute and relative neutrophilia would be associated with adverse angiographic outcomes in the 394 patient Limitation of Myocardial Infarction Following Thrombolysis in Acute Myocardial Infarction (LIMIT) Acute Myocardial Infarction (AMI) trial of fibrinolysis in ST-elevation myocardial infarction. The mean neutrophil count was 7.9 x 10(9)/L, with a mean neutrophil percentage of 72%. Patients with time from symptom onset to fibrinolytic treatment more than the median (2.7 hours) had a higher neutrophil count and percentage of neutrophils than patients with shorter time to treatment. Patients with a closed infarct-related artery at 90 minutes (Thrombolysis In Myocardial Infarction [TIMI] grade 0/1 flow) had higher neutrophil counts (8.8 +/- 3.8 vs 7.6 +/- 3.0, p = 0.02) but no difference in the percentage of neutrophils than patients with an open artery. Higher neutrophil counts were also mildly correlated with longer corrected TIMI frame counts (CTFC) in the infarct-related artery (r = 0.14, p = 0.02). Patients with impaired myocardial perfusion by TIMI myocardial perfusion grade (TMPG) had a greater percentage of neutrophils (73.2 +/- 10.7% for TMPG 0/1 vs 69.9 +/- 12.6% for TMPG 2/3, p = 0.047) but no detectable difference in neutrophil counts (8.2 +/- 3.3 vs 7.7 +/- 2.9, p = 0.24). There were no significant associations between other indexes in the cell differential and angiographic or clinical outcomes. Higher neutrophil counts remained independently associated with both closed arteries and CTFC in multivariable models controlling for age, left anterior descending artery infarct location, time to treatment, and pulse and blood pressure on admission. A greater percentage of neutrophils remained independently associated with impaired microvascular perfusion in a similar multivariable model. In patients with ST-elevation myocardial infarction, absolute and relative neutrophilia were associated with impaired epicardial and microvascular perfusion.     

急性心肌梗死患者急诊介入治疗中应用盐酸替罗非班对无复流的影响

目的评价急性心肌梗死患者冠状动脉急诊介入治疗中应用盐酸替罗非班对无复流现象的影响。方法自2006年1月至2008年12月,共104例接受急诊经皮冠状动脉介入(PCI)治疗的急性心肌梗死患者纳入研究,治疗组48例,对照组56例。比较两组间的基础临床状况、造影情况、介入治疗结果。病变血管术后均行TIMI分级、TIMI计帧。结果两组间的基础临床状况、术前造影情况差异均无显著性。但治疗组与对照组介入治疗后TIMI3级血流为91.7%和76.8%(P=0.0408),发生无复流现象为4.2%和16.1%(P=0.0491),远端小血管栓塞为8.3%和23.2%(P=0.0408),TIMI帧数为20.2±2.8和31.2±4.4(P=0.0225),治疗组优于对照组,两组均无严重出血事件发生,主要心血管事件(12.5%vs8.9%,P=0.011)对照组明显高于治疗组。结论急性心肌梗死患者急诊PCI治疗中应用盐酸替罗非班,可以改善术后梗死相关动脉无复流现象。     

Association of a pulsatile blood flow pattern on coronary arteriography and short-term clinical outcomes in acute myocardial infarction

OBJECTIVES: We hypothesized that recognition of systolic flow reversal (pulsatile flow) after thrombolytic administration on coronary angiography is associated with angiographic and electrocardiogram findings reflecting impaired myocardial perfusion, as well as poorer clinical outcomes. BACKGROUND: Reversal of systolic flow on Doppler velocity wire recordings has been associated with impaired tissue perfusion on myocardial contrast echocardiography in the setting of myocardial infarction (MI). METHODS: Patients (n = 1,062) with a patent infarct-related artery were drawn from the Thrombolysis In Myocardial Infarction (TIMI) 10, TIMI 14, and Integrillin and Tenecteplase acute MI trials. RESULTS: Pulsatile flow (systolic flow reversal with cessation of antegrade contrast-dye motion or frank reversal of contrast-dye motion during systole) at 60 min after fibrinolytic administration was present in 11.0% of patients. Pulsatile flow was associated with higher corrected TIMI frame counts (slower epicardial flow) (median 40.1 frames, IQ 30 of 63 vs. 30 frames, interquartile 22 of 42, p < 0.0001), a closed microvasculature (TIMI myocardial perfusion grades 0 of 1, 57.1% vs. 37.8%, p = 0.03) and less complete (> or =70%) ST-segment resolution (23.5% vs. 58.9%, p = 0.008). Patients with pulsatile flow had a higher risk of death or reinfarction at 30 days (10.3% vs. 5.0%, p = 0.019). After controlling for age, pulse, blood pressure, anterior MI location, epicardial flow, and creatine kinase, pulsatile flow remained associated with an increased risk of death/MI (odds ratio 3.1, p = 0.006). CONCLUSIONS: A pulsatile pattern of flow is associated with impaired myocardial perfusion and poorer clinical outcomes independent of the velocity of antegrade flow in the epicardial artery. This simple and easily identifiable angiographic flow pattern may be useful in clinical risk stratification.     

Association of duration of symptoms at presentation with angiographic and clinical outcomes after fibrinolytic therapy in patients with ST-segment elevation myocardial infarction.

OBJECTIVES: We sought to determine if an underlying mechanism of the association between prolonged symptom-to-treatment times and adverse outcomes may be an association of symptom-to-treatment times with impaired Thrombolysis In Myocardial Infarction myocardial perfusion grades (TMPGs). BACKGROUND: Prolonged symptom duration among ST-segment elevation myocardial infarction (STEMI) patients undergoing fibrinolytic therapy is associated with adverse outcomes. METHODS: Angiography was performed 60 min after fibrinolytic administration in 3,845 Thrombolysis In Myocardial Infarction (TIMI) trial patients. RESULTS: The median time from symptom onset to treatment was longer among patients with impaired myocardial perfusion (3.0 h for TMPG 0/1 vs. 2.7 h for TMPG 2/3; p = 0.001). In a multivariate model, impaired tissue perfusion (TMPG 0/1) remained associated with increased time to treatment (odds ratio 1.14 per hour of delay; p = 0.007) even after adjusting for Thrombolysis In Myocardial Infarction flow grade (TFG) 3, left anterior descending infarct location, and baseline clinical characteristics. Impaired myocardial perfusion after rescue/adjunctive percutaneous coronary intervention (PCI) was associated with longer median times to treatment (3.0 h for TMPG 2/3 vs. 2.7 h for TMPG 0/1; p = 0.017), as was abnormal epicardial flow after rescue/adjunctive PCI (3.3 h for TFG 0/1/2 vs. 2.8 h for TFG 3; p = 0.005). Thirty-day mortality was associated with longer time from onset of symptoms to treatment (6.6% mortality for time to treatment >4 h vs. 3.3%; p < 0.001), even among patients undergoing rescue PCI. CONCLUSIONS: A prolonged symptom to treatment time among STEMI patients is associated with impaired myocardial perfusion independent of epicardial flow both immediately after fibrinolytic administration and after rescue/adjunctive PCI. These data provide a pathophysiologic link between prolonged symptoms due to vessel occlusion, impaired myocardial perfusion, and poor clinical outcomes.     

Association of culprit lesion calcium with angiographic and clinical outcomes in patients with ST-elevation myocardial infarction treated with fibrinolytic therapy

Coronary artery calcium has been associated with a greater extent of angiographically significant coronary artery stenoses, but the angiographic and clinical outcomes associated with culprit lesion calcium (CLC) have not been fully evaluated, particularly in the stetting of ST-elevation myocardial infarction. We hypothesized that CLC would be associated with adverse angiographic and clinical outcomes in patients who had ST-elevation myocardial infarction. Data were evaluated in 3,292 patients from 6 trials of fibrinolytic therapy for ST-elevation myocardial infarction; 243 culprit lesions (7.4%) were calcified. CLC was associated with advanced age, history of hypertension, previous coronary artery disease, greater extent of disease, angiographically evident residual thrombus, smaller minimum luminal diameter, and larger percent residual stenosis after fibrinolytic therapy. CLC was associated with lower rates of arterial patency after fibrinolytic therapy (63.3% vs 81.3% p <0.001), lower rates of Thrombolysis In Myocardial Infarction grade 3 flow (41.5% vs 57.2%, p <0.001), and higher (slower) Thrombolysis In Myocardial Infarction frame counts (52 vs 36 frames, p <0.0001, multivariate p = 0.02). CLC was also associated with increased 30-day mortality rates (6.2% vs 3.4%, p = 0.028) and 30-day rates of death, myocardial infarction, or congestive heart failure (16.5% vs 8.9%, p <0.001) and independently associated with 30-day rates of death, myocardial infarction, or congestive heart failure (odds ratio 1.6, p = 0.016) after multivariate adjustment for baseline clinical and lesion characteristics, epicardial flow, and performance of rescue/adjunctive percutaneous coronary intervention. In a model restricted to patients who had successful restoration of epicardial patency after fibrinolytic therapy, CLC was independently associated with 30-day mortality (odds ratio 2.2, p = 0.045). CLC is independently associated with indexes of poorer epicardial flow and a higher incidence of adverse clinical outcomes after fibrinolytic administration in patients who have ST-elevation myocardial infarction.     

Comparison of angiographic and other findings and mortality in non-ST-segment elevation versus ST-segment elevation myocardial infarction in patients undergoing early invasive intervention

We sought to compare the angiographic findings and mortality in patients with non-ST-segment elevation (NSTEMI) versus ST-segment elevation myocardial infarction (STEMI) undergoing early invasive intervention. Of 11,872 patients enrolled in the Korean Acute Myocardial Infarction Registry from November 2005 to January 2008, we studied patients with NSTEMI undergoing early invasive intervention (n = 1,486) and those with STEMI undergoing primary percutaneous coronary intervention (n = 4,392). Multivessel coronary disease, baseline Thrombolysis In Myocardial Infarction (TIMI) flow grade 3, and the left circumflex artery as a culprit lesion occurred more frequently in patients with NSTEMI than in those with STEMI. Those with NSTEMI had a significantly lower mortality rate than those with STEMI during a median follow-up of about 12 months (3.8% vs 6.7%, p <0.001). In the patients with NSTEMI, the independent predictors of mortality included postprocedural TIMI flow grade 0 to 2 (hazard ratio [HR] 3.07, 95% confidence interval [CI] 1.01 to 9.29, p = 0.047) and multivessel coronary disease (HR 3.83, 95% CI 1.36 to 10.81, p = 0.010) but not baseline TIMI flow or infarct location. However, baseline TIMI flow grade 0 to 2 (HR 1.56, 95% CI 1.03 to 2.36, p = 0.035), anterior infarction (HR 1.69, 95% CI 1.28 to 2.23, p <0.001), multivessel coronary disease (HR 1.45, 95% CI 1.10 to 1.91, p = 0.008), and postprocedural TIMI flow grade 0 to 2 (HR 2.00, 95% CI 1.42 to 2.82, p <0.001) were all independent predictors of mortality in the patients with STEMI. In conclusion, the angiographic findings in patients from NSTEMI differ from those in patients with STEMI. Postprocedural TIMI flow and multivessel coronary disease were independent predictors of mortality in patients with NSTEMI undergoing early invasive intervention.     

Virtual histology-intravascular ultrasound assessment of lesion coverage after angiographically-guided stent implantation in patients with ST Elevation myocardial infarction undergoing primary percutaneous coronary intervention

An occlusion or severe stenosis (angiographic culprit lesion) of the infarct-related artery is frequently located at the site of the maximum thrombus burden, whereas the origin of the plaque rupture (the true culprit) can be situated proximal or distal to it. The aim of this study was to examine stent coverage of true culprit lesions in 20 patients who underwent primary percutaneous coronary intervention and had Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow restored in the infarct-related artery by angiographically guided direct stenting. Images of lesions were obtained using virtual histology-intravascular ultrasound before and after intervention (blinded to the operator). Plaque rupture sites were identified by intravascular ultrasound in 12 lesions (60%), 11 proximal and 1 distal to the minimum luminal area (MLA). Maximum necrotic core sites were found proximal to the MLA in 16 lesions, at the MLA in 3 lesions, and distal to the MLA in 1 lesion. Plaque rupture sites were fully covered by stents in 11 lesions. Virtual histology-intravascular ultrasound-derived thin-cap fibroatheroma longitudinal geographic misses were found in 10 lesions, 7 in the proximal reference segment and in 3 patients in the proximal and distal reference segments. In conclusion, in about 50% of patients who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction with optimal angiographic results, the stent does not fully cover the maximum necrotic core site related to the culprit lesion.     

Comparative early and late outcomes after primary percutaneous coronary intervention in ST-segment elevation and non-ST-segment elevation acute myocardial infarction (from the CADILLAC trial)

We determined the outcomes of patients with acute ST-segment elevation (STE) myocardial infarction (STEMI) and non-STEMI (NSTEMI) after primary percutaneous coronary intervention (PCI). The prognosis after primary PCI in STEMI has been extensively studied and defined. Outcomes of patients who undergo primary PCI for NSTEMI are less well established. In total, 2,082 patients with ongoing chest pain for > 30 minutes consistent with acute MI were randomized to balloon angioplasty versus stenting, each with/without abciximab. Of 1,964 patients, STEMI was present in 1,725 (87.8%) and NSTEMI in 239 (12.2%). Compared with STEMI, those with NSTEMI were more likely to have delayed time-to-hospital arrival (2.4 vs 1.8 hours, p = 0.0002) and increased door-to-balloon time (3.2 vs 1.9 hours, p < 0.0001). Patients with NSTEMI were more likely to have Thrombolysis In Myocardial Infarction grade 3 flow at baseline (37.3% vs 19.4%, p < 0.0001) and higher ejection fraction (58.7% vs 55.8%, p = 0.001), but similar rates of postprocedural Thrombolysis In Myocardial Infarction grade 3 flow. At 1 year, patients with NTEMI had similar mortality (3.4% vs 4.4%, p = 0.40) but higher rates of major adverse cardiac events (24.0% vs 16.6%, p = 0.007) that was driven by more frequent ischemic target vessel revascularization (21.8% vs 11.9%, p <0.0001). In conclusion, patients with acute MI without STE who are treated with primary PCI have marked delays to treatment, similar late mortality, and increased rates of ischemic target vessel revascularization compared with patients with STEMI, despite more favorable angiographic features at presentation and similar reperfusion success. The adverse prognosis of patients with NSTEMI should be recognized and efforts made to decrease reperfusion times.     

Relation between leucocyte count, myonecrosis, myocardial perfusion, and outcomes following primary angioplasty

We examined whether leukocytosis is a negative prognostic factor in patients who underwent primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI), and, if so, determined whether it is associated with impaired myocardial perfusion. Previous studies have identified leukocytosis as a predictor of mortality in AMI. Whether this association holds in patients how have undergone primary PCI using contemporary pharmacotherapy and correlates with impaired myocardial perfusion is unknown. Clinical outcomes and reperfusion success, using Thrombolysis In Myocardial Infarction (TIMI) flow and myocardial blush grades, were examined according to tertiles of baseline leukocyte count in 1,268 patients who underwent primary PCI for AMI in the CADILLAC trial. Patients with higher leukocyte count were younger and more likely to be current smokers. Preprocedure TIMI grade 0 flow was more frequent in patients with higher leukocyte counts, but postprocedural TIMI grade 3 flow rates were equally high (>94%) in all 3 groups. Myocardial blush grade 2/3 was achieved at similar rates after PCI in patients with low, intermediate, and high baseline leukocyte counts (52.0% vs 51.5% vs 50.1%, p = 0.8). Higher baseline leukocyte counts were associated with greater myonecrosis (p <0.0001) and increased mortality at 1 year (2.7% vs 4.6% vs 5.4%, respectively, p = 0.047). By multivariate analysis, baseline leukocyte count (in increments of 1,000, hazard ratio 1.07, 95% confidence interval 1.02 to 1.10, p = 0.005) and peak creatine phosphokinase (hazard ratio 1.22, 95% confidence interval 1.14 to 1.29, p <0.001) were independent predictors of 1-year mortality. In conclusion, baseline leukocytosis is an independent correlate of larger infarct and increased mortality after primary PCI in AMI, an effect not explained by decreased myocardial perfusion.     

Effects of prior beta-blocker therapy on clinical outcomes after primary coronary angioplasty for acute myocardial infarction

We hypothesized that pretreatment with beta blockers may improve clinical outcomes after primary angioplasty for acute myocardial infarction. We pooled clinical, angiographic, and outcomes data on 2,537 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI), PAMI-2, and Stent PAMI trials. We classified patients into a beta group (n = 1,132) if they received beta-blocker therapy before primary angioplasty or a no-beta group (n = 1,405) if they did not. We evaluated procedural complications and in-hospital and 1-year outcomes (death and major adverse cardiac events [death, reinfarction, target vessel revascularization, or stroke]) between groups. Beta patients were younger, had higher systolic blood pressure and heart rate, and were more likely to be in Killip class I at admission. They had lower left ventricular ejection fraction, greater door-to-balloon time, greater likelihood of having a left anterior descending artery culprit lesion, but a similar incidence of Thrombolysis In Myocardial Infarction 3 flow after angioplasty (92.6% vs 92.7%, p = 0.91). The beta group had less procedural complications (23% vs 34%, p <0.0001) and a lower incidence of death (1.8% vs 3.7%, p = 0.0035) and major adverse cardiac events (5.5% vs 7.8%, p = 0.027) during hospitalization. At 1 year, mortality remained lower in beta patients (4.9% vs 6.7%, log-rank p = 0.055). After adjustment for baseline differences, beta patients had significantly lower in-hospital mortality (odds ratio 0.41; 95% confidence interval 0.20 to 0.84; p <0.0148) and nonsignificantly lower 1-year mortality (odds ratio 0.72; 95% confidence interval 0.47 to 1.08; p = 0.11). Thus, pretreatment with beta blockers has an independent beneficial effect on short-term clinical outcomes in patients undergoing primary angioplasty for acute myocardial infarction.     

Atherosclerotic plaque with ultrasonic attenuation affects coronary reflow and infarct size in patients with acute coronary syndrome: an intravascular ultrasound study.

BACKGROUND: No reflow following percutaneous coronary intervention (PCI) is a major concern in patients with acute coronary syndrome (ACS) and it may be influenced by the preexisting plaque type. METHODS AND RESULTS: To evaluate the impact of plaque characteristics on coronary reflow following PCI in patients with ACS, a total of 110 patients (89 acute myocardial infarction, 21 unstable angina) were assessed by intravascular ultrasound. Plaque type was categorized as either atherosclerotic plaque without ultrasonic attenuation (group 1) or atherosclerotic plaque with attenuation (group 2). External elastic membrane, plaque plus media, and lumen area were measured. Coronary flow was assessed by Thrombolysis in Myocardial Infarction (TIMI) grade and TIMI frame count. Although the final TIMI frame count was similar between the 2 groups, TIMI frame count immediately after the first balloon inflation was significantly higher in group 2 (p=0.03). Despite the similar final TIMI grade and TIMI frame count, peak creatine kinase level was significantly higher (3,035+/-2,553 vs 1,950+/-1,958 IU/L, p=0.04) and fatal arrhythmia more frequently observed (16.4% vs 2.7%, p=0.04) in group 2 than in group 1. CONCLUSIONS: Atherosclerotic plaque with ultrasonic attenuation may be related to a transient deterioration in coronary flow and as a result larger infarct size and higher incidence of fatal arrhythmia following PCI in patients with ACS. These results may help in selecting lesions suitable for distal protection devices.