Prognostic utility of comparative methods for assessment of ST-segment resolution after primary angioplasty for acute myocardial infarction: the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial

The role and mechanisms of microvascular damage in the ischemic myocardium

Following myocardial ischemic injury, the most effective clinical intervention is timely restoration of blood perfusion to ischemic but viable myocardium to reduce irreversible myocardial necrosis, limit infarct size, and prevent cardiac insufficiency. However, reperfusion itself may exacerbate cell death and myocardial injury, a process commonly referred to as ischemia/reperfusion (I/R) injury, which primarily involves cardiomyocytes and cardiac microvascular endothelial cells (CMECs) and is characterized by myocardial stunning, microvascular damage (MVD), reperfusion arrhythmia, and lethal reperfusion injury. MVD caused by I/R has been a neglected problem compared to myocardial injury. Clinically, the incidence of microvascular angina and/or no-reflow due to ineffective coronary perfusion accounts for 5-50% in patients after acute revascularization. MVD limiting drug diffusion into injured myocardium, is strongly associated with the development of heart failure. CMECs account for > 60% of the cardiac cellular components, and their role in myocardial I/R injury cannot be ignored. There are many studies on microvascular obstruction, but few studies on microvascular leakage, which may be mainly due to the lack of corresponding detection methods. In this review, we summarize the clinical manifestations, related mechanisms of MVD during myocardial I/R, laboratory and clinical examination means, as well as the research progress on potential therapies for MVD in recent years. Better understanding the characteristics and risk factors of MVD in patients after hemodynamic reconstruction is of great significance for managing MVD, preventing heart failure and improving patient prognosis.

Role of ST-Segment Resolution Alone and in Combination With TIMI Flow After Primary Percutaneous Coronary Intervention for ST-Segment-Elevation Myocardial Infarction

Background To evaluate the role of ST-segment resolution (STR) alone and in combination with Thrombolysis in Myocardial Infarction (TIMI) flow in reperfusion evaluation after primary percutaneous coronary intervention (PPCI) for ST-segment-elevation myocardial infarction by investigating the long-term prognostic impact. Methods and Results From January 2013 through September 2014, we studied 5966 patients with ST-segment-elevation myocardial infarction enrolled in the CAMI (China Acute Myocardial Infarction) registry with available data of STR evaluated at 120 minutes after PPCI. Successful STR included STR ≥50% and complete STR (ST-segment back to the equipotential line). After PPCI, the TIMI flow was assessed. The primary outcome was 2-year all-cause mortality. STR < 50%, STR ≥50%, and complete STR occurred in 20.6%, 64.3%, and 15.1% of patients, respectively. By multivariable analysis, STR ≥50% (5.6%; adjusted hazard ratio [HR], 0.45 [95% CI, 0.36-0.56]) and complete STR (5.1%; adjusted HR, 0.48 [95% CI, 0.34-0.67]) were significantly associated with lower 2-year mortality than STR <50% (11.7%). Successful STR was an independent predictor of 2-year mortality across the spectrum of clinical variables. After combining TIMI flow with STR, different 2-year mortality was observed in subgroups, with the lowest in successful STR and TIMI 3 flow, intermediate when either of these measures was reduced, and highest when both were abnormal. Conclusions Post-PPCI STR is a robust long-term prognosticator for ST-segment-elevation myocardial infarction, whereas the integrated analysis of STR plus TIMI flow yields incremental prognostic information beyond either measure alone, supporting it as a convenient and reliable surrogate end point for defining successful PPCI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01874691.

Reperfusion After Fibrinolytic Therapy (RAFT): An open-label, multi-centre, randomised controlled trial of bivalirudin versus heparin in rescue percutaneous coronary intervention

BACKGROUND

The safety and efficacy profile of bivalirudin has not been examined in a randomised controlled trial of patients undergoing rescue PCI.

OBJECTIVES

We conducted an open-label, multi-centre, randomised controlled trial to compare bivalirudin with heparin ± glycoprotein IIb/IIIa inhibitors (GPIs) in patients undergoing rescue PCI.

METHODS

Between 2010-2015, we randomly assigned 83 patients undergoing rescue PCI to bivalirudin (n = 42) or heparin ± GPIs (n = 41). The primary safety endpoint was any ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) bleeding at 90 days. The primary efficacy endpoint was infarct size measured by peak troponin levels as a multiple of the local upper reference limit (Tn/URL). Secondary endpoints included periprocedural change in haemoglobin adjusted for red cells transfused, TIMI (Thrombolysis in Myocardial Infarction) bleeding, ST-segment recovery and infarct size determined by the Selvester QRS score.

RESULTS

The trial was terminated due to slow recruitment and futility after an interim analysis of 83 patients. The primary safety endpoint occurred in 6 (14%) patients in the bivalirudin group (4.8% GPIs) and 3 (7.3%) in the heparin ± GPIs group (54% GPIs) (risk ratio, 1.95, 95% confidence interval [CI], 0.52-7.3, P = 0.48). Infarct size was similar between the two groups (mean Tn/URL, 730 [±675] for bivalirudin, versus 984 [±1585] for heparin ± GPIs, difference, 254, 95% CI, -283-794, P = 0.86). There was a smaller decrease in the periprocedural haemoglobin level with bivalirudin than heparin ± GPIs (-7.5% [±15] versus -14% [±17], difference, -6.5%, 95% CI, -0.83-14, P = 0.0067). The rate of complete (≥70%) ST-segment recovery post-PCI was higher in patients randomised to heparin ± GPIs compared with bivalirudin.

CONCLUSIONS

Whether bivalirudin compared with heparin ± GPI reduces bleeding in rescue PCI could not be determined. Slow recruitment and futility in the context of lower-than-expected bleeding event rates led to the termination of this trial (ANZCTR.org.au, ACTRN12610000152022).

Accuracy of Post-thrombolysis ST-segment Reduction as an Adequate Reperfusion Predictor in the Pharmaco-Invasive Approach

Fundamento

A intervenção coronária percutânea primária é considerada o “padrão-ouro” para reperfusão coronária. Entretanto, quando não disponível, a estratégia fármaco-invasiva é método alternativo, e o eletrocardiograma (ECG) tem sido utilizado para identificar sucesso na reperfusão.

Objetivos

Nosso estudo teve como objetivo examinar alterações no segmento-ST pós-lise e seu poder de prever a recanalização, usando os escores angiográficos TIMI e blush miocárdio (MBG) como critério de reperfusão ideal.

Métodos

Foram estudados 2.215 pacientes com infarto agudo do miocárdio com supra-ST submetidos à fibrinólise [(Tenecteplase)-TNK] e encaminhados para angiografia coronária em até 24 h pós-fibrinólise ou imediatamente encaminhados à terapia de resgate. O ECG foi realizado pré-TNK e 60 min-pós. Os pacientes foram categorizados em dois grupos: aqueles com reperfusão ideal (TIMI-3 e MBG-3) e aqueles com reperfusão inadequada (fluxo TIMI <3). Foi definido o critério de reperfusão do ECG pela redução do segmento ST >50%. Consideramos p-valor <0,05 para as análises, com testes bicaudais.

Resultados

O critério de reperfusão pelo ECG apresentou valor preditivo positivo de 56%; valor preditivo negativo de 66%; sensibilidade de 79%; e especificidade de 40%. Houve fraca correlação positiva entre a redução do segmento-ST e os dados angiográficos de reperfusão ideal (r = 0,21; p <0,001) e baixa precisão diagnóstica, com AUC de 0,60 (IC-95%; 0,57-0,62).

Conclusão

Em nossos resultados, a redução do segmento-ST não conseguiu identificar com precisão os pacientes com reperfusão angiográfica apropriada. Portanto, mesmo pacientes com reperfusão aparentemente bem-sucedida devem ser encaminhados à angiografia brevemente, a fim de garantir fluxo coronário macro e microvascular adequados.

Outcome of manual thrombus aspiration for patients undergoing primary PCI for acute STEMI showing large thrombus burden

Background

Routine thrombus aspiration during primary PCI does not improve clinical outcomes. Although recent guidelines for management of patient presented by ST-elevation myocardial infarction treated by primary PCI does not recommend routine use of thrombus aspiration and ranking it as class III recommendation. However, there is remaining uncertainty about rule of TA in group of patients presented by STEMI and their initial coronary angiogram shows large thrombus burden as there is a logical rationale for greater benefit, and still, there are no clear guidelines for management of this group of patients; the aim of this study is to evaluate the in-hospital and short-term outcome of using manual thrombus aspiration in STEMI patients undergoing primary PCI and showing large thrombus burden.

Results

The study was prospective observational study included 209 patients referred to coronary care unit (CCU) with diagnosis of STEMI who had undergone primary PCI; their initial coronary angiography show totally occluded infarct-related artery with heavy thrombus burden. Patients were divided into 2 groups: group (B) which included 73 patients, who had undergone PTCA and manual thrombus aspiration followed by stent to culprit lesion, and group (A) which included 136 patients, who had undergone conventional PTCA and stent of culprit lesion within the period from November 2016 till July 2018. Patients had a pre-discharge echo and were followed up for 4 weeks for major adverse cardiac events (MACE) and echo repeated after 1 month of discharge.

It was found that thrombus aspiration in heavy thrombus burden cases had improved in-hospital mortality and in-hospital secondary endpoints (TIMI flow, MBG, ST-segment resolution), as well as 30-day MACE and LV systolic function.

Conclusion

In patients presented with STEMI and heavy thrombus burden culprit artery, manual thrombus aspiration has great value in reducing index hospitalization and 1 month mortality and improve TIMI flow, MBG, ST-segment resolution, and left ventricular systolic function.

Association between Variation of Troponin and Prognosis of Acute Myocardial Infarction before and after Primary Percutaneous Coronary Intervention

Background

Circulating levels of cardiac troponin I (cTnI) after ST-segment elevation myocardial infarction (STEMI) were considered as prognostic factors for predicting the incidence of major adverse cardiovascular events (MACE). △cTnI is the difference between peak cTnI after primary percutaneous coronary intervention (PPCI) and cTnI on initial admission.

Purpose

This study aimed to assess the relationship between △cTnI, the ratio of △cTnI to cTnI on initial admission, and the incidence of MACE during the follow-up period.

Methods

A total of 2596 patients with cTnI measured upon admission and one-time measurement of cTnI during hospitalization were enrolled.

Results

In the adjusted models of the survival receiver operating characteristic (ROC) curve, △cTnI and the ratio of △cTnI to cTnI on initial admission have stronger discrimination power of MACE (area under curve (AUC) 0.730 and 0.717) compared with peak cTnI after PPCI and cTnI at admission (AUC 0.590, 0.546). Multivariate Cox regression analysis identified △cTnI (hazard ratio (HR) 1.018, 95% confidence interval (CI) 1.001 to 1.035) as a relevant factor for MACE during follow-up. △cTnI was divided into quartiles, and maximum △ cTnI between 4.845 and 19.073 ng/ml comprised more patients with anterior wall myocardial infarction (p < 0.001), higher GRACE score (p = 0.038), CK-MB (p = 0.023), and Myoglobin (p < 0.001). On the K–M survival curves, the incidence of MACE, mortality, and angina pectoris were significantly higher in the group with maximum △cTnI (p = 0.035, 0.049, 0.026).

Conclusion

The △cTnI level and the ratio of △cTnI have stronger discrimination power of predicting the incidence of MACE. The group with maximum △cTnI has higher incidence of MACE, mortality, and angina pectoris during the follow-up period.

Worst lead ST deviation and resolution of ST elevation at one hour for prediction of myocardial salvage, infarct size, and microvascular obstruction in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

Background

ECG changes after revascularization predicts improved outcome for patients with ST‐elevation myocardial infarction (STEMI). Worst lead residual (WLR) ST deviation and resolution of worst lead ST elevation (rST elevation) are simple measures that can be obtained early after PCI. The objective of the current study was to investigate whether simple ECG measures, obtained one hour following PCI, could predict cardiac magnetic resonance (CMR)‐derived myocardial salvage index (MSI), infarct size (IS), and microvascular obstruction (MVO) in patients with STEMI included in the MITOCARE trial.

Methods

The MITOCARE trial included 165 patients with a first‐time STEMI presenting within six hours of symptom onset. The current analysis included patients that had an ECG recorded at baseline and one hour after PCI and underwent CMR imaging after 3–5 days. Independent core laboratories determined WLR ST deviation, rST elevation, and the CMR variables (MSI, IS, and MVO).

Results

83 patients with a mean age of 61 years were included. 83.1% were males and 41% had anterior infarctions. In logistic regression models, WLR ST deviation was a statistically significant predictor of IS (OR 2.2, 95% CI 1.3–3.8) and MVO (OR 2.8, 95% CI 1.5–5.2), but not of MSI (OR 0.8, 95% CI 0.5–1.2). rST elevation showed a trend toward a significant association with IS (OR 0.3, 95% CI 0.1–1.0), but not with the other CMR variables.

Conclusion

WLR ST deviation one hour after PCI was a predictor of IS and MVO. WLR ST deviation, a measure easily obtained from ECGs following PCI, may provide important prognostic information in patients with STEMI.

Does pre-angiography Total ST-segment resolution reliably predict spontaneous reperfusion of the infarct-related artery in patients with acute myocardial infarction?

BACKGROUND

ST resolution (STR) after AMI is a non-invasive indicator of IRA reperfusion. We investigated whether pre-angiography STR predicted spontaneous IRA reperfusion in STEMI patients.

METHOD

Patients with STEMI undergoing primary PCI were recruited. Standard 12-lead ECG tracings were recorded at first medical contact, immediately prior to arterial puncture and 60 min after PCI. STR was classified as total (≥70%; group I), partial (≥30 and < 70%; group II) or none (< 30%; group III). Patients were followed up for 1-year.

RESULTS

The final analysis included 349 patients (n = 77, 160 and 112 for groups I, II and III, respectively). Compared with groups I/II, pre-procedural TIMI flow in group III was less frequently grades 2 or 3 (P < 0.001). Pre-PCI STR ≥70% was an independent predictor of pre-PCI TIMI-3 flow (OR: 2.8; P < 0.001). Pre-PCI STR < 30% was independently associated with pre-PCI TIMI flow 0-2 (OR: 3.1; P < 0.001). STR = 35.55% seems to be an optimal cut off for pre-procedural TIMI-3 flow prediction with sensitivity 0.943, specificity 0.456, Youden index 0.399, P = 0.027. STR prior to PCI was inversely correlated with 1-year combined CV events rate. STR > 70% may predict a better clinical outcome.

CONCLUSIONS

Assessment of STR could potentially be used to stratify risk in patients with STEMI before PCI.

Relationship between the ST-Segment Resolution and Microvascular Dysfunction in Patients Who Underwent Primary Percutaneous Coronary Intervention

Objectives

Incomplete ST-segment elevation resolution (STR) occasionally occurs despite successful revascularization of epicardial coronary artery after primary percutaneous coronary intervention (PPCI). The aim of this study was to evaluate the relationship between the degree of STR and the severity of microvascular dysfunction.

Methods

A total of 73 consecutive patients with ST-segment elevation myocardial infarction (STEMI) who underwent successful PPCI were evaluated. Serial 12-lead electrocardiography was performed at baseline and at 90 minutes after PPCI. Microvascular dysfunction was assessed by index of microvascular resistance (IMR) immediately after PPCI.

Results

Patients were classified into 2 groups: 50 patients with complete STR (STR ≥50%) and 23 patients with incomplete STR (STR <50%). The incomplete STR group had a higher IMR value and lower left ventricular ejection fraction (LVEF), compared with the complete STR group. The degree of STR was significantly correlated with IMR (r = −0.416, P=0.002) and LVEF (r = 0.300, P=0.011). These correlations were only observed in patients with left anterior descending artery (LAD) infarction but not observed in patients with non-LAD infarction. A cutoff IMR value was 27.3 for predicting incomplete STR after PPCI.

Conclusion

Incomplete STR after PPCI in patients with STEMI reflects the presence of microvascular and left ventricular dysfunction, especially in patients with LAD infarction.

Mangafodipir as a cardioprotective adjunct to reperfusion therapy: a feasibility study in patients with ST-segment elevation myocardial infarction

AIMS

The aim of the present study was to examine the feasibility of applying the catalytic antioxidant mangafodipir [MnDPDP, manganese (Mn) dipyridoxyl diphosphate] as a cardioprotective adjunct to primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation (STE) myocardial infarction (STEMI). Both MnDPDP and a metabolite (Mn dipyridoxyl ethyldiamine) possess properties as mitochondrial superoxide dismutase mimetics and iron chelators, and combat oxidative stress in various tissues and conditions.

METHODS AND RESULTS

The study tested MnDPDP (n = 10) vs. saline placebo (n = 10), given as a brief intravenous (i.v.) infusion prior to balloon inflation during pPCI in patients with STEMI. Mangafodipir was well tolerated and did not affect heart rate or blood pressure. Despite longer ischaemic time (205 vs. 144 min, P = 0.019) in the MnDPDP group, plasma biomarker releases were identical for the two groups. With placebo vs. MnDPDP, mean STE resolutions were 69.8 vs. 81.9% (P = 0.224) at 6 h and 73.1 vs. 84.3% (P = 0.077) at 48 h. Cardiac magnetic resonance revealed mean infarct sizes of 32.5 vs. 26.2% (P = 0.406) and mean left ventricular (LV) ejection fractions of 41.8 vs. 47.7% (P = 0.617) with placebo vs. MnDPDP. More LV thrombi were detected in placebo hearts (5 of 8) than MnDPDP-treated hearts (1 of 10; P = 0.011).

CONCLUSIONS

Mangafodipir is a safe drug for use as an adjunct to reperfusion therapy. A tendency to benefit of MnDPDP needs confirmation in a larger population. The study revealed important information for the design of a Phase II trial.

Effect of chronic pretreatment with beta-blockers on no-reflow phenomenon in diabetic patients with acute ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

No-reflow is an important factor as it predicts a poor outcome in patients undergoing primary angioplasty. In comparison with patients attaining TIMI 3 flow, patients with no-reflow have an increased incidence of ventricular arrhythmias, early congestive cardiac failure, cardiac rupture and cardiac death. As such, it is of paramount importance to consider strategies to prevent the occurrence of no-reflow phenomenon. Previous evidence suggests that Beta (β) blockers have multiple favorable effects on the vascular system not directly related to their effect on blood pressure. However, there are insufficient data regarding the effects of prior Beta blocker use on coronary blood flow after primary PCI in patients with AMI.

Aim

The aim of this study was to test the hypothesis that Beta blocker treatment before admission would have beneficial effects on the development of the no-reflow phenomenon after acute myocardial infarction.

Methods and results

The study included 107 diabetic patients who had presented with acute STEMI within 12 h from the onset of chest pain. All of them have undergone primary angioplasty at Ain Shams University hospitals or National Heart institute. The incidence of no-reflow phenomenon was 21%. No-reflow phenomenon was significantly lower in patients on chronic B-blocker therapy (12% vs. 28%; P = 0.04). The heart rate was significantly lower in the normal reflow group than in the no-reflow group (P = 0.03). The study also showed that B-blocker pretreatment is an independent protective predictor for the no-reflow phenomenon (P = 0.045).

Conclusion

Chronic pre-treatment with B-blocker in diabetic patients presenting with STEMI, is associated with lower rate of occurrence of no-reflow phenomenon after primary PCI.

In-Lab Upfront Use of Tirofiban May Reduce the Occurrence of No-Reflow During Primary Percutaneous Coronary Intervention. A Pilot Randomized Study

Background

Despite successful opening of culprit coronary artery, myocardial reperfusion does not always follows primary percutaneous coronary intervention (PPCI). Glycoprotein IIb/IIIa inhibitors are used in the treatment of no-reflow (NR), but their role to prevent it is unproven.

Objective

To evaluate the effect of in-lab administration of tirofiban on the incidence of NR in ST-elevation myocardial infarction (STEMI) treated with PPCI.

Methods

STEMI patients treated with PPCI were randomized (24 tirofiban and 34 placebo) in this double-blinded study to assess the impact of intravenous tirofiban on the incidence of NR after PPCI according to angiographic and electrocardiographic methods. End-points of the study were: TIMI-epicardial flow grade; myocardial blush grade (MBG); resolution of ST-elevation < 70% (RST < 70%) at 90min and 24h after PPCI.

Results

Baseline anthropometric, clinical and angiographic characteristics were balanced between the groups. The occurrence of TIMI flow < 3 was not significantly different between the tirofiban (25%) and placebo (35.3%) groups. MBG ≤ 2 did not occur in the tirofiban group, and was seen in 11.7% of patients in the placebo group (p=0.13). RST < 70% occurred in 41.6% x 55.8% (p=0.42) at 90min and in 29% x 55.9% (p=0.06) at 24h in tirofiban and placebo groups, respectively. Severe NR (RST ≤ 30%) was detected in 0% x 26.5% (p=0.01) at 90 min, and in 4.2% x 23.5% (p=0.06) at 24h in tirofiban and placebo groups, respectively.

Conclusion

This pilot study showed a trend toward reduction of NR associated with in-lab upfront use of tirofiban in STEMI patients treated with PPCI and paves the way for a full-scale study testing this hypothesis.

Importance of Endogenous Fibrinolysis in Platelet Thrombus Formation

The processes of thrombosis and coagulation are finely regulated by endogenous fibrinolysis maintaining healthy equilibrium. When the balance is altered in favour of platelet activation and/or coagulation, or if endogenous fibrinolysis becomes less efficient, pathological thrombosis can occur. Arterial thrombosis remains a major cause of morbidity and mortality in the world despite advances in medical therapies. The role endogenous fibrinolysis in the pathogenesis of arterial thrombosis has gained increasing attention in recent years as it presents novel ways to prevent and treat existing diseases. In this review article, we discuss the role of endogenous fibrinolysis in platelet thrombus formation, methods of measurement of fibrinolytic activity, its role in predicting cardiovascular diseases and clinical outcomes and future directions.

Integrated ST Segment Elevation Scores and In-hospital Mortality in STEMI Patients Undergoing Primary PCI

The objective of this study was to study the integrated score of ST-segment resolution (ISSTE) and in-hospital death in patients undergoing primary percutaneous intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI).

Material and Methods: This prospective study included 586 consecutive patients admitted with STEMI to the Cardiology Clinic of the County Emergency Clinical Hospital of Tîrgu Mureș, between January 1st, 2013 and December 31, 2014, who underwent pPCI in less than twelve hours after the onset of symptoms. Clinical and demographic data were analyzed in 539 (91.9%) survivors (Group 1) and 47 (8.1%) nonsurvivors (Group 2). The Integrated Score of ST elevation (ISSTE) was calculated by summing the amplitude of the ST segment elevation in all the 12 leads, before and at 2 hours after revascularization.

Results: The ISSTE score calculated at baseline, immediately before the primary percutaneous coronary intervention, was significantly higher in Group 2 as compared to Group 1 (13.9 ± 1.2 vs. 11.0 ± 0.2, p = 0.026). At the same time, the ISSTE score calculated at 2 hours after the coronary intervention was significantly higher for patients in Group 2 (7.36 ± 1.12 vs. 2.9 ± 0.1, p <0.0001). Analysis of the dynamics of the ISSTE score indicated that patients who survived presented a more expressed reduction in the ISSTE score following pPCI, as compared to those who subsequently died (73.5% reduction in Group 1 compared to 47.2% reduction in Group 2, p <0.0001). In-hospital mortality was significantly higher in the group of patients with >50% reduction in the ISSTE score. The in-hospital death rate was 5.4% in patients with >50% reduction in the ISSTE score, compared to 19.4% for those who presented less than 50% reduction in the ISSTE score following pPCI (p <0.0001). The rate of successful reperfusion rate, expressed by the reduction in ISSTE score, was 83.8% in Group 1, compared to 55.3% in Group 2 (p <0.0001), indicating that the absence of an efficient reperfusion after pPCI is associated with a higher mortality in STEMI patients, and could be evaluated using regression of the ISSTE score, which proved to be directly associated with mortality.

Conclusion: The ISSTE score is shown to be an effective ECG-derived marker of myocardial damage in STEMI patients. A high ISSTE score is associated with higher mortality, while a reduction in the ISSTE score after pPCI may indicate an efficient reperfusion and a decrease in mortality in the first days after infarction.

Coronary microvascular obstruction in acute myocardial infarction

The success of a primary percutaneous intervention (PCI) in the setting of ST elevation myocardial infarction depends on the functional and structural integrity of coronary microcirculation. Coronary microvascular dysfunction and obstruction (CMVO) occurs in up to half of patients submitted to apparently successful primary PCI and is associated to a much worse outcome. The current review summarizes the complex mechanisms responsible for CMVO, including pre-existing coronary microvascular dysfunction, and highlights the current limitations in the assessment of microvascular function. More importantly, at the light of the substantial failure of trials hitherto published on the treatment of CMVO, this review proposes a novel integrated therapeutic approach, which should overcome the limitations of previous studies.

Infarct Size, Shock, and Heart Failure: Does Reperfusion Strategy Matter in Early Presenting Patients With ST-Segment Elevation Myocardial Infarction?

Background

A pharmacoinvasive (PI) strategy for early presenting ST-segment elevation myocardial infarction nominally reduced 30-day cardiogenic shock and congestive heart failure compared with primary percutaneous coronary intervention (PPCI). We evaluated whether infarct size (IS) was related to this finding.

Methods and Results

Using the peak cardiac biomarker in patients randomized to PI versus PPCI within the Strategic Reperfusion Early After Myocardial Infarction (STREAM) trial, IS was divided into 3 groups: small (≤2 times the upper limit normal [ULN]), medium (>2 to ≤5 times the upper limit normal) and large (>5 times the upper limit normal). The association between IS and 30-day shock and congestive heart failure was subsequently examined. Data on 1701 of 1892 (89.9%) patients randomized to PI (n=853, 50.1%) versus PPCI (n=848, 49.9%) within STREAM were evaluated. A higher proportion of PPCI patients had a large IS (PI versus PPCI: small, 49.8% versus 50.2%; medium, 56.9% versus 43.1%; large, 48.4% versus 51.6%; P=0.035), despite comparable intergroup ischemic times for each reperfusion strategy. As IS increased, a parallel increment in shock and congestive heart failure occurred in both treatment arms, except for the small IS group. The difference in shock and congestive heart failure in the small IS group (4.4% versus 11.6%, P=0.026) in favor of PI likely relates to higher rates of aborted myocardial infarction with the PI strategy (72.7% versus 54.3%, P=0.005). After adjustment, a trend favoring PI persisted in this subgroup (relative risk 0.40, 95% CI 0.15 to 1.06, P=0.064); no difference in treatment-related outcomes was evident in the other 2 groups.

Conclusion

A PI strategy appears to alter the pattern of IS after ST-segment elevation myocardial infarction, resulting in more medium and fewer large infarcts compared with PPCI. Despite a comparable number of small infarcts, PI patients in this group had more aborted myocardial infarctions and less 30-day shock and congestive heart failure.

Clinical Trial Registration

URL: http://ClinicalTrials.gov. Unique identifier: NCT00623623.

Combination therapy reduces the incidence of no-reflow after primary per-cutaneous coronary intervention in patients with ST-segment elevation acute myocardial infarction

Background

No-reflow is associated with an adverse outcome and higher mortality in patients with ST-segment elevation acute myocardial infarction (STEMI) who undergo percutaneous coronary intervention (PCI) and is considered a dynamic process characterized by multiple pathogenetic components. The aim of this study was to investigate the effectiveness of a combination therapy for the prevention of no-reflow in patient with acute myocardial infarction (AMI) undergoing primary PCI.

Methods

A total of 621 patients with STEMI who underwent emergency primary PCI were enrolled in this study. Patients with high risk of no-reflow (no-flow score ≥ 10, by using a no-flow risk prediction model, n = 216) were randomly divided into a controlled group (n = 108) and a combination therapy group (n = 108). Patients in the controlled group received conventional treatment, while patients in combination therapy group received high-dose (80 mg) atorvastatin pre-treatment, intracoronary administration of adenosine (140 µg/min per kilogram) during PCI procedure, platelet membrane glycoprotein IIb/IIIa receptor antagonist (tirofiban, 10µg/kg bolus followed by 0.15 µg/kg per minute) and thrombus aspiration. Myocardial contrast echocardiography was performed to assess the myocardial perfusion 72 h after PCI. Major adverse cardiac events (MACE) were followed up for six months.

Results

Incidence of no-reflow in combination therapy group was 2.8%, which was similar to that in low risk group 2.7% and was significantly lower than that in control group (35.2%, P < 0.01). The myocardial perfusion (A × β) values were higher in combination therapy group than that in control group 72 h after PCI. After 6 months, there were six (6.3%) MACE events (one death, two non-fatal MIs and three revascularizations) in combination therapy group and 12 (13.2%) (four deaths, three non-fatal MIs and five revascularizations, P < 0.05) in control group.

Conclusions

Combination of thrombus aspiration, high-dose statin pre-treatment, intracoronary administration of adenosine during PCI procedure and platelet membrane glycoprotein IIb/IIIa receptor antagonist reduce the incidence of no-reflow after primary PCI in patients with acute myocardial infarction who are at high risk of no-reflow.

Aspirin ‘Resistance': Impact on No-Reflow, Platelet and Inflammatory Biomarkers in Diabetics after ST-Segment Elevation Myocardial Infarction

Background: The no-reflow (NR) phenomenon exists despite percutaneous coronary intervention (PCI), and is especially prevalent in diabetics. The causes(s) of NR are not fully elucidated, but may be associated with impaired residual platelet and inflammatory reactivity during dual-antiplatelet therapy. Objective: To assess the relationship between dual-antiplatelet therapy, NR and conventional biomarkers suggestive of platelet and inflammatory response in diabetics following ST-segment elevation myocardial infarction (STEMI) treated with PCI. Methods: Sixty diabetics with (n = 27) and without NR (n = 33) were prospectively enrolled. All patients were treated with clopidogrel and aspirin. Platelet and inflammatory biomarkers were assessed serially in the peripheral blood and right atrium before and after PCI and then at 24 h, 7 days and 30 days. Results: Arachidonic acid (AA)-induced platelet aggregation and the serum thromboxane B2 level before and after PCI (in the peripheral and right atrium blood) were significantly higher in the NR patients than in those with no NR. AA-induced aggregation >100 (AUC*min) before PCI predicted NR in diabetic patients with 96.2% sensitivity and 38.5% specificity (AUC 0.66; 95% CI 0.52-0.71; p = 0.029). There were no other correlations between NR and platelet reactivity (collagen, adenosine diphosphate, thrombin receptor agonist peptide-induced aggregation, vasodilator-stimulated phosphoprotein platelet reactivity index, soluble P-selectin, soluble CD40 ligand, platelet-derived growth factor AB and the level of platelet-monocyte aggregates) or between NR and inflammatory indices (i.e. high-sensitivity C-reactive protein, interleukin 6 and interleukin 10). Conclusion: An inadequate response to aspirin, but not to clopidogrel, may be associated with the occurrence of the NR phenomenon in diabetics with STEMI who have been treated with primary PCI.

Angiographic and Clinical Impact of Successful Manual Thrombus Aspiration in Diabetic Patients Undergoing Primary PCI

Background. Diabetes mellitus is associated with worse angiographic and clinical outcomes after percutaneous coronary intervention (PCI). Aim. To investigate the impact of manual thrombus aspiration on in-stent restenosis (ISR) and clinical outcome in patients treated by bare-metal stent (BMS) implantation for ST-segment elevation myocardial infarction (STEMI). Methods. 100 diabetic patients were prospectively enrolled. They were randomly assigned to undergo either standard primary PCI (group A, 50 patients) or PCI with thrombus aspiration using Export catheter (group B, 50 patients). The primary endpoint was the rate of eight-month ISR. The secondary endpoint included follow-up for major adverse cardiac events (MACE). Results. Mean age of the study cohort was 59.86 ± 8.3 years, with 64 (64%) being males. Baseline characteristics did not differ between both groups. Eight-month angiogram showed that group B patients had significantly less late lumen loss (0.17 ± 0.35 versus 0.60 ± 0.42 mm, P < 0.001), with lower incidence of ISR (4% versus 16.6%, P < 0.001). There was a trend towards lower rate of MACE in the same group of patients. Conclusion. In diabetic patients undergoing primary PCI, manual thrombus aspiration (compared with standard PCI) was associated with better ISR rate after BMS implantation.

Relationship between ST-segment resolution and anterior infarct size after primary percutaneous coronary intervention: analysis from the INFUSE-AMI trial

AIMS

ST-segment resolution (STR) after reperfusion therapy has been shown to correlate with prognosis in patients with ST-segment elevation myocardial infarction (STEMI). We investigated whether acute ECG measurements also correlate with ultimate infarct size.

METHODS AND RESULTS

The INFUSE-AMI trial randomized 452 patients with anterior STEMI to intracoronary bolus abciximab vs. no abciximab, and to thrombus aspiration vs. no aspiration. Infarct size as percentage of total LV mass was calculated by cardiac magnetic resonance imaging (MRI) 30 days post intervention. Five ECG methods were analysed for their ability to predict MRI infarct mass: (1) summed STR across all infarct-related ECG leads (ΣSTR); (2) STR in the single lead with maximum baseline ST-segment elevation (maxSTR); (3) summed residual ST-segment elevation across all infarct-related leads at 60 min post intervention (ΣST residual); (4) maximum residual ST-segment elevation in the worst single lead at 60 min post intervention (maxST residual); (5) number of new significant Q-waves (Qwave) at 60 min. All ECG methods strongly correlated with 30-day MRI infarct mass (all p<0.003). Simpler ECG measurements such as maxSTresidual and Qwave were as predictive as more complex measurements. A subset analysis of 158 patients who had microvascular obstruction (MVO) determined by MRI 5 days post intervention also showed strong correlations of MVO with the ECG measures.

CONCLUSIONS

ST-segment and Q-wave changes after primary PCI in anterior STEMI strongly correlated with 30-day infarct size by MRI. In particular, maxST residual and Qwave at 60 min are simple ECG parameters that offer rapid analysis for prognostication.

Diagnostic ultrasound induced inertial cavitation to non-invasively restore coronary and microvascular flow in acute myocardial infarction

Ultrasound induced cavitation has been explored as a method of dissolving intravascular and microvascular thrombi in acute myocardial infarction. The purpose of this study was to determine the type of cavitation required for success, and whether longer pulse duration therapeutic impulses (sustaining the duration of cavitation) could restore both microvascular and epicardial flow with this technique. Accordingly, in 36 hyperlipidemic atherosclerotic pigs, thrombotic occlusions were induced in the mid-left anterior descending artery. Pigs were then randomized to either a) ½ dose tissue plasminogen activator (0.5 mg/kg) alone; or same dose plasminogen activator and an intravenous microbubble infusion with either b) guided high mechanical index short pulse (2.0 MI; 5 usec) therapeutic ultrasound impulses; or c) guided 1.0 mechanical index long pulse (20 usec) impulses. Passive cavitation detectors indicated the high mechanical index impulses (both long and short pulse duration) induced inertial cavitation within the microvasculature. Epicardial recanalization rates following randomized treatments were highest in pigs treated with the long pulse duration therapeutic impulses (83% versus 59% for short pulse, and 49% for tissue plasminogen activator alone; p<0.05). Even without epicardial recanalization, however, early microvascular recovery occurred with both short and long pulse therapeutic impulses (p<0.005 compared to tissue plasminogen activator alone), and wall thickening improved within the risk area only in pigs treated with ultrasound and microbubbles. We conclude that although short pulse duration guided therapeutic impulses from a diagnostic transducer transiently improve microvascular flow, long pulse duration therapeutic impulses produce sustained epicardial and microvascular re-flow in acute myocardial infarction.

Recent Advances in the Treatment of ST-Segment Elevation Myocardial Infarction

ST-segment elevation myocardial infarction (STEMI) represents the most urgent condition for patients with coronary artery disease. Prompt diagnosis and therapy, mainly with primary angioplasty using stents, are important in improving not only acute survival but also long-term prognosis. Recent advances in angioplasty devices, including manual aspiration catheters and drug-eluting stents, and pharmacologic therapy, such as potent antiplatelet and anticoagulant agents, have significantly enhanced the acute outcome for these patients. Continuing efforts to educate the public and to decrease the door-to-balloon time are essential to further improve the outcome for these high-risk patients. Future research to normalize the left ventricular function by autologous stem cell therapy may also contribute to the quality of life and longevity of the patients surviving STEMI.

Pathophysiology of coronary thrombus formation and adverse consequences of thrombus during PCI

Atherosclerosis is a systemic vascular pathology that is preceded by endothelial dysfunction. Vascular inflammation "fuels" atherosclerosis and creates the milieu for episodes of intravascular thromboses. Thrombotic events in the coronary vasculature may lead to asymptomatic progression of atherosclerosis or could manifest as acute coronary syndromes or even sudden cardiac death. Thrombus encountered in the setting of acute coronary syndromes has been correlated with acute complications during percutaneous coronary interventions such as no-reflow, acute coronary occlusion and long term complications such as stent thrombus. This article reviews the pathophysiology of coronary thrombogenesis and explores the complications associated with thrombus during coronary interventions.

Combined Assessments of Biochemical Markers and ST-Segment Resolution Provide Additional Prognostic Information for Patients With ST-Segment Elevation Myocardial Infarction

Background and Objectives

The prognostic value of biochemical markers and the resolution of ST-segment elevation on electrocardiogram are well established. However, how a combination of these two tools affects the evaluation of risk stratification has not yet been evaluated.

Subjects and Methods

Between January 2006 and June 2008, 178 consecutive patients treated with primary percutaneous coronary interventions after ST-segment elevation myocardial infarctions (STEMI) were analyzed at two coronary care units. Patients were divided into the following three groups according to ST-segment resolution: complete (≥70% depression of the elevated ST-segment, n=63), partial (30% to 70%, n=90), and incomplete (<30%, n=25). Demographic data, including history, electrocardiography, biochemical markers, initial ejection fraction, and angiographic findings were also evaluated.

Results

There were 7 deaths, 3 repeated myocardial infarctions, and 17 readmissions for worsening heart failure during six months of follow-up. In a multivariate analysis to predict clinical outcomes, ejection fraction {hazard ratio (HR): 0.83 (0.76-0.91), p<0.01}, high-sensitivity C-reactive protein {HR: 1.15 (1.05-1.26), p<0.05}, and the degree of ST-segment resolution {HR: 0.96 (0.93-0.09), p<0.05} were independently associated with clinical outcomes. According to the Cox-proportional hazards model, the addition of ST-segment resolution markedly improved the prognostic utility of the model containing biochemical markers and ejection fraction.

Conclusion

Assessment of biomarkers upon admission and ST-segment resolution are strong predictors of clinical outcomes. The combination of these data provides additive information about prognosis at an early point in the disease progression and further improves risk stratification for STEMI.

Early versus late ST-segment resolution and clinical outcomes after percutaneous coronary intervention for acute myocardial infarction

Background. Absence of complete ST-segment resolution (STR) after percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction (STEMI) is a determinant of mortality. Traditionally, STR is determined on the coronary care unit (CCU) 60 to 90 minutes after the initiation of reperfusion therapy. We studied the prognostic value of STR immediately after PCI. Methods. We analysed 223 consecutive patients with STEMI and successful PCI. Continuous ECG data were collected during PCI and at 30 minutes after arrival on the CCU (mean time 81±17 minutes after reflow of the culprit artery). Patients were divided into three groups: patients with complete STR immediately after PCI ('early'), patients with complete and persistent STR at 30 minutes on the CCU, but not immediately after PCI ('late') and patients without STR. One-year follow-up was obtained for death and rehospitalisation for major adverse cardiac events. Cox proportional hazards regression was used to evaluate the association between STR and outcome. Results. Early STR occurred in 115 (52%) and late STR in 43 (19%) patients. Patients with early or late STR had a lower incidence of one-year cardiac death than those without STR (1.9 vs. 9.2%; p=0.02). In contrast, rehospitalisation occurred more frequently in patients with early or late STR (20.3 vs. 6.2%; p=0.009). As compared with patients without STR, early and late STR had a similar prognostic value (hazard ratios [95% confidence interval] for cardiac death 0.40 [0.08-2.03] and 0.25 [0.03-2.08]).Conclusions. We found no (major) change in prognostic value of STR during the 0 to 90 minutes time window after PCI. (Neth Heart J 2010;18:416-22.).

ST-segment resolution prior to primary percutaneous coronary intervention is a poor indicator of coronary artery patency in patients with acute myocardial infarction

BACKGROUND

The prognostic value of ST-segment resolution (STR) after initiation of reperfusion therapy has been established by various studies conducted in both the thrombolytic and mechanic reperfusion era. However, data regarding the value of STR immediately prior to primary percutaneous coronary intervention (PCI) to predict infarct-related artery (IRA) patency remain limited. We investigated whether STR prior to primary PCI is a reliable, noninvasive indicator of IRA patency in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

The study population consisted of STEMI patients who underwent primary PCI at our institution between 2000 and 2007. STR was analyzed in 12-lead electrocardiograms recorded at first medical contact and immediately prior to primary PCI and defined as complete (> or =70%), partial (70%- 30%), or absent (<30%).

RESULTS

In 1253 patients with a complete data set, STR was inversely related to the probability of impaired preprocedural flow (P(for trend) < 0.001). Although the sensitivity of incomplete (<70%) STR to predict a Thrombolysis in Myocardial Infarction (TIMI) flow of <3 was 96%, the specificity was 23%, and the negative predictive value of incomplete STR to predict normal coronary flow was only 44%.

CONCLUSIONS

This study establishes the correlation between STR prior to primary PCI and preprocedural TIMI flow in STEMI patients treated with primary PCI. However, the negative predictive value of incomplete STR for detection of TIMI-3 flow is only 44% and therefore should not be a criterion to refrain from immediate coronary angiography in STEMI patients.

Angiographic perfusion score assessed in patients with acute myocardial infarction is correlated with cardiac magnetic resonance infarct size and N-terminal pro-brain natriuretic peptide in 6-month follow-up

Angiographic Perfusion Score (APS) proposed as a simple, angiographic score linking epicardial and myocardial perfusion parameters before and after percutaneous coronary intervention (PCI) is a predictor of short-term outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with PCI. Aim of the study was to analyze the correlation between APS and both infarct size and left ventricular function in long-term follow-up. In a cohort of 68 patients with STEMI treated with PCI APS was calculated for infarct-related artery based on angiographic parameters and was defined as the sum of the Thrombolysis in Myocardial Infarction (TIMI) flow grade (0-3 points) and the TIMI myocardial perfusion grade (0-3 points) before and after PCI (range of points from 0 to 12). Full perfusion was defined as APS ≥ 10. Cardiac magnetic resonance (CMR) parameters and N-terminal pro-brain natriuretic peptide (NT pro-BNP) were assessed at 6 months.

RESULTS

Median APS was 7.5 points. APS ≥ 10 was present in 42% of patients. The significant correlation was found between APS and: CMR infarct size (r = - 0.48; P = 0.0001), CMR left ventricular (LV) ejection fraction (r = 0.5; P = 0.002), LV end-diastolic volume index (r = - 0.37; P = 0.004), LV end-systolic volume index (r = -0.41; P = 0.001), NT pro-BNP (r = - 0.5; P = 0.02). Patients with APS ≥ 10 had significantly lower infarct size, LV volumes, higher EF and lower NT pro-BNP. APS assessed in patients with STEMI treated with PCI is a good predictor of infarct size and left ventricular function in 6-month follow-up.

ST segment resolution in patients with tenecteplase-facilitated percutaneous coronary intervention versus tenecteplase alone: Insights from the Combined Angioplasty and Pharmacological Intervention versus Thrombolysis ALone in Acute Myocardial Infarction (CAPITAL AMI) trial

BACKGROUND

Compared with fibrinolysis alone, fibrinolysis followed by immediate percutaneous coronary intervention (PCI) reduced clinical events in the Combined Angioplasty and Pharmacological Intervention versus Thrombolysis ALone in Acute Myocardial Infarction (CAPITAL AMI) study. It is unclear whether the benefits go beyond achieving epicardial reperfusion.

OBJECTIVES

To determine the differences in ST segment resolution (STR) among patients treated with tenecteplase (TNK)-facilitated PCI compared with patients treated with TNK alone.

METHODS AND RESULTS

A formal ST segment analysis was conducted on the 170 patients with ST elevation myocardial infarction in the CAPITAL AMI trial: 86 patients treated with TNK-facilitated PCI were compared with 84 patients who were treated with TNK alone. Epicardial flow measured by percentage with Thrombolysis In Myocardial Infarction (TIMI) 3 flow improved from 52% (pre-PCI) to 89% (post-PCI) in those assigned to facilitated PCI. ST segment resolution was stratified by complete (70% or greater), partial (less than 70% to 30%) or no (less than 30% to 0%) resolution. The baseline mean ST segment elevation was 11.3+/-7.5 mm in the facilitated PCI patients and 11.8+/-7.1 mm in patients with TNK alone (P=0.66). Complete STR in the facilitated PCI patients versus the TNK-alone patients was present in 55.6% versus 54.6%, respectively (P=0.58) at 180 min and 62.0% versus 55.3% (P=0.64), respectively at day 1. The mean STR at 180 min and day 1 were similar in patients who experienced death, reinfarction, recurrent unstable ischemia or stroke at six months compared with patients who remained event free: 56.3% versus 64.6% at 180 min (P=0.40); and 67.7% versus 67.6% at day 1 (P=0.99), respectively.

CONCLUSIONS

TNK-facilitated PCI did not demonstrate differences in ST segment resolution compared with TNK alone, despite improvement in epicardial flow after PCI. Further studies are required to clarify these findings.

Clinical Predictors of Incomplete ST-Segment Resolution in the Patients With Acute ST Segment Elevation Myocardial Infarction

Background and Objectives

The failure of ST-segment resolution (STR) after primary percutaneous coronary intervention (pPCI) is associated with adverse clinical outcomes. However, the clinical predictors on admission for incomplete STR are poorly known.

Subjects and Methods

Patients undergoing pPCI (n=101, 79 males and 22 females, mean age 60.0 years) were divided into complete STR group (≥70%, n=58) and incomplete STR group (<70%, n=43). The groups were compared according to clinical factors including history, electrocardiographic (ECG) patterns, angiographic features and laboratory data.

Results

The incomplete STR group contained more frequent hypertensive patients (p=0.04) and patients displaying longer tendency in total chest pain duration (p=0.08). This group was associated with worse clinical factors such as low ejection fraction (p=0.06), higher Killip class (p=0.08) and more death (p=0.042). Grade 3 ischemia pattern of ECG and precordial ST elevation (i,e anterior myocardial infarction) at admission were more frequent in the incomplete STR group (p=0.001 and 0.002, respectively). Initial troponin I, creatinin kinase -MB and brain natriuretic peptide levels were higher in the incomplete STR group (p=0.001, 0.002, and 0.043, respectively). Coronary angiography showed that culprit lesions were more frequent in left anterior descending artery than other arteries in the incomplete STR group of patients (p=0.002). Thrombolysis In Myocardial Infarction (TIMI) flow grades 2 or less before PCI was more frequent in the incomplete STR group (p=0.029). However, TIMI flow grade after PCI was not appreciably different between the two groups. Logistic regression analysis demonstrated that TIMI flow grade 2 or less was most powerful predictor for incomplete STR {odds ratio (OR)=12.12, 95% confidence interval (CI) 1.23-119.35, p=0.032}. Other independent predictors were anterior infarction (OR=3.39, CI 1.46-10.57, p=0.007), ischemia grade 3 ECG at admission (OR=3.87, CI 1.31-11.41, p=0.014), and hypertensive patients (OR=3.03, CI 1.13-8.15, p=0.027).

Conclusion

Incomplete STR after pPCI is associated with poor prognostic clinical factors. TIMI flow grade 2 or less before pPCI, ST elevation on precordial leads, ischemia grade 3 pattern of initial ECG, and hypertensive patients are independent predictors for incomplete STR in the early stage.

Thrombus aspiration during primary percutaneous coronary intervention

BACKGROUND

Primary percutaneous coronary intervention (PCI) is effective in opening the infarct-related artery in patients with myocardial infarction with ST-segment elevation. However, the embolization of atherothrombotic debris induces microvascular obstruction and diminishes myocardial reperfusion.

METHODS

We performed a randomized trial assessing whether manual aspiration was superior to conventional treatment during primary PCI. A total of 1071 patients were randomly assigned to the thrombus-aspiration group or the conventional-PCI group before undergoing coronary angiography. Aspiration was considered to be successful if there was histopathological evidence of atherothrombotic material. We assessed angiographic and electrocardiographic signs of myocardial reperfusion, as well as clinical outcome. The primary end point was a myocardial blush grade of 0 or 1 (defined as absent or minimal myocardial reperfusion, respectively).

RESULTS

A myocardial blush grade of 0 or 1 occurred in 17.1% of the patients in the thrombus-aspiration group and in 26.3% of those in the conventional-PCI group (P<0.001). Complete resolution of ST-segment elevation occurred in 56.6% and 44.2% of patients, respectively (P<0.001). The benefit did not show heterogeneity among the baseline levels of the prespecified covariates. At 30 days, the rate of death in patients with a myocardial blush grade of 0 or 1, 2, and 3 was 5.2%, 2.9%, and 1.0%, respectively (P=0.003), and the rate of adverse events was 14.1%, 8.8%, and 4.2%, respectively (P<0.001). Histopathological examination confirmed successful aspiration in 72.9% of patients.

CONCLUSIONS

Thrombus aspiration is applicable in a large majority of patients with myocardial infarction with ST-segment elevation, and it results in better reperfusion and clinical outcomes than conventional PCI, irrespective of clinical and angiographic characteristics at baseline. (Current Controlled Trials number, ISRCTN16716833.)

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.

Comparison of different methods of ST segment resolution analysis for prediction of 1-year mortality after primary angioplasty for acute myocardial infarction

BACKGROUND

Resolution of ST segment elevation corresponds with myocardial tissue reperfusion and correlates with clinical outcome after ST elevation myocardial infarction. Simpler method evaluating the extent of maximal deviation persisting in a single ECG lead was an even stronger mortality predictor. Our aim was to evaluate and compare prognostic accuracy of different methods of ST segment elevation resolution analysis after primary percutaneous coronary intervention (PCI) in a real-life setting.

METHODS

Paired 12-lead ECGs were analyzed in 324 consecutive and unselected patients treated routinely with primary PCI in a single high-volume center. ST segment resolution was quantified and categorized into complete, partial, or none, upon the (1) sum of multilead ST elevations (sumSTE) and (2) sum of ST elevations plus reciprocal depressions (sumSTE+D); or into the low-, medium-, and high-risk groups by (3) the single-lead extent of maximal postprocedural ST deviation (maxSTE).

RESULTS

Complete, partial, and nonresolution groups by sumSTE constituted 39%, 40%, and 21% of patients, respective groups by sumSTE+D comprised 40%, 39%, and 21%. The low-, medium-, and high-risk groups constituted 43%, 32%, and 25%. One-year mortality rates for rising risk groups by sumSTE were 4.7%, 10.2%, and 14.5% (P = 0.049), for sumSTE+D 3.8%, 9.6%, and 17.6% (P = 0.004) and for maxSTE 5.1%, 6.7%, and 18.5% (P = 0.001), respectively. After adjustment for multiple covariates only maxSTE (high vs low-risk, odds ratio [OR] 3.10; 95% confidence interval [CI] 1.11-8.63; P = 0.030) and age (OR 1.07; 95% CI 1.02-1.11; P = 0.002) remained independent predictors of mortality.

CONCLUSIONS

In unselected population risk stratifications based on the postprocedural ST resolution analysis correlate with 1-year mortality after primary PCI. However, only the single-lead ST deviation analysis allows an independent mortality prediction.

Comparison of the X-SIZER Thrombectomy Device with Adjunct Abciximab During Primary Angioplasty and Stenting for ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To evaluate the safety and efficacy of the X-SIZER thrombectomy device versus the use of abciximab during primary angioplasty for acute ST-elevation myocardial infarction (STEMI).

DESIGN

Retrospective analysis of patients undergoing primary angioplasty for STEMI from October 2000 to December 2002 using the X-SIZER thrombectomy device versus abciximab.

SETTING

National University Hospital, Singapore.

PATIENTS

Out of 79 patients, 44 underwent X-SIZER use, while 35 received adjunct abciximab. Both groups were similarly represented with regards to age, gender, risk factors, target vessel site/diameter, cardiogenic shock, and onset of chest pain to procedure time. The infarct-related artery was occluded in 88.6% in both groups.

INTERVENTIONS

A 2-mm X-SIZER was used in 34/44 (77.3%), while a 1.5-mm device was used in the remainder. Final TIMI 3 flow was obtained in 38/44 (86.4%) in the X-SIZER group compared to 26/35 (74.3%) in the abciximab group (P = 0.175).

MAIN OUTCOME MEASURES

Coronary TIMI flow rate, electrocardiogram (ECG) resolution, slow flow/no reflow phenomenon, and patient outcome (death, cardiac failure, or repeat revascularization) at 1 month.

RESULTS

ECG resolution and slow flow/no reflow were better in the X-SIZER group (77.3% vs 54.3%, P = 0.031; 9.1% vs 25.7%, P = 0.047, respectively). Patient outcome at 1 month was, however, not significantly different (18.2% vs 17.1%, P = 0.904, respectively, for X-SIZER and abciximab).

CONCLUSION

X-SIZER thrombectomy during primary percutaneous coronary intervention for thrombus-laden STEMI is a safe and effective strategy. When compared to patients receiving abciximab, it was associated with improved ECG resolution, less slow flow/no reflow and a trend to better TIMI 3 flow.

Early eptifibatide improves TIMI 3 patency before primary percutaneous coronary intervention for acute ST elevation myocardial infarction: results of the randomized integrilin in acute myocardial infarction (INTAMI) pilot trial

AIMS

Adjunctive therapy with glycoprotein IIb/IIIa inhibitors has been shown to reduce ischaemic complications and improve clinical outcome in patients with primary percutaneous coronary intervention (PCI) for acute ST elevation myocardial infarction. Little is known about the use of eptifibatide in this setting.

METHODS AND RESULTS

One hundred and two patients with ST elevation myocardial infarction <12 h scheduled for primary percutaneous intervention were randomly assigned to early eptifibatide given in the emergency room (early) or optional eptifibatide at the time of PCI (late or no). Primary endpoint was the patency of the infarct vessel before PCI. Patients in the early group received their first eptifibatide bolus, a mean of 45 min before angiography. TIMI 3 patency before PCI was observed in 34% in the early group and 10% in late or no group (P=0.01). The incidence of complete ST resolution 1 h after PCI was 61% in early group and 66% in the late or no group, respectively (P=n.s.). There were no significant differences in the rates of TIMI 3 flow after PCI, death, reinfarction, stroke, and major bleeding complications until day 30.

CONCLUSION

In this pilot trial, double bolus eptifibatide given in the emergency room improved TIMI 3 grade flow of the infarct-related coronary artery before PCI. These results should be confirmed in a larger trial and whether this advantage translates into an improvement in clinical outcome should be tested in a trial with primary clinical endpoints.

Combined prognostic utility of ST-segment recovery and myocardial blush after primary percutaneous coronary intervention in acute myocardial infarction

AIMS

ST-segment recovery (SigmaSTR) and myocardial blush (MB) evaluate different elements of microcirculatory integrity after reperfusion therapy in acute myocardial infarction (AMI). We sought to determine whether the combination of SigmaSTR and MB after primary percutaneous coronary intervention (PCI) in AMI has greater prognostic utility than either measure alone.

METHODS AND RESULTS

The 30 days and 1 year clinical outcomes of 456 patients were assessed as a function of SigmaSTR and MB after primary PCI from the CADILLAC trial. SigmaSTR and MB were concordant (> or =70% SigmaSTR and MB grade 2/3 or <70% SigmaSTR and MB grade 0/1) in 60.1% of patients and discordant in 39.9% of patients. The greatest survival was observed among patients with complete SigmaSTR (> or =70%) and MB grade 2/3 in whom the cumulative rates of death at 30 days and 1 year were 0.6 and 1.2%, respectively. Poorest survival was observed among patients with incomplete SigmaSTR (<70%) and reduced MB (grade 0/1), in whom 30 days and 1 year rates of death were 8.3 and 10.1%, respectively. Intermediate outcomes were present in patients with discordant MB and SigmaSTR. By multivariable analysis, however, SigmaSTR was an independent correlate of survival at 30 days and 1 year (P=0.05 and 0.01, respectively), whereas MB was no longer predictive (P=0.38 and 0.72, respectively).

CONCLUSION

SigmaSTR and MB are not infrequently discordant after primary PCI. By univariate analysis, both measures of reperfusion success strongly correlate with survival and assessment of both yields incremental prognostic information beyond either measure alone. By multivariable analysis, however, SigmaSTR is the stronger prognostic variable.

Relation between electrocardiographic ST-segment resolution and early and late outcomes after primary percutaneous coronary intervention for acute myocardial infarction

ST-segment resolution (STR) is a surrogate end point in reperfusion trials of acute myocardial infarction, but there are few data regarding the optimum methods of measurement, clinical predictors, and correlation with late cardiac mortality. Consecutive patients (n = 1,005) who had acute myocardial infarction and >/=2 mm ST-segment elevation controlled with primary percutaneous coronary intervention (PCI) constituted our study group. Follow-up was obtained in 97% of patients at a median of 6.2 years. STR measured as maximum ST-segment elevation after PCI provided better discrimination of late cardiac mortality than did STR measured as percent resolution. Complete STR (<1.0 mm ST-segment elevation after PCI) was achieved in only 42% of patients. Anterior infarction, Killip's class 3 to 4, and Thrombolysis In Myocardial Infarction flow grades <2 before PCI and <3 after PCI were strong independent predictors of partial or poor STR. STR (complete [<1.0 mm] vs partial [1.0 to 2.0 mm] vs poor [>2.0 mm]) correlated with in-hospital mortality (4.0% vs 6.7% vs 11.6%, p = 0.005), reinfarction (1.4% vs 3.4% vs 6.1%, p = 0.01), and late cardiac mortality (17% vs 25% vs 44%, p <0.0001). Correlation with late mortality was stronger for nonanterior than for anterior infarction. Poor STR was a strong independent predictor of late mortality (hazard ratio 1.63, 95% confidence interval 1.06 to 2.50, p = 0.028), even after adjusting for Thrombolysis In Myocardial Infarction flow. These data support the use of STR as a simple method to stratify patients by risk after primary PCI for acute myocardial infarction and support the use of STR as a surrogate end point in reperfusion trials of acute myocardial infarction.