Normal flow (TIMI-3) before mechanical reperfusion therapy is an independent determinant of survival in acute myocardial infarction: analysis from the primary angioplasty in myocardial infarction trials

Association of initial thrombolysis in myocardial infarction flow grade with mortality among patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a National Registry of Myocardial Infarction-5 (NRMI-5) analysis

BACKGROUND

Initial epicardial coronary flow, as assessed by the Thrombolysis in Myocardial Infarction flow grade (TFG), prior to primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI) has been associated with short- and long-term mortality in randomized clinical trials. This study was designed to determine the relationship between initial TFG and mortality in a large, heterogeneous, real-world population of STEMI patients undergoing pPCI.

METHODS

The relationship between pre-pPCI TFG among patients undergoing pPCI and in-hospital mortality was evaluated among STEMI patients from 2004 to 2006 in the National Registry of Myocardial Infarction.

RESULTS

Of 8,337 STEMI patients, 6,595 (79.1%) had pre-pPCI TFG 0/1, 1,126 (13.5%) had pre-pPCI TFG 2, and 616 (7.4%) had pre-pPCI TFG 3. TFG 0/1 prior to pPCI was associated with 3.4% in-hospital mortality, whereas TFG 2 (2.0%) and TFG 3 (1.8%) were associated with significantly lower mortality (TFG 0/1 vs TFG 2, P = .013; TFG 0/1 vs TFG 3, P = .035). TFG 0/1 prior to pPCI was also associated with a significant increase in the composite of death, recurrent myocardial infarction, heart failure, and shock (16.1%) when compared with patients presenting with TFG 2 (11.5%; P < .001) and TFG 3 (7.6%; P < .001). The difference in this composite was also significant between patients presenting with TFG 2 and TFG 3 (P = .01).

CONCLUSIONS

In a large, heterogeneous group of real-world patients presenting with STEMI, pre-pPCI TFG 0/1 is associated with higher in-hospital mortality and other major adverse cardiovascular events. These results corroborate prior to post hoc analyses from randomized clinical trials and support continued efforts aimed at safely establishing early infarct-related artery patency among patients with STEMI.

The relationship between platelet reactivity and infarct-related artery patency in patients presenting with a ST-elevation myocardial infarction

Both heightened platelet reactivity and an occluded infarct related artery (IRA) on initial angiography and at the time of primary percutaneous coronary intervention (PCI) are associated with a worsened clinical outcome in patients with ST-elevation myocardial infarction (STEMI). However, the relationship between platelet reactivity and IRA patency has not yet been established. Consecutive STEMI-patients were enrolled in this study. Patients who had TIMI-flow (thrombolysis in myocardial infarction) 0 or 1 on initial angiography constituted the occluded IRA group and patients having TIMI-flow 2 or 3 comprised the IRA patent group. Platelet function measurements were performed using the PFA-100 COL/ADP cartridge and light transmittance aggregometry without agonist (spontaneous) and after stimulation with adenosine diphosphate (ADP) and arachidonic acid (AA). Ninety-nine patients were enrolled, of whom 49 presented with an occluded IRA. Multivariate analysis identified the following independent factors to be associated with an occluded IRA; short COL/ADP closure time (ORper quartile increase=0.60; 95% CI, 0.39-.93; p=0.02), the 20 μM ADP-induced light transmittance aggregometry (ORper quartile increase =1.77; 95% CI, 1.15-2.73; p=0.01) and leukocyte counts (odds ratio [OR]=1.21; 95% CI, 1.05-1.39; p = 0.008). In conclusion, heightened platelet reactivity and elevated leukocyte counts are associated with an occluded IRA upon presentation in STEMI-patients. These results emphasise the importance of potent antithrombotic therapy early after the onset of symptoms, to obtain early recanalisation of the IRA.

Local delivery versus intracoronary infusion of abciximab in patients with acute coronary syndromes

OBJECTIVES

We investigated whether local abciximab delivery to the site of intracoronary thrombus is more effective than intracoronary bolus infusion in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention and downstream clopidogrel administration.

BACKGROUND

The intracoronary route of administration does not allow an optimal contact between the plaque components and abciximab, which is rapidly washed out by the coronary flow.

METHODS

A total of 50 patients with ACS and a significant lesion in the culprit artery indicative of local thrombosis were randomly assigned to receive local intracoronary delivery of abciximab through a dedicated perfusion catheter or intracoronary infusion through the guiding catheter. The primary end point was the change in thrombus score after angioplasty by optical coherence tomography.

RESULTS

After the intervention, the mean percentage change of the thrombus score was significantly higher among patients of the local delivery group compared with those of the intracoronary infusion group (33.8% vs. 3.9%, p = 0.002). Post-procedural corrected Thrombolysis in Myocardial Infarction frame count was shorter in the local delivery group compared with the intracoronary infusion group (15.3 ± 10.2 vs. 21.1 ± 9.9, p = 0.049). Procedure-related myocardial infarction was observed in 10% and 43% of patients in the local delivery and intracoronary infusion groups, respectively (p = 0.018). At 1 year, MACE were observed in 5.9% and 27.2% of patients in the local delivery and intracoronary infusion groups, respectively (p = 0.046).

CONCLUSIONS

Local intracoronary delivery of abciximab by means of a dedicated perfusion catheter reduces thrombus burden with the potential to improve coronary microcirculation.

Abortion of myocardial infarction by primary angioplasty mainly depends on preprocedural TIMI flow

AIMS

To define frequency and predictors of aborted myocardial infarctions (MI) after primary angioplasty.

METHODS AND RESULTS

We analysed 196 consecutive patients with the clinical diagnosis of ST-elevation acute coronary syndrome (ST-ACS) admitted for primary angioplasty to one interventional facility between October 2005 and September 2006. Aborted MI was defined as a creatine increase of less than two times the upper limit of normal, combined with typical evolutionary electrocardiographic changes. Masquerading MI was diagnosed if evolutionary changes were missing or could be attributed to other causes. Thirty-four patients (17,3%) had an aborted and nine (4,6%) a masquerading MI. The main predictor of abortion was Thrombolysis In Myocardial Infarction (TIMI) flow 2 or 3 prior to procedure. The in-hospital mortality of aborted MI was 0%, the one year mortality 2.9%. Sixteen patients without prior or inter-current myocardial infarction had a preserved ejection fraction on cardiac MR at 12 months; in six patients even without any detection of late enhancement.

CONCLUSIONS

There is a substantial proportion of aborted myocardial infarction after primary angioplasty, corresponding to a small or even non detectable scar formation in terms of late enhancement on cardiac MR. Preprocedural TIMI flow 2 or 3 is the main predictor of aborted MI.

Comparison of impact of mortality risk on the survival benefit of primary percutaneous coronary intervention versus facilitated percutaneous coronary intervention

Available data suggest that thrombolytic therapy facilitated percutaneous coronary intervention (FPCI) is not beneficial, and recent analyses have shown a correlation between mortality risk and outcomes of patients with ST elevation myocardial infarctions treated with FPCI. The aim of this study was to analyze the impact of the mortality risk on the survival benefit of primary percutaneous coronary intervention (PPCI) compared to FPCI. A total of 13 trials enrolling 5,789 patients were pooled for analyses. PPCI survival benefit was calculated as the 30-day mortality after FPCI minus the 30-day mortality after PPCI, and the mortality rate of FPCI was interpreted as a proxy for mortality risk. A weighted metaregression was used to test the relation between mortality risk and explanatory variables. A fixed-effect linear regression analysis modeling the log odds ratio (PPCI/FPCI) as a linear function of the log odds of FPCI mortality was used to estimate the mortality risk that nullified the 30-day survival benefit of PPCI over FPCI. Across all studies, the absolute survival benefit ranged from -5.6 (favoring FPCI) to +7.2 (favoring PPCI). According to the slope of the regression line (-0.7, x-axis intercept -2.1) for the patients with baseline mortality risk > 4.2%, it is unlikely to obtain a survival benefit by FPCI compared to PPCI. In conclusion, the higher the mortality risk of patients with ST elevation myocardial infarctions, the higher the likelihood of a survival advantage of PPCI over FPCI.

Persistent coronary no flow after wire insertion is an early and readily available mortality risk factor despite successful mechanical intervention in acute myocardial infarction: a pooled analysis from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials

OBJECTIVES

These studies sought to investigate the impact on mortality of coronary flow after passage of the wire through the culprit vessel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing mechanical reperfusion.

BACKGROUND

Reduced spontaneous coronary flow before percutaneous coronary intervention influences mortality in patients with STEMI. Response to vessel wiring in patients with an occluded coronary artery before intervention might further discriminate outcomes irrespective of pre- and post-intervention coronary flow.

METHODS

Data from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials were pooled: of 919 index procedures, 902 films (98%) were technically adequate for core laboratory TIMI (Thrombolysis In Myocardial Infarction) flow determination.

RESULTS

TIMI flow grade 0 was present before percutaneous coronary intervention in 59% of infarct vessels, TIMI flow grade 1 to 2 was found in 21%, whereas the remainder of infarct arteries presented with TIMI flow grade 3. In 49% of patients who showed persistent TIMI flow grade 0 after wire insertion (AWI), mortality was higher at 30 days (5.3%) and 1 year (9.4%) compared with patients in whom TIMI flow grade before percutaneous coronary intervention was either >0 (0.8%; p < 0.003 and 3.6%, p < 0.008) or improved from 0 AWI (1.5%, p < 0.04 and 3.6%, p < 0.02). After correcting for multiple imbalances, including baseline and final flow, persistent TIMI flow grade 0 AWI remained associated at 30 days to 2-fold (risk ratio [RR]: 2.1, 95% confidence interval [CI]: 1.08 to 5.00; p = 0.038) and at 1 year to almost 3-fold increases of mortality (RR: 2.7, 95% CI: 1.3 to 5.6; p = 0.008).

CONCLUSIONS

STEMI patients displaying persistent no-flow AWI have a lower survival rate despite an apparently successful mechanical intervention. As an early marker for high residual mortality risk, persistent no-flow AWI may qualify STEMI patients for dedicated pharmacomechanical treatment strategies.

Prolonged door-to-balloon time: is treatment delayed always treatment denied?

Rapid reperfusion following the onset of ST-segment elevation myocardial infarction has been shown to provide life-saving benefit. Both systemic fibrinolytic therapy and percutaneous coronary intervention have been shown to be effective in reducing mortality, and their effectiveness is greater the sooner they are applied. Percutaneous coronary intervention has become the dominant method of reperfusion and may offer benefit over systemic fibrinolysis in some patients. Accordingly, physicians, hospitals, and professional organizations have developed guidelines and algorithms to both speed and standardize care. In addition, the institutional rapidity of therapy-the mean or median door-to-balloon time-is often publically reported providing further impetus to rapid triage and treatment of ST-segment elevation myocardial infarction. However, some patients do not receive reperfusion within the time guidelines set out by professional organizations. In many instances, this delay relates to medical issues that exist in addition to the patient's myocardial infarction. These data raise the question of whether the most rapid reperfusion is always superior to more delayed but potentially more comprehensive therapy.

Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia (TASTE trial). A multicenter, prospective, randomized, controlled clinical registry trial based on the Swedish angiography and angioplasty registry (SCAAR) platform. Study design and rationale

BACKGROUND

In ST-elevation myocardial infarction (STEMI), distal embolization of thrombus material often precludes restoration of normal coronary artery flow. Small-scaled studies have demonstrated that intracoronary thrombus aspiration improves flow and myocardial perfusion, but only one larger randomized single-center study has suggested a survival benefit. Thrombus aspiration is widely used in clinical practice and is recommended by international guidelines despite limited evidence.

METHODS/DESIGN

The Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia is a multicenter, prospective, randomized, controlled, clinical open-label trial based on the Swedish angiography and angioplasty registry (SCAAR) platform with blinded evaluation of end points. A total of 5,000 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) will randomly be assigned either to conventional PCI or to thrombus aspiration followed by PCI. SCAAR will be used as the platform for randomization, allowing a broad population of all-comers in the registry network to be enrolled. All follow-up will also be done in SCAAR and other national registries. The primary end point is time to all-cause death at 30 days.

DISCUSSION

The Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia trial is the largest trial to date to evaluate the effect of thrombus aspiration on death following PCI in patients with STEMI. We propose the term randomized clinical registry trial to describe the novel entity of using an online national registry as platform for case records, randomization, and follow-up.

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.

Patent coronary artery and myocardial infarction in the era of primary angioplasty: assessment of an old problem in a new setting with data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

AIMS

The purpose of this study was to evaluate factors that contribute to a patent IRA (infarct - related artery) and the prognostic impact of a patent IRA in patients with ST-elevation myocardial infarction.

METHODS AND RESULTS

Using the Swedish angiography and angioplasty registry (SCAAR) we included all patients with STEMI and one-vessel coronary artery disease who underwent primary PCI of the culprit lesion only from May 2005 to December 2007. A patent IRA was found in 1,104 of 3,284 patients. Patients with an occluded IRA had significantly increased 7-day mortality (HR, 3.03, 95% CI 1.68-5.46, P<0.001). The incidence of an occluded IRA increased with higher age, in patients over 80 years of age (OR, 1.23, 95% CI; 0.92-1.64), lower in patients on lipid-lowering drugs (OR, 0.68, 95% CI; 0.54-0.86) and lower in patients pre-treated with heparin (OR 0.71, 95% CI; 0.60-0.83) or GPIIb/IIIa receptor blockade (OR 0.77, 95% CI; 0.61-0.97). Treatment with acetylsalicylic acid or clopidogrel had no effect on IRA patency.

CONCLUSIONS

IRA patency was associated with a lower 7-day mortality. Older STEMI patients and patients not taking lipid-lowering drugs or pre-treated with heparin or GPIIb/IIIa receptor blockers seem to constitute risk groups for having an occluded IRA.

Usefulness of peak systolic strain measurement by automated function imaging in the prediction of coronary perfusion in patients with acute myocardial infarction

BACKGROUND/AIMS

The usefulness of global longitudinal peak systolic strain (GLPSS) measurement by automated function imaging (AFI) in the prediction of perfusion status of infarct-related artery (IRA) before percutaneous coronary intervention (PCI) was evaluated.

METHODS

Sixty-nine patients with acute myocardial infarction (AMI) who underwent successful primary PCI were divided into two groups; the patients with occlusion of IRA (Group I, 41 patients, 63.0 ± 14.9 years of age, 31 males) versus the patients with patent IRA (Group II, 28 patients, 63.8 ± 11.2 years of age, 15 males). GLPSS by AFI and wall-motion score index (WMSI) were analyzed in both groups.

RESULTS

GLPSS was significantly decreased in Group I compared with Group II (-11.2 ± 3.7 vs. -14.1 ± 4.7%, p = 0.005), but WMSI (1.49 ± 0.28 vs. 1.35 ± 0.32, p = 0.062) did not differ between groups. GLPSS of infarct segments was significantly lower (-3.7 ± 5.4 vs. -11.4 ± 4.8%, p < 0.001), and WMSI of infarct segments was significantly higher (2.13 ± 0.57 vs. 1.66 ± 0.57, p = 0.001) in Group I compared with Group II. By receiver operation curve analysis, the area under the curve to predict IRA occlusion was 0.850 in GLPSS of infarct segments and 0.719 in WMSI of infarct segments. The optimal cut-off value to predict IRA occlusion was -9.4% in GLPSS of infarct segments (sensitivity, 85.4%; specificity, 67.9%) and 1.68 in WMSI of infarct segments (sensitivity, 78.0%; specificity, 60.7%).

CONCLUSIONS

The present study suggested that GLPSS measured by AFI is a more sensitive predictor of IRA occlusion than is WMSI before PCI. Routine measurement of GLPSS by AFI can be a very useful tool in risk stratification of AMI.

A multicenter randomized study to evaluate intracoronary abciximab with the ClearWay catheter to improve outcomes with Lysis (IC ClearLy): trial study design and rationale

BACKGROUND

Percutaneous coronary intervention (PCI) is a highly effective therapy for acute ST-elevation myocardial infarction. Adjunctive therapy with platelet glycoprotein (GP) IIb/IIIa inhibitor can result in increased vessel patency and improved outcomes in ST-elevation myocardial infarction patients undergoing PCI. The investigation of novel dosing and delivery strategies of this therapy may help to further improve outcomes.

METHODS

IC-Clearly is a randomized, open-label, multicenter trial, with the purpose of evaluating the effectiveness of an intracoronary bolus dose of abciximab delivered using the ClearWay RX catheter vs. an intravenous bolus of abciximab for ST-elevation myocardial infarction with angiographically visible thrombus (thrombus grade >or=2). A total of 150 patients will be randomized 1: 1 to treatment of the culprit artery with intracoronary abciximab (75 patients) or intravenous abciximab (75 patients) in addition to a maintenance infusion regimen of abciximab administered intravenously for 12 h after PCI. The number of patients included in this study is based on the estimation of sample size needed to identify a statistically significant difference in the primary endpoints between the two groups. The primary endpoint chosen to evaluate this hypothesis is infarct size assessed by cardiac magnetic resonance. Clinical outcomes will be assessed for each patient through hospital discharge and at 30-day follow-up.

CONCLUSION

The purpose of this study is to evaluate whether an intracoronary bolus of abciximab delivered with the ClearWay RX catheter prior to the 12 h post-PCI intravenous infusion regimen of abciximab will result in significant additional clot resolution in vivo and improved myocardial perfusion when compared with an intravenous bolus of abciximab on top of the 12 h post-PCI intravenous infusion regimen of abciximab as per standard practice. The primary endpoint chosen to evaluate this hypothesis is infarct size as assessed by cardiac magnetic resonance.

Upstream vs deferred administration of small-molecule glycoprotein IIb/IIIa inhibitors in primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: insights from randomized clinical trials

BACKGROUND

Recent data have demonstrated similar outcomes for patients with ST-segment elevation myocardial infarction (STEMI) who undergo primary percutaneous coronary intervention (PCI) and are treated with small-molecule glycoprotein IIb/IIIa inhibitors (smGPIs) compared with those treated with abciximab. In the present study, a meta-analysis was performed to evaluate the relative safety and efficacy of upstream vs deferred administration of smGPIs in STEMI patients.

METHODS AND RESULTS

A total of 10 randomized clinical trials comparing upstream vs deferred administration of smGPIs in 2,724 patients were located in the electronic databases of the published literature. Preprocedural Thrombolysis In Myocardial Infarction Study (TIMI) grade 2 or 3 flow was present in 45.0% of the upstream group compared with 36.9% in the deferred group (odds ratio (OR) 1.40, P<0.001). However, no difference in post-procedural TIMI 3 flow (OR 0.87, P=0.25) was found between the groups. The 30-day mortality rate in the upstream group did not differ from that of the deferred group (OR 1.04, P=0.85). No significant difference was noted with respect to major bleeding complications (OR 1.25, P=0.38).

CONCLUSIONS

In STEMI patients scheduled for primary PCI, although early smGPIs treatment improved initial epicardial patency, no beneficial effect on post-procedural angiographic or 30-day clinical outcome was found. Thus, the current available data do not support the routine utilization of upstream smGPIs in STEMI patients treated with primary PCI.

Prehospital high-dose tirofiban in patients undergoing primary percutaneous intervention. The AGIR-2 study

BACKGROUND

Compared with administration in the catheterization laboratory, early treatment with glycoprotein IIb/IIIa inhibitors provides benefits to patients with ST-segment elevation myocardial infarction who undergo primary percutaneous intervention. Whether this benefit is maintained on top of a 600 mg loading dose of clopidogrel is unknown.

METHODS

In a multicentre, controlled, randomized study, 320 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention received a high-dose bolus of tirofiban given either in the ambulance (prehospital group) or in the catheterization laboratory. The primary endpoint was a TIMI flow grade 2-3 of the infarct-related vessel at initial angiography. Secondary endpoints included ST-segment resolution 1h after percutaneous coronary intervention and peak serum troponin I concentration.

RESULTS

Tirofiban was administered 48 (95% confidence interval 21.4-75.0) min earlier in the prehospital group. At initial angiography, the combined incidence of TIMI 2-3 flow was 39.7% in the catheterization-laboratory group and 44.2% in the prehospital group (p=0.45). No difference was found on postpercutaneous intervention angiography or peak troponin concentration. Complete ST-segment resolution 60 min after the start of intervention was 55.4% in the catheterization-laboratory group and 52.6% in the prehospital group (p=0.32).

CONCLUSION

Prehospital initiation of high-dose bolus tirofiban did not improve significantly initial TIMI 2 or 3 flow of the infarct-related artery or complete ST-segment resolution after coronary intervention compared with initiation of tirofiban in the catheterization laboratory (NCT00538317).

Prognostic significance and determinants of myocardial salvage assessed by cardiovascular magnetic resonance in acute reperfused myocardial infarction

OBJECTIVES

The aim of the study was to determine the prognostic significance and determinants of myocardial salvage assessed by cardiovascular magnetic resonance (CMR) in reperfused ST-segment elevation myocardial infarction.

BACKGROUND

In acute myocardial infarction, CMR can retrospectively detect the myocardium at risk and the irreversible injury. This allows for quantifying the extent of salvaged myocardium after reperfusion as a potential strong end point for clinical trials and outcome.

METHODS

We analyzed 208 consecutive ST-segment elevation myocardial infarction patients undergoing primary angioplasty <12 h after symptom onset. T2-weighted and contrast-enhanced CMR was used to calculate the myocardial salvage index (MSI). Patients were categorized into 2 groups defined by the median MSI. The primary end point of the study was occurrence of major adverse cardiovascular events defined as death, reinfarction, and occurrence of new congestive heart failure within 6 months after the index event.

RESULTS

The median MSI was 48 (interquartile range 27 to 73). Major adverse cardiovascular events were significantly lower in the MSI >or= median group (2.9% vs. 22.1%, p < 0.001). The stepwise Cox proportional hazards model revealed that the MSI was the strongest predictor of major adverse cardiovascular events at 6-month follow-up (p < 0.001). All prognostic clinical (symptom onset to reperfusion), angiographic (Thrombolysis In Myocardial Infarction flow grade before angioplasty), and electrocardiographic (ST-segment resolution) parameters showed significant correlations with the MSI (p < 0.001 for all).

CONCLUSIONS

This study for the first time demonstrates that the MSI assessed by CMR predicts the outcome in acute reperfused ST-segment elevation myocardial infarction. Therefore, MSI assessment has important implications for patient prognosis as well as for the design of future trials intended to test new reperfusion therapy efficacy. (Myocardial Salvage Assessed by Cardiovascular Magnetic Resonance-Impact on Outcome; NCT00952224).

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.

Early administration of small-molecule glycoprotein IIb/IIIa inhibitors before primary percutaneous coronary intervention for ST-elevation myocardial infarction: insights from randomized clinical trials

BACKGROUND

Current guidelines recommend abciximab (ReoPro) as an adjunctive pharmacologic agent to primary percutaneous coronary intervention (PPCI) for patients with ST-segment elevation myocardial infarction (STEMI). However, small-molecule glycoprotein IIb/IIIa receptor inhibitors (smGPIs), such as tirofiban (aggrastat) and eptifibatide (integrilin), are more commonly used in clinical practice.

METHOD AND RESULT

We performed a meta-analysis to compare the safety and efficacy of early administration of smGPIs versus abciximab before PPCI. The literature was scanned by formal searches of electronic databases from January 1990 to April 2009. A total of 4 randomized trials meeting the prespecified criteria were analyzed, involving 2040 patients. Rates of initial Thrombolysis in Myocardial Infarction Study (TIMI) 3 flow before procedure as well as complete ST resolution after PPCI were not inferior in smGPIs group compared with abciximab group (odds ratio [OR] 1.12, P = .31; and OR 1.05, P = .66, respectively). There was no significant difference in the risk of 30-day (OR 0.83, P = .54) or 8-month mortality (OR 0.78, P = .43) between smGPI and abciximab group. With regard to the safety end points, neither the major nor the minor bleeding complications in smGPIs group differed significantly from those in abciximab group (OR 1.32, P = .43; and OR 0.82, P = .37, respectively).

CONCLUSION

This meta-analysis shows that early administration of smGPIs is as effective as abciximab in the setting of PPCI for STEMI, without an increase in bleeding complications.

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.

Upstream high-dose tirofiban does not reduce myocardial infarct size in patients undergoing primary percutaneous coronary intervention: a magnetic resonance imaging pilot study

BACKGROUND

Primary percutaneous coronary intervention (PCI) is more effective than fibrinolytic therapy for ST-segment elevation myocardial infarction (STEMI), but initial treatment delay to intervention is the main limitation of this strategy.

HYPOTHESIS

Upstream use of high-dose tirofiban could reduce myocardial infarct size, using analysis of contrast-enhanced magnetic resonance imaging (CE-MRI).

METHODS

Patients with STEMI within 12 hours after symptom onset were randomized to a facilitated PCI group (n = 19) or to a primary PCI group (n = 20). The primary endpoint was myocardial infarct size evaluated by the volume of delayed hyperenhancement on CE-MRI at 1 month after index procedure.

RESULTS

The baseline clinical characteristics were not significantly different between the 2 groups. Although the incidence of pre-PCI thrombolysis in myocardial infarction (TIMI) flow grade 2 to 3 was significantly higher in the facilitated PCI group than in the primary PCI group (47.4% vs 15.0%, P = 0.03), the achievement of myocardial blush grade 2 to 3 or ST-segment resolution at 30 minutes after procedure was not significantly different between the facilitated PCI and the primary PCI group (36.8% vs 40%, P = 0.84 and 31.6% vs 20%, P = 0.41, respectively). Infarct size on CE-MRI was similar in the facilitated PCI group and the conventional primary PCI group (22.1% +/- 11.7% vs 25.2% +/- 13.2%, P = 0.44). At 6 months, the left ventricular ejection fraction (LVEF) on echocardiography was 52.6% +/- 10.4% in the facilitated PCI group and 50.9% +/- 9.8% in the primary PCI group (P = 0.68).

CONCLUSION

Despite the improvement of initial TIMI flow grade, the upstream use of high-dose tirofiban did not reduce myocardial infarct size measured by CE-MRI.

ST deviation pattern and infarct related artery in acute myocardial infarction

BACKGROUND

Myocardial infarction (MI) may be classified as ST-elevation MI (STEMI) or non-ST-elevation MI (NSTEMI). There is little data regarding the relationship between the infarct related artery (IRA), clinical characteristics of the patients, and the ST deviation pattern (ie, STEMI or NSTEMI).

HYPOTHESIS

There is a predilection of any coronary artery to a particular ST deviation pattern of acute MI.

METHODS

We reviewed our institutional database and selected patients who presented with an acute MI and underwent coronary angiography within 7 days of admission. The analysis included 830 patients of whom 563 had STEMI and 267 had NSTEMI. The culprit lesion was defined by reviewing each patient's angiographic report, electrocardiogram, and echocardiogram. TIMI flow rate was determined.

RESULTS

The IRA in STEMI was most frequently the left anterior descending coronary artery (LAD) followed by the right coronary artery (RCA) and then the left circumflex coronary artery (LCX), a statistically significant difference. In patients with NSTEMI there were no significant differences in IRA. Patients with STEMI and LCX as the IRA were significantly younger and had a higher percentage of TIMI grade 3 flow then patients with STEMI and LAD or RCA as IRAs. These differences were not noted in patients with NSTEMI regardless of IRA.

CONCLUSIONS

In STEMI there were significant differences in age and TIMI flow depending on the IRA. These findings were not demonstrated in patients with NSTEMI.

Plasma N-terminal fragment of the prohormone B-type natriuretic peptide concentrations in relation to time to treatment and Thrombolysis in Myocardial Infarction (TIMI) flow: a substudy of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial

BACKGROUND

We investigated the prognostic significance of plasma N-terminal fragment of the prohormone B-type natriuretic peptide (Nt-proBNP) concentrations in addition to time to reperfusion and Thrombolysis in Myocardial Infarction (TIMI) flow before and after coronary intervention in patients with ST elevation myocardial infarction (STEMI) from the database of the Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention (ASSENT IV-PCI) trial.

METHODS

Plasma Nt-proBNP was available in 1,037 patients with STEMI. Patients were randomized either to primary (p-PCI) or to full-dose tenecteplase before PCI (f-PCI).The study end point was the composite of death, cardiogenic shock, or congestive heart failure at 90 days.

RESULTS

According to classification tree analysis, patients with Nt-proBNP levels >694 pg/mL had the highest primary end point rates (33.8% vs 11%, P < .001). In Cox regression analysis, Nt-proBNP >694 pg/mL strongly predicted 90-day survival even among patients with short treatment delay (f-PCI < or =3 hours: hazard ratio [HR] 2.63, P = .002 and p-PCI < or =3 hours: HR 4.87, P < .001, respectively). Patients with TIMI 3 flow after coronary intervention were at significantly higher risk of the primary end point if admission Nt-proBNP exceeded 694 pg/mL (f-PCI: HR 2.88, P < .001 and p-PCI: HR 3.84, P < .001, respectively). In multivariable analysis, Nt-proBNP >694 pg/mL significantly (P = .001) predicted 90-day survival in addition to age (P < .001), TIMI flow after PCI (P < .001), body mass index (P = .026), anterior wall infarction (P = .035), and systolic blood pressure at randomization (P = .036), respectively.

CONCLUSION

Elevated plasma concentrations of Nt-proBNP in the early phase of STEMI determine in-hospital and 90-day outcome after infarction irrespective of time to treatment and pre- or postinterventional TIMI flow.

Prognostic significance and magnetic resonance imaging findings in aborted myocardial infarction after primary angioplasty

BACKGROUND

Aborted myocardial infarction (MI) is defined by major (> or =50%) ST-segment resolution and a lack of subsequent cardiac enzyme rise > or =2 the upper normal limit. This ultimate myocardial salvage has been observed in approximately 15% of ST-elevation MI (STEMI) patients after fibrinolysis. So far, the prognostic significance and magnetic resonance imaging (MRI) findings of an aborted MI after primary angioplasty have not been evaluated appropriately.

METHODS

We examined 420 consecutive STEMI patients undergoing primary angioplasty within 12 hours after symptom onset. All patients underwent MRI within 1 to 4 days. Clinical end points were major adverse cardiovascular events within 6 months after the index event.

RESULTS

Of the 420 STEMI patients, 58 (14%) fulfilled aborted MI criteria. As compared with true MI, patients with aborted MI had a significant lower infarct size, shorter pain-to-balloon time, and better left ventricular ejection fraction (P < .001, respectively). Aborted MI patients had a 6-month major adverse cardiovascular event rate of 1.7% versus 19.6% of true MI patients (P = .001). In aborted MI patients, MRI detected no myocardial scar in 30 (56%), and a minor necrosis/scar formation in 24 patients (44%).

CONCLUSION

The proven prognostic relevance of aborted MI makes it a meaningful end point and therapeutic target in future MI studies. MRI can further distinguish between true aborted MI with absence of myocardial scar and aborted MI with scar formations.

Evolution of myocardial perfusion during primary angioplasty in spontaneously reperfused infarct-related artery: impact on long-term clinical outcomes and left ventricular function recovery

BACKGROUND

TIMI myocardial perfusion grade (TMPG) reflects the integrity of microvasculature in ST-elevation myocardial infarction (STEMI). We sought to investigate whether TMPG evolution during primary angioplasty (pPCI) in spontaneously reperfused STEMI patients might predict long-term outcomes.

METHODS

392 patients with TIMI-3 flow before pPCI were analyzed. According to pre- and post-pPCI TMPG four reperfusion patterns were created: A. TMPG deterioration from grade 2/3 to 0/1 after pPCI (n = 55, 14.0%), B. TMPG-0/1 before and after pPCI (n = 111, 28.3%), C. TMPG improvement from grade 0/1 to 2/3 (n = 52, 13.3%), D. TMPG-2/3 before and after pPCI (n = 174, 44.4%). 30-day and 1-year mortality and heart failure requiring hospitalization (HF-hosp) were recorded. Left ventricular ejection fraction (LVEF) was measured at first day (1D) and after 6 months (6M).

RESULTS

1D-LVEF was similar in A-D groups. After 6M, LVEF improved in pattern D (7.5 ± 5.4%, p<0.01) and C (3.7 ± 3.4%, p < 0.05), deteriorated in pattern A (5.2 ± 3.9%, p<0.01) and did not change in pattern B. 6M-LVEF increased (p < 0.001) and frequency of 1-year HF-hosp decreased (p < 0.001) in stepwise fashion among A-D patterns. A 30-day mortality rate for A-D patterns was 9.1%, 2.7%, 1.9% and 0%, respectively (p < 0.001). 1-year mortality was 16.3%, 7.2%, 5.8% and 0.6%, respectively (p < 0.001). By multivariate analysis (c-index = 0.79), TMPG evolution was independent predictor of 1-year mortality (HR = 2.5, 95%CI 1.3-4.0, p = 0.006).

CONCLUSIONS

Maintaining TMPG-2/3 or improving TMPG-0/1 through pPCI in STEMI implies LV function recovery and good long-term survival. In contrast, substantial deterioration of TMPG is associated with lack of LV function recovery, and the highest mortality rate.

Explicit risk in acute coronary syndrome management

At least implicitly, most clinical decisions represent an integration of disease and treatment-based risk assessments. Often, as is the case with acute coronary syndrome (ACS), these decisions need to be made quickly at a time when data elements are limited, and published risk models are very useful in clarifying time-dependent determinants of risk. The present review emphasizes the value of explicit risk assessment and reinforces the fact that patients at highest risk are often those most likely to benefit from newer and more invasive therapies. Suggested ways to incorporate published ACS risk models into clinical practice are included. In addition, the need to adopt a longer-term view of risk in ACS patients is stressed, with particular regard to the important role of heart failure prediction and treatment.

Mean platelet volume predicts patency of the infarct-related artery before mechanical reperfusion and short-term mortality in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND AND AIMS

Patency of infarct-related artery (IRA) before mechanical reperfusion with primary percutaneous coronary intervention (PPCI) has been associated with better prognosis in patients with ST-Elevation myocardial infarction (STEMI). Mean platelet volume (MPV) increases in STEMI patients and may be associated with increased thrombotic potential. In STEMI patients scheduled for PPCI we sought to assess whether mean platelet volume (MPV), as measured at admission, correlates with "spontaneous" reperfusion of the IRA and short-term clinical outcome.

METHODS

Blood samples were obtained on hospital admission in 617 consecutive patients (82% men; age 64 + or - 12 years) with STEMI, before PPCI. 372 (61%) patients were treated with the GP IIb/IIIa blocker abciximab. The main study endpoint was mortality at 30 days.

RESULTS

MPV was significantly lower in patients with basal TIMI flow grade 2 -3 compared to patients with TIMI grade 0-1 (median, 9 vs. 8.5 fL, p<0.0001). After adjustment, MPV remained an independent predictor of the patency of the IRA (OR 0.63, CI 95% 0.51 - 0.78). A cut off value of 8.95 fL had a predictive negative value of 82% to identify patients with patent IRA. Using this cut point, and after adjusting for confounders, MPV was an independent predictor of 30-day mortality (HR 2.92, CI 95% 1.36 - 6.29). When patients were subdivided according to abciximab use, MPV was a marker of worse outcome but only in patients who did not receive abciximab (HR 3.67, CI 95% 1.13 - 11.49).

CONCLUSION

An increased MPV is an independent predictor of both a patent IRA (TIMI flow 2 or 3 before PPCI) and 30-day mortality. This marker may be able to identify patients requiring more aggressive antiplatelet therapy.

Systematic review of fibrinolytic-facilitated percutaneous coronary intervention: potential benefits and future challenges

BACKGROUND

Facilitated percutaneous coronary intervention (PCI) is defined as the administration of fibrinolytic therapy and/or glycoprotein (GP) IIb/IIIa inhibitors to minimize myocardial ischemia time while waiting for PCI. A pooled meta-analysis suggested that facilitated PCI was associated with higher rates of mortality and morbidity compared with nonfacilitated PCI.

OBJECTIVE

The heterogeneous and complex trials of facilitated PCI were systematically reviewed to identify where this strategy may be beneficial and deserving of further research.

METHODS

MEDLINE, EMBASE, the Cochrane database, the Internet and conference proceedings were searched to obtain relevant trials. Human studies that randomly assigned patients to fibrinolytic-facilitated PCI (administration of fibrinolytic therapy alone or in combination with GP IIb/IIIa inhibitors before angiography) versus nonfacilitated PCI were included.

RESULTS

Nine trials encompassing 3836 patients were reviewed. The facilitated PCI strategy was fibrinolytic therapy alone in seven trials and half-dose fibrinolytic therapy plus GP IIb/IIIa inhibitors in two trials. In patients who had fibrinolysis less than 2 h after symptom onset (mainly in the prehospital setting) and/or slightly delayed PCI 3 h to 24 h after fibrinolysis, facilitated PCI was associated with the greatest Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow and a trend toward reduced mortality. Overall, facilitated PCI was associated with increased intracranial hemorrhage and reinfarction. Combining half-dose fibrinolytic therapy and GP IIb/IIIa inhibitors reduced reinfarction but increased major bleeding.

CONCLUSIONS

Facilitated PCI cannot be recommended outside of experimental protocols at this time. Further research should focus on selecting patients with higher benefit-to-risk ratios and performing prehospital fibrinolysis with optimal antiplatelet or antithrombin therapy, as well as slightly delayed PCI in patients who are stable or geographically removed from PCI facilities.