pre-PCI TIMI Flow Research Articles

The Coronary Reperfusion Effect and Safety of Prehospital P2Y12 Inhibitor in Primary-PCI STEMI Patients: A Systematic Review and Meta-Analysis

Background The concept of early administration of P2Y12 inhibitor in ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) is widely accepted, but whether prehospital administration results in greater coronary reperfusion remains unclear. Our study aims to analyze the benefit and safety of prehospital P2Y12 inhibitor compared to in-hospital P2Y12 inhibitor administration. Method Three databases (PubMed, EMBASE, and Cochrane Library) were searched from database inception to June 2023. We included all types of studies except for conference publications, abstract presentations, reviews, and case reports. The primary outcomes were pre-PCI TIMI flow grade 2–3 (TIMI = Thrombolysis in Myocardial Infarction) and major bleeding. The secondary outcomes included post-PCI TIMI flow grade 2–3, major adverse cardiac events (MACE), recurrent myocardial infarction (MI), and short-term (30-day) mortality. Result Eight individual studies with a total of 10823 patients were included in our meta-analysis. Compared with in-hospital P2Y12 inhibitor, prehospital P2Y12 inhibitor were associated with significantly higher rates of pre-PCI TIMI flow grade 2–3 (OR 1.32, 95% CI: 1.09–1.61, p = 0.005) and post-PCI TIMI flow grade 2–3 (OR 1.43, 95% CI: 1.04–1.97, p = 0.03), and a significantly lower risk of recurrent MI (OR 0.69, 95% CI: 0.49–0.96, p = 0.03). There were no significant difference in the risk of major bleeding (OR 1.00, 95% CI: 0.75–1.32, p = 0.98), MACE (OR 0.94, 95% CI: 0.70–1.25, p = 0.65), or short-term mortality (OR 0.87, 95% CI: 0.50–1.51, p = 0.61). Conclusion Prehospital P2Y12 inhibitor compared to in-hospital P2Y12 inhibitor is associated with a significantly higher rate of pre-PCI and post-PCI TIMI flow grade 2–3, a reduced risk of recurrent MI, and no increase in major bleeding in STEMI patients undergoing primary PCI.

CMR analysis of the cardioprotective effects of chronic statin therapy prior to first STEMI: a propensity score analysis

Abstract Background In addition to their lipid-lowering properties, statins possess cardioprotective effects. However, the impact of the latter on acute cardioprotection and adverse left ventricular (LV) remodelling following ST-elevation myocardial infarction (STEMI) have not been investigated through cardiac magnetic resonance (CMR) analysis to date. Purpose To investigate the cardioprotective effects of chronic oral statin treatment prior to first STEMI. Methods The study included 1236 patients with a first STEMI and a CMR performed during the index admission. Among them, 923 underwent a second CMR at 6 months follow-up. The effects of chronic oral statin treatment prior to STEMI on acute infarct size (IS) as a percentage of LV mass, LV ejection fraction (LVEF), microvascular obstruction (MVO), and changes in LV end-diastolic volume (EDVi) and end-systolic volume indexes (ESVi)] at 6 months were evaluated. A propensity score to receive treatment prior to STEMI with statins was calculated based on the inverse probability of treatment weighting (IPTW) from the following parameters: age on admission, sex, smoking status, type 2 diabetes, hypertension, family history of coronary artery disease, current co-treatments (ACEis/ARBs and/or beta-blockers), heart rate (HR), blood pressure (BP) and creatinine levels on admission, and pre-PCI TIMI flow in the culprit artery. Results were stratified according to a symptom-to-balloon time (S2Bt) ≤ or >3 hours. Results The study population's median age was 59 years (IQR 50–68), 16.3% were women; 18.9% were receiving treatment with statins prior to STEMI (table 1). Despite no effect on MVO occurrence (OR: 0.81 [0.60; 1.09], p=0.166), prior treatment with statins was associated with a reduction in IS (18.43% [16.67; 20.19] vs 21.50% [20.67; 22.34], p=0.002), particularly among subjects with ≤3 hours of S2Bt. Accordingly, prior treatment with statins conferred a benefit in mean baseline LVEF (50.23% [48.73; 51.73] vs 48.15% [47.43; 48.87], p=0.014). At 6 months, treatment with statins prior to STEMI blunted the changes in EDVi and ESVi, but only among patients with ≤3 hours of S2Bt (table 2). In addition, a reduction in the probability of adverse LV remodelling, defined as an increase in ESVi >10%, was observed in statin pre-treated patients (OR: 0.67 [0.45; 0.99], p=0.043). Conclusion Treatment with statins before STEMI is associated with improved indexes of cardioprotection as assessed by CMR, particularly among subjects with S2Bt ≤3 hours. Those effects seem to have an impact in limiting adverse LV remodelling as early as 6 months follow-up, and a greater than 10% change in ESVi. These findings warrant further and prospective evaluation of the potential cardioprotective effects of chronic oral statin treatment prior to STEMI. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): This study was partially funded by several grants from Fundaciό La Marato TV3 (2015 30 31 32), Instituto de Salud Carlos III (FIS15/00531) and La Caixa Banking Foundation (HR17-00527).

Angiographic predictors of outcome in myocardial infarction patients presenting with cardiogenic shock: a CULPRIT-SHOCK angiographic substudy.

The aim of this study was to determine the prognostic impact of pre- and post-PCI TIMI flow grade and TIMI myocardial perfusion grade (TMPG) in a well-defined group of patients with cardiogenic shock due to acute myocardial infarction. Patients with infarct-related cardiogenic shock randomised into the CULPRIT-SHOCK trial were included in the angiographic predictor analysis whenever their TIMI flow grade or TMPG was available in the core lab database (96.9% of cases). A multivariable logistic regression analysis, adjusted on non-angiographic covariates, was performed to investigate whether TIMI flow grade or TMPG was independently associated with all-cause mortality or renal replacement therapy up to one year. Pre-PCI TIMI flow grade and TMPG did not impact on mortality. When analysed in separate multivariable models, post-PCI TIMI 3 flow and TMPG grade 3 were both significantly associated with reduced risk of 30-day mortality: aOR 0.61 (95% CI: 0.38-0.97, p=0.037) and 0.46 (95% CI: 0.29-0.72, p<0.001), respectively. When considered in the same multivariable model, only TMPG was significantly associated with 30-day mortality (aOR 0.38 [0.20-0.71], p=0.002), the 30-day composite of all-cause mortality and renal replacement therapy (aOR 0.34 [0.18-0.66], p=0.001) and mortality at one-year follow-up (aOR 0.46 [0.24-0.88], p=0.02). Post-PCI TIMI flow grade and TMPG are associated with mortality after PCI. TMPG is a better discriminator, supporting microcirculation rather than epicardial reperfusion for prognosis estimation.

Association of lipoprotein (a) and in-hospital outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention

ABSTRACT Objective: The current study was to evaluate the association of Lipoprotein (a) [Lp(a)] and in-hospital outcomes in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). Methods: ACS patients undergoing PCI were retrospectively enrolled. Based on Lp(a) level, patients were divided into low (<30 mg/dL) and high (≥30 mg/dL) Lp(a) groups. Results: Compared to those with low Lp(a), patients with high Lp(a) had larger numbers of coronary arteries ≥70% stenosis and had longer coronary artery lesion (P < 0.05). After adjustment for covariates, high Lp(a) remained associated with higher odds of having coronary artery ≥70% stenosis, type C coronary lesion and pre-PCI TIMI flow grade 1/0. Patients with high Lp(a) had a higher unadjusted odds of acute stent thrombosis (odds ratio [OR] 1.10 and 95% confidence interval [CI] 1.01–2.27), congestive heart failure (OR 1.24 and 95% CI 1.15–2.38) and composite in-hospital outcomes (OR 1.28 and 95% CI 1.18–2.42). After adjustment for covariates, patients with high Lp(a) still had a higher odds of congestive heart failure (OR 1.08 and 95% CI 1.01–1.78) and composite in-hospital outcomes (OR 1.12 and 95% CI 1.04–1.81). Conclusion: In ACS patients undergoing PCI, compared to those with low Lp(a), patients with high Lp(a) had more severe coronary artery lesion, higher risk of congestive heart failure and composite in-hospital outcomes.

Abstract 17305: Frequency, Predictors and Outcomes of Unplanned Coronary Angiography Following Successful Primary Percutaneous Coronary Intervention in ST Elevation Myocardial Infarction Patients

Introduction: There is limited data regarding the frequency, predictors and impact of repeat, unplanned coronary angiography following successful reperfusion with primary PCI in STEMI pts. Methods: We used the prospective, multicenter Midwest STEMI Consortium database, which was created by unique consolidation of 4 large STEMI systems of care: Iowa Heart Center, Minneapolis Heart Institute Foundation, Prairie Cardiovascular, and The Christ Hospital. Each center has similar, well-established standardized STEMI protocols with collaboration over 100 non-PCI-capable hospitals in Midwest. We included all consecutive STEMI pts who underwent repeat, unplanned coronary angiography within 48-hour of successful primary PCI. We excluded pts who underwent a planned or staged coronary angiography. We compared pts with repeat, unplanned coronary angiography to a propensity-score matched (1:2) pts without repeat coronary angiography within 48-hour. Results: Among 6507 STEMI pts treated with primary PCI from 03/2003 to 01/2020, only 136 (2.1%) underwent repeat, unplanned coronary angiography. These pts had higher rates of LAD culprit, history of prior MI, poor pre-PCI TIMI flow (0 or 1) and lower EF. Nearly half of the repeat, unplanned coronary angiographies revealed patent stent (63/136). There were only 32 (24%) in-stent thrombosis and 30 (22%) new occlusions. Compare to the control group, pts with repeat, unplanned coronary angiography were more likely to have major bleeding and longer LOS (p=&lt;0.001) but similar MI, stroke, CV- or all-cause mortality up to 1-year follow-up. Of note, in-hospital MI, which was significantly higher reported in pts with repeat, unplanned coronary angiography, occurred basically prior to repeat coronary angiography (Table). Conclusions: Repeat, unplanned coronary angiography is relatively uncommon after contemporary primary PCI for STEMI pts and is more common with larger, anterior MIs.

The effect of aspirin, ticagrelor and heparin pre-transfer vs. similar precatherization treatment in STEMI on pre-PCI TIMI flow

Abstract Aims Whether early combined antithrombotic therapy with aspirin, ticagrelor and unfractionated heparin (UFH) in STEMI patients can improve clinical outcomes is unknown. Data regarding the efficacy of UFH in this clinical setting is lacking. The objective of this novel study was to evaluate the effects of early pretreatment with aspirin, ticagrelor and UFH on pre-PCI TIMI flow in the IRA in acute STEMI patients. Methods and results Between January 2015 and June 2018, we retrospectively compared 488 STEMI patients receiving aspirin, ticagrelor and UFH pretreatment in a spoke peripheral hospital before transfer (PHT) versus 233 prehospital triage setting (PTS) STEMI patients receiving in-ambulance aspirin, followed by ticagrelor and UFH pretreatment in the hub catheterization laboratory before PCI. The primary outcome was the presence of a pre-PCI TIMI flow 2–3 in the IRA. The median times from ticagrelor and UFH administration to angiography in the PHT group and in the PTS group were 80 minutes (95% CI: 68.5–93.9) and 10 minutes (95% CI: 5–15.5) respectively (p&amp;lt;0.0001). Inverse probability of treatment weighting was used to minimize differences between groups. Main results are shown in Table 1. Each 10-minute delay between ticagrelor and heparin administration and angiography was associated with a reduced pre-PCI TIMI flow (OR 0.89, 95% CI: 0.85–0.93). Conclusion STEMI patients receiving aspirin, ticagrelor and UFH before peripheral hospital transfer have a significantly greater pre-PCI TIMI flow 2–3 and a lower rate of definite in-hospital stent thrombosis compared to patients receiving in-ambulance aspirin in the prehospital setting followed by ticagrelor and heparin in the catheterization laboratory without greater bleeding risk. While prehospital triage with rapid primary PCI remains the preferred scenario for STEMI patients, a prompt UFH initiation may play a synergistic role with ticagrelor and aspirin in decreasing pre-PCI thrombus burden in the presence of organizational delays. Figure 1. Study Design and Main Results Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): Université de Sherbrooke's Department of Medicine, Division of Cardiology

Infarct characteristics and outcome of patients with transient ST-segment elevation myocardial infarction compared to ST-segment and non-ST-segment elevation myocardial infarction

Abstract Background Up to one out of four patients with signs of ST-segment elevation myocardial infarction (STEMI) express complete normalization of ST elevation before primary revascularization procedure. This condition is commonly referred to as “transient ST-segment elevation myocardial infarction” (TSTEMI) and recent data suggests that this group of patients may have favorable outcome compared to STEMI patients. However, it is currently unknown how these patients compare to both STEMI and non-ST-segment elevation myocardial infarction (NSTEMI) patients with respect to infarct size characteristics and outcome. Objective This study aims to explore cardiac magnetic resonance (CMR) derived scar tissue and 1-year outcome in patients with TSTEMI by comparison to STEMI and NSTEMI. Methods Patients with STEMI were enrolled from two prospective studies (n=170); the patients with TSTEMI were recruited from the TRANSIENT trial (n=141); the patients with NSTEMI were prospectively and consecutively collected from local registries of Amsterdam UMC (n=57) and Maastricht UMC (n=51). All patients underwent CMR examination 2–8 days after the index event. Cine imaging was done for volume and function assessment. Late gadolinium enhancement imaging was performed to identify infarct size (in grams) and the presence of microvascular obstruction (MVO). All CMR images were processed in a single core laboratory (Amsterdam UMC). Clinical outcome after 1 year was measured by the incidence of major adverse cardiac events (MACE), defined as recurrent myocardial infarction (MI), revascularization and all cause death. Results The TSTEMI group demonstrated the lowest end-systolic left ventricular volume and highest left ventricular ejection fraction across the groups (overall p&amp;lt;0.001). Although there was a remarkably lower infarct size in TSTEMI patients compared to STEMI (1.41g [0.00–3.91] vs 13.48g [5.31–26.81], p&amp;lt;0.001), there was only a trend towards lower infarct size compared to NSTEMI patients (1.41g [0.00–3.91] vs 2.13g [0.00–8.64], p=0.06). Whilst MVO was observed less frequently in TSTEMI compared to STEMI patients (5 (4%) vs 53 (31%), p&amp;lt;0.001), no significant difference was seen between TSTEMI and NSTEMI patients (5 (4%) vs 5 (5%), p=0.72). Multivariable linear regression analysis identified infarct type, smoking, peak troponin-T and pre-PCI TIMI flow as predictors for infarct size (p=0.03, p=0.03, p&amp;lt;0.001 and p&amp;lt;0.001, respectively). One-year mortality rate was low in all 3 MI types (TSTEMI 3 (2.2%), NSTEMI 3 (3.1%), 4 (2.4%), log-rank test p=0.91). However, there was a significant difference in MACE at 1 year across the 3 MI types (TSTEMI 18 (13.2%), NSTEMI 19 (19.4%), STEMI 11 (6.7%), overall p&amp;lt;0.01). Conclusion In comparison to NSTEMI and STEMI, TSTEMI yielded favorable cardiac left ventricular function and scar mass. However, this did not lead to benefit in short term (1-year) outcome; further studies are needed with longer follow-up. Funding Acknowledgement Type of funding source: Other. Main funding source(s): European Association of Cardiovascular Imaging (EACVI) Research Grant

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

BackgroundST 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.MethodPatients 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.ResultsThe 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.ConclusionsAssessment of STR could potentially be used to stratify risk in patients with STEMI before PCI.

Relationship between early administration of abciximab and TIMI flow in STEMI patients undergoing primary angioplasty: findings from a large regional STEMI network.

The aim of this study is to assess whether in S-T Elevation Myocardial Infarction (STEMI) a relationship between early administration of abciximab and Thrombolysis In Myocardial Infarction (TIMI) flow before and after primary percutaneous coronary intervention (PCI) in 960 consecutive patients exists. From 1 February 2001 onward, in the Province of Mantua it has been operating a 'Cardiology Network for the Acute Infarction Care' having its Hub in the Central Coronary ICU/Cath Lab of Mantua Hospital and being its Spokes centers represented by the emergency rooms and Central Coronary ICUs of the four territorial hospitals. T1 (time from symptoms onset to first medical contact) and T2 (time from first medical contact to angioplasty) are shorter for patients rescued by first aid units rather than for those presented in emergency rooms as well as Ta (time from symptoms onset to abciximab administration). Furthermore, the patients that received abciximab before hospital arrival had less frequently a coronary occlusion [odds ratio = 0.74, 95% confidence interval (0.57-0.96), P = 0.013]. The patients with T1 less than 4 h are 753/960 (78.4%). For this type of patients, there was a significant Ta difference between the pre-PCI TIMI-flow classes (F = 4.467, df = 3, P = 0.04). Planned contrasts revealed that mean time of TIMI flow 0 (M = 104.2) is statistically different from mean time of TIMI flow 3 (M = 85.7), P = 0.013. Our results suggest that the use of abciximab, free from pharmacokinetic limits of oral P2Y12 inhibitors, should be considered in STEMI patients with early presentation before primary PCI.

Pre-PCI angiographic TIMI flow in the culprit coronary artery influences infarct size and microvascular obstruction in STEMI patients

ObjectiveThe influence of initial-thrombolysis in myocardial infarction (i-TIMI) coronary flow in the culprit coronary artery on myocardial infarct and microvascular obstruction (MVO) size is unclear. We assessed the impact on infarct size of i-TIMI flow in the culprit coronary artery, as well as on MVO incidence and size, by contrast-enhanced cardiac magnetic resonance (ce-CMR). MethodsIn a prospective, multicenter study, pre-percutaneous coronary intervention (PCI) coronary occlusion was defined by an i-TIMI flow ≤1, and patency was defined by an i-TIMI flow ≥2. Infarct size, as well as MVO presence and size, were measured on ce-CMR 72h after admission. ResultsA total of 140 patients presenting with ST-elevated myocardial infarction referred for primary PCI were included. There was no significant difference in final post-PCI TIMI flow between the groups (2.95±0.02 vs. 2.97±0.02, respectively; p=0.44). In the i-TIMI flow ≤1 group, infarct size was significantly larger (32±17g vs. 21±17g, respectively; p=0.002), MVO was significantly more frequent (74% vs. 53%, respectively; p=0.012), and MVO size was significantly larger [1.3 IQR (0; 7.1) vs. 0 IQR (0; 1.6)], compared to in the i-TIMI ≥2 patient group. ConclusionInitial angiographic TIMI flow in the culprit coronary artery prior to any PCI predicted final infarct size and MVO size: the better was the i-TIMI flow, the smaller were the infarct and MVO size.

Intra-Coronary Administration of Tacrolimus Prior to First-Balloon Inflation Attenuates Infarct Size and Improves Left Ventricular Function in Patients with ST-segment Elevation Myocardial Infarction (COAT-STEMI) Undergoing Primary Coronary Intervention

Background: Slow-flow and no-reflow phenomenon which occurred frequently during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) caused unfavorable prognostic outcomes. Currently, no effectively therapeutic strategy to prevent this phenomenon. Objectives/Design: To evaluate the efficacy and safety of intra-Coronary Administration of Tacrolimus prior to firstballoon inflation, a pilot study was performed. Methods/Results of Pilot Study: Twenty-nine STEMI patients (group 1) were first prospectively administered tacrolimus (2.5 mg intra-coronary slow injection using thrombuster) prior to first-balloon inflation. A historical-control group (group 2) was chosen from fifty-two consecutive patients undergoing primary PCI just prior to the pilot study. Age, gender, CAD-risk factors, peak CK-BM, and baseline left-ventricular performance were not different between groups 1 and 2 (all p>0.1). Chest pain onset-to-door and door-to-balloon times, mean Killip score upon presentation, number of multi-vessel disease, pre-PCI TIMI flow, and 30-day death were similar between these two groups (all p>0.1). The incidences of advanced CHF (≥ NYHA 3) and pulmonary edema were higher in group 2 than in group 1, whereas the incidence of anterior-wall infarction, final TIMI-3 flow and 90 minute ST-segment-resolution rate showed an opposite pattern of advanced CHF between these two groups. The incidence of myocardial blushing grade was significantly higher in group 2 than in group 1 (p=0.034). Conclusion: Tacrolimus therapy shows promise as a safe and effective therapeutic agent for STEMI. The positive preliminary outcomes from this pilot study suggests randomized-controlled trials are now required to evaluate the effectiveness and safety of Tacrolimus for STEMI patients. (clinical trials no: ISRCTN38455499).

Does pre-PCI angiographic TIMI flow in the culprit coronary artery influence infarct size and microvascular obstruction in acute STEMI patients?

Does pre-PCI angiographic TIMI flow in the culprit coronary artery influence infarct size and microvascular obstruction in acute STEMI patients?

Clinical, angiographic, and intravascular ultrasound predictors of early stent thrombosis in patients with acute myocardial infarction

Risk factors reported for early stent thrombosis (EST) included acute coronary syndrome, suboptimal antiplatelet therapy, procedural factors such as residual dissection and underexpansion of stents, and smaller final lumen area and inflow/outflow disease (residual stenosis or dissection) by intravascular ultrasound (IVUS) [1–4]. However, the predictors of EST including all variables such as baseline characteristics, laboratory data, angiographic and IVUS findings in patients with acute myocardial infarction (AMI) are still not well known. From January 2007 to December 2009, we identified 418 consecutive patients with a first AMI who underwent pre-percutaneous coronary intervention (PCI) IVUS within 24 h from symptom onset, were stented successfully, and had post-PCI IVUS imaging. EST included acute (b24 h) and subacute ST (1 to 30 days) after stent implantation. Cardiac-specific troponin I (cTnI) levels were measured by a paramagnetic particle, chemiluminescent immunoenzymatic assay (Beckman, Coulter Inc., Fullerton, California). No-reflow was defined as postPCI TIMI grade 0, 1, or 2 flow. Tissue prolapse was defined as tissue extrusion through the stent strut at post-PCI. The baseline characteristics, angiographic and IVUS findings are summarized in Table 1. EST occurred in 16 patients (3.8%). Glycoprotein IIb/IIIa inhibitor was used more frequently in patients with EST compared with those without EST. Pre-PCI peak creatine kinase-MB and cTnI were significantly higher in patients with EST compared with those without EST. Pre-PCI TIMI flow grade was significantly lower in patients with EST compared with those without EST. More stents were deployed in patients with EST compared with those without EST. Noreflow during or after PCI was developed more frequently in EST group than in non-EST group (87.5% vs. 12.2%, p b 0.001). Plaque burden at the minimum lumen site was significantly greater in patients with EST compared with those without EST. Pre-PCI plaque rupture and IVUSdetected thrombuswere observedmore frequently in patients with EST compared with those without EST. Post-stenting tissue prolapse was observed more frequently in patients with EST compared with those without EST (68.8% vs. 32.6%, p= 0.003). Independent predictors of EST are summarized in Table 2. Multivariate analysis showed that noreflow, pre-PCI peak cTnI, and tissue prolapse were the independent predictors of EST. No-reflow can occur easily in lesions with various kinds of vulnerable plaque including plaque rupture and thrombus and this no-reflow is associated with microvascular damage which is likely to slow the epicardial coronary blood flow and to stagnate blood flow which may accelerate local thrombus formation [5]. The mechanism underlying the association between pre-PCI peak cTnI level and EST is not clear, although cTnI is associated with high thrombus grade with promoted thrombus formation in patients with AMI, who already have heightened systemic and intracoronary platelet reactivity, thrombin generation, and inflammation. Tissue prolapse may represent a source for thrombus accumulation in an environment that already has a high potential for thrombogenesis. Impaired arterial healing and ST have been associated with the prolapse of the necrotic core between stent struts. This is especially relevant in the setting of AMI, because such patients already have an increased risk for this devastating event [6]. In conclusion, the incidence of EST after stenting of infarct-related arteries was 3.8%. No-reflow, pre-PCI peak cTnI and tissue prolapse were associated with the development of EST after stent implantation in patients with AMI.

Abstract 8826: Association of TIMI-3 Epicardial Blood Flow Before and After Percutaneous Coronary Intervention with Microvascular Obstruction in Patients with ST-Segment Elevation Myocardial Infarction

Background: The beneficial effects of full restoration of the epicardial coronary flow (TIMI flow grade 3) and spontaneous reperfusion before percutaneous coronary intervention (PCI) are well known. However, previous studies evaluating the influence of pre-PCI and post-PCI TIMI flow grade on cardiac mortality reported conflicting results. The impact of epicardial flow before and after PCI on microvascular damage in patients with ST-segment elevation myocardial infarction (STEMI) has been insufficiently studied. The purpose of this study was to examine the interaction of TIMI-3 antegrade flow before and after PCI on degree of microvascular damage in patients with STEMI. Methods: Two hundred and eleven consecutive patients with first anterior STEMI who underwent successful PCI (post-TIMI 2,3 flow) were subjected to coronary flow measurement with a Doppler guidewire. The coronary flow velocity spectrum provided the following parameters: systolic peak velocity (SPV) and diastolic deceleration time (DDT). We defined the presence of microvascular obstruction as DDT of ≤ 600 ms and the presence of systolic flow reversal. We classified the patients into three categories according to the post-TIMI 2 flow (group 1), the pre-TIMI 0-2 and post-TIMI 3 flow (group 2), the pre- and post-TIMI 3 flow (group 3). Results: As for the relationship between the epicardial blood flow before and after PCI and the severity of microvascular damage, group 1 was at the highest risk of microvascular obstruction, while group 3 was at the lowest: 32/40 (80%) for group 1, 55/142 (39%) for group 2, and 0/29 (0%) for group 3 (p&lt;0.05). The DDT were shortest in group 1 and longest in group 3 (358±226 vs. 596±227 vs. 784±133 ms; p&lt;0.05) and the SPV were lowest in group 1 and highest in group 3 (-23±22 vs. -1±24 vs. 14±16 cm/s; p&lt;0.05). Conclusions: In patients with STEMI, epicardial blood flow both before and after PCI may have significant impacts on ischemic microvascular damage. In particular, all patients who achieved reperfusion with TIMI-3 epicardial blood flow before and after PCI were successfully salvaged from microvascular obstruction. Of critical importance, the effect of pre-procedural TIMI-3 flow on microvascular integrity persisted even when corrected for post-procedural TIMI-3 flow.

Abstract 32: Cardiac Arrest: Who Goes to the Catheterization Lab?

Introduction: Therapeutic hypothermia (TH) is neuroprotective and increases survival in resuscitated cardiac arrest patients. Approximately 70% of sudden cardiac deaths are caused by coronary heart disease. For patients requiring angiography/PCI, TH can occur simultaneously. Methods: “Cool It” is a comprehensive TH protocol integrated into a regional STEMI network. From Feb 2006 to July 2010, 192 consecutive cardiac arrest patients who remained unresponsive following return of spontaneous circulation were enrolled in the Cool It protocol. Those patients with suspicion for ischemic etiology or evidence of STEMI were transferred directly to the cath lab. Results: On the 192 patients, angiogram was performed in 144 (75.0%). Patients sent for angiography had higher prevalence of initial rhythm VF/VT 116 (80.6%) vs. 19 (39.6%), cardiogenic shock 66 (45.8%) vs. 11 (22.9%), and ST elevation 54 (37.5%) vs. 1 (2.1%) than the 48 patients not undergoing angiography. PCI was performed in 73 (50.7% of patients undergoing angiogram, 38.0% all patients). Of these 73 patients, 64 (87.7%) had initial rhythm VF/VT, 38 (52.1%) were in cardiogenic shock, and 39 (53.4%) had ST elevation. Identified culprit arteries were LAD n=30 (41.1%), RCA n=24 (32.9%), CMX n=12 (16.4%), left main n=4 (5.5%), and none n=3 (4.1%). Mean pre-PCI TIMI flow was 1.36, and post-PCI TIMI flow was 2.91. BMS was used in 31 (42.5%), DES in 40 (54.8%), and one had balloon angioplasty only. Three were referred for CABG. Survival to hospital discharge was 43/73 (58.9%), and survival with favorable neurologic outcome (cerebral performance category 1 or 2) was 39/73 (53.4%). Patients who underwent angiography but did not receive PCI had the similar outcomes: survival was 46/71 (64.8%) and favorable neurologic outcome was seen in 44/71 (62.0%). Patients who did not undergo angiography had the poorest outcome: survival was 11/48 (22.9%) and with favorable neurologic outcome was seen in 9/48 (18.8%). Conclusion: The majority of unresponsive cardiac arrest survivors underwent angiography. Patients who underwent angiography with PCI had the similar outcomes to those with angiography alone. Favorable baseline patient characteristics appear to account for the improved outcomes in the angiography group.

007 Predictors of Infarct Size and Microvascular Obstruction Assessed by Cardiac Magnetic Resonance Imaging in patients with Acute ST elevation MI

Background Time-to-reperfusion, electrocardiographic and angiographic parameters are of prognostic relevance in ST-elevation myocardial infarction (STEMI) patients. We sought to evaluate predictors of Infarct size (IS) and presence of microvascular obstruction (MO) using delayed hyper-enhancement magnetic resonance imaging (CMR). Methods and results We analyzed 128 consecutive STEMI patients reperfused by primary PCI within 12 hours after symptom onset. IS and MO were assessed by delayed hyper-enhancement MRI as percentage of LV mass, 4±2 days after acute MI. Reperfusion times, TIMI-flow grades pre and post PCI, 90 min ST-segment resolution, cardiovascular risk factors, Killip-class, and infarct location were assessed. In patients with TIMI flow 0-1 before PCI, IS was significantly higher compared to patients with TIMI-flow 2-3 (22±12% versus 16±15%; p Conclusions The pre-PCI TIMI flow, infarct location, Killip class and ST-segment resolution are the strongest predictors of IS and extent of MO as assed by delayed Hyper-enhancement MRI. CMR allow for strong evaluation in STEMI patients, giving important information regarding prognostic.

Clinical impact of thrombectomy in acute ST-elevation myocardial infarction: an individual patient-data pooled analysis of 11 trials

Thrombectomy in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) is associated to better myocardial reperfusion. However, no single trial was adequately powered to asses the impact of thrombectomy on long-term clinical outcome and to identify patients at higher benefit. Thus, we sought to assess these issues in a collaborative individual patient-data pooled analysis of randomized studies (study acronym: ATTEMPT, number of registration: NCT00766740). Individual data of 2686 patients enrolled in 11 trials entered the pooled analysis. Primary endpoint of the study was all-cause mortality. Major adverse cardiac events (MACE) were considered as the occurrence of all-cause death and/or target lesion/vessel revascularization and/or myocardial infarction (MI). Subgroups analysis was planned according to type of thrombectomy device (manual or non-manual), diabetic status, IIb/IIIa-inhibitor therapy, ischaemic time, infarct-related artery, pre-PCI TIMI flow. Clinical follow-up was available in 2674 (99.6%) patients at a median of 365 days. Kaplan-Meier analysis showed that allocation to thrombectomy was associated with significantly lower all-cause mortality (P = 0.049). Thrombectomy was also associated with significantly reduced MACE (P = 0.011) and death + MI rate during the follow-up (P = 0.015). Subgroups analysis showed that thrombectomy is associated to improved survival in patients treated with IIb/IIIa-inhibitors (P = 0.045) and that the survival benefit is confined to patients treated in manual thrombectomy trials (P = 0.011). The present large pooled analysis of randomized trials suggests that thrombectomy (in particular manual thrombectomy) significantly improves the clinical outcome in patients with STEMI undergoing mechanical reperfusion and that its effect may be additional to that of IIb/IIIa-inhibitors.

Impact of prehospital diagnosis in the management of ST elevation myocardial infarction in the era of primary percutaneous coronary intervention: reduction of treatment delay and mortality

The aim of the study is to assess, as primary endpoints, in-hospital mortality and percutaneous coronary intervention (PCI) mortality and to compare the outcome in ST elevation myocardial infarction (STEMI) patients with different pathways to a catheterization laboratory in the context of an area with 24 h availability of catheter facilities. Three hundred and ninety-nine STEMI patients, referred to an interventional centre for primary PCI, were divided into two groups according to the different pathways to the catheterization laboratory. Group A had 263 patients diagnosed following admission to First Aid. Group B had 136 patients diagnosed in a prehospital setting with telemedicine equipment and transferred directly to the interventional centre by advanced life support (ALS) ambulance. Significantly shorter treatment delay was observed in group B patients than in group A (262 +/- 112 vs. 148 +/- 81 min in group A vs. B, P < 0.001). A significant reduction in total mortality was observed in group B compared with group A (8.7 vs. 3% in group A vs. B, P < 0.05). After multivariate analysis, predictors of in-hospital mortality are age and Killip class (P < 0.01), different pathways to catheterization laboratory, pre-PCI TIMI flow and onset-to-balloon time (P < 0.05). The present study shows a reduction in treatment delay and in-hospital mortality by prehospital ECG and direct referral to catheterization laboratory.

Relationship between blood viscosity and infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background Previous studies explored the association between hemorheological alterations and acute myocardial infarction, pointing out the role of hematological components on microvascular flow. The aim of this study was to evaluate the association between blood viscosity and infarct size, estimated by creatine kinase (CK) peak activity and cardiac Troponin I (cTnI) peak concentration in ST-segment elevation myocardial infarction (STEMI) patients after primary percutaneous coronary intervention (PCI). Methods The study population included 197 patients with diagnosis of STEMI undergoing PCI. Hemorheological studies were performed by assessing whole blood viscosity (measured at shear rates of 0.512 s − 1 and 94.5 s − 1 ) and plasma viscosity using the Rotational Viscosimeter LS 30 and erythrocyte deformability index by Myrenne filtrometer. Results Significant correlations between CK peak activity, cTnI peak concentration, left ventricular ejection fraction and hemorheological variables were observed. At linear regression analysis (adjusted for age, gender, traditional cardiovascular risk factors, renal dysfunction, timeliness of reperfusion, pre-PCI TIMI flow, infarct location, multivessel disease and previous coronary artery disease) leukocytes and whole blood viscosity at 0.512 s − 1 and 94.5 s − 1 were independently and positively associated with infarct size. Conclusions These results demonstrate a significant and independent association between hemorheology and infarct size in STEMI patients after PCI suggesting that blood viscosity, in a condition of low flow, might worsen myocardial perfusion leading to an increased infarct size. The measurement of whole blood viscosity in STEMI patients could help to identify those who may benefit from new therapeutic strategies.

Abstract 3163: Association of Pre-PCI TIMI flow grade (TFG) with Subsequent Mortality in Patients Presenting with ST-Elevation Myocardial Infarction (STEMI)

Background: Pre-procedural TIMI flow grade has been associated with mortality (both in-hospital and long-term) in patients (pts) undergoing percutaneous coronary intervention (PCI) following STEMI in randomized trials. This relationship has not been well characterized in a large heterogeneous real world population. Methods: A cohort of 8,133 patients presenting with STEMI in the National Registry of Myocardial Infarction (NRMI) was studied. Analysis of the relationship between pre-PCI TFG and in-hospital mortality was performed. Results: Of the 8133 patients, 6307 (77.5%) had TFG 0/1, 1178 (14.5%) had TFG 2, and 648 (8.0%) had TFG 3. Patients with TFG 0/1 before PCI (primary, rescue or facilitated) had an in-hospital mortality rate of 3.3% compared with TFG 2 of 1.6% and TFG 3 of 1.2% ( P &lt; 0.001). Pre-PCI TFG was associated with significant differences in mortality in all subgroups including age, gender, and location of infarct (see table ). Among pts with TFG 3 post PCI, mortality was still associated with pre-PCI TFG (pre-TFG 0/1 = 2.7%, pre-TFG 2 = 1.5%, TFG 3 = 1.2%, P = 0.002). Conclusion: Pre-PCI TFG is associated with in-hospital mortality in a heterogeneous group of real world patients presenting with STEMI treated with PCI, including those with TFG 3 following PCI.