Impaired Myocardial Reperfusion Research Articles

Cangrelor use in ticagrelor-loaded ST-elevation myocardial infarction patients with high residual platelet reactivity: a randomized controlled trial

Abstract Background Despite the use of potent P2Y12 inhibitor, many patients still present with high platelet reactivity (HPR) at the time of primary percutaneous coronary intervention (PCI). HPR is associated with impaired myocardial reperfusion and the subsequent poor outcome. Purpose We sought to determine the impact of Cangrelor -a rapid and potent intravenous P2Y12 inhibitor- on myocardial reperfusion in patients with HPR admitted for primary PCI in a randomized trial. Methods Patients pre-treated with ticagrelor and aspirin with residual HPR (baseline platelet reactivity unit (PRU) > 208) were randomly assigned in a 1:1 ratio to receive cangrelor (experimental group) or not (control group) just before PCI. The primary endpoint was optimal myocardial reperfusion defined as a final myocardial blush grade (MBG) 3 assessed by an independent core laboratory. Results After screening of 128 patients, a total of 60 patients were with HPR were enrolled and randomized. The ticagrelor loading dose to PRU measurement times were 83 ± 32 and 90 ± 47 minutes in the experimental and control groups, respectively. Baseline PRU were 245 ± 30 and 252 ± 35 in the experimental and standard group, respectively. A final MBG 3 was observed in 21/30 (55%) and 17/30 (45%) the experimental and standard groups (p=0.29). A final TIMI flow grade 3 was observed in 30/30 (100%) and 27/30 (90%) the experimental and standard groups (p=0.24). Peak troponin levels after PCI were 51381 ± 50047 and 51078 ± 63960 ng/L (p=0.98) in the experimental and standard group, respectively. At the end of the PCI, control PRU were 36 ± 57 and 198 ± 107 (p<0.0001) in the experimental and standard group, respectively. One patient of the experimental group presented an in-hospital major bleeding (BARC 3). Conclusion In ticagrelor-loaded STEMI patients with residual HPR at the time of PCI, cangrelor use was associated with a more effective platelet inhibition but failed to significantly improve the rates of optimal final myocardial blush grades.

Latent cytomegalovirus infection associates with impairments in myocardial reperfusion, left-ventricular function, and quality of life after ST-elevation myocardial infarction

Abstract Introduction Cytomegalovirus (CMV) is a ubiquitous herpesvirus affecting the majority of adults in European countries. CMV influences T-lymphocyte biology throughout life. We have previously associated CMV status with adverse left ventricular (LV) remodeling after ST-elevation myocardial infarction (STEMI) in a single-centre study. In this study, we aimed to assess the external validity of these findings. Methods This study is a retrospective analysis of 354 patients presenting with STEMI, who were recruited to A Trial of Low-Dose Adjunctive Alteplase During Primary PCI (T-TIME) and had blood samples archived. The participants underwent immediate coronary angiography and percutaneous coronary intervention (PCI), serial cardiovascular magnetic resonance (CMR) imaging at 2-7 days and 3 months post-STEMI, and serial assessment of health-related quality of life with the standardised EQ-5D visual analogue scale (VAS). CMV IgG titre was measured in cryopreserved samples from each patient, and patients were categorised as CMV negative, low-positive or high-positive. All analyses were adjusted for infarct location. Results Of 354 patients, 175 (49.4%) were CMV IgG titre negative, 89 (25.1%) were low-positive and 90 (25.4%) were high-positive. CMV+ patients were older (62.5 vs 58.7 years) and more likely to be non-White (6.7% vs 2.3%). CMV+ patients displayed several adverse outcomes. First, myocardial reperfusion was impaired. Thrombolysis in myocardial infarction (TIMI) flow grade 3 after PCI, indicating complete reperfusion, was less common in CMV+ patients (76.0% vs 84.6%; p=0.042). CMV+ patients also had a higher TIMI frame count after PCI (p=0.021), and non-significantly less ST-segment resolution at 60 minutes (38.8% vs 48.4%; p=0.066). Impaired myocardial reperfusion appeared to lead to impaired LV function, with LV ejection fraction (LVEF) measured on early CMR lower in CMV+ patients (42.6% vs 45.3%, p=0.004). At 3 months, LV function remained impaired in CMV+ patients (LVEF: 47.8% vs 49.7%; p=0.035). This was mirrored by CMV+ patients displaying higher NT-pro BNP levels at 2-7 days (1381 vs 1172pg/mL, p=0.097) and 3 months (575 vs 338pg/mL, p=0.021). Finally, impaired LV function appeared to affect quality of life. Over 3 months, in contrast to CMV-negative patients, those with the highest CMV IgG experienced almost no improvement in quality of life, measured by change in the EQ-5D VAS (negative: +9.93; high-positive: +0.70; p=0.0002). Conclusion CMV+ patients with STEMI experience worse outcomes, with impaired reperfusion, persistently reduced LV function and less improvement in health-related quality of life over 3 months. We hypothesise that the effect of CMV is mediated through immune activation. Future research should explore the mechanisms by which CMV-specific lymphocytes interact with myocardial reperfusion and repair post-STEMI.

Clinical significance of 12-lead electrocardiogram QRS scores on admission in ST-segment elevation myocardial infarction

Abstract Background A QRS scoring system by 12-lead electrocardiography (ECG) is a quick and simple method to evaluate degree and extension of myocardial infarction. Previous studies have shown that high QRS scores (≥5) at hospitalization (before reperfusion) related to impaired myocardial reperfusion during percutaneous coronary intervention (PCI) and subsequent poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI) (Figure 1). However, the pathogenesis and associated factors with high QRS scores remain poorly defined. Therefore, this study aimed to explore clinical and lesion characteristics associated with QRS scores at hospitalization in patients with STEMI. Methods This retrospective observational study enrolled 138 broad anterior-wall STEMI patients who underwent PCI in the proximal left anterior descending artery and achieved reperfusion within 3 hours of onset. Patients were divided by QRS scores at hospitalization into low (<5: n=97) and high (≥5: n=41) QRS-scores, and clinical and lesion characteristics were compared between the 2 groups. Lesion characteristics were evaluated by intravascular ultrasound (IVUS). Results Despite early phase of STEMI, QRS scores at hospitalization varied (3 [2-5] points). Clinical characteristics, including onset-to-door time (66 [41-101] min vs. 55 [42-76] min) and onset-to-reperfusion time (112 [88-145] min vs. 106 [81-120] min), were comparable between patients with low and high QRS-scores. In contrast, significantly higher percentages of lipid plaques, plaque rupture and large thrombus were seen at the culprit lesion sites in patients with high versus low QRS scores (Figure 2). As a result, patients with high QRS scores had higher incidence of no-reflow phenomenon during PCI (36.6% vs. 12.6%, p<0.05) and larger infarct size assessed by peak CK values (5333 [3307-7443] IU/l vs. 1941 [759-3559], p<0.05) compared with those with low QRS-scores. Conclusions High QRS scores at hospitalization were associated with vulnerable lesion characteristics, as well as impaired coronary reperfusion and large infarct size. Although the exact mechanisms of the associations require future studies, QRS scores may help risk stratification before reperfusion and prognostic prediction after reperfusion.Figure 1.Figure 2.

Effects of intracoronary supersaturated oxygen infusion on the time course of myocardial blood flow and extent of microvascular obstruction in an ischemia/reperfusion preclinical swine model

Abstract Introduction Despite successful epicardial reperfusion with primary PCI, reactive changes in microvascular function lead to impaired myocardial reperfusion. Intracoronary SuperSaturated Oxygen Therapy (SSO2) is the only approved therapy that improves myocardial salvage in STEMI pts through the delivery of hyperbaric levels of oxygen to viable ischemic vascular and myocardial cells. Several important questions remain unanswered regarding the potential mechanisms of this benefit. Therefore, the purpose of this study is to determine the effects of SSO2 on the time course of myocardial blood flow (MBF) and the extent of microvascular obstruction (MVO) in an ischemia/reperfusion model. Methods 10 swine (32-40 kg) surviving 90-minute balloon-induced anterior STEMI, and 15-min auto reperfusion, were assigned to 120-min of SSO2 (n=5) or control (n=5) with 120-min auto reperfusion. MBF was evaluated at various time points during the experiment by injection of 15–µm microspheres (BioPal, USA) through a catheter placed in the left ventricle. Before euthanasia, 4% thioflavin-S (TS) was injected into the left anterior descending artery. The left ventricle was sectioned into 10-mm thick slices, and the myocardial rings were photographed under UV light to determine areas at risk (TS positive), MVO (lack of TS staining within TS positive area), and remote zones (contiguous areas unstained by TS). MBF was calculated as the total blood flow within the areas at risk normalized to the total flow within the remote zones. Results All animals experienced significant reduction (p = 0.02) in MBF due to balloon occlusion at the 85-minute MI timepoint compared to baseline (Fig). Following the removal of occlusion, reactive hyperemic flows were observed for both groups at the 15-minute auto reperfusion time point (Fig). Starting at the 30-min time point of autoperfusion to 120-min, the MBF significantly decreased (p=0.02) in the controls (Fig). In contrast during these time points, for the SSO2 group the MBF values were numerically higher than the controls, with average MBF for the SSO2 group being significantly higher (p = 0.03) than the controls (1.1 ± 0.18 vs 0.6 ± 0.13, respectively) at the 120-min timepoint (Fig). MVO was found within the areas at risk in all animals, but the extent of MVO in relation to the area at risk was significantly reduced (p < 0.001) in the SSO2 group versus controls (15.2 ± 7.3% vs 41.8% ± 6.2%, respectively). Conclusions Results from this study showed that in a STEMI swine model, SSO2 prevented reduction in MBF during the 120-min reperfusion period, with significantly increased MBF at the end of the experiment compared to controls. This flow improvement translated to a 64% relative reduction in the extent of MVO compared to controls. These results suggest that one of the mechanisms by which SSO2 improves myocardial salvage may be by limiting early microcirculatory alterations set in motion by a cascade of reduced myocardial flow and MVO.Myocardial Blood Flow vs Time

Morphine Use in ST-Elevation Myocardial Infarction With Downstream P2Y12 Receptor Blockers-Insight From Observational Study.

Morphine use for patients presenting with NSTE-ACS is associated with excess mortality. However, the role of morphine in STE-ACS is ill characterized. We have recently confirmed direct prothrombotic effect of morphine using murine models. We sought to explore whether morphine use in STE-ACS patients, used to be scheduled for downstream P2Y12 blockers, is negatively associated with procedural and clinical outcomes. A single-center, observational retrospective analysis enrolling 130 non-randomized stable patients sustaining STE-ACS as their first manifestation of coronary disease, who presented between December 2010 and June 2013. All were managed by early invasive approach. Of study patients, 55 were treated by morphine, and 75 were not. All were administered downstream P2Y12 blockers according to an already abandoned local policy. Outcomes evaluated included TIMI grade flow, thrombus burden, ST-segment resolution, myocardial function by echocardiography, and cardiovascular death. Morphine administration was associated with a significantly higher incidence of impaired final TIMI grade flow (TIMI < 3, 40% vs 4%, P < .05), lower incidence of ST-segment resolution >70% (40.7% vs 76.5%, P < .05), and a higher incidence of moderate or severe systolic dysfunction (48.1% vs 29.1%, P < .05) compared with morphine naive patients. Interestingly, the overall mortality rate was higher in the morphine-treated group (18% vs 5.3%, P < .05). Morphine administration combined with the downstream P2Y12 blockers practice signify a group with a higher occurrence of impaired myocardial reperfusion and cardiovascular death despite established on-time primary angioplasty.

Comparison of myocardial tissue reperfusion of inferior wall and a right ventricle among patients after primary angioplasty for an inferior myocardial infarction with right ventricular infarction.

Impaired myocardial tissue reperfusion affects prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) and can be identified by ST-segment analysis. To date, evaluation of the myocardial tissue reperfusion of the right ventricle (RV) among the patients treated with PCI for inferior STEMI with right ventricular infarction (RVI) has not been made yet. Patients with inferior STEMI were screened for RVI. Tissue reperfusion was evaluated by maximal residual ST-segment deviation post PCI, independently for the RV and for inferior wall. Myocardial injury was assessed by the peak creatine kinase-mb (CK-MB) value. Among 456 patients with inferior STEMI, concomitant RVI occurred in 153 (33.5%) subjects (59.86±10.35 years old, 71.9% females). Tissue reperfusion of LV was present in 75 (49%), whereas 55 (35.9%) had both successful LV and RV reperfusion. Among 97 (63.4%) with successful tissue reperfusion of RV, 55 (56.7%) had associated successful tissue reperfusion of inferior wall. Adequate LV reperfusion was accompanied by RV in over 73.3% of patients (P=0.006). Mean peak CK-MB was lower in the group with adequate versus impaired RV tissue-perfusion (197±143 vs. 305±199 U/L, P=0.021 respectively). Impaired reperfusion of RV is observed in more than one third of inferior STEMIs with RVI and is not strictly associated with impaired reperfusion of inferior wall and clinical or angiographic variables, therefore ST-segment analysis for RV is mandatory.

Predictive value of soluble suppression of tumourigenicity 2 on myocardial reperfusion

High baseline level of soluble suppression of tumourigenicity 2 (sST2) was an independent predictor of cardiovascular death and heart failure in ST-segment elevation myocardial infarction (STEMI). To investigate the value of serum sST2 baseline levels in predicting myocardial reperfusion in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI). Consecutive STEMI patients who underwent PPCI within 12 h after the onset of chest pain were enrolled, and were divided into Thrombolysis In Myocardial Infarction (TIMI) myocardial perfusion grading (TMPG) 0/1/2 group and TMPG 3 group based on post-procedural TMPG. Baseline clinical characteristics, lesions and procedural characteristics were compared. Univariate logistic regression and multivariate linear logistic analysis were performed to identify independent predictors of impaired myocardial reperfusion (TMPG 0/1/2). Receiver-operating characteristics curve (ROC) analysis of sST2 was performed to identify the optimum cut-off value for predicting the myocardial reperfusion. A total of 121 patients was enrolled in this study. Univariate logistic regression analysis showed that Killip II-III, high levels of sST2 and brain natriuretic peptide were risk factors of TMPG 0/1/2. Multivariable logistic regression analysis revealed that sST2 was an independent predictor of impaired myocardial reperfusion (odds ratio 12.318, 95% confidence interval 4.567-33.220, P < 0.001). ROC curve analysis showed that the area under curve of sST2 was 0.849, and the best cut-off value was 2.003 ng/mL, with a sensitivity of 89.2% and a specificity of 67.9%. The elevated levels of sST2 on admission were associated with impaired myocardial reperfusion in STEMI patients undergoing PPCI.

Comparison of myocardial tissue-reperfusion of inferior wall and a right ventricle among patients after primary angioplasty for an inferior myocardial infarction with right ventricular infarction

Impaired myocardial tissue reperfusion affects prognosis of patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) and can be identified by ST-segment analysis. To date, evaluation of the myocardial tissue reperfusion of the right ventricle (RV) among the patients treated with PCI for inferior STEMI with right ventricular infarction (RVI) has not been made yet. Patients with inferior STEMI were screened for RVI. Tissue reperfusion was evaluated by maximal residual ST-segment deviation post PCI, independently for the RV and for inferior wall. Myocardial injury was assessed by the peak creatine kinase-mb (CK-MB) value. Among 456 patients with inferior STEMI, concomitant RVI occurred in 153 (33.5%) subjects (59.86±10.35 years old, 71.9% females). Tissue reperfusion of LV was present in 75 (49%), whereas 55 (35.9%) had both successful LV and RV reperfusion. Among 97 (63.4%) with successful tissue reperfusion of RV, 55 (56.7%) had associated successful tissue reperfusion of inferior wall. Adequate LV reperfusion was accompanied by RV in over 73.3% of patients (P=0.006). Mean peak CK-MB was lower in the group with adequate versus impaired RV tissue-perfusion (197±143 vs. 305±199 U/L, P=0.021 respectively). Impaired reperfusion of RV is observed in more than one third of inferior STEMIs with RVI and is not strictly associated with impaired reperfusion of inferior wall and clinical or angiographic variables, therefore ST-segment analysis for RV is mandatory.

Prognostic significance of fragmented QRS in patients with ST-elevation myocardial infarction undergoing revascularization

Background & ObjectivesThis longitudinal study was carried out to evaluate the prognostic significance of fragmented QRS (fQRS) in patients with acute ST elevation myocardial infarction (STEMI) undergoing revascularization. MethodsThis study included 103 STEMI patients belonging to Killip class I and II who underwent primary revascularization. All patients underwent twelve lead ECG at admission before PCI. Serial ECG were done after PCI at 3 hours, 6 hours, 24 hours, 48 hours and at discharge for detection of fQRS and echocardiography on day 3 post revascularization. Patients developing fQRS within 48 hours and with persistence of fQRS till discharge were included in “persistent fQRS” group. They were followed up after 30 days for major adverse cardiac events (MACE) and assessment of LV function by echocardiography. ResultsfQRS was present in 64 patients (61.5%) of study population with 37 patients (57.8%) having persistent fQRS. MACE rates were low (4.8%) and did not differ with respect to fQRS. fQRS significantly correlated with LV dysfunction at 30 days on univariate analysis (p-0.003) but not on multivariate analysis (p -0.10). fQRS was significantly related to impaired myocardial reperfusion as assessed by ΣSTR (percent of total ST segment resolution) (adjusted odds ratio, 95% CI [4.265 (1.034 – 17.58)], p = 0.04). ConclusionIn our study, fQRS did not predict MACE and LV dysfunction in acute STEMI patients belonging to Killip class I and II on short term follow-up of 30 days. But, fQRS independently predicted impaired microvascular myocardial reperfusion as assessed by ΣSTR.

Relationship between thrombus age in aspirated coronary material and mid-term major adverse cardiac and cerebrovascular events in patients with acute myocardial infarction

Background and aimsRecent studies have shown that coronary thrombus histopathology is associated with impaired myocardial reperfusion and poor clinical outcome in patients with acute myocardial infarction (AMI). We sought to investigate the age of thrombi aspirated during percutaneous coronary intervention (PCI) in patients with AMI and evaluate the relationship between histopathologic findings and major adverse cardiac and cerebrovascular events (MACCEs) defined as all-cause death, stroke, or myocardial infarction within 6 months of PCI. MethodsIn this prospective 2-center observational study, coronary material was obtained during PCI from 305 patients with AMI within 24 h of symptom onset. Thrombi were morphologically classified as either only fresh or older (lytic changes or organization). ResultsMACCE occurred in 38 (12.5%) patients. Only fresh thrombi were observed in 114 (37%) of 305 patients; older thrombi were identified in 191 (63%). The rate of MACCE was significantly higher among patients with older thrombus (p = 0.011). Multivariate analysis also showed the presence of older thrombus [odds ratio (OR) 3.03, 95% confidence interval (CI) 1.122–9.522] is an independent predictor of MACCE within 6 months of PCI, as well as age (OR 1.051, 95% CI 1.013–1.094) and creatine kinase concentration (OR 1.025, 95% CI 1.013–1.037). The prevalence of slow flow or distal embolization during PCI and peak creatine kinase concentration were significantly higher in the older thrombus group (p < 0.05, respectively). ConclusionsOlder thrombus found in aspirated coronary material is associated with impaired myocardial reperfusion and is an independent predictor of mid-term MACCE in patients with AMI.

Quantified coronary frequency domain optical coherence tomography signal analysis for the evaluation of erythrocyte-rich thrombus: ex-vivo validation study.

Previous study has demonstrated that erythrocyte-rich thrombi contain more inflammatory cells and reflect high thrombus burden, leading to impaired myocardial reperfusion in myocardial infarction. The aim of this study is to investigate the utility of quantified frequency domain optical coherence tomography (FD-OCT) signal analysis in evaluating the erythrocyte-rich thrombus with ex-vivo materials. We evaluated 54 specimens of coronary artery thrombus obtained by thrombectomy catheter from 8 patients who underwent primary percutaneous coronary intervention. The thrombi were immersed in saline immediately after thrombectomy and FD-OCT image acquisition was performed ex-vivo. Quantitative analysis for all contiguous frames was performed by the dedicated automated software (OCT system software, Light Lab Inc.). For the maximum thrombus area, mean signal intensity (MSI) and normalized standard deviation of signal (NSD) was evaluated. All thrombi were stained using double staining of phosphotungstic acid-hematoxylin and eosin to enable automatic extraction of erythrocyte from fibrin. Computer-assisted analysis was performed using dedicated image processing software (WinROOF, Mitani Corp., Tokyo, Japan) for color identification of the erythrocyte area. Erythrocyte-rich thrombus, defined as % erythrocyte [(erythrocyte area/total thrombus area) × 100] ≥ 10%, showed significantly lower MSI [4.39 ± 0.24 vs. 4.74 ± 0.35, p = 0.002] than that of <10%. The cut-off point for prediction of erythrocyte-rich thrombus was defined as MSI ≤ 4.56, sensitivity: 87.5%, specificity: 82.9%, area under the curve: 0.836, respectively). The present ex-vivo study suggested the utility of quantified FD-OCT signal analysis on the detection of erythrocyte-rich thrombus.

Morphine use and myocardial reperfusion in patients with acute myocardial infarction treated with primary PCI

BackgroundMorphine is frequently used in ST-segment elevation myocardial infarction (STEMI) patients, even if recently it has been associated with a delayed onset of action of the oral antiplatelet agents. There are no data regarding the impact of morphine on myocardial reperfusion after primary percutaneous coronary intervention (PPCI). ObjectiveThis study sought to assess myocardial reperfusion by early ST-segment resolution (≥50% at 30minutes) according to morphine use in STEMI patients undergoing PPCI. Methods182 STEMI patients undergoing PPCI and receiving either prasugrel (n=51) or ticagrelor (n=131), who were antiplatelet and anticoagulant therapies naïve, were included in the study. All patients had serial ST-segment elevation evaluations by ECG and residual platelet reactivity assessments by VerifyNow P2Y12 Reactivity Units (PRU). ResultsOverall, 74 (41%) patients received morphine according to the attending physician's preference and showed lower ST-segment resolution rate as compared with patients without morphine (76% vs 87%, p=0.047). Higher baseline TIMI flow<2 rate (79% vs 64%, p=0.036) and peak CPK values (1821 [924–3283] U/L vs 1483 [718–2327] U/L, p=0.034) were observed in morphine patients. Moreover, a delayed response to oral antiplatelet (PRU area under the curve [AOU0–8]: 1448±448 vs 686±292, p=0.001) was documented in patients with morphine as compared with those without. The independent predictors of early ST-segment elevation resolution failure were PRU≥208 after antiplatelet loading (OR 2.78, 95% CI 1.08–7.14; p=0.034) and TIMI flow grade<3 after PPCI (OR 5.89, 95% CI 1.64–21.12; p=0.009), but not morphine use. ConclusionsIn STEMI patients undergoing PPCI, morphine use is associated with a higher residual platelet reactivity and a poorer myocardial reperfusion. Independent predictors of impaired myocardial reperfusion were high residual platelet reactivity and TIMI flow grade after PPCI but not morphine use, questioning the direct relationship between morphine and worse myocardial reperfusion.

Association of mean platelet volume with impaired myocardial reperfusion and short-term mortality in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Impaired myocardial reperfusion, defined angiographically by myocardial blush grade (MBG) 0 or 1, is associated with adverse clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to investigate the impact of admission mean platelet volume (MPV) on the myocardial reperfusion and 30-day all-cause mortality in patients with STEMI with successful epicardial reperfusion after primary percutaneous coronary intervention (PCI). A total of 453 patients with STEMI who underwent primary PCI within 12 h of symptoms onset and achieved thrombolysis in myocardial infarction (TIMI) 3 flow at infarct-related artery after PCI were enrolled and divided into two groups based on postinterventional MBG: those with MBG 2/3 and those with MBG 0/1. Admission MPV was measured before coronary angiography. The primary endpoint was all-cause mortality at 30 days. MPV was significantly higher in patients with MBG 0/1 than in patients with MBG 2/3 (10.38 ± 0.98 vs. 9.59 ± 0.73, P < 0.001). The cumulative 30-day all-cause mortality rate was significantly higher in the groups with high MPV and MBG 0/1 (6.8 vs. 1.5%, P = 0.005, 7.6 vs. 1.9%, P = 0.006, respectively). Multivariate logistic regression analysis demonstrated MPV was independently associated with postinterventional impaired myocardial reperfusion (odds ratio 2.684, 95% confidence interval 2.010-3.585, P < 0.001) and 30-day all-cause mortality (hazard ratio 1.763, 95% confidence interval 1.009-3.079, P = 0.046). Increased MPV on admission is an independent predictor of impaired myocardial reperfusion and short-term mortality in patients with STEMI with successful epicardial reperfusion after primary PCI. Admission MPV may be additive to conventional risk factors in patients with STEMI undergoing PCI.

GW26-e2173 Association of Mean Platelet Volume with Impaired Myocardial Reperfusion and Short-term Mortality in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Impaired myocardial reperfusion is associated with adverse clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to investigate the impact of admission mean platelet volume (MPV) on the myocardial reperfusion and 30-day all-cause mortality

The MGuard coronary stent: safety, efficacy, and clinical utility.

Atheromatous and thrombotic embolization during percutaneous coronary revascularization is a feared complication that may cause impaired myocardial reperfusion even with a patent epicardial vessel. The MGuard stent is a cobalt chromium bare metal stent with a porous net attached to its outer surface that has been designed to prevent thrombus fragmentation and distal embolization during stent implantation. This review summarizes the available evidence supporting the use of the MGuard stent in different scenarios such as lesions with high thrombus burden, saphenous vein graft interventions, coronary perforations, or carotid lesions.

An inspection of therapeutic hypothermia preceding coronary reperfusion in patients with a cardiogenic shock complicating anterior ST-segment elevation myocardial infarction

BackgroundWe retrospectively investigated our hypothesis that pre-percutaneous coronary intervention (PCI) procedural therapeutic hypothermia may have clinical advantages in patients with a profound cardiogenic shock complicating anterior ST-segment elevation myocardial infarction (STEMI). MethodsOf 483 consecutive patients treated with PCI for a first anterior STEMI including 31 patients with aborted sudden cardiac arrest between 2009 and 2013, a total of 37 consecutive patients with an anterior STEMI complicated with profound cardiogenic shock defined as the presence of hyperlactic acidemia (serum levels of lactate >4mmol/L) with mechanical circulatory support were identified. An impaired myocardial tissue-level reperfusion (angiographic myocardial blush grade 0 or 1) and in-hospital mortality were evaluated in accordance with the presence or absence of pre-PCI procedural therapeutic hypothermia. ResultsThirteen patients were treated with pre-PCI procedural therapeutic hypothermia and 24 were not inducted with therapeutic hypothermia. Five patients with and 18 without pre-PCI procedural therapeutic hypothermia impaired myocardial tissue-level reperfusion (38% vs. 75%, p=0.037). A total of 26 patients with in-hospital death (overall in-hospital mortality 70%) were composed of 6 with and 20 without therapeutic hypothermia (in-hospital mortality 46% vs. 83%, p=0.028). A multivariate analysis demonstrated a significant association of pre-PCI procedural therapeutic hypothermia (p=0.021) with in-hospital survival benefit. Adverse events associated with therapeutic hypothermia were not found in 12 patients who completed this treatment. ConclusionsThe present study may imply a crucial possibility of clinical benefits of pre-PCI procedural therapeutic hypothermia in patients with a cardiogenic shock complicating anterior STEMI.

Abstract 12930: Neutrophil Extracellular Traps Correlate With Impaired Myocardial Reperfusion in Patients With St Elevation Myocardial Infarction After Primary Percutaneous Coronary Intervention

Introduction: Impaired myocardial reperfusion after successful percutaneous coronary intervention (PCI) is an important determinant of prognosis of patients with ST elevation myocardial infarction (STEMI). Neutrophil extracellular traps (NETs) are toxic DNA-protein complexes, upregulated in pro-thrombotic states and may induce endothelial injury. Aim: We aimed to assess in systemic and culprit coronary plasma, the level of NETs and their relationship with microvascular perfusion after PCI. Methods: Forty-nine STEMI patients treated with thrombectomy and PCI were enrolled. Patients with past history of coronary revascularization were excluded. Systemic blood was drawn at baseline and post PCI, and from the culprit lesion during thrombectomy. NETs and extracellular histone-DNA (E-DNA) were measured by capture ELISA (myeloperoxidase-DNA complex, histone-DNA complex, respectively). Corrected thrombolysis in MI (TIMI) frame count (cTFC) was calculated from coronary angiography. Results: The relation between NETs and cTFC is summarized in the figure. Both NETs and E-DNA were highest in culprit lesion plasma (p&lt;0.05). Baseline and post-PCI levels of NETs were similar (p=0.56). Baseline, aspirate, and post-PCI NETs levels were inversely correlated with cTFC (ρ=-0.43, -0.31, -0.39, respectively, all p&lt;0.05), and baseline NETs was an independent predictor of cTFC (β=-0.40, p=0.04), not age, gender, total ischemia time or troponin T level at admission. All E-DNA levels positively correlated with troponin T at admission (ρ=0.58, 0.47, 0.38, p&lt;0.05, respectively), and were higher post PCI than at baseline (p&lt;0.01), suggesting a reflection of myocardial damage. E-DNA showed no correlation with cTFC. Conclusions: Prior to PCI, baseline NETs level predict impaired reperfusion and may assist in tailored therapy and follow up.

Abstract 16205: Validation Study of the Quantified Frequency Domain Optical Coherence Tomography Analysis for the Detection of Erythrocyte-Rich Thrombus

Introduction: Frequency domain optical coherence tomography (FDOCT) can evaluate erythrocyte-rich thrombus, containing more inflammatory cells and reflect high thrombus burden, leading to impaired myocardial reperfusion in myocardial infarction patients. Hypothesis: The purpose of this study was to validate the quantified FDOCT signal analysis in evaluating the erythrocyte-rich thrombus with ex-vivo materials. Methods: We evaluated 55 specimens of coronary artery thrombus obtained by thrombectomy from 9 patients with acute coronary syndrome. The thrombi were immersed in saline immediately after the thrombectomy and FDOCT image acquisition was performed. Quantitative FDOCT analysis for all contiguous frames was performed by the dedicated automated software (OCT system software, Light Lab Inc.). In each sample, signal intensity and normalized standard deviation of signal (NSD) were evaluated quantitatively for a frame showing the biggest thrombus area. All thrombi were stained with hematoxylin-eosin, and the cellular component of erythrocyte were stained using monoclonal antibodies against a protein specific to erythrocyte membranes (glycophorin-A). Computer-assisted analysis was performed using dedicated software (WinROOF, Mitani Corp., Tokyo, Japan) for color identification of the erythrocyte area. Results: Erythrocyte-rich thrombus (n=26), defined as %erythrocyte area (erythrocyte area/total area X100)≧67%, showed higher [NSD / mean signal intensity X100] than white thrombus (n=21), defined as %erythrocyte area&lt;33% (4.14±0.67 vs. 3.62±0.73, p=0.016). The optimal cut-off point of [NSD/mean signal intensity X100] for prediction of erythrocyte-rich thrombus was 4.20 (sensitivity: 50.0%, specificity: 81.9%, area under the receiver operating characteristic curve: 0.67, respectively). Conclusions: This study showed the utility of quantified FDOCT signal analysis on the evaluation of erythrocyte-rich thrombus.

MGuard Mesh‐Covered Stent for Treatment of ST‐Segment Elevation Myocardial Infarction with High Thrombus Burden Despite Manual Aspiration

To assess the usefulness of the MGuard stent in patients with ST-segment elevation myocardial infarction (STEMI) in whom a high thrombus burden persists after manual aspiration. In some patients with STEMI, a high thrombus burden may persist after manual aspiration. These patients may be at high risk of distal embolization and therefore impaired myocardial reperfusion. The MGuard is a novel mesh-covered stent designed to minimize thrombus embolization. Single-arm, prospective registry of patients with STEMI and high thrombus burden after aggressive thrombus aspiration treated with the MGuard stent. High thrombus burden was defined as thrombus burden grade 4 or 5 according to the TIMI score. Lesions with a side branch ≥2 mm and patients with cardiogenic shock were not included. The study end-points were proportion of final TIMI 3 flow, normal myocardial blush, and complete ST-segment resolution. Fifty-six patients were included. After MGuard stent implantation >85% of cases had thrombus score = 0. Final TIMI 3 flow was achieved in 82% of cases, normal myocardial blush in 55%, and complete ST-segment resolution in 59%. Occlusion of a side branch (<2 mm) occurred in 2 cases (3.5%), embolization to a distal branch in 5 cases (8.9%), and transient no-reflow in 4 cases (7.1%). Major adverse cardiac events rate at 9 months was 3.6%, including 1 definite acute stent thrombosis and 1 target-vessel revascularization. The MGuard stent may be useful to prevent distal embolization in patients with STEMI and high thrombus burden despite mechanical aspiration.

Abstract 8952: ST-Segment Depression in Lead aVR Predicts In-Hospital Adverse Outcomes in Patients With Inferior Wall Acute Myocardial Infarction

Introduction: During inferior wall acute myocardial infarction (IWMI), lead aVR is frequently ignored. However, ST-segment depression in lead aVR (ST↓aVR) during IWMI might represent a reciprocal change in response to an opposite vector resulting from ST-segment elevation in the apical region, suggesting a larger area at risk. Hypothesis: We assessed the hypothesis that ST↓aVR can provide important prognostic information in patients with reperfused IWMI. Methods: We studied 268 patients with a first IWMI who had TIMI 3 flow of the right coronary artery or left circumflex coronary artery after fibrinolysis or primary percutaneous coronary intervention within 6 h after symptom onset. Patients were divided into the 3 groups according to the degree of ST↓aVR on admission ECG: G-A, 122 patients with no ST↓aVR; G-B, 95 patients with ST↓aVR ≤1.0 mm; and G-C, 51 patients with ST↓aVR &gt;1.0 mm. The perfusion territory of the culprit artery was assessed on the basis of the angiographic distribution score. Impaired myocardial reperfusion was defined as myocardial blush grade 0/1 on the final angiogram. Results: There were no differences in age, coronary risk factors, time to admission, reperfusion therapy, culprit artery, or final TIMI flow grade among the 3 groups. In G-A, G-B, and G-C, the sum of ST-segment elevation in leads II, III, aVF and V5-6 on admission ECG was 4±4, 9±5, and 17±7 mm (p&lt;0.01); the angiographic distribution score was 0.5±0.2, 0.6±0.2, and 0.7±0.1 (p&lt;0.01); peak creatine kinase level was 2225±1515, 3150±1792, and 4911±2238 mU/ml (p&lt;0.01); and the frequencies of impaired myocardial reperfusion was 4%, 18%, and 71% (p&lt;0.01); the combined outcome of in-hospital death, reinfarction, or congestive heart failure was 2%, 7%, and 14% (p&lt;0.01), respectively. Multivariate analysis showed that as compared with no ST↓aVR, the odds ratios (95% CI) for in-hospital adverse events associated with ST↓aVR ≤1.0 mm and ST↓aVR &gt;1.0 mm were 1.49 (0.64-3.39; p=0.15) and 2.01 (1.18-4.51; p&lt;0.05), respectively. Conclusions: In patients with reperfused IWMI, greater ST↓aVR on admission ECG is associated with a larger area at risk, impaired myocardial reperfusion, and a larger infarct size. ST↓aVR &gt;1.0 mm is an independent predictor of in-hospital adverse outcomes.