Extent of early ST segment elevation resolution: a strong predictor of outcome in patients with acute myocardial infarction and a sensitive measure to compare thrombolytic regimens. A substudy of the International Joint Efficacy Comparison of Thrombolytics (INJECT) trial

Synbiotic supplementation ameliorates anxiety and myocardial ischaemia-reperfusion injury in hyperglycaemic rats by modulating gut microbiota

Hyperglycaemia, hyperlipidaemia, hypertension and obesity are the main risk factors affecting the development and prognosis of ischaemic heart disease, which is still an important cause of death today. In our study, male Sprague-Dawley rats were fed either a standard diet (SD) or a high fat and high carbohydrate diet (HF-HCD) for 8 weeks and streptozotocin (STZ) was injected at the seventh week of the feeding period. In one set of rats, a mixture of a prebiotic and probiotics (synbiotic, SYN) was administered by gavage starting from the beginning of the feeding period. Experimental myocardial ischaemia-reperfusion (30 min/60 min) was induced at the end of 8 weeks. Hyperglycaemia, hypertension and increased serum low-density lipoprotein levels occurred in SD- and HF-HCD-fed and STZ-treated rats followed for 8 weeks. Increased density of the Proteobacteria phylum was observed in rats with increased blood glucose levels, indicating intestinal dysbiosis. The severity of cardiac damage was highest in the dysbiotic HF-HCD-fed hyperglycaemic rats, which was evident with increased serum creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), tumour necrosis factor-α, and interleukin-6 levels, along with a decrease in ST-segment resolution index. SYN supplementation to either a normal or a high-fat high-carbohydrate diet improved gut dysbiosis, reduced anxiety, decreased CK-MB and cTnI levels, and alleviated myocardial ischaemia-reperfusion injury in hyperglycaemic rats.

Sonothrombolysis in Patients With ST-Elevation Myocardial Infarction With Electrocardiographic No-Reflow After Percutaneous Coronary Intervention: A Randomized Controlled Trial

BACKGROUND AND AIMS

Approximately 50% of patients with ST elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) experience microvascular no-reflow. Pre- and post-PCI sonothrombolysis has been shown to decrease infarct size and improve left ventricular (LV) systolic function in STEMI patients receiving urgent PCI. The aim of this study was to investigate whether post-PCI sonothrombolysis alone in STEMI patients with persistent ST elevation could reduce no-reflow and infarct size.

METHODS

Patients with STEMI with symptoms <12 hours who had persistent ST elevation (≤70% ST resolution) after primary PCI were randomized to sonothrombolysis or control. The primary end point was summed (Σ) ST elevation 60 minutes after study intervention. Secondary end points included infarct size, myocardial perfusion score, LV ejection fraction on cardiovascular magnetic resonance imaging at 2 months follow-up, and clinical outcome at 6-month follow-up.

RESULTS

Sixty-seven STEMI patients with persistent ST elevation after PCI were randomized (49 left anterior descending, 18 right coronary/left circumflex artery). No difference was observed in Σ ST elevation 60 minutes after study intervention (mean difference, 0.6 mm; 95% CI, -1.1 to 2.2, P = .50). Complete ST resolution occurred in 14 (40%) of patients treated with sonothrombolysis compared to 6 (19%) of controls (P = .16). Myocardial perfusion score index (1.5 ± 0.3 vs 1.5 ± 0.3, P = .93), infarct size (18.0% ± 10% vs 16.8% ± 11%; P = .29) and LV ejection fraction on cardiovascular magnetic resonance (46% ± 8% vs 47% ± 11% in the control group; P = .86) were comparable. Incidence of all-cause death, acute coronary syndrome, and hospital admission for heart failure at 6-month follow-up was similar between the groups (sonothrombolysis, 2; control, 5).

CONCLUSIONS

In STEMI patients with persistent ST elevation after PCI, post-PCI sonothrombolysis did not result in more ST resolution or smaller infarct size compared to control subjects. The incidence of the combined clinical end points was remarkably low in this high-risk patient population.

Predicting 30-Day Mortality Using ST-Segment Elevation Resolution in ST-Elevation Myocardial Infarction Patients Undergoing Primary Percutaneous Coronary Intervention: An Indian Scenario

BACKGROUND

The relationship between ST-segment elevation (STE) resolution and 30-day mortality has been evaluated, although limitedly, in non-Indian patients undergoing primary percutaneous coronary intervention (pPCI). We aimed to evaluate the prognostic utility of STE resolution in predicting 30-day mortality in Indian patients undergoing pPCI for ST-elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

This prospective, single-center, observational study investigated the correlation between 30-day mortality rate and extent of STE resolution in real-world Indian patients undergoing pPCI for STEMI. A total of 64 patients underwent pPCI for STEMI at a tertiary care center in India. The patients were classified into three groups based on the extent of STE resolution: complete resolution (≥70%), partial resolution (30-70%), and no resolution (<30%). The primary endpoint of the study was occurrence of major adverse cardiovascular events consisting of all-cause death, reinfarction, disabling stroke, and ischemia-induced target vessel revascularization at 30 days follow-up.

RESULTS

The study enrolled 56 patients. The mean age of patients was 59.7±6.8 years and there were 46 (82.1%) males. Complete STE resolution (≥70%) occurred in 7.1%, partial resolution (<70-30%) in 82.1% and no resolution (<30%) in 10.7%. The mortality rate was 2.1% and 33.3% in patients with partial and no STE resolution. No mortality was seen in patients with complete STE resolution. The 30-day survival analysis revealed significant differences between the three groups (P<0.01). STE resolution served as an independent predictor of 30-day mortality across all clinical variables, including patients with post-PCI thrombolysis in myocardial infarction (TIMI) 3 flow.

CONCLUSIONS

Persistent STE after PCI is a reliable indicator of 30-day mortality in real-world STEMI patients. The extent of STE resolution can be used as a simple and affordable tool to stratify patients by the risk of mortality soon after the acute event. Due to their higher mortality at 30 days follow-up, individuals with persistent STE should be the focus for further treatment interventions.

Assessment of Selected Baseline and Post-PCI Electrocardiographic Parameters as Predictors of Left Ventricular Systolic Dysfunction after a First ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To assess the performance of ten electrocardiographic (ECG) parameters regarding the prediction of left ventricular systolic dysfunction (LVSD) after a first ST-segment-elevation myocardial infarction (STEMI).

METHODS

We analyzed 249 patients (74.7% males) treated with primary percutaneous coronary intervention (PCI) included into a single-center cohort study. We sought associations between baseline and post-PCI ECG parameters and the presence of LVSD (defined as left ventricular ejection fraction [LVEF] ≤ 40% on echocardiography) 6 months after STEMI.

RESULTS

Patients presenting with LVSD (n = 52) had significantly higher values of heart rate, number of leads with ST-segment elevation and pathological Q-waves, as well as total and maximal ST-segment elevation at baseline and directly after PCI compared with patients without LVSD. They also showed a significantly higher prevalence of anterior STEMI and considerably wider QRS complex after PCI, while QRS duration measurement at baseline showed no significant difference. Additionally, patients presenting with LVSD after 6 months showed markedly more severe ischemia on admission, as assessed with the Sclarovsky-Birnbaum ischemia score, smaller reciprocal ST-segment depression at baseline and less profound ST-segment resolution post PCI. In multivariate regression analysis adjusted for demographic, clinical, biochemical and angiographic variables, anterior location of STEMI (OR 17.78; 95% CI 6.45-48.96; p < 0.001), post-PCI QRS duration (OR 1.56; 95% CI 1.22-2.00; p < 0.001) expressed per increments of 10 ms and impaired post-PCI flow in the infarct-related artery (IRA; TIMI 3 vs. <3; OR 0.14; 95% CI 0.04-0.46; p = 0.001) were identified as independent predictors of LVSD (Nagelkerke's pseudo R2 for the logistic regression model = 0.462). Similarly, in multiple regression analysis, anterior location of STEMI, wider post-PCI QRS, higher baseline number of pathological Q-waves and a higher baseline Sclarovsky-Birnbaum ischemia score, together with impaired post-PCI flow in the IRA, higher values of body mass index and glucose concentration on admission were independently associated with lower values of LVEF at 6 months (corrected R2 = 0.448; p < 0.00001).

CONCLUSIONS

According to our study, baseline and post-PCI ECG parameters are of modest value for the prediction of LVSD occurrence 6 months after a first STEMI.

ST-segment resolution as a marker for severe myocardial fibrosis in ST-segment elevation myocardial infarction

Objective

To investigate the relationship between ST-segment resolution (STR) and myocardial scar thickness after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).

Methods

Forty-two STEMI patients with single-branch coronary artery stenosis or occlusion were enrolled. ST-segment elevations were measured at emergency admission and at 24 h after PCI. Late gadolinium-enhanced cardiac magnetic resonance imaging (CMR-LGE) was performed 7 days after PCI to evaluate myocardial scars. Statistical analyses were performed to assess the utility of STR to predict the development of transmural (> 75%) or non-transmural (< 75%) myocardial scars, according to previous study.

Results

The sensitivity and specificity of STR for predicting transmural scars were 96% and 88%, respectively, at an STR cut-off value of 40.15%. The area under the curve was 0.925. Multivariate logistic proportional hazards regression analysis disclosed that patients with STR < 40.15% had a 170.90-fold higher probability of developing transmural scars compared with patients with STR ≥ 40.15%. Pearson correlation and linear regression analyses showed STR percentage was significantly associated with myocardial scar thickness and size.

Conclusion

STR < 40.15% at 24 h after PCI may provide meaningful diagnostic information regarding the extent of myocardial scarification in STEMI patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02269-y.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

Novel Biomarkers, ST-Elevation Resolution, and Clinical Outcomes Following Primary Percutaneous Coronary Intervention

Background Despite restoration of epicardial flow following primary percutaneous coronary intervention (PPCI), microvascular reperfusion as reflected by ST-elevation resolution (ST-ER) resolution remains variable and its pathophysiology remains unclear. Methods and Results Using principal component analyses, we explored associations between 91 serum biomarkers drawn before PPCI clustered into 14 pathobiologic processes (including NT-proBNP [N-terminal pro-B-type natriuretic peptide] as an independent cluster), and (1) ST-ER resolution ≥50% versus <50%; and (2) 90-day composite of death, shock, and heart failure. Network analyses were performed to understand interbiomarker relationships between the ST-ER groups. Among the 1160 patients studied, 861 (74%) had ST-ER ≥50% at a median 40 (interquartile range, 23-70) minutes following PPCI, yet both groups had comparable post-PPCI TIMI (Thrombolysis in Myocardial Infarction) grade 3 flow (86.6% versus 82.9%; P=0.25). ST-ER ≥50% was associated with significantly lower pre-PPCI concentrations of platelet activation cluster (particularly P-selectin, von Willebrand factor, and platelet-derived growth factor A) and NT-proBNP, including after risk adjustment. Across both ST-ER groups, strong interbiomarker relationships were noted between pathways indicative of myocardial stretch, platelet activation, and inflammation, whereas with ST-ER <50% correlations between iron homeostasis and inflammation were observed. Of all 14 biomarker clusters, only NT-proBNP was significantly associated with the 90-day clinical composite. Conclusions Suboptimal ST-ER is common despite achieving post-PPCI TIMI grade 3 flow. The cluster of platelet activation proteins and NT-proBNP were strongly correlated with suboptimal ST-ER and NT-proBNP was independently associated with 90-day outcomes. This analysis provides insights into the pathophysiology of microvascular reperfusion in ST-segment-elevation myocardial infarction and suggests novel pre-PPCI risk targets potentially amenable to enhancing tissue-level reperfusion following PPCI.

An Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction

BACKGROUND

Incomplete restoration of myocardial blood flow (MBF) is reported in up to 30% of ST-segment elevation myocardial infarction (STEMI) despite prompt mechanical revascularization. Experimental hyperinsulinemic euglycemia (HE) increases MBF reserve (MBFR). If fully exploited, this effect may also improve MBF to ischemic myocardium. Using insulin-dextrose infusions to induce HE, we conducted four experiments to determine (1) how insulin infusion duration, dose, and presence of insulin resistance affect MBFR response; and (2) the effect of an insulin-dextrose infusion given immediately following revascularization of STEMI on myocardial perfusion.

METHODS

The MBFR was determined using myocardial contrast echocardiography. Experiment 1 (insulin duration): 12 participants received an insulin-dextrose or saline infusion for 120 minutes. MBFR was measured at four time intervals during infusion. Experiment 2 (insulin dose): 22 participants received one of three insulin doses (0.5, 1.5, 3.0 mU/kg/minute) for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 3 (insulin resistance): five metabolic syndrome and six type 2 diabetes (T2DM) participants received 1.5 mU/kg/minute of insulin-dextrose for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 4 (STEMI): following revascularization for STEMI, 20 patients were randomized to receive either 1.5 mU/kg/minute insulin-dextrose infusion for 120 minutes or standard care. Myocardial contrast echocardiography was performed at four time intervals to quantify percentage contrast defect length.

RESULTS

Experiment 1: MBFR increased with time through to 120 minutes in the insulin-dextrose group and did not change in controls. Experiment 2: compared with baseline, MBFR increased in the 1.5 (2.42 ± 0.39 to 3.25 ± 0.77, P = .002), did not change in the 0.5, and decreased in the 3.0 (2.64 ± 0.25 to 2.16 ± 0.33, P = .02) mU/kg/minute groups. Experiment 3: compared with baseline, MBFR increase was only borderline significant in metabolic syndrome and T2DM participants (1.98 ± 0.33 to 2.59 ± 0.45, P = .04, and 1.67 ± 0.35 to 2.14 ± 0.21, P = .05). Experiment 4: baseline percentage contrast defect length was similar in both groups but with insulin decreased with time and was significantly lower than in controls at 60 minutes (2.8 ± 5.7 vs 13.7 ± 10.6, P = .02).

CONCLUSIONS

Presence of T2DM, insulin infusion duration, and dose are important determinants of the MBFR response to HE. When given immediately following revascularization for STEMI, insulin-dextrose reduces perfusion defect size at one hour. Hyperinsulinemic euglycemia may improve MBF following ischemia, but further studies are needed to clarify this.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Chip-based digital PCR as a novel detection method for quantifying microRNAs in acute myocardial infarction patients

miRNAs have shown promise as potential biomarkers for acute myocardial infarction (AMI). However, the current used quantitative real-time PCR (qRT-PCR) allows solely for relative expression of nucleic acids and it is susceptible to day-to-day variability, which has limited the validity of using the miRNAs as biomarkers. In this study we explored the technical qualities and diagnostic potential of a new technique, chip-based digital PCR, in quantifying the miRNAs in patients with AMI and ischaemia-reperfusion injury (I/R). In a dilution series of synthetic C.elegans-miR-39, chip-based digital PCR displayed a lower coefficient of variation (8.9% vs 46.3%) and a lower limit of detection (0.2 copies/μL vs 1.1 copies/μL) compared with qRT-PCR. In the serum collected from 24 patients with ST-elevation myocardial infarction (STEMI) and 20 patients with stable coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI), we used qRT-PCR and multiplexed chip-based digital PCR to quantify the serum levels of miRNA-21 and miRNA-499 as they have been validated in AMI in prior studies. In STEMI, I/R injury was assessed via measurement of ST-segment resolution (ST-R). Chip-based digital PCR revealed a statistical significance in the difference of miR-21 levels between stable CAD and STEMI groups (118.8 copies/μL vs 59 copies/μL; P=0.0300), whereas qRT-PCR was unable to reach significance (136.4 copies/μL vs 122.8 copies/μL; P=0.2273). For miR-499 levels, both chip-based digital PCR and qRT-PCR revealed statistically significant differences between stable CAD and STEMI groups (2 copies/μL vs 8.5 copies/μL, P=0.0011; 0 copies/μL vs 19.4 copies/μL; P<0.0001). There was no association between miR-21/499 levels and ST-R post-PCI. Our results show that the chip-based digital PCR exhibits superior technical qualities and promises to be a superior method for quantifying miRNA levels in the circulation, which may become a more accurate and reproducible method for directly quantifying miRNAs, particularly for use in large multi-centre clinical trials.

Pharmacologic inhibition of the mitochondrial Na+/Ca2+ exchanger protects against ventricular arrhythmias in a porcine model of ischemia-reperfusion

BACKGROUND

The mitochondrial Na+/Ca2+ exchanger (mNCX) has been implicated in the pathogenesis of arrhythmogenicity and myocardial reperfusion injury, rendering its inhibition a potential therapeutic strategy. We examined the effects of CGP-37157, a selective mNCX inhibitor, on arrhythmogenesis, infarct size (IS), and no reflow area (NRA) in a porcine model of ischemia-reperfusion.

METHODS

Forty pigs underwent myocardial ischemia for 60 minutes, followed by 2 hours of reperfusion. Animals were randomized to receive intracoronary infusion of 0.02 mg/kg CGP-37157 or vehicle, either before ischemia (n=17) or before reperfusion (n=17). Animals were monitored for arrhythmias. Myocardial area at risk (AR), IS, and NRA were measured by histopathology.

RESULTS

AR, NRA, and IS were comparable between groups. Administration of CGP-37157 before ischemia resulted in the following: (a) suppression of ventricular tachyarrhythmias (events/pig: 1.5±1.1 vs 3.5±1.9, p=0.014), (b) easier cardioversion of ventricular tachyarrhythmias (defibrillations required for cardioversion of each episode: 2.6±2.3 vs 6.2±2.1, p=0.006), and (c) decreased maximal depression of the J point (0.75±0.27 mm vs 1.75±0.82 mm, p=0.007), compared to controls. Administration of CGP-37157 before reperfusion expedited ST-segment resolution; complete ST-segment resolution within 30 minutes of reperfusion was observed in 7/8 CGP-37157-treated animals versus 1/9 controls (p=0.003).

CONCLUSIONS

In a porcine model of myocardial infarction, intracoronary administration of CGP-37157 did not decrease IS or NRA. However, it suppressed ventricular arrhythmias, decreased depression of the J point during ischemia and expedited ST-segment resolution after reperfusion. These findings motivate further investigation of pharmacologic mNCX inhibition as a potential therapeutic strategy to suppress arrhythmias in the injured heart.

Glycemic variability is associated with myocardial damage in nondiabetic patients with ST-elevation myocardial infarction

Background

Glycemic variability (GV) induces coronary microcirculatory disturbance and myocardial damage in diabetic patients with acute myocardial infarction. However, in nondiabetic acute myocardial infarction patients, the relationship between GV and myocardial damage remains unclear.

Patients and methods

We investigated GV with a continuous glucose monitoring system in nondiabetic ST-segment elevation myocardial infarction patients treated with emergent percutaneous coronary intervention. GV was expressed as the mean amplitude of glycemic excursions (MAGE). Myocardial damage was estimated by myocardial blush grade and ST-segment resolution (STRes). STRes was defined as complete (>70%), partial (30–70%), or none (<30%).

Results

Consecutive patients (n=73) were enrolled and classified into a lower or higher MAGE group on the basis of the median MAGE. The higher MAGE group showed lower levels of myocardial blush grade (2.41±0.76 vs. 1.72±0.85, P=0.001) and STRes (complete: 56.8 vs. 33.3%, P=0.044; partial: 32.4 vs. 36.1%, P=0.741; none: 10.8 vs. 30.6%, P=0.037).

Conclusion

GV was associated with myocardial damage after percutaneous coronary intervention in nondiabetic ST-segment elevation myocardial infarction patients.

Incidence and Significance of Spontaneous ST Segment Re-elevation After Reperfused Anterior Acute Myocardial Infarction - Relationship With Infarct Size, Adverse Remodeling, and Events at 1 Year

BACKGROUND

Up to 25% of patients with ST elevation myocardial infarction (STEMI) have ST segment re-elevation after initial regression post-reperfusion and there are few data regarding its prognostic significance.Methods and Results:A standard 12-lead electrocardiogram (ECG) was recorded in 662 patients with anterior STEMI referred for primary percutaneous coronary intervention (PPCI). ECGs were recorded 60-90 min after PPCI and at discharge. ST segment re-elevation was defined as a ≥0.1-mV increase in STMax between the post-PPCI and discharge ECGs. Infarct size (assessed as creatine kinase [CK] peak), echocardiography at baseline and follow-up, and all-cause death and heart failure events at 1 year were assessed. In all, 128 patients (19%) had ST segment re-elevation. There was no difference between patients with and without re-elevation in infarct size (CK peak [mean±SD] 4,231±2,656 vs. 3,993±2,819 IU/L; P=0.402), left ventricular (LV) ejection fraction (50.7±11.6% vs. 52.2±10.8%; P=0.186), LV adverse remodeling (20.1±38.9% vs. 18.3±30.9%; P=0.631), or all-cause mortality and heart failure events (22 [19.8%] vs. 106 [19.2%]; P=0.887) at 1 year.

CONCLUSIONS

Among anterior STEMI patients treated by PPCI, ST segment re-elevation was present in 19% and was not associated with increased infarct size or major adverse events at 1 year.

Single Derivation Fragmented QRS Can Predict Poor Prognosis in Successfully Revascularized Acute STEMI Patients

Background

QRS fragmentation (fQRS) is classically defined as the presence of slurred QRS morphology in at least two contiguous leads, and its prognostic importance has been shown in ST elevation myocardial infarction (STEMI). However, no study has investigated the significance of single lead fQRS (sl-fQRS) in surface electrocardiography (ECG).

Objectives

To evaluate whether sl-fQRS is as valuable as classical fQRS in patients with acute STEMI who had successful revascularization with primary percutaneous coronary intervention (pPCI).

Methods

We included 330 patients with a first STEMI who had been successfully revascularized with pPCI. The patient’s electrocardiography was obtained in the first 48 hours, and the patients were divided into three groups according to the absence of fQRS (no-fQRS); fQRS presence in a single lead (sl-fQRS); and ≥2 leads with fQRS (classical fQRS).

Results

In-hospital mortality was significantly higher both in patients with sl-fQRS and in patients with ≥ 2 leads with fQRS compared to patients with no-fQRS. In ROC curve analysis, ≥ 1 leads with fQRS yielded a sensitivity of 75% and specificity of 57.4% for the prediction of in-hospital mortality. Multivariate analysis showed that sl-fQRS is an independent predictor of in-hospital mortality (OR: 3.989, 95% CI: 1.237-12.869, p = 0.021).

Conclusions

Although the concept of at least two derivations is mentioned for the classical definition of fQRS, our study showed that fQRS in only one lead is also associated with poor outcomes. Therefore, ≥1 leads with fQRS can be useful when describing the patients under high cardiac risk in acute STEMI.

Safety and Efficacy of Using a Single Transradial MAC Guiding Catheter for Coronary Angiography and Intervention in Patients with ST Elevation Myocardial Infarction

BACKGROUND

There are limited data on the impact of using a single dedicated radial guiding catheter in primary percutaneous coronary intervention (PCI) via radial access.

OBJECTIVES

To investigate the effect of using a single guiding catheter (MAC 3.5) for left and right coronary angiography and intervention on catheterization laboratory door to balloon (C2B) time in patients with ST elevation myocardial infarction (STEMI).

METHODS

Three hundred and sixty patients were randomized (1:1) to using a single MAC3.5 guiding catheter (MAC group) or diagnostic Tiger catheter first for coronary angiography followed by guiding catheter selection (control group) for intervention. The primary outcomes were C2B. The secondary outcomes were major adverse cardiac events (MACE) at 30 days and 6 months.

RESULTS

Median C2B time (16.6 min, interquartile range [IQR] 14.3-20.2 min vs 19.0 min, IQR 14.3-23.1 min; P < 0.001), total procedure time (31.0 min, IQR 26.4-37.7 min vs 34.8 min, IQR 29.7-42.5 min, P < 0.001), and overall fluoroscopy time (8.0 min, IQR 6.4-10.4 min vs 8.8 min, IQR 6.5-12.2, P = 0.04) were significantly reduced in MAC Group. Contrast consumption were similar among both groups (103 ± 37 ml vs 110 ± 41 ml, P = 0.16). The MACE rate in MAC group and control group was 3.3 versus 4.4% (P = 0.586) at 30 days and 3.3 versus 5.0% (P = 0.429) at 6 months, respectively.

CONCLUSIONS

A single MAC3.5 guiding catheter for coronary angiography and intervention can shorten C2B time, procedure time, and fluoroscopy time. (RAPID study; NCT01759043).

A prospective evaluation of a standardized strategy for the use of a polymeric everolimus-eluting bioresorbable scaffold in ST-segment elevation myocardial infarction: Rationale and design of the BVS STEMI STRATEGY-IT study

OBJECTIVES

To assess the feasibility and the clinical results following a prespecified bioresorbable vascular scaffold (Absorb BVS) implantation strategy in ST-elevation myocardial infarction (STEMI) patients.

BACKGROUNDS

Concerns raised about the BVS safety in STEMI setting because a not negligible thrombosis rate was reported within 30 days and 12 months after implantation. Technical procedural issues related to the structural BVS features were advocated as probable causes for the thrombotic events.

METHODS

This is an investigators-owned and -directed, prospective, nonrandomized, single-arm multicenter registry intended to obtain data from 500 consecutive STEMI patients undergoing primary PCI with BVS (1.1 or GT1) following a prespecified implantation protocol. The study is recorded in ClinicalTrials.gov with the identifier: NCT02601781.

RESULTS

The primary endpoint is a device-oriented composite end-point (DOCE) of cardiac death, any myocardial infarction clearly attributable to the intervention culprit vessel and ischemic-driven target lesion revascularization within 30 days after the index procedure. The DOCE will be assessed even at 6-month, 1-, 3-, and 5-year follow-up.

CONCLUSIONS

This will be the first study investigating the feasibility and the early- and long-term clinical impact of a prespecified BVS implantation protocol in thrombotic lesions causing STEMI. Here, we describe the rationale and the design of the study. © 2016 Wiley Periodicals, Inc.

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

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

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

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

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

The Effect of Interventional Treatment in Acute Myocardial Infarction on ST Resolution: A Comparison of Coronary Angioplasty with Excimer Laser Angioplasty

The treatment methods for acute myocardial infarction (MI) have started to change in the new millennium. Myocardial perfusion (ST-segment resolution) is the target rather than achieving TIMI-III flow in the infarct-related artery. In this study the authors compared the effect of percutaneous transluminal coronary angioplasty (PTCA) and excimer laser angioplasty (ELCA), which was accepted as one of the thrombolysis methods, on ST-segment resolution. A stent was applied after ELCA to 36 patients (4 women, 32 men; mean age 50.44 ±9.8 years) in group I and a stent was applied after balloon angioplasty to 44 patients (5 women, 39 men; mean age 50.77 ±12.2 years) in group II. Fisher’s exact test was used in the analysis of data, and p<0.05 was accepted as significant. There was no difference between the groups with respect to symptom duration, time to angioplasty, risk factors, infarct localization, stent diameter, and length. TIMI-III flow was achieved in 33 patients (92%) in group I and in 40 patients (91%) in group II. There was no statistical difference in TIMI flow between the groups. In group I, complete ST resolution was observed in 75% (27/36) of the patients, partial resolution in 22% (8/36), and resolution was unsuccessful in 3% (1/36). In group II, complete, partial, and unsuccessful ST resolution were 41% (18/44), 45% (20/44), and 14% (6/44), respectively. The mean ST resolution was 82.78 ±11.8% in group I and 66.36 ±10% in group II (p=0.001). ST segment resolution, which is a good predictor of tissue perfusion, was higher with ELCA than with balloon angioplasty. These findings should be supported by large randomized studies.

Percutaneous Mechanical Reperfusion During Acute Myocardial Infarction

The treatment of acute myocardial infarction has progressed from bedrest to mechanical, catheter-based reperfusion. The authors review the use of percutaneous coronary intervention (PCI) as a primary treatment for acute myocardial infarction and the use of adjunctive agents. The most recent American College of Cardiology/ American Heart Association (ACC/AHA) guidelines for the use of PCI in ST segment elevation myocardial infarction (MI) advocate the use of PCI as primary therapy at those centers in which the procedure can be performed within accepted standards. Because a majority of hospitals (80%) do not have the capability of performing primary PCI, most patients are treated with thrombolytic therapy. PCI should be considered in those patients treated with thrombolytic therapy who have persistent or recurrent ischemia and/or cardiogenic shock. For patients with non-ST elevation MI, the use of an invasive strategy (early angiography and PCI if needed) has recently shown to be beneficial. Although revascularization is the basis of the acute therapy of MI, additional pharmacologic therapy in the acute setting is now recognized as a key to favorable long-term outcome.

Effect of a combination of antiplatelet and antithrombotic pretreatment on myocardial perfusion in patients with an acute ST-segment elevation myocardial infarction undergoing a primary percutaneous coronary intervention

INTRODUCTION

Primary percutaneous coronary intervention (PCI) is the preferred method of reperfusion in ST-segment elevation myocardial infarction patients. Adjunctive pharmacotherapy is, however, still under investigation.

OBJECTIVE

To assess the effect of combined pharmacologic therapy on myocardial perfusion and infarct size in relation to time delays.

MATERIALS AND METHODS

We studied 309 consecutive ST-segment elevation myocardial infarction patients admitted within 12 h from symptom onset with (a) chest pain persisting for more than 30 min, (b) ST-segment elevation more than 1 mm in at least two contiguous leads, and (c) pretreatment with 600 mg of clopidogrel, 300 mg of aspirin, and 5000 U of intravenous heparin. Group I (n=90) included patients transferred directly to cathlab (immediate transfer) and group II (n=219) included patients transferred by referring hospitals (staged transfer). The results of thrombolysis in myocardial infarction (TIMI) flow before and after PCI, ST-segment resolution (STSR), troponin T level, and myocardial blush grade were analyzed in relation to delay to intervention.

RESULTS

The delay between pharmacologic pretreatment and angiography was two times longer in cases of staged transfer (80 vs. 47.5 min; P<0.0001). Despite the longer delay, higher rates of preangiography total STSR (26.4 vs. 15.5%; P=0.039) and initial TIMI flow 3 (20.1 vs. 11.1%; P=0.059) were observed in those patients. Differences in the rate of total STSR (70.3 vs. 66.7%; P=0.52), TIMI flow 3 (91.3 vs. 88.9%; P=0.33), and myocardial blush grade (60.7 vs. 63.3%; P=0.66) were no longer observed after PCI. Similarly, the peak troponin T level was also comparable (3.6 vs. 3.9 ng/ml; P=0.74).

CONCLUSION

Pretreatment with a combination of antiplatelet and antithrombotic agents may improve myocardial perfusion and compromise longer delay to a mechanical intervention.

The Importance of the Number of Leads with fQRS for Predicting In-Hospital Mortality in Acute STEMI Patients Treated with Primary PCI

BACKGROUND

Fragmented QRS (fQRS) has been shown to be related to increased cardiovascular mortality and morbidity. However, limited data are available for evaluating the relationship between the number of leads with fQRS and in-hospital all-cause mortality in patients with acute ST segment elevation myocardial infarction (STEMI). The aim of our study is to investigate the prognostic importance of the number of leads with fQRS in acute STEMI patients treated by primary percutaneous coronary intervention (PCI).

METHODS

Two hundred ten eligible patients with acute STEMI that underwent primary PCI were enrolled in this study. Each patient's 12-lead electrocardiography (ECG) taken in the first 48 hours was analyzed and the number of leads with fQRS were recorded.

RESULTS

The number derivations with fQRS were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality (2.6 ± 2.6 vs 0.9 ± 1.3; P = 0.002). Also, patients with ≥3 leads with fQRS had higher rate of in-hospital all-cause mortality (23.5% vs 7.4%, P = 0.009), higher frequency of Q wave (67.6% vs 36.9%, P = 0.001), and higher frequency of fQRS with Q wave (67.6% vs 15.9%, P < 0.001) than those patients with <3 leads with fQRS. By a multivariate regression analysis, the number of leads with fQRS was found to be an independent predictor of in-hospital all-cause mortality (odds ratio: 1.415, 95% confidence interval: 1.049-1.909, P = 0.023).

CONCLUSIONS

The number of leads with fQRS on 12-lead ECG is an independent predictor of in-hospital all-cause mortality in patients with acute STEMI treated by primary PCI.

ST-segment resolution with bivalirudin versus heparin and routine glycoprotein IIb/IIIa inhibitors started in the ambulance in ST-segment elevation myocardial infarction patients transported for primary percutaneous coronary intervention: The EUROMAX ST-segment resolution substudy

BACKGROUND

Myocardial reperfusion after primary percutaneous coronary intervention (PCI) can be assessed by the extent of post-procedural ST-segment resolution. The European Ambulance Acute Coronary Syndrome Angiography (EUROMAX) trial compared pre-hospital bivalirudin and pre-hospital heparin or enoxaparin with or without GPIIb/IIIa inhibitors (GPIs) in primary PCI. This nested substudy was performed in centres routinely using pre-hospital GPI in order to compare the impact of randomized treatments on ST-resolution after primary PCI.

METHODS

Residual cumulative ST-segment deviation on the single one hour post-procedure electrocardiogram (ECG) was assessed by an independent core laboratory and was the primary endpoint. It was calculated that 762 evaluable patients were needed to show non-inferiority (85% power, alpha 2.5%) between randomized treatments.

RESULTS

A total of 871 participated with electrocardiographic data available in 824 patients (95%). Residual ST-segment deviation one hour after PCI was 3.8±4.9 mm versus 3.9±5.2 mm for bivalirudin and heparin+GPI, respectively ( p=0.0019 for non-inferiority). Overall, there were no differences between randomized treatments in any measures of ST-segment resolution either before or after the index procedure.

CONCLUSIONS

Pre-hospital treatment with bivalirudin is non-inferior to pre-hospital heparin + GPI with regard to residual ST-segment deviation or ST-segment resolution, reflecting comparable myocardial reperfusion with the two strategies.

Pre-angiography total ST-segment resolution is not a reliable predictor of an open infarct-related artery

BACKGROUND

While the cutoffs of predictive value for ST-segment elevations resolution (STSR) following thrombolysis and/or primary PCI were well documented, the impact of pre-angiography STSR has not been established yet.

OBJECTIVES

The aim of this study is to assess prognostic utility of pre-angiography STSR to predict pre-procedural TIMI flow in the infarct-related artery (IRA) and infarct size in STEMI patients undergoing primary PCI.

METHODS

A prospective study was performed, including 310 patients, admitted within 12h of symptom onset and who underwent primary PCI. ST-segment elevations were measured in: (1) qualifying ECG, (2) ECG before angiography, and (3) ECG post PCI. STSR was defined as: total (≥70%), partial (between 70% and 30%) and none (<30%). Relationships between pre-angiography STSR, initial TIMI flow and troponin T level (TnT) were analyzed.

RESULTS

Pre-angiography STSR correlated with initial TIMI flow in the IRA (rS=0.619; p<0.001). Pre-angiography total STSR was observed in 23.2% patients. It was noted in 79.2% of patients with pre-procedural TIMI flow ≥2 and in 20.8% with TIMI flow ≤1 (p<0.001). Although the sensitivity of pre-angiography total STSR to detect pre-procedural TIMI flow ≥2 was 93%, its specificity was only 56% and the likelihood ratio was 2.1. Pre-angiography total STSR was associated with lower peak TnT level (2.2±2.5ng/ml vs. 6.4±5.0ng/ml, p<0.0001) when compared to the remaining patients.

CONCLUSIONS

1. Pre-angiography STSR correlates with preprocedural TIMI flow. 2. The sensitivity of pre-angiography total STSR in detection of pre-procedural TIMI flow ≥2 is high, but low specificity of only 56% makes it an unreliable predictor of an open IRA.

Concordance of angiographic and electrocardiographic indexes of microvascular obstruction: myocardial haemorrhage role

BACKGROUND

Angiographic and electrocardiographic (ECG) indexes of microvascular obstruction (MVO) have been described. We aimed at assessing by cardiac magnetic resonance (CMR) anatomical features underlying concordance between them.

METHODS

Forty-one patients were enrolled. Patients presented with neither angiographic nor ECG indexes of MVO (without MVO) (44%), with either angiographic or ECG indexes of MVO (discordant with MVO) (22%) or with both angiographic and ECG indexes of MVO (concordant with MVO) (34%). All patients underwent in-hospital CMR. Echocardiographic data obtained after 6 months were compared with those obtained in hospital.

RESULTS

Concordant patients with MVO had larger infarct size, lower myocardial salvage index and higher rate of myocardial haemorrhage (all assessed by CMR) [33% (25-41%), 15% (10-29%) and 88%, respectively] as compared with patients without MVO [12% (9-16%), 66% (52-79%) and 0%; Bonferroni-adjusted P < 0.001, Bonferroni-adjusted P < 0.001 and P < 0.001, respectively], or with discordant ones [25% (21-39%), 35% (20-48%) and 7%; Bonferroni-adjusted P = 0.03, Bonferroni-adjusted P = 0.002 and P = 0.04, respectively]. After 6 months, ejection fraction significantly decreased in concordant patients with MVO (P < 0.001) without significant changes in the other groups.

CONCLUSIONS

Concordance of angiographic and ECG indexes of MVO reflects more severe myocardial damage translating into unfavourable left ventricular remodelling.

Rapid recovery of baroreceptor reflexes in acute myocardial infarction is a marker of effective tissue reperfusion

Baroreflex sensitivity (BRS) measured several days after myocardial infarction (MI) is a powerful predictor of cardiovascular mortality. No information is available on BRS in the early hours of MI. The possibility to reliably assess BRS in the acute phase of MI and its clinical correlates were evaluated in 45 patients treated with primary percutaneous coronary intervention (pPCI). BRS (sequence method) was assessed 1, 3, 6, and 12 h after PCI. ST resolution (STRes) was considered present if ST had decreased ≥70 % 3 h after PCI. BRS was 10.7 ± 6.2 1 h after PCI; at 12 h it was 15.4 ± 5.2 and 8.4 ± 4.8 ms/mmHg in patients with and without STRes, respectively (p < 0.001). STRes was an independent predictor of 12 h BRS (p = 0.005) and of 1-12 h BRS difference (p = 0.002). BRS can be reliably assessed in the first hours of MI; it shows a rapid recovery in patients with STRes and a significant depression in patients without STres.

Therapy in ST-elevation myocardial infarction: reperfusion strategies, pharmacology and stent selection

OPINION STATEMENT

The estimated annual incidence of new and recurrent myocardial infarction (MI) in the U.S. is 715,000 events. Primary percutaneous coronary intervention (PCI) is the reperfusion strategy of choice in most patients with acute ST-elevation myocardial infarction (STEMI). Recent advances in percutaneous techniques and devices, including manual aspiration catheters and newer generation drug eluting stents and pharmacologic therapies, such as novel antiplatelets and anticoagulants have led to significant improvements in the acute and long-term outcomes for these patients. Implementation of community-wide systems directed to shorten treatment times tied to closely monitored quality improvement processes have led to further advances in STEMI care. Recent data suggests that transradial access for primary PCI is associated with improved outcomes. This contemporary review discusses the strategies for reperfusion, pharmacological therapy and stent selection process involved in STEMI.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Decreases in electrocardiographic R-wave amplitude and QT interval predict myocardial ischemic infarction in Rhesus monkeys with left anterior descending artery ligation

Clinical studies have demonstrated the predictive values of changes in electrocardiographic (ECG) parameters for the preexisting myocardial ischemic infarction. However, a simple and early predictor for the subsequent development of myocardial infarction during the ischemic phase is of significant value for the identification of ischemic patients at high risk. The present study was undertaken by using non-human primate model of myocardial ischemic infarction to fulfill this gap. Twenty male Rhesus monkeys at age of 2–3 years old were subjected to left anterior descending artery ligation. This ligation was performed at varying position along the artery so that it produced varying sizes of myocardial infarction at the late stage. The ECG recording was undertaken before the surgical procedure, at 2 h after the ligation, and 8 weeks after the surgery for each animal. The correlation of the changes in the ECG waves in the early or the late stage with the myocardial infarction size was analyzed. The R wave depression and the QT shortening in the early ischemic stage were found to have an inverse correlation with the myocardial infarction size. At the late stage, the R wave depression, the QT prolongation, the QRS score, and the ST segment elevation were all closely correlated with the developed infarction size. The poor R wave progression was identified at both the early ischemic and the late infarction stages. Therefore, the present study using non-human primate model of myocardial ischemic infarction identified the decreases in the R wave and the QT interval as early predictors of myocardial infarction. Validation of these parameters in clinical studies would greatly help identifying patients with myocardial ischemia at high risk for the subsequent development of myocardial infarction.

A prospective randomized trial of thrombectomy versus no thrombectomy in patients with ST-segment elevation myocardial infarction and thrombus-rich lesions: MUSTELA (MUltidevice Thrombectomy in Acute ST-Segment ELevation Acute Myocardial Infarction) trial

OBJECTIVES

The aim of this study was to evaluate whether thrombectomy during primary percutaneous coronary intervention (pPCI) in patients with high thrombus burden improves myocardial reperfusion and reduces infarct size.

BACKGROUND

Thrombectomy aims at reducing distal thrombotic embolization during pPCI, improving myocardial reperfusion and clinical outcome.

METHODS

We randomized 208 patients with high thrombus burden in a 1:1 ratio to either pPCI with thrombectomy (Group T) or standard pPCI (Group S). Thrombectomy was performed with either rheolytic or manual aspiration catheters. Three-month magnetic resonance imaging was performed to assess infarct size and transmurality and microvascular obstruction (MVO). The primary endpoints were ST-segment elevation resolution (STR) >70% at 60 min and 3-month infarct size.

RESULTS

The baseline profile was similar between groups, except for a higher rate of initial Thrombolysis In Myocardial Infarction flow grade 3 in Group S (p = 0.002). Group T showed a significantly higher rate of STR (57.4% vs. 37.3%; p = 0.004) and of final myocardial blush 3 (68.3% vs. 52.9%; p = 0.03). Group T and Group S did not differ with regard to infarct size (20.4 ± 10.5% vs. 19.3 ± 10.6%; p = 0.54) and transmurality (11.9 ± 12.0% vs. 11.6 ± 12.7%; p = 0.92), but Group T showed significantly less MVO (11.4% vs. 26.7%; p = 0.02) and a higher prevalence of inhomogeneous scar (p < 0.0001). One-year freedom from major adverse cardiac events was similar between groups.

CONCLUSIONS

Thrombectomy as an adjunct to pPCI in patients with high thrombus load yielded better post-procedural STR and reduced MVO at 3 months but was not associated with a reduction in infarct size and transmurality. Thromboaspiration in Patients With High Thrombotic Burden Undergoing Primary Percutaneous (Coronary Intervention; NCT01472718).

Coronary reperfusion and clinical outcomes after thrombus aspiration during primary percutaneous coronary intervention: findings from the HORIZONS-AMI trial

OBJECTIVES

To assess the quality of coronary reperfusion and long-term clinical outcomes of patients enrolled in the HORIZONS-AMI trial according to the use of thrombus aspiration (TA).

BACKGROUND

The impact of manual TA on microvascular perfusion and clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) is unsettled.

METHODS

In this retrospective, nonrandomized, subgroup analysis, the authors evaluated thrombolysis in myocardial infarction (TIMI) flow, tissue myocardial perfusion grade (TMPG), ST-segment resolution (STR), net adverse clinical events (NACE), and major adverse cardiac events (MACE) in patients undergoing pPCI with or without manual TA.

RESULTS

A total of 318 patients had pPCI with upfront TA, and 2,917 patients had pPCI without TA. Patients who had TA were more likely to have TIMI 0/1 flow at baseline (75.1% vs. 63.7%, P < 0.0001). There was no difference in the rates of final TIMI 3 flow (90.2% vs. 92.3%, P = 0.19) or dynamic TMPG 2-3 (77.4% vs. 76.4%, P = 0.68). STR ≥70% was similar in both groups at 60 minutes but higher in the TA group at discharge (71.8% vs. 64.6%, P = 0.02). After multivariable adjustment, TA did not predict MACE at 30 days (HR 0.96 [0.51-1.80], P = 0.90), 1 year (HR 1.03 [0.68-1.55], P = 0.89), or 3 years (HR 1.13 [0.86-1.48], P = 0.39). Stent thrombosis did not differ at 1 year or 3 years.

CONCLUSIONS

In STEMI patients undergoing pPCI, the use of manual TA was associated with improved STR at discharge, but not with any difference in final TIMI flow, TMPG, or MACE.

Comparison of outcomes of patients with ST-segment elevation myocardial infarction with versus without previous coronary artery bypass grafting (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction [HORIZONS-AMI] trial)

The present substudy from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial assessed the outcomes and their relation to different antithrombotic regimens in patients with previous coronary artery bypass grafting (CABG) treated with primary percutaneous coronary intervention. Of 3,599 patients with information regarding a history of CABG, 105 (2.9%) had previously undergone CABG. Of these 105 patients, 46 were randomized to heparin plus a glycoprotein IIb/IIIa inhibitor and 59 to bivalirudin. The patients with versus without previous CABG were less frequently triaged to primary percutaneous coronary intervention (83.8% vs 93.2%, p = 0.0002) and had a longer door-to-balloon time (median 1.9 vs 1.6 hours, p = 0.047), lower rates of final Thrombolysis In Myocardial Infarction flow grade 2 to 3 in the intervened vessel (92.6% vs 97.8%, p = 0.007), and less frequent rates of complete or partial ST-segment resolution (66.3% vs 77.6%, p = 0.019). At 3 years, previous CABG was associated with a significantly greater incidence of major adverse cardiovascular events (36.4% vs 21.4%, p <0.001) owing to greater rates of mortality (11.2% vs 6.7%, p = 0.08), reinfarction (11.6% vs 7.1%, p = 0.09), stroke (5.1% vs 1.8%, p = 0.013), and ischemic target vessel revascularization (23.6% vs 12.9%, p = 0.005). The outcomes did not differ significantly as a function of the antithrombotic regimen. On multivariate analysis, previous CABG was an independent predictor of 3-year ischemic stroke (hazard ratio 3.57, 95% confidence interval 1.09 to 11.66). Intervention on the saphenous vein graft versus the native vessel predicted 3-year major adverse cardiovascular events (hazard ratio 2.69, 95% confidence interval 1.17 to 6.19). In the HORIZONS-AMI trial, previous CABG was associated with a delay to mechanical reperfusion and lower rates of percutaneous coronary intervention and patency of the infarct related vessel along with worse clinical outcomes.

Assessment of the ST segment deviation area as a potential physiological marker of the acute myocardial infarction

The purpose of this article is to present the assessment of the ST segment deviation area as a feature estimated from electrocardiographic signals to improve the current quantitative measures, which have low correlation with standard measures, such as biomarkers. In total 20 subjects were involved in the study. They were classified into two distinct groups (anterior and inferior) related to the localization of the acute myocardial infarction (AMI). The area of the ST segment was calculated by using customized software developed in Matlab®. From the analysis of this parameter it may be possible to correlate the ST deviation area with the necrosis risk area on myocardial tissue. The correlation between the ST area estimates were compared with Aldrich score, which uses the height of the J point instead of the area. It was calculated the correlation between the ST area, the Aldrich score and biomarkers of myocardial injury in patients. A Spearman correlation coefficient of 0.58 was estimated when comparing Aldrich score and the biomarkers for inferior AMI. The coefficient was 0.99 when correlating the biomarkers to the ST area. Therefore, this feature is a potential physiological marker of inferior AMI. The possibility of estimating the necrosis extent by means of electrocardiographic analysis allows for the reduction of cost and time since there may be no requirement for additional laboratorial exams, consequently improving the treatment efficacy and the prognosis of patients affected by acute myocardial infarction.

Baseline Q waves as a prognostic modulator in patients with ST-segment elevation: insights from the PLATO trial

BACKGROUND

Baseline Q waves may provide additional value compared with time from the onset of symptoms in predicting outcomes for patients with ST-segment elevation. We evaluated whether baseline Q waves superseded time from symptom onset as a prognostic marker of one-year mortality in patients with ST-segment elevation acute coronary syndrome. Our study was derived from data from patients undergoing primary percutaneous coronary intervention within 24 hours in the PLATelet inhibition and patient Outcomes trial

METHODS

Q waves on the baseline electrocardiogram were evaluated by a blinded core laboratory. We assessed the associations between baseline Q waves and time from symptom onset to percutaneous coronary intervention with peak biomarkers, ST-segment resolution on the discharge electrocardiogram, and one-year all-cause and vascular mortality.

RESULTS

Of 4341 patients with ST-segment elevation, 46% had baseline Q waves. Compared to those without Q waves, those with baseline Q waves were older, more frequently male, had higher heart rates, more advanced Killip class and had a longer time between the onset of symptoms and percutaneous coronary intervention. They also had higher one-year all-cause mortality than patients without baseline Q waves (baseline Q waves: 4.9%; no baseline Q waves: 2.8%; hazard ratio [HR] 1.78, 95% confidence interval [CI] 1.29-2.45, p < 0.001). Complete ST-segment resolution was greatest and all-cause mortality lowest among those with symptom onset three hours or less before percutaneous coronary intervention and no baseline Q waves. After multivariable adjustment, baseline Q waves, but not time from symptom onset, were associated with a significant increase in all-cause mortality (adjusted HR 1.42, 95% CI 1.10-2.01, p = 0.046) and vascular mortality (adjusted HR 1.58, 95% CI 1.09-2.28, p = 0.02).

INTERPRETATION

The presence of baseline Q waves provides useful additional prognostic insight into the clinical outcome of patients with ST-segment elevation. Clinical Trials.gov registration no. NCT00391872.

A randomized controlled trial of oxygen therapy in acute myocardial infarction Air Verses Oxygen In myocarDial infarction study (AVOID Study)

BACKGROUND

The role of routine supplemental oxygen for patients with uncomplicated acute myocardial infarction (AMI) has recently been questioned. There is conflicting data on the possible effects of hyperoxia on ischemic myocardium. The few clinical trials examining the role of oxygen in AMI were performed prior to the modern approach of emergent reperfusion and advanced medical management.

METHODS

Air Verses Oxygen In myocarDial infarction study (AVOID Study) is a prospective, multi-centre, randomized, controlled trial conducted by Ambulance Victoria and participating metropolitan Melbourne hospitals with primary percutaneous coronary intervention capabilities. The purpose of the study is to determine whether withholding routine supplemental oxygen therapy in patients with acute ST-elevation myocardial infarction but without hypoxia prior to reperfusion decreases myocardial infarct size. AVOID will enroll 490 patients, >18 years of age with acute ST-elevation myocardial infarction of less than 12 hours duration.

CONCLUSIONS

There is an urgent need for clinical trials examining the role of oxygen in AMI. AVOID will seek to clarify this important issue. Results from this study may have widespread implications on the treatment of AMI and the use of oxygen in both the pre-hospital and hospital settings.

Effect of prolonged Bivalirudin infusion on ST-segment resolution following primary percutaneous coronary intervention (from the PROBI VIRI 2 study)

Bivalirudin is widely used as an anticoagulant during percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction. However, an increase in acute stent thrombosis rates has been found in the HORIZONS-AMI trial. A prolonged infusion after PCI has been shown to be a safe and effective tool in patients undergoing urgent or elective PCI in the PROBI VIRI study. We examined the effects of prolonged drug infusion after primary PCI. From databases of 5 high-volume centers we compared a group of patients treated with a 4-hour prolonged infusion after PCI to 2 groups treated with a peri-PCI infusion and heparin plus abciximab. The primary study end point was >70% ST-segment resolution within 90 minutes after PCI; secondary end points were partial (>50%) ST-segment resolution within 90 minutes and intrahospital major and minor bleedings on the Acuity scale. The study population consisted of 264 patients undergoing primary PCI who were pretreated with aspirin and clopidogrel. The 3 study groups did not differ significantly by baseline characteristics. The primary end point was achieved in 69.8%, 48.8%, and 69.6% of patients in the prolonged bivalirudin, bivalirudin, and heparin/abciximab groups, respectively (p = 0.048 for prolonged vs standard infusion, p = 0.98 for prolonged infusion vs abciximab). Major bleedings and other secondary study end points were not significantly different among study groups. In conclusion, a strategy of prolonged bivalirudin infusion after primary PCI seems equivalent to a strategy with heparin plus abciximab, with an improvement in standard infusion in obtaining early microvascular reperfusion.