Acute Coronary Occlusion Research Articles

Impact of maintenance dose of eptifibatide in patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention

BackgroundST-segment elevation myocardial infarction (STEMI) is usually caused by a rupture in the atherosclerotic plaque, followed by platelet aggregation which ultimately leads to acute coronary artery occlusion. So far, few studies have investigated the effect of maintenance dose of Eptifibatide (glycoprotein IIb/IIIa inhibitor) in STEMI patients who underwent primary percutaneous coronary intervention (PPCI). Therefore, in this study, we investigated the effect of maintenance dose of Eptifibatide in patients with STEMI who underwent PPCI. 264 patients who had acute chest pain suggestive of STEMI were entered in the study. All patients received the same dose of bolus dose of Eptifibatide in the cardiac catheterization laboratory. Then the patients were randomly divided into two groups, one group (n = 147) received a maintenance dose of intravenous Eptifibatide (infusion of 2 μg/kg/min) and the other group (n = 117) did not receive this treatment. Standard medical treatment of STEMI after PPCI was performed based on guidelines and the same in both groups. All patients were evaluated 1, 2, and 3 months after the start of treatment in terms of predicted outcomes.ResultsThe occurrence of 3-month major adverse cardiovascular events (MACE) between the case and control groups did not have a statistically significant difference (28.6% versus 35.0%; P value: 0.286). Also, investigations showed that the rate of re-infarction (P value: 0.024) and target lesion revascularization (P value: 0.003) was significantly lower in the group that received Eptifibatide infusion.ConclusionsEptifibatide maintenance dose infusion in patients who undergo PPCI in the context of STEMI, does not significantly reduce MACE, although it does significantly reduce re-infarction and target lesion revascularization. It also does not increase the risk of bleeding and cerebrovascular events.

FOCUS may detect wall motion abnormalities in patients with ACS

BackgroundChest pain is a common presentation to the Emergency Department (ED) with roughly 6 million visits a year. The primary diagnostic modality for the identification of acute coronary syndrome (ACS) is the electrocardiogram (ECG), which is used to screen for electrocardiographic findings representing acute coronary occlusion. It is known that the ischemia generated by an acutely occluded coronary vessel generates a wall motion abnormality which can be visualized by echocardiogram; however, emergency physician-performed focused cardiac ultrasound (FOCUS) currently does not have a formal role in the diagnosis of OMI within the emergency department. PurposeWe sought to define the characteristics of FOCUS performed by emergency physicians of variable training levels in the identification of RWMA in patients presenting to the emergency department with high suspicion for ACS before undergoing cardiac catheterization or formal echocardiography. We also explored whether RWMA was associated with OMI in these patients. MethodsWe performed a structured, retrospective review of adult patients presenting to a large, academic, tertiary care center with suspected ACS from July 1st, 2019, and October 24th, 2020. Patients were included if they underwent FOCUS in the ED during the time-period above for suspected ACS looking for RWMA and FOCUS images were stored and reviewable in our middleware software. The primary outcome was the accuracy, sensitivity, and specificity of FOCUS compared to formal echocardiography for the detection of RWMA. Secondary outcomes were sensitivity of FOCUS compared to formal echocardiography for detection of RWMA in patients with and without cardiac catheterization proven OMI and sensitivity and specificity of FOCUS operators based on training. ResultsFOCUS for RWMA performed by emergency physicians had a sensitivity of 94% (95% CI, 82–98), specificity 35% (95% CI, 15–61), and overall accuracy of 78% (95% CI, 66–87). Of all subjects, 82% underwent urgent or emergency coronary angiography, of which 71% had OMI at the time of coronary angiography of the procedure. FOCUS identified RWMA in 87% of patients with coronary angiography proven OMI. Residents (PGY-1 - PGY-3) (n = 31) were able to detect RWMA with a sensitivity of 86% (95% CI, 64–96), a specificity of 56% (95% CI, 23–85%), and an accuracy of 77 (95% CI, 58–90%). Emergency ultrasound fellows and attendings (n = 34) were able to detect RWMA with a sensitivity of 85% (95% CI, 64–95%), a specificity of 75% (95% CI, 36–96%), and an accuracy of 82% (95% CI, 65–93%). ConclusionsOur retrospective study concludes FOCUS performed by emergency physicians may be used to detect RWMA in patients with high concern for acute coronary syndrome. This may have its greatest utility in patients presenting without STEMI where the ECG is felt to be equivocal, but the clinician has high concern for OMI, in which the presence of RWMA might result in emergent cath lab activation, though this requires further study. The presence of RWMA in such cases may help to rule in OMI as a cause; however, the absence of RWMA should exclude OMI. Further research is necessary to confirm these findings.

TCTAP C-136 Acute Coronary Occlusion After Drug-Eluting Balloon

TCTAP C-136 Acute Coronary Occlusion After Drug-Eluting Balloon

Impact of the use of cusp-overlap projection on the incidence of permanent pacemaker implantation post-transcatheter aortic valve implantation with self-expanding valves

IntroductionCurrent rates of permanent pacemaker implantation (PPMI) after transcatheter aortic valve implantation (TAVI) range between 3.4% and 25.9%. PPMI is associated with a worse prognosis. A lower valve implantation depth is associated with an increased risk of conduction disturbances. Theoretically, cusp-overlap projection (COP) has the potential to enable higher valve deployment. ObjectiveTo compare the 30-day PPMI incidence post-TAVI using self-expanding valves according to the fluoroscopic guidance technique. MethodsThis retrospective single-center study assessed consecutive patients undergoing TAVI with CoreValve™ valves between April 2019 and November 2021, grouped according to the fluoroscopic guidance technique (COP vs. coplanar implantation technique [CIT]). ResultsA total of 122 patients were included, predominantly women (52.5%), with a mean age of 81.6±5.5 years. COP was used in 49.2% of the sample. The CIT group had a significantly higher prevalence of previous beta-blocker use (p<0.01), lower baseline left ventricular ejection fraction (p=0.04) and a higher EuroSCORE II (p=0.02). The 30-day PPMI rate was 27.9% (n=34), with no significant difference between the COP and CIT groups (26.7% vs. 29.0%, p=0.77). Complete atrioventricular block was the main cause (38.5%). Likewise, mean fluoroscopy time (p=0.14) and contrast volume (p=0.35) used were similar between the two groups. Radiation dose was lower in the COP group (p=0.02). There was no significant difference between post-TAVI grades III and IV aortic valve regurgitation (p=0.27) and there were no cases of periprocedural acute coronary occlusion. ConclusionsThis study shows that the COP technique, although safe and not associated with increased complexity, did not significantly reduce the 30-day PPMI rate compared to the traditional CIT view.

Inferior Subtle ST Elevation. Would You Activate Cardiac Catheterization Laboratory?

BackgroundAccording to guidelines, patients with inferior myocardial infarction only qualify for emergent reperfusion if they have at least 1 mm of ST elevation in two contiguous inferior leads. Although this has remained the standard for years, acute coronary occlusion may occur in patients with nondiagnostic ST elevation. Accordingly, a paradigm change is instigated, shifting the focus to physiopathology (occlusion myocardial infarction) rather than ST criteria. Case ReportA middle-aged man presented to our emergency department with chest pain and subtle nondiagnostic electrocardiography (ECG) changes in inferior leads. A careful examination of aVL to detect ST depression in this lead was the key to successfully diagnosing occlusion myocardial infarction, allowing early revascularization of an occluded right coronary artery. Why Should an Emergency Physician Be Aware of This?Accurate diagnosis of coronary occlusion by means of ECG can be challenging in certain situations, as acute myocardial ischemia may occur in patients with nondiagnostic ST elevation, especially in the inferior leads. A thorough examination of aVL searching for ST depression is essential in these situations.

Acute Coronary Occlusion in Patients With Non-ST-Segment Elevation Out-of-Hospital Cardiac Arrest

BackgroundAccording to current guidelines, hemodynamic status should guide the decision between immediate and delayed coronary angiography (CAG) in out-of-hospital cardiac arrest (OHCA) patients without ST-segment elevation. A delayed strategy is advised in hemodynamically stable patients, and an immediate approach is recommended in unstable patients. ObjectivesThis study sought to assess the frequency, predictors, and clinical impact of acute coronary occlusion in hemodynamically stable and unstable OHCA patients without ST-segment elevation. MethodsConsecutive unconscious OHCA patients without ST-segment elevation who were undergoing CAG at Bern University Hospital (Bern, Switzerland) between 2011 and 2019 were included. Frequency and predictors of acute coronary artery occlusions and their impact on all-cause and cardiovascular mortality at 1 year were assessed. ResultsAmong the 386 patients, 169 (43.8%) were hemodynamically stable. Acute coronary occlusions were found in 19.5% of stable and 24.0% of unstable OHCA patients (P = 0.407), and the presence of these occlusions was predicted by initial chest pain and shockable rhythm, but not by hemodynamic status. Acute coronary occlusion was associated with an increased risk of cardiovascular death (adjusted HR: 2.74; 95% CI: 1.22-6.15) but not of all-cause death (adjusted HR: 0.72; 95% CI: 0.44-1.18). Hemodynamic instability was not predictive of fatal outcomes. ConclusionsAcute coronary artery occlusions were found in 1 in 5 OHCA patients without ST-segment elevation. The frequency of these occlusions did not differ between stable and unstable patients, and the occlusions were associated with a higher risk of cardiovascular death. In OHCA patients without ST-segment elevation, chest pain or shockable rhythm rather than hemodynamic status identifies patients with acute coronary occlusion.

Automated tissue Doppler imaging for identification of occluded coronary artery in patients with suspected non-ST-elevation myocardial infarction

PurposeIdentification of regional dysfunction is important for early risk stratification in patients with suspected non-ST-elevation myocardial infarction (NSTEMI). Strain echocardiography enables quantification of segmental myocardial deformation. However, the clinical use is hampered by time-consuming manual measurements. We aimed to evaluate whether an in-house developed software for automated analysis of segmental myocardial deformation based on tissue Doppler imaging (TDI) could predict coronary occlusion in patients with suspected NSTEMI.MethodsEighty-four patients with suspected NSTEMI were included in the analysis. Echocardiography was performed at admission. Strain, strain rate and post-systolic shortening index (PSI) were analyzed by the automated TDI-based tool and the ability to predict coronary occlusion was assessed. For comparison, strain measurements were performed both by manual TDI-based analyses and by semi-automatic speckle tracking echocardiography (STE). All patients underwent coronary angiography.ResultsSeventeen patients had an acute coronary occlusion. Global strain and PSI by STE were able to differentiate occluded from non-occluded culprit lesions (respectively − 15.0% vs. -17.1%, and 8.1% vs. 5.1%, both p-values < 0.05) and identify patients with an acute coronary occlusion (AUC 0.66 for both strain and PSI). Measurements of strain, strain rate and PSI based on TDI were not significantly different between occluded and non-occluded territories.ConclusionAutomated measurements of myocardial deformation based on TDI were not able to identify acute coronary occlusion in patients with suspected NSTEMI. However, this study confirms the potential of strain by STE for early risk stratification in patients with chest pain.

Damage to the left descending coronary artery due to radiofrequency ablation in the right ventricular outflow tract: Clinical case series and anatomical considerations.

The purpose of this paper was to highlight the importance of the anatomy of the right ventricular outflow tract (RVOT) and the proximity of the mid segment of the left anterior descending coronary artery (LAD) to the RVOT in the setting of ablation of ventricular arrhythmias in the RVOT. During the period from 2014 till 2017, five patients with injury to the LAD during ablation within RVOT were identified in three centers, in Belgium, Germany and Israel. The clinical characteristics, procedural data and follow up data, where available, are reported. The literature review over coronary artery damage during radiofrequency ablation procedures is provided and the anatomy of the RVOT and the neighboring vascular structures is discussed. We present five patients who underwent radiofrequency ablation of ventricular arrhythmias mapped to the inferior and anterior part of the RVOT, at the insertion of the right ventricular wall to the septum, whereby ablation resulted in occlusion in four and severe stenosis in one, of the mid segment of the LAD coronary artery. All patients underwent percutaneous coronary intervention and stenting, four of them immediately during the same procedure and one 3 days later because of lack of signs and symptoms of acute coronary occlusion. In conclusion, the mid segment of the LAD at the level of the second septal perforator/second diagonal branch runs in very close proximity to the endocardial aspect of the lower part of the RVOT and care should be taken during ablation of ventricular arrhythmias in this region. Additional imaging such as intracardiac echocardiography and coronary angiography may be helpful in avoiding complications.

Radiomics-based machine learning models in STEMI: a promising tool for the prediction of major adverse cardiac events.

To evaluate the potential value of the machine learning (ML) models using radiomic features of late gadolinium enhancement (LGE) and cine images on magnetic resonance imaging (MRI) along with relevant clinical information and conventional MRI parameters for the prediction of major adverse cardiac events (MACE) in ST-segment elevation myocardial infarction (STEMI) patients. This retrospective study included 60 patients with the first STEMI. MACE consisted of new-onset congestive heart failure, ventricular arrhythmia, and cardiac death. Radiomic features were extracted from cine and LGE images. Inter-class correlation coefficients (ICCs) were calculated to assess inter-observer reproducibility. LASSO (least absolute shrinkage and selection operator) method was used for radiomic feature selection. Seven separate models using a different combination of the available information were investigated. Classifications with repeat random sampling were done using adaptive boosting, k-nearest neighbor, naive Bayes, neural network, random forest, stochastic gradient descent, and support vector machine algorithms. Of the 1748 extracted radiomic features, 1393 showed good inter-observer agreement. With LASSO, 25 features were selected. Among the ML algorithms, the neural network showed the highest predictive performance on average (area under the curve (AUC) 0.822 ± 0.181). Of the best-calculated model, the one using clinical parameters, CMRI parameters, and selected radiomic features (model 7), the diagnostic performance was as follows: 0.965 AUC, 0.894 classification accuracy, 0.906 sensitivity, 0.883 specificity, 0.875 positive predictive value (PPV), and 0.912 negative predictive value (NPV). The radiomics-based ML models incorporating clinical and conventional MRI parameters are promising for predicting MACE occurrence in STEMI patients in the follow-up period. • Acute coronary occlusion results in variable changes at the cellular level ranging from myocyte swelling to myonecrosis depending on the duration of the ischemia and the metabolic state of the heart, which causes subtle heterogeneous signal changes that are imperceptible to the human eye with cardiac MRI. • Radiomics-based machine learning analysis of cardiac MR images is promising for risk prediction. • Combining MRI-derived parameters and clinical variables increases the accuracy of predictive models.

Clinical Features of the Aslanger Pattern to Compensate for the Limitation of ST-Elevation Myocardial Infarction (STEMI) Criteria.

ST-elevation is one of the most valuable electrocardiogram findingsto diagnose acute myocardial infarction. However, more than a quarter of acute coronary occlusions are missed by this criterion, causing a delay in revascularization. Therefore, there should be awareness of the limitations of the current criteria and new electrocardiographic findings are required as a diagnostic tool to compensate for them. The Aslanger patternis a specific electrocardiographic finding in acute inferior myocardial infarction with multivessel disease and allows the detection of inferior myocardial infarction that does not show ST-elevation, leading to rapid revascularization. However, in patients with the Aslanger pattern, the hemodynamic characteristics, such as the rate of shock and the use of mechanical circulatory support, as well as prognostic characteristics such as the in-hospital mortality rate, have not yet been clarified. In this study, we retrospectively surveyed the current practice on the basis of ST-elevation myocardial infarction (STEMI) criteria in patients with acute coronary artery occlusion presenting with inferior myocardial infarction. We examined the clinical characteristics of the Aslanger pattern. Based on the STEMI criteria, 71.8% (51/72) of patients were diagnosed with STEMI from an acute electrocardiogram, and 28.2% (21/78) were diagnosed with non-STEMI. As expected, ruling out in all acute coronary artery occlusions using STEMI criteria alone was difficult. A total of 48% of patients with non-STEMI had the Aslanger pattern. In addition, 80% of patients with the Aslanger pattern had multivessel disease, 30% had the use of the mechanical circulatory support, and 20% had in-hospital mortality. This study suggests that the Aslanger pattern is useful not only for diagnosis, but also for predicting hemodynamic collapse and a poor prognosis. Therefore, we should share information on Aslanger pattern with other physicians and use this pattern in daily practice.

Beyond the ST-segment in Occlusion Myocardial Infarction (OMI): Diagnosing the OMI-nous.

The ST-segment elevation (STE) myocardial infarction (MI)/non-STEMI (NSTEMI) paradigm has been the central dogma of emergency cardiology for the last 30 years. Although it was a major breakthrough when it was first introduced, it is now one of the most important obstacles to the further progression of modern MI care. In this article, we trace why a disease with an established underlying pathology (acute coronary occlusion [ACO]) was unintentionally labeled with a surrogate electrocardiographic sign (STEMI/NSTEMI) instead of pathologic substrate itself (ACO-MI/non-ACO-MI or occlusion MI [OMI]/non-OMI [NOMI] for short), how this fundamental mistake caused important clinical consequences, and why we should change this paradigm with a better one, namely OMI/NOMI paradigm.

Clinical and electrocardiographic features in acute total left main coronary artery occlusion without collateral circulation

BackgroundsStudy concerning the clinical features, electrocardiogram (ECG) findings and outcomes in patients presenting with acute total occlusion of left main coronary artery (LM) without collateral circulation is limited. Methods25 patients with acute total LM occlusion without collateral circulation by emergency coronary angiography, from muti-center registry, were retrospectively studied. The clinical and angiographic characteristics, ECG and in-hospital mortality were reviewed. ResultsNineteen patients (76%) presented with cardiogenic shock. Twelve (60%, 12/20) patients had coronary slow flow or no reflow phenomenon after primary percutaneous coronary intervention (PCI). The in-hospital mortality rate was 88% (n = 22). All the patients presented with ST-segment elevation myocardial ischemia (STEMI) pattern, mostly involving leads I, aVL, V2, V3, V4, V5 and ST-segment depression in leads II, III and aVF. ConclusionsAcute total LM occlusion without collateral circulation portends high in-hospital mortality. Anterior ST elevation in the precordial leads from V2 to V4 through V6, and ST elevation in leads I and aVL, accompanying with ST depression in the inferior leads is associated with acute total LM occlusion without collateral circulation.

Kenichi Harumi Plenary Address at Annual Meeting of the International Society of Computers in Electrocardiology: “What Should ECG Deep Learning Focus on? The diagnosis of acute coronary occlusion!”

According to the STEMI paradigm, only patients whose ECGs meet STEMI criteria require immediate reperfusion. This leads to reperfusion delays and significantly increases the mortality for the quarter of “non-STEMI” patients with totally occluded arteries. The Occlusion MI (OMI) paradigm has developed advanced ECG interpretation to identify this high-risk group, including examining the ECG in totality and assessing ST/T changes in proportion to the QRS. If neural networks are only developed based on STEMI databases and to identify STEMI criteria, they will simply reinforce a failed paradigm. But if deep learning is trained to identify OMI it could revolutionize patient care. This article reviews the paradigm shift from STEMI and OMI, and examines the potential and pitfalls of deep learning. This is based on the Kenichi Harumi Plenary Address at the Annual Meeting of the International Society of Computers in Electrocardiology, given by OMI expert Dr. Stephen Smith.

Clinical validation of a 13-lead electrocardiogram derived from a self-applicable 3-lead recording for diagnosis of myocardial supply ischaemia and common non-ischaemic electrocardiogram abnormalities at rest.

In this study, we compare the diagnostic accuracy of a standard 12-lead electrocardiogram (ECG) with a novel 13-lead ECG derived from a self-applicable 3-lead ECG recorded with the right exploratory left foot (RELF) device. The 13th lead is a novel age and sex orthonormalized computed ST (ASO-ST) lead to increase the sensitivity for detecting ischaemia during acute coronary artery occlusion. A database of simultaneously recorded 12-lead ECGs and RELF recordings from 110 patients undergoing coronary angioplasty and 30 healthy subjects was used. Five cardiologists scored the learning data set and five other cardiologists scored the validation data set. In addition, the presence of non-ischaemic ECG abnormalities was compared. The accuracy for detection of myocardial supply ischaemia with the derived 12 leads was comparable with that of the standard 12-lead ECG (P = 0.126). By adding the ASO-ST lead, the accuracy increased to 77.4% [95% confidence interval (CI): 72.4-82.3; P < 0.001], which was attributed to a higher sensitivity of 81.9% (95% CI: 74.8-89.1) for the RELF 13-lead ECG compared with a sensitivity of 76.8% (95% CI: 71.9-81.7; P < 0.001) for the 12-lead ECG. There was no significant difference in the diagnosis of non-ischaemic ECG abnormalities, except for Q-waves that were more frequently detected on the standard ECG compared with the derived ECG (25.9 vs. 13.8%; P < 0.001). A self-applicable and easy-to-use 3-lead RELF device can compute a 12-lead ECG plus an ischaemia-specific 13th lead that is, compared with the standard 12-lead ECG, more accurate for the visual diagnosis of myocardial supply ischaemia by cardiologists.

Acute Left Circumflex Coronary Artery Occlusion - Diagnostic Problems of Initial Electrocardiographic Changes.

Background: Acute coronary syndrome (ACS) with occlusion of the left circumflex coronary artery (LCX) poses diagnostic problems that may lead to a delay in reperfusion.Methods and Results: From a group of 1,269 consecutive patients with ACS, 138 patients with ACS due to LCX occlusion were analyzed for clinical, electrocardiographic, and angiographic presentations, as well as door-to-balloon (DTB) time. Electrocardiographic changes were classified into 4 patterns: ST-segment elevation in inferior/lateral leads (ST-E); ST-segment depression in V1–V4 (ST-D); no significant ST changes (No-ST); and others. The No-ST group was associated with a longer DTB time (P<0.0001) compared with the ST-E and ST-D groups. Compared with the No-ST and ST-E groups, the ST-D group presented with a more advanced Killip class (P=0.003), greater peak creatine phosphokinase (P=0.007) and peak creatine kinase-MB (P=0.006), more frequent proximal LCX occlusion (P=0.007), and worse 1-year outcomes (P=0.0034).Conclusions: One-third of ACS patients with LCX occlusion showed no ST-segment changes, resulting in significantly longer DTB time. Improving diagnostic accuracy is challenging but critical to avoid delayed reperfusion in these patients without electrocardiographic changes.

Differential electrocardiographic changes related to the culprit coronary artery in patients with acute myocardial infarction and left bundle branch block

Abstract Background The electrocardiographic (ECG) recognition of acute myocardial infarction (AMI) in patients with concurrent left bundle branch block (LBBB) is hampered by background changes in QRS complex duration and ST segment, potential directly caused by LBBB. Currently available ECG algorithms were constructed to suspect the presence of AMI but they not take into a count the culprit coronary artery and this fact could explain their low sensitivity. Objectives To analyze the influence of the culprit coronary artery on the ECG changes and on the diagnostic yielding of ECG algorithms in patients with acute myocardial infarction and LBBB. Methods We analyzed the index ECG of 240 patients with acute chest pain and LBBB referred to emergent coronary angiography. Patients were classified in 3 groups according their coronary anatomy: a) acute coronary occlusion (n=48); b) critical non occlusive lesion (n=45); and c) absence of coronary lesions (n=76). In all ECGs we measured the ST-segment shifts and QRS duration and compared the pattern of changes in relation to the culprit coronary artery. Results Location of the culprit coronary artery induced differential ECG patterns: a) mean ST segment elevation ≥3mm in leads V2-V3 in patients with LAD occlusion (n=27); b) absence of ST segment depression in leads V5-V6 in LCX occlusion (n=11); and c) mean ST segment elevation ≥1.5 mm in leads III-aVF and attenuation of the ST elevation in leads V1-V2 (mean &amp;lt;1mm) in cases of RCA occlusion (n=10). Patients with critical non occlusive lesions (n=45) did not show particular ECG changes. QRS complex duration was longer in patients with LCX occlusion. Sensitivity of the Sgarbossa score was around 50%, sensitivity of the Smith score was &amp;gt;70% in all coronary groups and sensitivity of Barcelona score was really good for LCX and RCA occlusion. The combination of the three algorithms increased the sensitivity in all groups (&amp;gt;74%) but more markedly in patients with LCX occlusion (90.9%) and RCA occlusion (90%). All the ECG algorithms lose sensitivity for the critical non occlusive lesions group. Conclusions Patients with acute myocardial infarction and LBBB present distinct patterns of QRS and ST segment changes and different diagnostic yielding of ECG algorithms in relation to the location of the occluded coronary artery. Data suggest that ECG prediction of the culprit coronary artery in patients with AMI and LBBB might be possible using artificial intelligence systems in larger series of patients. Funding Acknowledgement Type of funding sources: None.

Comparing Door-To-Balloon Time between ST-Elevation Myocardial Infarction Electrocardiogram and Its Equivalents.

Background: In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (pPCI), longer door-to-balloon (DTB) time is known to be associated with an unfavorable outcome. A percentage of patients with acute coronary occlusion present with atypical electrocardiographic (ECG) findings, known as STEMI-equivalents. We investigated whether DTB time for STEMI-equivalent patients was delayed. Methods: This is a retrospective study including patients arriving at an emergency department with the acute coronary syndrome in whom emergent pPCI was performed. ECGs were classified into STEMI and STEMI-equivalent groups. We compared DTB time, with its components, between the groups. We also investigated whether STEMI-equivalent ECG was an independent predictor of DTB time delayed for more than 90 min. Results: A total of 180 patients were included in the present study, and 23 patients (12.8%) presented with STEMI-equivalent ECGs. DTB time was significantly delayed in patients with STEMI-equivalent ECGs (89 (80–122) vs. 81 (70–88) min, p = 0.001). Multivariable logistic regression analysis showed that STEMI-equivalent ECG was an independent predictor of delayed DTB time (odds ratio: 4.692; 95% confidence interval: 1.632–13.490, p = 0.004). Conclusions: DTB time was significantly delayed in patients presenting with STEMI-equivalent ECGs. Prompt recognition of STEMI-equivalent ECGs by emergency physicians and interventional cardiologists might reduce DTB time and lead to a better clinical outcome.

Non-specific intraventricular conduction delay or atypical LBBB - How to predict acute coronary occlusion?

We describe two patient cases with acute coronary syndrome (ACS) and broad QRS in the acute phase electrocardiogram (ECG). The patients' ECG findings resembled left bundle branch block (LBBB), but with atypical features. Broad QRS not fulfilling the criteria for LBBB or right bundle branch block (RBBB) is diagnosed as non-specific intraventricular conduction delay (NSIVCD). The case report deals with the challenges of predicting acute coronary occlusion in patients with NSIVCD in their acute phase ECG. In one of the cases, the ECG changed from typical LBBB to NSIVCD or atypical LBBB with the development of systolic dysfunction and clinical heart failure.

TCT-8 Frequency, Predictors, and Impact of Acute Coronary Occlusion in Patients With Out-of-Hospital Cardiac Arrest and Non–ST-Segment Elevation

TCT-8 Frequency, Predictors, and Impact of Acute Coronary Occlusion in Patients With Out-of-Hospital Cardiac Arrest and Non–ST-Segment Elevation

Effect of Classic or Delayed Ischemic Conditioning on Left Ventricular Pressure-Volume Relations in Dogs

Objective: Non-pharmacologic interventions such as ischemic conditioning (IC) markedly reduce infarct size but it remains unclear whether this protection translates to a significant attenuation of ischemia-mediated LV contractile dysfunction. In this study we evaluated pressure-volume (P-V) data obtained by the load-insensitive conductance catheter method, to examine LV pressure-volume (LVP-V), diastolic function and ventricular-arterial coupling in anesthetized dogs exposed to ischemic conditioning (IC) or delayed IC (dIC; 48h prior to ischemia). The objective was to determine if IC, or dIC pre-treatment could influence post-ischemic recovery of LV contractile function. Methods: Three groups were studied – nIC, IC and dIC; all dogs underwent 90-min acute coronary occlusion (CO) followed by 180-min reperfusion (REP). IC consisted of 4 cycles of 5-min CO and 5-min REP of the left main coronary artery. LV P-V relations were constructed under steady-state conditions (by transient occlusion of the inferior vena cava) prior to IC treatment and at the end of the experiment; P-V loop data was also acquired at different points during the experiment to evaluate changes in end-systolic and end-diastolic parameters. Results: During CO dP/dtmax and dP/dtmin (indicator of rate of LV relaxation) decreased significantly compared to baseline in the IC group; these variables were unchanged in the dIC group. LVEF decreased during CO and REP in the nIC and IC groups but was stable in the dIC group. Tau was increased only in the IC group during CO and REP. ESV and EDV increased significantly in all groups during CO and REP; none of these negative effects was resorbed by the end of the experimental period. Conclusions: Diminished LV contractile function caused by CO did not improve with IC, or dIC pre-treatment, despite significant reduction in infarct size.