Complete Coronary Occlusion Research Articles

H-type hypertension is a risk factor for chronic total coronary artery occlusion: a cross-sectional study from southwest China

BackgroundChronic total coronary occlusion (CTO) is serious and the "last bastion" of percutaneous coronary intervention. Hypertension and hyperhomocysteinemia (HHCY) are synergistic and significantly increase cardiovascular event risk. The relationship between H-type hypertension and CTO remains unclear; thus, this cross-sectional study investigated this potential association.MethodsBetween January 2018 and June 2022, 1446 individuals from southwest China were recruited to participate in this study. CTO was defined as complete coronary artery occlusion persisting for over three months. H-type hypertension was defined as hypertension with plasma homocysteine levels ≥ 15 µmol/L. Multivariate logistic regression models were applied to assess the association between H-type hypertension and CTO. Receiver operating characteristic (ROC) curves were generated to determine the accuracy of H-type hypertension in predicting CTO.ResultsOf the 1446 individuals, 397 had CTO, and 545 had H-type hypertension. After multivariate adjustment, the odds ratio (OR) for CTO in individuals with H-type hypertension was 2.3-fold higher (95% CI 1.01–5.26) than that in healthy controls. The risk of CTO is higher in individuals with H-type hypertension than in those with isolated HHCY and hypertension. The area under the ROC curve for CTO was 0.685 (95% CI, 0.653–0.717) for H-type hypertension.ConclusionsIn southwest China, H-type hypertension is significantly related to the occurrence of CTO.Trial registrationThis retrospective study was registered with the Chinese Clinical Trials Registry (http://www.chictr.org.cn, ChiCTR2100050519.2.2).

Copeptin levels as a predictor of acute kidney injury (AKI) in ST-segment elevation myocardial infarction (STEMI)

Background: Acute myocardial infarction is a cardiac emergency with a high mortality rate. The ST-segment elevation myocardial infarction (STEMI) patients have complete coronary artery occlusion, so they usually present with severe symptoms and a higher risk of early mortality. The prevalence of type 1 cardiorenal syndrome (CRS), namely acute kidney injury (AKI) in acute heart failure, is 24%-45%. Copeptin is the C-terminus of pro-vasopressin's peptide, the arginine vasopressin's precursor. This study aimed to prove whether copeptin is a predictor of AKI in the STEMI patient population after adjusting for confounding variables. Methods: This prospective cohort study was conducted between March and December 2020. Eighty-four subjects with STEMI who came to the emergency department at Dr. Moewardi Hospital and met the inclusion and exclusion criteria were enrolled. The data were analyzed to calculate relative risk and 95%CI for each variable, followed by multivariate analysis with logistic regression. Data were analyzed using SPSS version 23 for Windows. Results: The prevalence of AKI in this study was 67%. The copeptin level at the cut-off of 273.6 pg/ml has an AUC of 0.774 (95%CI=0.676-0.873, p=0.000). Copeptin level, acute heart failure, and risk of renal ischemia associated with AKI in STEMI. Copeptin >273.6 pg/ml showed a statistically significant association with AKI in STEMI (adjusted RR 5.298; 95%CI=1.771-15.847; p=0.003). Conclusion: Copeptin levels higher than 273.6 pg/ml is known to be an independent predictor of AKI in STEMI.

Influence of circadian rhythms and seasonal and annual variations on acute myocardial infarction incidence

Background/Aim: Acute myocardial infarction (AMI) is a consequence of complete coronary artery occlusion. There is a considerable seasonal variation in the incidence of AMI. The aim of the study was to establish a circadian and seasonal pattern of AMI. Methods: A retrospective observational study was conducted, using the database of the Institute of Emergency Medical Service of the City of Novi Sad. The study included 982 patients, both male and female, diagnosed with AMI (I.21 - ICD-10 code) in the period between 15 March 2018 and 14 March 2022. Data were classified according to the time of the day, days of the week, quarters and months. Data were analysed by using descriptive statistical methods, Mann-Whitney U test, Chi-squared test and Fisher's exact test. Results: AMI most frequently occurred between 6 am and 2 pm (389; 39.6 %). A statistically significant incidence of AMI was calculated for the periods between 6 am and 2 pm (ch2 = 39.69; p < 0.001) and between 2 pm and 10 pm (ch2 = 28.06; p < 0.001). Most cases of AMI were noted on Monday (153; 15.6 %) and in January (93; 9.5 %). The highest incidence of AMI was in the period between 15 March 2021 and 14 March 2022 (304; 31.0 %), while the lowest incidence was noted between 15 March 2019 and 14 March 2020 (190; 19.3 %). Conclusion: Circadian, seasonal and annual rhythm may have a significant impact on the incidence of AMI. This fact can have an important role in the prevention, timely recognition and adequate treatment of acute coronary disease.

Wellens Syndrome on the basis of critical occlusion of the medial segment of the anterior ventricultural branch of the left coronary artery (clinical type)

The aim of the work is to determine the peculiarities of the clinical course of Wellens syndrome due to the presence of critical occlusion of the medial segment of the anterior interventricular coronary artery bifurcation.Material and Methods. Clinical manifestations of the disease, including dynamics of ECG changes; coronary angiography data; results of echocardiographic and laboratory tests.Results. This article presents the peculiarities of the clinical course of Wellens syndrome in patient L., 70, who met the currently recognized diagnostic criteria of the syndrome, but the critical occlusion of the anterior interventricular branch of the left coronary artery was localized in its medial segment. Along with this, there was hemodynamically irrelevant stenosis of the proximal coronary artery section (60%). Electrocardiographic changes were consistent with pattern B (deeply inverted T waves in V2-V6). Сonditional normalization of the T waves, indicating the absence of repeated coronary artery occlusion after spontaneous reperfusion. Stenting of the anterior interventricular coronary artery vein of the left coronary artery prevented the possible occurrence of “stuttering” pattern and the occurrence of myocardial infarction.Conclusions. Acute coronary syndrome with complete coronary artery occlusion is often accompanied by spontaneous reperfusion, which contributes to the relief of chest pain and the appearance of characteristic T waves on ECG and is the basis of the so-called Wellens syndrome. The most frequent localization of coronary artery occlusion is the proximal segment of the anterior interventricular branch of the left coronary artery, but we witnessed the occlusion in the medial segment of these coronary arteries. Immediate coronary angiography with stenting of the occluded artery will prevent the occurrence of myocardial infarction in the patient.

Meta-analysis on efficacy of PCI treatment or conservative treatment among patients with chronic total occlusions

Objective: To compare the efficacy between percutaneous coronary intervention (PCI) and conservative medication treatment in chronic total occlusions (CTO) patients. Methods: It was a meta-analysis.Articles on drug therapy and PCI for complete coronary artery occlusion were retrieved from Pubmed, Embase and Web of Science databases. The search time was from the database construction to May 10, 2020, and the following search criteria were used for the search "chronic total occlusion" "percutaneous coronary intervention" and "medical therapy". References from searched literatures were also searched to identify more eligible studies. Randomized controlled trials (RCT) and cohort studies comparing efficacy of PCI versus oral medication as well as medication as initial therapy option for CTO patients with single or multiple lesions were included. The primary endpoints included all-cause death, cardiac death, recurrent myocardial infarction, re-revascularization, major adverse cardiac events (MACE) and stroke. Data were analyzed with ReviewManager5.3.0 software. Pooled effect size RR and 95%CI were calculated by randomization effect model. Heterogeneity was evaluated by I2. Bege test was used to evaluate publication bias. Subgroup analyses were performed for RCT and cohort studies. Results: A total of 1 079 articles were retrieved and 16 studies (RCT=4, cohort study=12) were included with 12 223 patients. Fourteen publications (RCT=4, cohort study=10) reported all-cause death post PCI and/or drug therapy. Results showed that risk of all-cause death was significantly lower in PCI group than in drug therapy group (RR=0.45,95%CI 0.39-0.53,P<0.001);subgroup analysis showed that risk of all-cause death was significantly lower in PCI group than in drug therapy group from cohort studies (RR=0.44,95%CI 0.38-0.52,P<0.001),but comparable in RCT (P=0.27). Thirteen studies (RCT=3, cohort study=10) reported cardiac death post PCI and/or drug therapy. Results showed that risk of cardiac death was significantly lower in PCI group than in drug therapy group (RR=0.44,95%CI 0.35-0.55,P<0.001);subgroup analysis showed that risk of cardiac death was significantly lower in PCI group than in drug therapy group in cohort studies (RR=0.43,95%CI 0.34-0.54,P<0.001),but not in RCT (P=0.25). Fourteen publications (RCT=4, cohort study=10) reported recurrent myocardial infarction post PCI and/or drug therapy. Results showed that risk of recurrent myocardial infarction was significantly lower in PCI group than in drug therapy group (RR=0.62,95%CI 0.44-0.88,P=0.007);subgroup analysis showed that risk of recurrent myocardial infarction was significantly lower in PCI group than in drug therapy group from cohort studies (RR=0.56,95%CI 0.40-0.78,P=0.000 5),but comparable in RCT (P=0.17). Fourteen publications (RCT=4, cohort study=10) reported re-revascularization post PCI and/or drug therapy. Results showed that risk of re-revascularization was comparable between PCI group and drug therapy group (P=0.91);subgroup analysis showed that risk of re-revascularization was comparable between PCI group and drug therapy group both in cohort study and RCT (P=0.60 and 0.41, respectively). Eleven publications (RCT=3, cohort study=8) reported MACE post PCI and/or drug therapy. Results showed that risk of MACE was significantly lower in PCI group than in drug therapy group (RR=0.74,95%CI 0.59-0.93,P=0.03);subgroup analysis showed that risk of MACE was significantly lower in PCI group than in drug therapy group in cohort studies (RR=0.72,95%CI 0.56-0.93,P=0.01), but not in RCT (P=0.8). Six publications (RCT=2, cohort study=4) reported stroke post PCI and/or drug therapy. Results showed that risk of stroke was comparable between PCI and drug therapy groups (RR=0.62,95%CI 0.32-1.20, P=0.15);subgroup analysis showed that risk of stroke was comparable between PCI and drug therapy groups both in cohort studies and RCT (P=0.48 and 0.32, respectively). Conclusion: Compared with oral drug therapy, PCI may have better efficacy for CTO patients based on results from this cohort study.

PO-626-07 VALIDATION OF A PORTABLE DEVICE FOR HF-ECG IN ISCHEMIA DETECTION DURING CORONARY BALLOON INFLATION IN ANGIOPLASTY - BRINGING THE PHYSIOLOGY LAB TO THE BEDSIDE !

High frequency QRS (HfQRS) analysis for rapid assessment of myocardial ischemia has never been evaluated owing to the logistical challenges of signal recording. We aim to evaluate, in a pilot study, the correlation between the HFQRS changes recorded on a novel wearable Sydäntek 12 lead ECG patch with balloon inflation induced ischaemia. To document utility of a portable device, Sydäntek, in ECG and HFECG during multiple balloon inflations. 10 patients (M:F = 8:2) undergoing coronary intervention for medically refractory chronic stable angina were screened for enrollment into the study ; 9/10 patients underwent the final recording. 1 patient was excluded owing to signal noise in the device due to reluctance in chest preparation. The mean recording time per case was 60+/-15 mins. ECG including HfQRS was recordable continuously during all intended times, using Sydäntek at 2k samples/secs. In 33 balloon inflation ischemia episodes , changes were seen on the HFQRS onset ∼ 10 secs, offset ∼45 secs after deflation . No significant changes were seen in the conventional ECG analysed for these upto ∼45 secs . Decrease in the amplitude of the HFQRS, and decrease in the real time RMS voltage of QRS in leads V2-V5 and the presence of RAZ ( reduced amplitude zone ) were considered to be changes suggestive of ischemia. RAZ disappeared ∼45 secs after the balloon deflation. The mean total ischemic was 1 +/-0.5 min per patient per balloon inflation. In this study , all 9 of the conventional ECGs were reported independently by 2 docs as not having significant ST-T changes of ischaemia. RAZ presence in HFQRS was seen in all 33 of complete coronary artery occlusion by balloon, in our study .There was reduction in the amplitude of HFQRS(mean 12+/-1 μV) and RMSv2-v5 (mean 7+/-0.5 μV) from the baseline during the inflation. Post intervention, both of the above parameters had a mean increase of 22+/-1 μV and 10+/-0.3 μV respectively. HFQRS measured using our novel, portable real time 12 lead ECG recording patch can reliably detect onset of coronary ischemia in a complete coronary occlusion even in absence of ST -T changes in 12 lead ECG . We submit this proof of concept for use in detecting ischemia in a variety of clinical situations including chest pain triage and post intervention monitoring.

When COVID-19 delays the management of an urgent heart condition: A rare case of a spontaneous dissection of two coronary arteries.

Some severe life‐threatening conditions could be misdiagnosed during the current COVID‐19 pandemic.

The effect of confounding data features on a deep learning algorithm to predict complete coronary occlusion in a retrospective observational setting.

Deep learning (DL) has emerged in recent years as an effective technique in automated ECG analysis. A retrospective, observational study was designed to assess the feasibility of detecting induced coronary artery occlusion in human subjects earlier than experienced cardiologists using a DL algorithm. A deep convolutional neural network was trained using data from the STAFF III database. The task was to classify ECG samples as showing acute coronary artery occlusion, or no occlusion. Occluded samples were recorded after 60 s of balloon occlusion of a single coronary artery. For the first iteration of the experiment, non-occluded samples were taken from ECGs recorded in a restroom prior to entering theatres. For the second iteration of the experiment, non-occluded samples were taken in the theatre prior to balloon inflation. Results were obtained using a cross-validation approach. In the first iteration of the experiment, the DL model achieved an F1 score of 0.814, which was higher than any of three reviewing cardiologists or STEMI criteria. In the second iteration of the experiment, the DL model achieved an F1 score of 0.533, which is akin to the performance of a random chance classifier. The dataset was too small for the second model to achieve meaningful performance, despite the use of transfer learning. However, 'data leakage' during the first iteration of the experiment led to falsely high results. This study highlights the risk of DL models leveraging data leaks to produce spurious results.

Obstructive sleep apnea during acute coronary syndrome is related to myocardial necrosis and wall stress

BackgroundThe relative contribution of pathophysiological mechanisms in acute coronary syndrome (ACS) towards obstructive sleep apnea (OSA) is not well-studied. We examined the correlation between severity of OSA and inflammation, myocardial necrosis, wall stress, and fibrosis. MethodsA total of 89 patients admitted with ACS underwent a sleep study during index admission. Plasma levels of high-sensitivity C-reactive protein (hs-CRP), troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded. ResultsThe recruited patients were divided into no (AHI <5 events/hour, 9.2%), mild (5-<15, 27.6%), moderate (15-<30, 21.8%), and severe (≥30, 41.4%) OSA. Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p = 0.005). They were also more likely to present with ST-segment elevation ACS (versus non-ST-segment elevation ACS) (p = 0.041), have undergone previous coronary artery bypass grafting (p = 0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p = 0.049), and have a larger left atrial diameter measured on echocardiography (p = 0.029). Likewise, the severe OSA group had higher plasma levels of hs-CRP (p = 0.004), troponin I (p = 0.017), and NT-proBNP (p = 0.004), but not ST2 (p = 0.10). After adjustment for the effects of confounding variables, OSA was independently associated with troponin I (ie, myocardial necrosis; p = 0.001) and NT-proBNP (ie, myocardial wall stress; p = 0.008). ConclusionSevere OSA during the acute phase of ACS was associated with extensive myocardial necrosis and high myocardial wall stress, but not with inflammation and myocardial fibrosis.

Effect of late culprit coronary artery revascularization on prognosis of patients with ST-elevation myocardial infarction

Aim. To evaluate the effect of culprit coronary artery revascularization after 48 hours from the symptoms’ onset on the prognosis of patients with ST-elevation myocardial infarction (STEMI).Material and methods. Of the 1172 patients admitted to City Clinical Hospital № 13 in 2018 due to STEMI, 43 patients (4%) were included in the retrospective study. There were following inclusion criteria: hospitalization after 48 hours from the symptoms’ onset, no clinical signs of myocardial ischemia, and complete coronary artery occlusion according to angiography. The mean age of the subjects was 61,3±10,6 years, 34 (79%) men and 9 (21%) women. The subjects were divided into two groups: group 1 (n=22) — management with percutaneous coronary intervention (PCI), group 2 (n=21) — management with medications. The groups differ only in the severity of coronary atherosclerosis according to SYNTAX score: group 1 — 14,0 [11.0; 19.5], group 2 — 26,0 [16,5; 31,0] (p=0,009). At the end of inpatient treatment, patients underwent echocardiography. Death and myocardial infarction were monitored during hospitalization and for 12 months after discharge.Results. During hospitalization, 2 patients died (4,7%; one in each group, p=1,00). No recurrent MI were reported. The left ventricular ejection fraction in the PCI group was 50 [46; 54] %, in the group with drug therapy — 43 [38; 50] % (p=0,01). Out of 43 included patients, long-term outcomes were followed up in 32 (74%). Among them, 1 (5,8%) patient died in group 1, 6 (33,3%) patients — in group 2 (p=0,04). In total, death or recurrent MI in the first group was observed in 2 (12%) patients, in the second group — in 5 (33%) patients (p=0,14).Conclusion. Revascularization of a fully occluded culprit coronary artery in stable patients with STEMI after 48 hours of symptoms’ onset is associated with a higher inhospital left ventricular ejection fraction and a decrease in 12-month mortality.

1013 Cardiovascular Biomarkers and Pathophysiological Insights into Obstructive Sleep Apnea During Acute Coronary Syndrome

Abstract Introduction Obstructive sleep apnea (OSA) is prevalent and carries prognostic implication in patients with acute coronary syndrome (ACS). The relative contribution of pathophysiological mechanisms in ACS towards OSA is not well-studied. We examined the correlation between severity of OSA and myocardial necrosis, inflammation, wall stress, and fibrosis. Methods A total of 89 patients admitted with ACS underwent an overnight sleep study during index admission. Plasma levels of peak troponin I, high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and suppression of tumorigenicity 2 (ST2) were prospectively analyzed. Two patients diagnosed with central sleep apnea were excluded. Results The recruited patients were divided into no (AHI &amp;lt;5 events/hour, 9.2%), mild (5-&amp;lt;15, 27.6%), moderate (15-&amp;lt;30, 21.8%), and severe (≥30, 41.4%) OSA. The respective Epworth Sleepiness Scale scores were 3.8±3.7, 5.3±4.9, 4.0±2.8, and 5.5±4.5 (p=0.734). Compared to the no, mild and moderate OSA groups, the severe OSA group had a higher body mass index (p=0.005). They were also more likely to present with ST-segment elevation ACS (vs non-ST-segment elevation ACS) (p=0.041), have undergone previous coronary artery bypass grafting (p=0.013), demonstrate complete coronary occlusion during baseline coronary angiography (p=0.049), and have a larger left atrium diameter measured on echocardiography (p=0.029). Likewise, the severe OSA group had higher plasma levels of troponin I (10584±13078, 11699±20130, 19280±30670, 37571±31269 µg/L; p=0.017), hs-CRP (8.1±9.2, 23.1±52.3, 9.3±17.1, 39.4±44.7 mg/L; p=0.004), and NT-proBNP (667±604, 765±856, 636±728, 1395±1220 pg/mL; p=0.004), but not ST2 (p=0.10). After adjusting for the effects of the confounding variables, severe OSA was independently associated with troponin I (i.e., myocardial necrosis; OR 1.00003, 95% CI 1.000013-1.000048; p=0.001) and NT-proBNP (i.e., myocardial wall stress; OR 1.00081, 95% CI 1.00021-1.00141; p=0.008). Conclusion Severe OSA during the acute phase of ACS was associated with extensive myocardial necrosis and myocardial wall stress, but not with inflammation and myocardial fibrosis. Support Nil

T2 and T2∗ mapping in ex situ porcine myocardium: myocardial intravariability, temporal stability and the effects of complete coronary occlusion.

Diagnosis of ischaemia-related sudden cardiac death in the absence of microscopic and macroscopic ischaemic lesions remains a challenge for medical examiners. Medical imaging techniques increasingly provide support in post-mortem examinations by detecting and documenting internal findings prior to autopsy. Previous studies have characterised MR relaxation times to investigate post-mortem signs of myocardial infarction in forensic cohorts. In this prospective study based on an ex situ porcine heart model, we report fundamental findings related to intramyocardial variability and temporal stability of T2 as well as the effects of permanent coronary occlusion on T2 and T2∗ relaxation in post-mortem myocardium. The ex situ porcine hearts included in this study (n= 19) were examined in two groups (Ss, n= 11 and Si, n= 8). All magnetic resonance imaging (MRI) examinations were performed ex situ, at room temperature and at 3 T. In the Ss group, T2 mapping was performed on slaughterhouse porcine hearts at different post-mortem intervals (PMI) between 7 and 26 h. Regarding the intramyocardial variability, no statistically significant differences in T2 were observed between myocardial segments (p= 0.167). Assessment of temporal stability indicated a weak negative correlation (r=- 0.21) between myocardial T2 and PMI. In the Si group, animals underwent ethanol-induced complete occlusion of the left anterior descending artery. T2 and T2∗ mapping were performed within 3 h of death. Differences between the expected ischaemic and remote regions were statistically significant for T2 (p= 0.007), however not for T2∗ (p= 0.062). Our results provide important information for future assessment of the diagnostic potential of quantitative MRI in the post-mortem detection of early acute myocardial infarction.

2183Intravenous administration of IV-STATIN CARDIOSHIELD during myocardial infarction renders higher cardioprotection than oral atorvastatin given shortly after reperfusion: a translational CMR study

Abstract Background Statins are known to exert rapid cardioprotective effects irrespective of their lipid-lowering properties. Several trials have suggested that high-dose statin treatment may reduce cardiovascular complications in patients undergoing invasive management. However, the ideal timing and administration regime is not clear. Purpose We compared the cardioprotective effects derived from IV-STATIN CARDIOSHIELD® administered intravenously during myocardial infarction (MI) with those attained by oral atorvastatin administration shortly after reperfusion. This study was conducted in a preclinical pig model of MI by serial CMR imaging. Methods Diet-induced hypercholesterolemic pigs (N=21; cholesterol: 387±74mg/dL) were subjected to 90 minutes of complete coronary occlusion (closed-chest model of MI), then reperfusion was established and animals were kept for 42 days. Within this experimental design animals were distributed in 3 groups (G) (7animals/arm): G1) animals received an intravenous bolus (0.3mg/kg) of IV-STATIN during MI; G2) animals received an intravenous bolus of the vehicle during MI (placebo-control); and G3) animals were administered atorvastatin p.o. initiated within the first 2h post-MI (Atorva-post-MI). G1 and G3 animals remained on atorvastatin p.o. for the following 42 days whereas G2 controls received placebo-pills. We assessed cardiac damage and global and regional functional parameters by CMR at day3 and day42 post-MI. Myocardial samples were processed for molecular studies on cardiac remodeling-related parameters (collagen and AMPK). Results CMR analysis at day-3 revealed that G1 pigs showed a marked reduction in infarct size as compared to both G3 and G2 animals (19.1±2.8% LV vs. 29.0±1.8% and 29.3%±3.2%, respectively; p&lt;0.05) with a resultant 50% increase in myocardial salvage (p&lt;0.05 vs. both). At day-42 both G1 and G3 animals showed a significant decrease in the size of the scar vs. G2 animals; however, G1 animals showed a further 24% scar reduction as compared to G3 (14.4±1.1% vs. 18.8±1.0% LV; p&lt;0.05). Functional analyses revealed higher LVESV in G1 animals as compared to G2 (p&lt;0.05) and less wall motion abnormalities in the jeopardized myocardium (p&lt;0.05) vs. both groups at day42 post-MI. Collagen expression and AMPK activation were found to be significantly enhanced in the scar of G1 (p&lt;0.05 vs. both groups). No changes were detected in lipids levels or liver and renal parameters throughout the study in any pig group. Conclusions Intravenous IV-STATIN CARDIOSHIELD® treatment during MI limited cardiac damage and improved cardiac function and remodeling to a larger extent than when atorvastatin was administered orally shortly after reperfusion. Our results support this novel regime of intravenous administration of IV-STATIN CARDIOSHIELD® as a routine procedure during MI. Further investigation of the potential benefits of this new therapeutic approach in STEMI patients is warranted.

Wasp sting induced STEMI with complete coronary artery occlusion: a case of Kounis syndrome

A 45-year-old previously healthy man with minimal coronary artery disease on imaging presented with an acute MI after sustaining a wasp sting following previous non-eventful exposures throughout his life. This...

Coronary Thrombosis without Dissection following Blunt Trauma.

Blunt trauma to the chest resulting in coronary thrombosis and ST elevation myocardial infarction (STEMI) is a rare but well-described occurrence in adults. Angiography in such cases has generally disclosed complete epicardial coronary occlusion with thrombus, indistinguishable from the findings commonly found in spontaneous plaque rupture due to atherosclerotic disease. In all previously reported cases in which coronary interrogation with intravascular ultrasound (IVUS) was performed in association with acute revascularization, coronary artery dissection was implicated as the etiology of coronary thrombosis. We present the first case report of blunt trauma-associated coronary thrombosis without underlying atherosclerosis or coronary dissection, as documented by IVUS imaging.

Myocardial Infarction Related to Trauma.

Myocardial infarction (MI) secondary to acute coronary occlusion related to trauma is rare. A previously healthy man developed acute MI shortly after a motor vehicle accident. This case illustrates the feasibility of primary percutaneous coronary intervention for acute MI due to complete coronary artery occlusion related to trauma, including the use of manual thrombectomy, stents, and dual antiplatelet therapy. This approach requires the intervention of a multidisciplinary team in a Level 1 trauma center that can rapidly evaluate the patient and rule out other life-threatening injuries that could preclude antiplatelet therapy.

Abstract 18134: Cardiomyocyte Overexpression of the alpha1A-Adrenergic Receptor in the Rat Protects Post-Infarct Heart Failure through Angiogenesis and the MEK-ERK Pathway

α1A-Adrenergic receptors (α1A-AR) are important for regulating cardiac contractility, but whether they regulate coronary vessels is not known. To examine this we investigated the effects of chronic, complete coronary artery occlusion (CAO) in rats with cardiac myocyte-restricted transgenic (TG) α1A-AR overexpression, since protection of the heart with complete CAO requires increased blood flow. 4 weeks after permanent left anterior descending CAO TG rats displayed improved contractility vs. non-transgenic littermates (NTL) (n=8/group, p&lt;0.05): 23% higher in LV dP/dt (7188±167mmHg/s), 13% higher in LV ejection fraction (57±0.9) and 23% lower in end-systolic wall stress (LVSWS) (79±6dynes/cm2) compared to NTLs. The scar size at 4 wks after CAO was significantly smaller in TG rats (18±2%) compared to NTL rats (28±3%), p&lt;0.05, but more importantly there were increased blood vessels within the scar in the TG rat hearts suggesting angiogenesis. This was confirmed using colored microspheres to measure coronary blood flow, which was higher in area at risk in TGs (1.4±0.2ml/min/g) as compared to NTLs (0.5±0.08ml/min/g), p&lt;0.05. This increased blood flow was further supported by a 41% increase in arterial density within the ischemic zone compared to NTLs at 2 weeks after CAO. In addition, capillary density was also found to be significantly increased, by 18% in the remote zone, compared to 2109 caps/mm2 in NTL. Utilizing an In vitro model, treatment with 25μM A61603 for 48 hours in cultured NTL neonatal myocytes resulted in an increase in VEGF-A secretion into the culture media and 26% increase in vascular tubule formation in HUVECs by a paracrine mechanism coinciding with an increased VEGF-A concentration compared to vehicle treated myocytes. Since VEGF is linked to the MEK-ERK signaling pathway, we blocked this mechanism by chronically administering the MEK blocker, U0126, sc. In these rats LV function was no longer different after 4 wks permanent CAO in TG and WTL treated with the blocker. Therefore, overexpression of cardiac myocyte specific α1A-AR in rats protected against cardiac dysfunction and remodeling associated with chronic myocardial infarction through the MEK-ERK pathway and via angiogenesis with a VEGF-A related paracrine mechanism.

External coronary artery compression due to prosthetic valve bacterial endocarditis

Acute coronary syndromes in the setting of infective endocarditis may be the result of coronary compression secondary to periannular aortic valve complications, coronary embolism, obstruction of the coronary ostium due to a large vegetation, coronary atherosclerosis, and severe aortic insufficiency. External coronary artery compression as a result of infective endocarditis is a rare and lethal finding with few reported cases available in the medical literature. We present a rare occurrence of an acute coronary syndrome occurring in the setting of a bioprosthetic aortic valve abscess in which there was no complete coronary occlusion visualized and given the patient's recent unremarkable catheterization and findings of diffuse tapering of the proximal left coronary system, the most likely etiology was external compression secondary to the known aortic root abscess, which caused myocardial ischemia, and was confirmed during surgery. Although uncommon, external compression should be considered in the differential diagnosis of acute coronary syndrome in this setting and coronary angiography can be diagnostic of this entity.

The bottleneck stent model for chronic myocardial ischemia and heart failure in pigs

A large animal model of chronic myocardial ischemia and heart failure is crucial for the development of novel therapeutic approaches. In this study we developed a novel percutaneous one- and two-vessel model for chronic myocardial ischemia using a stent coated with a polytetrafluoroethylene tube formed in a bottleneck shape. The bottleneck stent was implanted in the proximal left anterior descending (LAD) or proximal circumflex artery (LCX), or in both proximal LCX and mid LAD 1 wk later (2-vessel model), and pigs were followed for 4-5 wk. Ejection fraction (EF), infarct size, collateral growth, and myocardial perfusion were assessed. Pigs were given antiarrhythmic medication to prevent sudden death. The occlusion time of the bottleneck stent and the timing of myocardial infarction could be modulated by the duration of antiplatelet medication. Fractional flow reserve measurements and positron emission tomography imaging showed severe ischemia after bottleneck stenting covering over 50% of the left ventricle in the proximal LAD model. Complete coronary occlusion was necessary for significant collateral growth, which mostly had occurred already during the first wk after the stent occlusion. Dynamic and competitive collateral growth patterns were observed. EF declined from 64 to 41% in the LCX model and to 44% in the LAD model 4 wk after stenting with 12 and 21% infarcted left ventricle in the LCX and LAD models, respectively. The mortality was 32 and 37% in the LCX and LAD models but very (71%) high in the two-vessel disease model. The implantation of a novel bottleneck stent in the proximal LAD or LCX is a novel porcine model of reversible myocardial ischemia (open stent) and ischemic heart failure (occluded stent) and is feasible for the development of new therapeutic approaches.

TCT-523 Complete Coronary Occlusion of the Infarct-Related Artery in Patients Presenting with Acute Non-ST-Elevation Myocardial Infarction: Role of the GRACE risk score

ST-segment elevation serves as a reliable electrocardiographic marker for complete coronary occlusion (CCO). However, we have recently shown that 34% of patients with acute non ST- elevation myocardial infarction also show CCO resulting in a poor prognosis due to late reperfusion. The role of the