Antegrade Flow Research Articles

Long-term patency of surgical left subclavian artery revascularization

ObjectiveLittle is known regarding the long-term patency rates of surgical left subclavian artery (LSA) revascularization, especially when performed concomitant to thoracic endovascular aortic repair and without arterial occlusive disease. Our aim is to contribute to the existing evidence by reporting the patency rates at mid- and long-term follow-up after surgical LSA revascularization. MethodsThis observational, retrospective, single-center cohort study included 90 eligible patients who underwent a left common carotid artery to LSA bypass (72%) or transposition (28%) from December 31, 2017 to January 1, 2000. Data regarding demographics, medical history, intraoperative characteristics, and outcomes regarding bypass graft or transposition patency, severe stenosis, or occlusion were assessed at discharge, 3 months, 1 year, and maximum follow-up using consecutive follow-up computed tomography scans. ResultsIn our predominantly male (74%) cohort with a mean age of 66 years (standard deviation, ±12 years), LSA revascularization was mostly performed concomitant to or adjacent to thoracic endovascular aneurysm repair procedures (98%) with the primary indication for surgery being degenerative or saccular aneurysmatic aortic disease (50%), subacute or acute type B aortic dissection (17%), post-dissection aortic aneurysm (16%), type B intramural hematoma (6%), and other indications (11%). Ninety-seven percent of our left common carotid artery to LSA bypasses were performed using a central, supraclavicular approach, and the other 3% were performed using an infraclavicular approach to the LSA. Median diameter of the bypass was 6 mm (range, 6-12 mm). We found two occlusions at 7.7 and 12.9 months follow-up and four severe stenoses at 21.2, 35.4, 38.3, and 46.7 months follow-up, respectively. Estimated freedom from occlusion was 97% ± 2% and freedom from severe stenosis was 90% ± 4% at both midterm (5 years) and long-term (10 years) follow-up, with a median follow-up duration of 42.2 months for occlusion (25th-75th percentile, 15.4-67.4 months) and 41.9 months (25th-75th percentile, 15.4-67.4 months) for severe stenosis. ConclusionsOpen surgical LSA revascularization may be considered the gold standard to preserve antegrade LSA flow in the context of debranching for thoracic endovascular aneurysm repair or open surgical aortic arch repair, with excellent patency rates at mid-term and long-term follow-up.

Sex differences in prehospital analgesia in patients presenting with acute coronary syndromes and their association with clinical outcomes.

This study examined if sex differences in prehospital pain scores, opioid administration, and clinical outcomes exist in acute coronary syndrome (ACS) patients. Sex differences persist in ACSpresentation, management, and outcomes. The impact of sex differences on prehospital pain management of ACS with opioids is unknown. Patients presenting with ACS via ambulance (2014-2018) that underwent percutaneous coronary intervention (PCI) were prospectively collected via the Victorian Cardiac Outcomes Registry and Melbourne Interventional Group, linked to the Ambulance Victoria database. The primary outcome was 30-day major adverse cardiac events (MACE). Secondary outcomes were descriptive analyses of prehospital pain score, intravenous morphine equivalent analgesic dosing, plus predictors of MACE and thrombolysis in myocardial infarction (TIMI) 0-1 flow pre-PCI. A total of 10,547 patients were included (female: 2775 [26%]). Opioids were administered to 1585 (57%) females, 5068 (65%) males (p < 0.001). Adjusted 30-day MACE was similar between opioid groups in both sexes (female: odds ratio [OR]: 1.21, confidence interval [CI] 0.82-1.79, p = 0.34; male: OR: 0.89, CI: 0.68-1.16, p = 0.40). Median pain score at presentation was 6 (interquartile range [IQR]: 4, 8) for both sexes. Median opioid dose was 2.5 mg (IQR: 0, 10) in females and 5 mg (IQR: 0, 10) in males (p < 0.001), with similar pain relief achieved. Adjusted rates of TIMI 0-1 pre-PCI were higher in patients administered opioids (female: OR 2.9, CI: 2.07-4.07, p < 0.001; male: OR: 2.67, CI: 2.19-3.25, p < 0.001). Female patients undergoing PCI received less opioid analgesia, but no sex differences in prehospital pain scores were seen. Opioid administration was associated with impaired antegrade flow in the culprit artery in both sexes, but not short-term MACE. Trials evaluating nonopioid analgesics in ACS are needed.

Helicopter emergency medical service for patients with acute coronary syndrome: selection validity and impact on clinical outcomes.

Helicopter emergency medical service (HEMS) has the potential to improve prognosis for acute coronary syndrome (ACS). However, adequacy and effectiveness of HEMS have not been fully evaluated. A total of 862 ACS patients transferred by emergency medical services were divided into two groups: patients transferred by HEMS (n = 171) or by ground ambulance (GA; n = 691). Among them, angiography images for 718 patients (149 in HEMS and 569 in GA group) and optical coherence tomography (OCT) images for 374 patients (75 in HEMS and 299 in GA groups) were analyzed. Additional analysis to compare 2-year cardiac mortality between groups was conducted following propensity score matching to adjust for inter-group differences. ST-segment elevation myocardial infarction (81% vs. 66%, p < 0.001) and cardiogenic shock (Killip IV; 20% vs. 10%, p < 0.001) at admission were more prevalent in HEMS than GA group. Time from admission to balloon angioplasty was shorter in HEMS group (median 54min vs. 69min, p < 0.001). Antegrade coronary flow was worse in HEMS group (TIMI flow grade 0 or 1; 68% vs. 51%, p < 0.001). Plaque rupture was more frequently detected by OCT in HEMS group (68% vs. 49%, p = 0.029). Following propensity score matching, the incidence of cardiac death was significantly lower in HEMS group (6.3% vs. 14.9%, p = 0.019). In conclusion, severe ACS patients requiring early reperfusion were appropriately triaged and transferred more rapidly by HEMS. Lower mortality in HEMS group after propensity score matching suggests that HEMS may improve cardiac mortality in ACS patients.

Simulating the Hydrodynamic Conditions of the Human Ascending Colon: A Digital Twin of the Dynamic Colon Model.

The performance of solid oral dosage forms targeting the colon is typically evaluated using standardised pharmacopeial dissolution apparatuses. However, these fail to replicate colonic hydrodynamics. This study develops a digital twin of the Dynamic Colon Model; a physiologically representative in vitro model of the human proximal colon. Magnetic resonance imaging of the Dynamic Colon Model verified that the digital twin robustly replicated flow patterns under different physiological conditions (media viscosity, volume, and peristaltic wave speed). During local contractile activity, antegrade flows of 0.06–0.78 cm s−1 and backflows of −2.16–−0.21 cm s−1 were measured. Mean wall shear rates were strongly time and viscosity dependent although peaks were measured between 3.05–10.12 s−1 and 5.11–20.34 s−1 in the Dynamic Colon Model and its digital twin respectively, comparable to previous estimates of the USPII with paddle speeds of 25 and 50 rpm. It is recommended that viscosity and shear rates are considered when designing future dissolution test methodologies for colon-targeted formulations. In the USPII, paddle speeds >50 rpm may not recreate physiologically relevant shear rates. These findings demonstrate how the combination of biorelevant in vitro and in silico models can provide new insights for dissolution testing beyond established pharmacopeial methods.

Questions on the Genesis and Growth of Coronary Lesions and their Answers Based on Fluid Mechanics Engineering: A New Dynamic Angiography Analysis

In the continuing debate regarding the mechanism of atherosclerotic plaque formation in arteries, one question remains unanswered: While all arteries in a patient are exposed to the same systemic risk factors (hypertension, diabetes, aging, nicotine of cigarettes, etc.), why do plaques frequently present in the coronary arteries, and to a lesser extent in the arteries of the lower extremities, and still less in the carotid or renal arteries? Over the past five years, in order to find an answer to the above question, there has been a radical shift in our research strategy: The principles of fluid dynamics in industrial and domestic pipes/pipelines were employed to decipher changes in the cardiovascular system. The types of flow under investigation included laminar, entrance, turbulent, and helical flows in systole and diastole, as well as the interface between antegrade and retrograde flows resulting in water hammer shock and cavitation phenomena. We aim to highlight the similarities and differences among flow types in arteries and pipes and apply the same methodologies to study the formation, growth, and rupture of coronary plaques leading to inactive and active clinical syndromes and the beneficial mechanism of percutaneous coronary interventions (PCI). In this article, we list the questions and the answers based on the primary data of several completed studies and the preliminary results of ongoing projects from a fluid mechanics perspective. The angiographic coronary images of recirculation flow, vortex formation, collision, hammer water shock, and cavitation will be showcased in detail, and their videos in slow motion are uploaded in the addendum for further in-depth review.

Mycotic coronary aneurysm: A rare complication of percutaneous coronary intervention

Coronary artery aneurysms are extremely rare, major causative factors associated with this condition are atherosclerosis, trauma, connective tissue disorders, vasculitis, idiopathic, mycotic, and congenital. We present a case of a 49-year-old male who underwent primary angioplasty for acute ST-elevation myocardial infarction and presented with chest pain, fresh ST elevation, and fever after 10 days of the index procedure. The patient was suspected to have subacute stent thrombosis along with some infective pathology. However, work up did not reveal any systemic localization, and blood cultures were negative. Coronary angiogram showed aneurysm of the left anterior descending artery (LAD) with Grade 3 thrombus in the proximal part of stent with thrombolysis in myocardial infarction (TIMI) II antegrade flow. A two-dimensional echo revealed mild left ventricular dysfunction with moderate pericardial effusion. Cardiac positron emission tomography scan confirmed the suspicion of a stent-related mycotic aneurysm. Therefore, the patient was managed with intravenous antibiotics, antiplatelets, and low-molecular-weight heparin, followed by newer oral anticoagulants.

Pulsatility Index in Different Modifications of Fontan Palliation: An Echocardiographic Assessment.

BACKGROUNDAdding pulsation to the Fontan circulation might change the fate of patients palliated by this procedure. Our aim was to compare the pulsatility index (PI) of the pulmonary artery (PA) between the various modifications of Fontan palliation.METHODSDoppler-derived PI was measured in PA branches of a cohort of 28 patients palliated by 6 modifications of Fontan procedure. A group of normal individuals was included for comparison.RESULTSAtriopulmonary connection (APC) group had the highest PA branches PI and statistically was close to the PI of the normal individuals (right pulmonary artery [RPA] PI of 1.58 vs. 1.63; p = 0.99 and left pulmonary artery [LPA] PI of 1.54 vs. 1.68; p = 0.46, respectively). The lowest PA branches PI was seen in the group of extracardiac total cavopulmonary connection (RPA PI of 0.62 and LPA PI of 0.65). Other 4 modifications including the extracardiac conduit with oversewn pulmonary valve, extracardiac conduit with preserved adjusted antegrade flow, extracardiac conduit from inferior vena cava onto the rudimentary right ventricle and lateral tunnel had a mean “RPA and LPA” PI of “1.19 and 1.17”, “1.16 and 1.11”, “1.13 and 1.11”, “0.82 and 0.84”, respectively. The modified Dunnett's post hoc test has shown a significant statistical decline in PI of all modifications compared to the normal individuals except for the APC group.CONCLUSIONSFontan palliated patients in different groups of surgical modification showed a spectrum of Doppler-derived PI with the highest amounts belong to the groups of pulsatile Fontan.

Bilateral Sudden Hearing Loss Caused by Basilar Artery Dissection: A Case Report

Bilateral sudden sensorineural hearing loss (SNHL) is rare, but a possible symptom of vertebrobasilar ischemia. A 69-year-old female patient with hypertension and atrial fibrillation presented with bilateral sudden hearing loss and vertigo without other neurological symptoms. On examination, she had left-beating horizontal nystagmus with positive head impulse on the left side. Pure tone audiometry revealed severe SNHL on both sides. Brain computed tomography angiography showed a dissection in the proximal portion of the basilar artery (BA) with occlusion of the mid-BA and bilateral anterior inferior cerebellar arteries (AICA), which confirmed on transfemoral cerebral angiography (TFCA). Left common carotid angiography demonstrated retrograde blood flow into the BA and right AICA via the left posterior communicating artery. During TFCA, her right hearing loss dramatically improved. Nine days later, follow-up TFCA showed an improvement of antegrade flow of the BA and AICA. We suggest that vertebrobasilar ischemia can be suspected in patients with bilateral sudden SNHL who present with risk factors for stroke.

Fetal aortic valvuloplasty in a patient with critical, congenital aortic valve stenosis and severe left ventricular dysfunction

We present a case of prenatal diagnosis of critical congenital aortic valve stenosis with progressive systolic left ventricular failure. An ultrasound-guided balloon aortic valvuloplasty was performed at 28 weeks of gestational age because of left ventricular dysfunction associated with signs of fetal heart failure. There were no significant post-procedural complications and the pregnancy was carried to term with elective cesarean section at 38 weeks of gestational age. At birth, an echocardiogram showed severe aortic valve stenosis with global hypokinesia of the left ventricle. Therefore a percutaneous balloon aortic valvuloplasty was repeated through transseptal approach with prompt improvement of the antegrade aortic flow and of the left ventricular systolic function. The baby is currently 2 months old and he is doing fine.

Access site complications of postcardiotomy extracorporeal life support

ObjectiveTo assess the influence of primary arterial access in patients receiving peripheral postcardiotomy extracorporeal life support on associated complications and outcome. MethodsOf 573 consecutive patients requiring PC-ECLS between 2000 and 2019 at a single center, 436 were included in a retrospective analysis and grouped according to primary arterial extracorporeal life support access site. Survival and rate of access-site–related complications with special emphasis on fatal/disabling stroke were compared. ResultsThe axillary artery was cannulated in 250 patients (57.3%), whereas the femoral artery was used as primary arterial access in 186 patients (42.6%). There was no significant difference in 30-day (axillary: 62%; femoral: 64.7%; P = .561) and 1-year survival (axillary: 42.5%; femoral: 44.8%; P = .657). Cerebral computed tomography-confirmed stroke with a modified ranking scale ≥4 was significantly more frequent in the axillary group (axillary: n = 28, 11.2%; femoral: n = 4, 2.2%; P = .0003). Stroke localization was right hemispheric (n = 20; 62.5%); left hemispheric (n = 5; 15.6%), bilateral (n = 5; 15.6%), or infratentorial (n = 2; 6.25%). Although no difference in major cannulation site bleeding was observed, cannulation site change for bleeding was more frequent in the axillary group (axillary: n = 13; 5.2%; femoral: n = 2; 1.1%; P = .03). Clinically apparent limb ischemia was significantly more frequent in the femoral group (axillary: n = 12, 4.8%; femoral: n = 31, 16.7%; P < .0001). ConclusionsAlthough survival did not differ, surgeons should be aware of access–site-specific complications when choosing peripheral PC-ECLS access. Although lower rates of limb ischemia and the advantage of antegrade flow seem beneficial for axillary cannulation, the high incidence of right hemispheric strokes in axillary artery cannulation should be considered.

Abstract 12211: Water Hammer Shock Causing Rupture Of Vulnerable Cap Of Culprit Lesions In Acute Coronary Syndrome: An Angiographic And Machine Learning Analysis

Introduction: Acute coronary syndrome (ACS) is caused by rupture of coronary plaques. What triggers these ruptures? Hypothesis: In the field of hydraulics, in a setting of a tank and draining pipe, if the valve at the distal end of the pipe is open, the fluid flows normally. If the valve closes abruptly, the flow next to the valve stops. However the fluid from the tank continues to flow forward and can collide with the distal stationary fluid. This is called water hammer shock. Could the same event happen in coronary arteries? The contraction of the left ventricle (LV) is similar to the abrupt closure of a valve, stopping the myocardial capillary flow. Could the systolic LV contraction trigger water hammer shock? Methods: Angiograms with culprit lesions of ACS (recorded at 15 images/second or 0.06 second per image) were reviewed. The first image was of the artery completely filled with contrast. The subsequent images showed the blood in white color blood moving in over a background of black contrast. The normal flow was laminar. When there was retrograde on top of turbulent flow, this was evidence of a collision between antegrade and retrograde flow (or water hammer shock). The measurements by visual angiographic evaluation and by Machine Learning (ML) included (1) the duration and (2) size of coronary segment with turbulence. The ML program had 2 models (build on Python). Model 1 was built based on U-net and Densenet-121 for vessel segmentation. Model 2 was used for classification of flow. The model 2 was trained based on the convolutional neural network. Results: Angiograms of 20 ACS patients showed laminar flow (90%) in diastole. The flow became turbulent during systole with retrograde flow. The area of collision or water hammer shock showed diffuse coarse mixing of black (contrast) and white (blood). The presence of turbulence matched the location of 85% of ruptured plaques. The duration of turbulence lasted 80% of systole. Special protocols were used successfully to train AI to recognize the lesions, retrograde and turbulent flow. Conclusions: With the new angiographic technique, detailed images of water hammer shock matched the location of ruptured plaques in ACS patients. These results may help to understand the genesis and offer precise prevention and treatment for ACS

Abstract 11177: Uncontrolled Systolic Hypertension Exaggerates the Effect of Water Hammer Shock from a Retrograde Direction While Diastolic Hypertension Aggravates the Injury from an Antegrade Direction: New Mechanism of Coronary Artery Disease by Angiographic and Machine Learning Investigation

Introduction: Hypertension (HTN) is a strong risk factor of coronary artery disease. Hypothesis: Based on the damages induced by flow abnormalities in pipes, our research is built on the hypothesis that flow disturbances start the atherosclerotic process. Our strategy is to use today’s practice of fluid mechanics to unlock the mechanism of HTN on coronary plaques. Methods: All patients with uncontrolled HTN and unstable angina underwent coronary angiography and were selected if they had 1 or 2 moderate lesions. At first. contrast was injected until the index artery was completely opacified. As the injection stopped, the blood moved in and displaced the contrast. The movements and interactions of the blood flow in white color above a black background could be clearly analyzed. At the same time, Artificial Intelligence (Machine Learning (ML algorithms) program had 2 models built on Python. Model 1 was based on U-net and Densenet-121 for vessel segmentation. Model 2 was used for classification and movement of flow. Model 2 was trained based on the convolutional neural network. The main measurements were the types, durations and directions of flows. Results: 20 patients were enrolled. 80% of lesions happened at the mid right coronary artery, near the bifurcation of the left anterior descending artery and diagonal, and of the circumflex artery and obtuse marginal. At the locations of lesions, 100% patients had turbulence caused by collision of the antegrade against the retrograde flow (water hammer shock). If there was excessive diastolic HTN &gt;100mmHg, the duration of retrograde flow was short (&lt;0.18 sec) and 75% turbulence happened DISTAL to the collision/bifurcation site. It happened due to higher gradient from proximal to distal. In severe systolic HTN, the duration of retrograde flow was longer (&gt; 0.30 sec) and 80% turbulence happened PROXIMAL to the collision/bifurcation site due to higher gradient from distal to proximal. Conclusions: Uncontrolled diastolic HTN exaggerated the strength of antegrade flow and turbulence DISTAL to the collision/bifurcation site while uncontrolled systolic HTN intensified the retrograde flow and turbulence PROXIMAL to the collision/bifurcation site. Both inflicted damage on the intima and started the atheroslerotic process.

Abstract 12972: Acute Left Main Coronary Artery Thrombosis During Exercise Testing

Background: Exercise stress testing (EST) is safe and effective in evaluating suspected coronary artery disease (CAD). Serious complications are rare. We present a unique case of acute left main coronary artery (LMCA) thrombosis during EST. Case presentation: A 58-year old man with hypertension and hyperlipidemia presented with two episodes of substernal chest pressure within 2 weeks. He had no known CAD, led an active lifestyle and did not smoke, drink, or use drugs. Initial vital signs, routine labs, troponin, ECG, and echocardiogram (TTE) were normal. EST (Bruce Protocol) was terminated at 3’ 54” due to chest pain, hypotension and down-sloping ST segment depressions in inferolateral leads followed by ST segment elevation in leads V1, V2, aVL and aVR. TTE showed severe hypokinesis of apex and anterior, anteroseptal, and anterolateral walls. Emergent coronary angiography (Figure) revealed complete thrombotic occlusion of LMCA. LMCA was wired and ballooned restoring antegrade flow and resolving ST segment elevation. Minutes later, recurrent ST elevations were noted due to LMCA reocclusion. Flow was restored and patient underwent emergent coronary artery bypass surgery. TTE two days later showed preserved LV systolic function with mild hypokinesis of the LV apex and apical septal wall. Conclusions: Pathophysiology of AMI triggered by exercise is only partially understood. Vigorous exercise is shown to increase relative risk of AMI particularly within first hour following exertion. In such a scenario, exercise likely acts as a trigger for plaque rupture in presence of an underlying vulnerable atherosclerotic lesion. Compared to other forms of AMI, those triggered by exercise occur more commonly in men and are more often characterized by total thrombotic occlusion of culprit coronary artery. To our knowledge, acute thrombosis of LMCA has not previously been reported as a complication of EST.

Prominent Neck and Pinna Pulsations

A young man presented with visible neck and pinna pulsations after a palliative bidirectional cavopulmonary (Glenn) shunt with open antegrade flow. This resulted in giant C-V waves in the jugular venous pulse. Giant C-V waves resulting from a Glenn procedure have not previously been described and represent a novel entity to recognize. (Level of Difficulty: Advanced.)

Outcomes of duct stenting and modified Blalock-Taussig shunt in cyanotic congenital heart disease with duct-dependent pulmonary circulation.

Transcatheter ductus arteriosus stenting (DS) is emerging as an alternative method to modified Blalock-Taussig shunt (MBTS) in providing pulmonary blood flow in cyanotic congenital heart disease (CCHD) with duct-dependent pulmonary circulation. To evaluate post-procedural outcomes and survival between patients undergoing DS and MBTS. All infants ≤ 60days of age having CCHD with diminished pulmonary blood flow who underwent palliative procedure either with MBTS or DS at King Chulalongkorn Memorial Hospital during January 1st, 2013 and December 31th, 2017 were retrospectively reviewed. 98 patients were included; 34 patients underwent a transcatheter DS and 64 patients underwent MBTS. There was no significant difference in post-procedural outcomes and overall mortality rate between two groups (17.6% in MBTS group and 6.1% in DS group, p = 0.09). Single ventricle morphology was the major risk factor associated with increased mortality compared with biventricular morphology (aHR 3.9, 95% CI 1.49-10.2, p = 0.01). There was similar number of early and pre-repair additional interventions focusing on MBTS/DS patency between two groups. The MBTS grouphad a greater number of early interventions on PA branch stenosisrelated to baseline diagnosis. Risk factors associated with additional intervention were pre-existing pulmonary branch stenosis (aHR 2.54, 95% CI 1.3-4.97, p = 0.006) and body weight less than 2.5kg (aHR 3.33, 95% CI 1.57-7.08, p = 0.003). Having pulmonic valve perforation or balloon pulmonary valvuloplasty to promote antegrade pulmonary blood flow could result in a lower number of additional interventions required before definitive repair. Duct stenting is a feasible and safe alternative to MBTS in cyanotic infants with duct-dependent pulmonary circulation. However, mortality rate was significantly higher in patients with single ventricle that required careful follow-up after procedure.

Sex differences in pre-hospital analgesia and outcomes in patients presenting with acute coronary syndromes

Abstract Background Opioid analgesia remains the mainstay of pain management in acute coronary syndromes (ACS). Significant sex differences persist in ACS presentation, management and outcomes, but the impact of sex-differences on pre-hospital pain management of ACS with opioids is unknown. There is increasing awareness of the importance of pre-hospital factors in ACS, as well as emerging concerns with opioid use impairing the gastrointestinal absorption of oral P2Y12 inhibitors. Purpose This study examined if sex-differences in pre-hospital pain scores, opioid administration and clinical outcomes exist in ACS patients. Methods Patients presenting with ACS via ambulance (2014–2018) that underwent percutaneous coronary intervention (PCI) were prospectively collected via the Victorian Cardiac Outcomes Registry (VCOR), the Melbourne Interventional Group (MIG), and linked to the Ambulance Victoria database. The primary outcome was 30-day major adverse cardiac events (MACE). Secondary outcomes were descriptive analyses of pre-hospital pain score, intravenous morphine equivalent analgesic dosing, plus predictors of MACE and Thrombolysis In Myocardial Infarction (TIMI) 0–1 flow pre-PCI using logistic regression. Results 10,547 patients were included (female: 2,775 [26.3%]). Opioids were administered to 1,585 (57%) females and 5,068 (65%) males (p&amp;lt;0.001). Adjusted 30-day MACE was similar between opioid groups in both sexes (female: OR 1.21, CI 0.82–1.79, p=0.34; male: OR 0.89, 0.68–1.16, p=0.40). Median pain score at presentation was 6 (IQR 4,8) for both sexes. Median opioid dose was 2.5 mg (IQR 0,10) in females and 5 mg (IQR 0,10) in males (p&amp;lt;0.001), with similar pain relief achieved. Adjusted rates of TIMI 0–1 pre-PCI were higher in patients administered opioids (female: OR 2.83, CI 2.14–3.56, p&amp;lt;0.001; male: OR 2.95, CI 2.49–3.49, p&amp;lt;0.001). Conclusions Female patients undergoing PCI received less opioid analgesia, but no sex-differences in pre-hospital pain scores were seen. Opioid administration was associated with impaired antegrade flow in the culprit artery in both sexes, but not short-term MACE. Randomised trials evaluating the clinical implications of opioid administration in ACS with sex subgroup analyses are needed to guide clinical practice. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Melbourne Interventional GroupVictorian Cardiac Outcomes Registry

Cavitation on top of collision breaks the cover of coronary plaques and triggers acute coronary syndrome

Abstract Background Coronary injuries are hypothesized to be caused by the cavitation phenomenon (explosion of air bubbles) which is seen frequently in industrial pipes. Based on hydraulics principles applied to the coronary circulation. during distal negative suctioning in diastole, if the coronary static pressure decreases below the vapor pressure (VP), bubbles will form. They explode when the coronary static pressure recovers &amp;gt; the VP during systole. These explosions create jet waves weakening and rupturing the cover of the coronary plaques, triggering acute coronary syndrome (ACS). How could these events be observed, recorded and compared? Methods Coronary angiograms of patients with ACS and stable coronary artery disease (CAD) (control) were selected. The arteries were recorded at 15 frames per second and saved in the electronic health records and reviewed image by image. After the index artery was completely filled with contrast, the following images showed the blood in white moving in on a background of black contrast. The flow could be laminar, turbulent (mixing of blood in white and contrast in black), antegrade or RETROGRADE (black column traveling backward). At the same time, an artificial intelligence (AI) program was used to detect and identify the flow. Results There were 104 patients with ACS enrolled and 20 patients with stable CAD as control. First, in the ACS group, 84 lesions (80%) were in the end of the proximal segment of the left anterior descending artery (LAD) and mid-segment of the right coronary artery (RCA). 20 lesions (19%) were at the distal RCA. Second, during diastole, 95% of the flow were laminar. The flow became turbulent at the beginning of systole. The turbulence was caused by the COLLISION of the antegrade flow (end of diastole) and the retrograde flow (at the beginning of systole). These collisions were seen in 95% at the location of vulnerable plaques of patients with ACS. In the control patients, there were only 2 cases (10%) with collision. Third, in the 20 patients with lesions at the distal RCA, the lesions were seen to be located at the areas of recirculating flow, at the ostium of the posterior descending artery (PDA) or proximal to the origin of the PDA. The cause of turbulence was most likely due to cavitation on top of collision. The cavitation happened because of continuous steady forward flow (of the PDA) in the myocardium during systole, while at the proximal RCA the blood flew forward more slowly. (Fig.1) The DSICREPANCY of velocities at the proximal and distal RCA allowed the formation of an empty gap (bubble of air). When the flow reversed during systole, this retrograde flow slammed on the bubble which collapsed violently, injured, ruptured the cover of the plaque and started ACS. Conclusions Rupture of bubbles (cavitation) on top of collision was most likely the cause of injury to the cover of vulnerable plaques, triggering ACS. Understanding the mechanism will help to better manage ACS. Funding Acknowledgement Type of funding sources: None. Cavity formation and collisionFormation of cavitation at the PDA

Percutaneous embolization of a ruptured mycotic visceral aortic aneurysm stump hemorrhage

Introduction and Objective Managing infected endovascular aortic stent grafts is difficult and often has morbid consequences. We report a complicated case of endovascular aortic stent graft infection treated through complex surgical and endovascular management. A standard attempt at open surgical correction was made, however, due to the complex nature of the patient's condition; much of the treatment accomplishedvia endovascular techniques for ultimate resolution. Case Report Graphical AbstractA) CTA maximum intensity projection after initial surgical repair demonstrating an axillary-femoral and femoral-femoral bypass creation (star), distal aortic and bilateral artery ligation (asterisks). B) Sagittal abdominal CTA 2 weeks after initial surgery demonstrating contrast extravasation from the aortic stump (arrow). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) Posterior projection of a volume rendered CTA after the second surgical repair demonstrating distal thoracic aorta ligation (open arrow), previous ligations (asterisks), bypass grafts from the distal thoracic aorta to the SMA (white arrow), splenic artery (open arrowhead), and left renal artery (white arrowhead). B) Sagittal abdominal CTA demonstrating recurrent hemorrhage in the visceral aorta (arrow), with themultiple ligations (asterisks) of the aorta and SMA, as well as the celiac bypass (arrowhead). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) Oblique image of the aortic stump access using an 18-gauge Hawkins needle (Cook, Bloomington, IN) (white arrowheads) shows inflow at the celiac ostium as a contrast void (white circle), opacification of the replaced right hepatic (black arrow), right renal artery (black arrowhead), and visceral aorta with extravasation of contrast (white arrow). B) SOS 2 catheter (Cook, Bloomington, IN) selection of the celiac artery (white arrow head) with retrograde flow in to the aortic lumen (white circle), inflow from the splenic artery stump bypass (black arrowhead), and antegrade flow into the common hepatic artery (black arrow). View Large Image Figure Viewer Download Hi-res image Graphical AbstractThe ostia of the celiac artery, right renal artery, and direct aortic origin right hepatic celiacartery origin were embolized using multiple techniques. A) A 0.24 microcatheter (white arrowhead) was advanced into the splenic artery and used to place an Amplatz IV (6 × 11mm) (St. Jude Medical, St. Paul, MN) (black arrowhead) into the ostium of the celiac artery to exclude the aortic stump but preserve hepatic arterial supply. Direction of blood flow from the splenic bypass towards the celiac ostium and into the common hepatic artery is demarcated with open arrows. B) The replaced right hepatic artery was embolized with multiple 0.018 6mm and 4mm detachable coils (Boston Scientific S Interlock, Marlboro, MA) (arrow). C) The visceral aortic lumen and right renal artery were embolized with 0.035 and 0.018 detachable coils (Boston Scientific S Interlock, Marlboro, MA), a 0.035 Benson wire with removed mandrel (Cook,Bloomington, IN) and n-BCA glue (TruFill Johnson and Johnson, Miami, FL). The aortic access track was then closed with an 8mm Amplatz plug and n-BCA glue (arrowhead). View Large Image Figure Viewer Download Hi-res image Graphical AbstractA) 3-year post-operative follow up 3D rendered image showing patents bypasses to the SMA (white arrow), splenic artery (open arrowhead), and left renal artery (white arrowhead), stable ligation of the distal thoracic aorta and embolized visceral abdominal aorta. B) 3-year post-operative sagittal CT showing absence of perfusion to the visceral aortic (arrow). View Large Image Figure Viewer Download Hi-res image Discussion Complex aortic surgery is challenging especially in the presence of recurrent infection. This case was a unique situation in which a less invasive endovascular correction was successful for a patient with multiple recent aortic surgeries in which perioperative mortality for any additional surgeries was likely. Managing infected endovascular aortic stent grafts is difficult and often has morbid consequences. We report a complicated case of endovascular aortic stent graft infection treated through complex surgical and endovascular management. A standard attempt at open surgical correction was made, however, due to the complex nature of the patient's condition; much of the treatment accomplishedvia endovascular techniques for ultimate resolution. Complex aortic surgery is challenging especially in the presence of recurrent infection. This case was a unique situation in which a less invasive endovascular correction was successful for a patient with multiple recent aortic surgeries in which perioperative mortality for any additional surgeries was likely.

OUTCOMES OF PALLIATIVE RIGHT VENTRICLE TO PULMONARY ARTERY CONNECTION FOR TETRALOGY OF FALLOT WITH PULMONARY ATRESIA AND MAPCAS

<h3>BACKGROUND</h3> Tetralogy of Fallot with pulmonary atresia with major aorto pulmonary artery collaterals (TOF-PA MAPCAS) is a rare and complex cyanotic congenital heart malformation with a high incidence of early mortality and morbidity. Different surgical interventions have been described including construction of a systemic to pulmonary artery shunt (Modified Blalock-Taussig shunt or central shunt) and unifocalization, however the perioperative mortality remains significant due to the high incidence of thrombosis, obstruction, and pulmonary artery (PA) distortion. Another alternative is a palliative right ventricle to pulmonary artery connection (RVPAC) to bring antegrade flow to diminutive PAs. The objective of our study was to evaluate the impact of RVPAC on mortality, survival, morbidity, PA growth and eligibility for biventricular repair. We believe that the RVPAC approach allows for better PA growth and obviates the need for a conduit at the time of complete repair. <h3>METHODS AND RESULTS</h3> We performed a retrospective single-institution study from January 2016 to March 2021 that included 15 consecutive patients diagnosed with TOF-PA MAPCAS who underwent an RVPAC at CHU Sainte-Justine as their initial palliation. Median age at palliation and complete repair was 18 (4 -100) and 309 (96 – 1044) days respectively. Mortality after a RVPAC was 0 % with a median hospital length of stay of 14,5 days (6 - 55), while the late interstage mortality rate was 0 %. Overall survival was 100 %. 9 patients (60%) had a biventricular repair, and 6 patients (40%) are awaiting repair. RVPAC allowed significant growth of the native pulmonary arteries with a mean Nakata index at CT scan of 70 ± 48,04 mm2/m2 before the RVPAC and 251 ± 121,05 mm2/m2 after (P = 0.001). 4 patients (44%) required reinterventions after completed repair by catheterization for stenotic pulmonary artery branches, while no patients required a late reoperation. 8 patients (53,33%) had embolization of collaterals and none required unifocalization. <h3>CONCLUSION</h3> This reproducible and safe technique allows for excellent growth of the PA tree. Biventricular repair was possible in most cases without the use of a conduit or unifocalization of collaterals. This technique appears to be suitable for any type of TOF-PA MAPCAS with confluent native branch pulmonary arteries.

Frequency and impact of slow flow / no flow in primary percutaneous coronary intervention.

To determine the frequency of slow/no flow in primary percutaneous coronary intervention, to know the clinical and angiographical predictors of the phenomenon, and to investigate the immediate impact of slow/no flow on haemodnamics. The cross-sectional study was conducted at the National Institute of Cardiovascular Diseases, Karachi, from June 2018 to July 2019, and comprised patients presenting with ST elevation myocardial infarction who underwent primary percutaneous coronary intervention. Demographic and clinical details of the patients were recorded. The antegrade flow was assessed and determined using the thrombolysis in myocardial infarction criterion. Patients were assessed for the occurrence, predictors and impact of slow/no flow. Data was analysed using SPSS 21. Of the 559 patients, 441(78.9%) were males. The overall mean age of the sample was 55.86±11.07 years. Angiographical slow/no flow during the procedure occurred in 53 (9.5%) patients, while normal flow was achieved in 506(90.5%). The thrombolysis in myocardial infarction grade in the affected patients was 0 in 10(1.8%), 1 in 15(2.7%), and 2 in 28(5%) patients. Smoking status, prior myocardial infarction, prior heart failure, no history of pre-infarct angina, cerebrovascular disease, New York Heart Association class III or IV, Killip class III or IV, and lower ejection fraction were significant predictors of slow/no flow (p<0.05). The angiographical and procedural predictors were total occlusion of culprit vessel and high thrombus burden (p<0.05). Direct stenting and use of bare metal stents had significantly less chance of developing slow/no flow (p<0.05). The most common immediate impact was hypotension 26(49.1%) and bradyarrhythmia 5(9.4%). However, 2(3.8%) patients developed haemodnamically unstable ventricular tachycardia that resulted in mortality. Predictors on the basis of history and angiographical features can be taken into account to anticipate the occurrence of slow/no flow phenomenon.