Pathophysiology, Diagnosis, and Management of Coronary No-Reflow Phenomenon

Coronary no-reflow phenomenon is a lethal mechanism of ongoing myocardial injury following successful revascularization of an infarct-related coronary artery. Incidence of this phenomenon is high following percutaneous intervention and is associated with adverse in-hospital and long-term outcomes. Several mechanisms such as ischemia-reperfusion injury and distal microthromboembolism in genetically susceptible patients and those with preexisting endothelial dysfunction have been implicated. However, the exact mechanism in humans is still poorly understood. Several investigative and treatment strategies within and outside the cardiac catheterization laboratory have been proposed, but they have not uniformly shown success in reducing mortality or in preventing adverse left ventricular remodeling resulting from this condition. The aim of this article is to provide a brief and concise review of the current understanding of the pathophysiology, clinical predictors, and investigations and management of coronary no-reflow phenomenon.

759 Platypnoea orthodeoxia syndrome following middle-lower bilobectomy: a case report

Aims PlatypneaOrthodeoxiasyndrome (POS) is a rare clinical condition characterized by dyspnoea and arterial desaturation, typically occurring in orthostatism and vanishing in a supine position. The real pathophysiologic triggers are still not completely understood. Methods and results In January 2021, a 76-year-old female patient was admitted to our department for the management of a large mass in the right lung (69 × 54 × 76 cm). Pre-operative Computed Tomography (CT)-scan showed a lesion of the right lower lobe, with suspected infiltration of posterior costal pleura and bronchoscopy revealed distal occlusion of intermedious bronchus. Surgical treatment was planned: extrapleural lower bilobectomy with the removal of the VI rib to reduce intracavity space was performed, using postero-lateral thoracotomy approach. On the third post-operative day, an acute neurologic deficit with left-sided paralysis, associated with desaturation and hypotension, occurred during a new attempt to mobilize the patient. Nonetheless the patient showed complete resolution of symptoms in supine position. A new similar episode of severe desaturation (SO2 80%) was observed in the 7th post-operative day. Arterial blood gas test showed PO2 37 mmHg; PCO2 27 mmHg; SO2 80.3%, pH 7.61, tHb 12.4 g/dl; O2Hb 78.4%. CT pulmonary angiography excluded a suspicious of pulmonary embolism. A right to left atrial shunt was suspected. Contrast-enhanced transcranial Doppler ultrasound showed microembolic signals in the basal cerebral arteries. Transoesophageal echocardiography was performed, confirming an interatrial septum with an exuberant hyperdynamic movement and showing an abundant passage of contrast from the right atrium to the left, even without the Valsalva manoeuvre, compatible with an important patent foramen ovale (PFO). Patient was referred to the cardiac Catheterization Laboratory for percutaneous closure of PFO. The device was successfully placed via right femoral venous catheter access and on transesophageal echocardiogram guidance. The procedure was performed without any complications. The implanted device was noted to be in a stable position with trivial residual inter-atrial shunting immediately after the procedure. The day after implantation, positional discomfort improved remarkably and the patient was able to stand-up with no symptoms, maintaining normal saturation (SaO2 100%). The patient was discharged and sent home on the third post-implantation day. The 4 month follow-up examination showed a good andstable condition. Conclusions Platypnoea Orthodeoxia Syndrome after lobectomy is a rare cause of postoperative dyspnoea/hypoxia.It is the result of right-to-left shunt via interatrial communication. Mediastinal relocation, stretching of the atrial septum are among the functional elements necessary for the clinical manifestations. It is essential to have a high index of suspicion to detect POS in patient with dyspnoea given the subtle and positional nature of the symptoms. Physicians should always consider POS in patients with unexplained dyspnoea; hence the treatment modalities could alleviate symptoms and be potentially curative.

Acute myocardial infarction and cardiogenic shock Interventional approach to management in the cardiac catheterization laboratories

: Despite advances in early reperfusion and a technologic renaissance in the space of mechanical circulatory support (MCS), cardiogenic shock (CS) remains the leading cause of in-hospital mortality following acute myocardial infarction (AMI). Given the challenges inherent to conducting adequately powered randomized controlled trials in this time-sensitive, hemodynamically complex, and highly lethal syndrome, treatment recommendations have been derived from AMI patient without shock. In this review, we aimed to (1) examine the pathophysiology and the new classification system for CS; (2) provide a comprehensive evidence-based review for best practices for interventional management of AMI-CS in the cardiac catheterization laboratory; and (3) highlight the concept of how frailty and geriatric syndromes can be integrated in the decision process and where medical futility lies in the spectrum of AMI-CS care. Management strategies in the cardiac catheterization laboratory for CS include optimal vascular access, periprocedural antithrombotic therapy, culprit lesion versus multi-vessel revascularization, selective utilization of hemodynamic MCS tailored to individual shock hemometabolic profiles, and management of cardiac arrest. Efforts to advance clinical evidence for patients with CS should be concentrated on (1) the coordination of multi-center registries; (2) development of pragmatic clinical trial designed to evaluate innovative therapies; (3) establishment of multidisciplinary care models that will inform quality care and improve clinical outcomes.

Left circumflex artery injury following surgical mitral valve replacement: a case report

Background Mitral valve (MV) repair or replacement surgery is indicated for a variety of conditions. Although uncommon, damage to the left circumflex (LCx) coronary artery, which courses in close proximity to the MV annulus, is a devastating complication. Case summary This report describes the case of a 63-year-old woman following re-operative MV replacement. Shortly after being transferred to the surgical intensive care unit after MV replacement, her EKG was notable for persistent inferolateral ST-segment elevations and reciprocal ST-segment depressions. Emergency transthoracic echocardiogram revealed a reduced left ventricular ejection fraction of 35–40% and mid to distal lateral wall motion hypokinesis. She was emergently taken to the cardiac catheterization laboratory where coronary angiography demonstrated complete occlusion of her mid LCx artery. She underwent urgent percutaneous coronary intervention of the lesion and was started on dual antiplatelet treatment, anticoagulation for comorbid atrial fibrillation, as well as guideline directed medical therapy with improvement in her EKG changes and cardiac function. Conclusion Prompt diagnosis and recognition of LCx injury is crucial. Management involves immediate percutaneous recanalization or surgical coronary bypass grafting.

Abstract 10476: Patient Characteristics and Survival Outcomes of Cardiac Arrest in the Cardiac Catheterization Laboratory: Insights from Get with the Guidelines-Resuscitation Registry

Background: The characteristics and outcomes of in-hospital cardiac arrest (IHCA) in the cardiac catheterization laboratory (CCL) have not been well-described. We compared the characteristics and outcomes of patients with an IHCA in the CCL versus those in the operating room (OR) and the intensive care unit (ICU). Methods: Within the American Heart Association’s Get With the Guidelines-Resuscitation® registry, we identified patients 18 years of age or older with an IHCA in the CCL, OR, or ICU between 2000 and 2019. We compared rates of survival to discharge for patients in the CCL, OR, and ICU. Additionally, we examined predictors of survival to discharge for patients with IHCA in the CCL. Results: There were 6866, 5181, and 181,832 patients with an IHCA in the CCL, OR, and ICU, respectively. Patients with IHCAs in the CCL were more likely to have a shockable cardiac arrest rhythm as compared with those in the OR and ICU. Overall, 2614 (38.1%) patients with IHCA in the CCL survived to discharge, as compared with 30,833 (16.9%) from the ICU and 2096 (40.5%) from the OR. After adjustment for 27 patient and cardiac arrest factors, patients with IHCA in CCL were more likely to survive to discharge as compared with those with IHCA from the ICU (odds ratio, 1.37 [95% CI: 1.29-1.46], p<0.001). In contrast, they were less likely to survive to discharge as compared with those with IHCA in the OR (odds ratio, 0.81 [95% CI: 0.69-0.94], p=0.006). Predictors of survival to discharge in patients with IHCA in the CCL included white race, pulseless ventricular tachycardia/fibrillation, and IHCA during normal hours and on weekdays, while having myocardial infarction during this or prior hospitalization was associated with less survival to discharge. (Table). Conclusion: IHCA in the CCL is not uncommon and has a lower survival rate as compared with IHCA in other procedural areas such as the OR. The reasons for this difference deserve further study given that response to IHCAs in both settings should be similar.

An Artificial Intelligence-Based Alarm Strategy Facilitates Management of Acute Myocardial Infarction

(1) Background: While an artificial intelligence (AI)-based, cardiologist-level, deep-learning model for detecting acute myocardial infarction (AMI), based on a 12-lead electrocardiogram (ECG), has been established to have extraordinary capabilities, its real-world performance and clinical applications are currently unknown. (2) Methods and Results: To set up an artificial intelligence-based alarm strategy (AI-S) for detecting AMI, we assembled a strategy development cohort including 25,002 visits from August 2019 to April 2020 and a prospective validation cohort including 14,296 visits from May to August 2020 at an emergency department. The components of AI-S consisted of chest pain symptoms, a 12-lead ECG, and high-sensitivity troponin I. The primary endpoint was to assess the performance of AI-S in the prospective validation cohort by evaluating F-measure, precision, and recall. The secondary endpoint was to evaluate the impact on door-to-balloon (DtoB) time before and after AI-S implementation in STEMI patients treated with primary percutaneous coronary intervention (PPCI). Patients with STEMI were alerted precisely by AI-S (F-measure = 0.932, precision of 93.2%, recall of 93.2%). Strikingly, in comparison with pre-AI-S (N = 57) and post-AI-S (N = 32) implantation in STEMI protocol, the median ECG-to-cardiac catheterization laboratory activation (EtoCCLA) time was significantly reduced from 6.0 (IQR, 5.0–8.0 min) to 4.0 min (IQR, 3.0–5.0 min) (p < 0.01). The median DtoB time was shortened from 69 (IQR, 61.0–82.0 min) to 61 min (IQR, 56.8–73.2 min) (p = 0.037). (3) Conclusions: AI-S offers front-line physicians a timely and reliable diagnostic decision-support system, thereby significantly reducing EtoCCLA and DtoB time, and facilitating the PPCI process. Nevertheless, large-scale, multi-institute, prospective, or randomized control studies are necessary to further confirm its real-world performance.

Comparison of PLANE Technique versus Standard Echocardiography Guidance for Pediatric Pericardiocentesis

Percutaneous pericardiocentesis remains a challenging and potentially dangerous procedure, particularly in small, critically ill patients. We present outcomes of the PLANE (pericardiocentesis using long-axis in-plane real-time echocardiography) technique for pediatric pericardiocentesis compared with a standard echocardiography (ECHO) guidance cohort. This was a retrospective chart review of all children undergoing percutaneous pericardiocentesis from March 2013 to February 2021 at a single center. A total of 78 procedures were performed, 52 utilizing PLANE technique and 26 utilizing standard ECHO-guidance technique. There was 100% technical success rate with only one minor complication for the entire cohort. Procedures were evenly split between the bedside intensive care unit and cardiac catheterization laboratory. PLANE technique was utilized in significantly younger (1.4 vs. 8.4 years, p = 0.008) and smaller (11.1 vs. 31.8 kg, p = 0.007) patients, as well as in most patients deemed high risk (postoperative < 7 days, extracorporeal membrane oxygenation (ECMO) support, and/or weight less than 5 kg; 19/22, p = 0.021). Other patient characteristics were similar between the two groups. There was a trend toward PLANE technique utilization by noncardiology trained operators. The PLANE technique for pediatric pericardiocentesis is safe and effective and can be effectively utilized in small and high-risk patient populations. The technical similarity to other long-axis ultrasound-guided procedures may facilitate adoption and mastery by critical care trained operators.