ICU Stay in Patients with Low Ejection Fraction Undergoing Cardiac Revascularization: Comparison of On-Pump Versus Off-Pump Coronary Artery Bypass Grafting

Background: Coronary artery bypass graft (CABG) surgery can result in serious complications for the patients. It is being currently performed with cardiopulmonary bypass with cardiac arrest in 80% of the cases across the world. There have debate in the past regarding the cardiac revascularization via CABG approaches. Aim: The aim of this study is to study the difference in the patient’s ICU stay who have low ejection fraction and are undergoing cardiac revascularization between off pump and on pump coronary artery bypass grafting. Methodology: A sample size of 60 patients has been taken in the study with 30 patients' in the on-pump surgery group and 30 patients' in the off-pump surgery group. The data has been collected from department of Cardiac Srugery AFIC/NIHD, Rawalpindi. Results and Conclusion: The study concludes that the on-pump CABG patients tend to have shorter ICU stay than the off-pump CABG patients who have low ejection fraction and are undergoing cardiac revascularization. Therefore, on-pump treatment is recommended in the study. Keywords: Off pump, on pump, coronary artery bypass grafting, ICU stay, low ejection fraction, cardiac revascularization

PFKFB3 gene deletion in endothelial cells inhibits intraplaque angiogenesis and lesion formation in a murine model of venous bypass grafting

Vein grafting is a frequently used surgical intervention for cardiac revascularization. However, vein grafts display regions with intraplaque (IP) angiogenesis, which promotes atherogenesis and formation of unstable plaques. Graft neovessels are mainly composed of endothelial cells (ECs) that largely depend on glycolysis for migration and proliferation. In the present study, we aimed to investigate whether loss of the glycolytic flux enzyme phosphofructokinase-2/fructose-2,6-bisphosphatase 3 (PFKFB3) in ECs inhibits IP angiogenesis and as such prevents unstable plaque formation. To this end, apolipoprotein E deficient (ApoE−/−) mice were backcrossed to a previously generated PFKFB3fl/fl Cdh5iCre mouse strain. Animals were injected with either corn oil (ApoE−/−PFKFB3fl/fl) or tamoxifen (ApoE−/−PFKFB3ECKO), and were fed a western-type diet for 4 weeks prior to vein grafting. Hereafter, mice received a western diet for an additional 28 days and were then sacrificed for graft assessment. Size and thickness of vein graft lesions decreased by 35 and 32%, respectively, in ApoE−/−PFKFB3ECKO mice compared to controls, while stenosis diminished by 23%. Moreover, vein graft lesions in ApoE−/−PFKFB3ECKO mice showed a significant reduction in macrophage infiltration (29%), number of neovessels (62%), and hemorrhages (86%). EC-specific PFKFB3 deletion did not show obvious adverse effects or changes in general metabolism. Interestingly, RT-PCR showed an increased M2 macrophage signature in vein grafts from ApoE−/−PFKFB3ECKO mice. Altogether, EC-specific PFKFB3 gene deletion leads to a significant reduction in lesion size, IP angiogenesis, and hemorrhagic complications in vein grafts. This study demonstrates that inhibition of endothelial glycolysis is a promising therapeutic strategy to slow down plaque progression.

Pilot Study on the Role of Circulating miRNAs for the Improvement of the Predictive Ability of the 2MACE Score in Patients with Atrial Fibrillation

Background. Atrial fibrillation (AF) increases the risk for stroke but also for non-stroke major adverse cardiovascular events (MACE). The 2MACE score was recently proposed to predict these events. Since the interest of microRNAs (miRNAs) in cardiovascular diseases is increasing, we aimed to investigate whether miRNA levels may improve the predictive performance of the 2MACE score. Methods. We included consecutive AF patients stable on vitamin K antagonist therapy. Blood samples were drawn at baseline and plasma expression of miRNAs was assessed. During a median of 7.6 (interquartile range (IQR) 5.4–8.0) years, the occurrence of any MACE (nonfatal myocardial infarction/cardiac revascularization and cardiovascular death) was recorded. Results. We conducted a miRNA expression analysis in plasma from 19 patients with and without cardiovascular events. The miRNAs selected (miR-22-3p, miR-107, and miR-146a-5p) were later measured in 166 patients (47% male, median age 77 (IQR 70–81) years) and all were associated with a higher risk of MACE. The addition of miR-107 and miR-146a-5p to the 2MACE score significantly increased the predictive performance (c-indexes: 0.759 vs. 0.694, p = 0.004), and the model with three miRNAs also improved the predictive performance compared to the original score (c-indexes: 0.762 vs. 0.694, p = 0.012). 2MACE models with the addition of miRNAs presented higher net benefit and potential clinical usefulness. Conclusions. Higher miR-22-3p andmiR-107 and lower miR-146a-5p levels were associated with a higher risk of MACE. The addition of these miRNAs to the 2MACE score significantly increased the predictive performance for MACE, which may aid to some extent in the decision-making process about risk stratification in AF.

P260 Left ventricular pseudoaneurysm manifesting as syncope

Introduction Left ventricular (LV) pseudoaneurysms form when cardiac rupture is contained by adherent pericardium or scar tissue. LV pseudoaneurysm is one of the mechanical complications of myocardial infarctions (MI), particularly inferior wall MI. Although LV pseudoaneurysms are not common, the diagnosis is difficult and they are prone to rupture. Transthoracic echocardiography is commonly used in clinical practice and is usually sufficient to make the diagnosis of LV pseudoaneurysm. Regardless of treatment, patients with LV pseudoaneurysms had a high mortality rate, especially those who did not undergo surgery. Description of the clinical case 74 years-old woman, with previous history of hypertension, dyslipidaemia and type 2 diabetes and stable coronary disease. In June 2018 the patient underwent coronary angiography that revealed left main and 3 vessels coronary disease, Cardiac revascularization surgery was proposed that the patient refused. The patient was stable during 6 months. Four days before presenting to emergency department the patient mentioned intermittent pre-cordial pain associated with exertion. At admission day she felt intense pre-cordial pain, accompanied by sudoresis and nausea, relieving with sublingual nitrate. The patient was hemodynamically stable at admission. Electrocardiogram showed sinus rhythm 65 bpm with 2mm ST-elevation of inferior leads. Troponin I was positive 30 ng/dL. Echocardiogram revealed marked hypokinesia of inferior and lateral wall with moderate depression of global systolic function ans presence of slight circumferential pericardial effusion (6mm in diastole on lateral wall) Emergent coronariography was performed and revealed progression of coronary disease of the right coronary artery with sub-occlusion of the mid segment. Cardiac revascularization surgery was proposed and the patient accepted this time. Echocardiogram was repeated during hospitalization revealed a stable pericardial effusion with reduced dimension comparing to admission. After 3 weeks, while waiting surgery in the ward, the patient was a syncope that resulted in fracture of the distal peroneum. Ecocardiogram was performed and revealed a LV posterior wall pseudoaneurysm through a narrow neck in parasternal long axis view and the presence of large pericardial effusion (Fig 1). The patient was submitted to definitive reparative cardiac surgery with pericardium patch and coronary artery bypass graft from left internal mammary to anterior descending coronary artery. The patient recovered well from the cardiac surgery and at 2 months follow up is alive and without signs of heart failure. This case illustrates the complexity in the management of patients with LV pseudoaneurysm. These patients require substantial critical care, imaging and surgical expertise. A high clinical index of suspicion is needed to avoid missing the diagnosis LV pseudoaneurysm and transthoracic echocardiography is essential to establish the diagnosis. Abstract P260 Figure. Fig 1 - LV pseudoaneurysm