Successful thrombolysis of early bioprosthetic mitral valve thrombosis following extracorporeal membrane oxygenation: Case report.

Introduction: Bioprosthetic mitral valve thrombosis (BPMVT) following post-operative extracorporeal membrane oxygenation (ECMO) is a rare complication with high mortality.Case Report: A 75-year-old man with a flail posterior mitral leaflet underwent a bioprosthetic mitral valve replacement and was subsequently placed on central veno-arterial high flow ECMO following intractable shock after protamine administration. He developed BPMVT over the following 48 hr, which did not resolve with 3 weeks of systemic heparin. He was then treated successfully with 3 days of continuous low dose (1 mg/hr) Tissue Plasminogen Activator (TPA). He suffered no bleeding consequences and had a complete cardiac and end-organ recovery.Discussion: Slow TPA infusion may be an acceptable treatment strategy for alleviating thrombotic burden from a bioprosthetic valve, even in the post-operative setting.

Ramping Up the Delivery of Cardiac Surgery During the COVID-19 Pandemic: A Guidance Statement From the Canadian Society of Cardiac Surgeons.

The coronavirus disease 2019 (COVID-19) has had a profound global effect. Its rapid transmissibility has forced whole countries to adopt strict measures to contain its spread. As part of necessary pandemic planning, most Canadian cardiac surgical programs have prioritized and delayed elective procedures in an effort to reduce the burden on the health care system and to mobilize resources in the event of a pandemic surge. While the number of COVID-19 cases continue to increase worldwide, new cases have begun to decline in many jurisdictions. This "flattening of the curve" has inevitably prompted discussions around reopening of the economy, relaxing some public health restrictions, and resuming nonurgent health care delivery. This document provides a template for cardiac surgical programs to begin to ramp-up the delivery of cardiac surgery in a deliberate and graded fashion as the COVID-19 pandemic burden begins to ease that is guided by 3 principles. First, all recommendations from public health authorities regarding COVID-19 containment must continue to be followed to minimize disease spread, ensure patient safety, and protect health care personnel. Second, patients awaiting elective cardiac surgery need to be proactively managed, reprioritizing those with high-risk anatomy or whose clinical status is deteriorating. Finally, case volumes should be steadily increased in a mutually agreed upon fashion and must balance the clinical needs of patients awaiting surgery against the overall requirements of the health care system.

Cardiac Surgery in Canada During the COVID-19 Pandemic: A Guidance Statement From the Canadian Society of Cardiac Surgeons.

On March 11, 2020, the World Health Organization declared that COVID-19 was a pandemic.1 At that time, only 118,000 cases had been reported globally, 90% of which had occurred in 4 countries.1 Since then, the world landscape has changed dramatically. As of March 31, 2020, there are now nearly 800,000 cases, with truly global involvement.2 Countries that were previously unaffected are currently experiencing mounting rates of the novel coronavirus infection with associated increases in COVID-19-related deaths. At present, Canada has more than 8000 cases of COVID-19, with considerable variation in rates of infection among provinces and territories.3 Amid concerns over growing resource constraints, cardiac surgeons from across Canada have been forced to make drastic changes to their clinical practices. From prioritizing and delaying elective cases to altering therapeutic strategies in high-risk patients, cardiac surgeons, along with their heart teams, are having to reconsider how best to manage their patients. It is with this in mind that the Canadian Society of Cardiac Surgeons (CSCS) and its Board of Directors have come together to formulate a series of guiding statements. With strong representation from across the country and the support of the Canadian Cardiovascular Society, the authors have attempted to provide guidance to their colleagues on the subjects of leadership roles that cardiac surgeons may assume during this pandemic: patient assessment and triage, risk reduction, and real-time sharing of expertise and experiences.

Early veno-venous extracorporeal membrane oxygenation is associated with lower mortality in patients who have severe hypoxemic respiratory failure: A retrospective multicenter cohort study.

PURPOSE: The purpose of the study is to compare outcomes in patients who had severe hypoxemic respiratory failure (Pao2/fraction of inspired oxygen <100) who received early veno-venous extracorporeal membrane oxygenation (ECMO) as an adjunct to mechanical ventilation, to those in patients who received conventional mechanical ventilation alone. MATERIALS AND METHODS: This is a multicenter, retrospective unmatched and matched cohort study of patients admitted between April 2006 and December 2013. Generalized logistic mixed-effects models and Cox proportional hazards models were used to determine the association between treatment with ECMO that was started within 3 days of intensive care unit (ICU) admission and ICU and hospital mortality and length of stay, respectively. RESULTS: A total of 2440 patients who had severe hypoxemic respiratory failure due to various etiologies were included, 46 who received early veno-venous ECMO and 2394 unmatched and 398 matched controls who received conventional ventilation alone. Compared to matched controls, ECMO was associated with a lower odds of ICU (odds ratio [95% confidence interval], 0.30 [0.13-0.67]) and inhospital death (odds ratio 0.30 [0.14-0.67]). In addition, ECMO was associated with longer times to discharge from ICU and hospital (hazard ratio, 0.42 [0.37-0.47] and 0.53 [0.38-0.73], respectively). CONCLUSIONS: In this observational study, use of early ECMO compared to conventional mechanical ventilation alone in patients who had severe hypoxemic respiratory failure was associated with a lower risk of mortality and a longer length of stay.

Dexmedetomidine as a procedural sedative for percutaneous tracheotomy: case report and systematic literature review.

Purpose. To describe the successful use of dexmedetomidine as the primary procedural sedative for a percutaneous tracheotomy procedure and to systematically present the supporting literature. Materials and Methods. A Case report of our experience and systematic literature search. PubMed, Embase, and Google Scholar were searched without restriction using the key words dexmedetomidine, percutaneous tracheotomy, and tracheotomy procedure. All relevant published references were retrieved irrespective of their methodological quality. Results. In total, only 3 relevant references were found. These include one small placebo controlled randomized trial and 2 case reports. The randomized, placebo controlled trial enrolled patients already sedated on midazolam and included 64 total patients. The 2 other case reports both described the use of dexmedetomidine as the primary procedural sedative. All of the cases reported the successful completion of the percutaneous tracheotomy without any major complication, but none reported the subjective patient experience. Conclusion. Based on the available published literature and our experience, we suggest that dexmedetomidine be considered for use as the primary procedural sedative for percutaneous tracheotomy procedure. Dexmedetomidine's ability to provide adequate sedation and amnesia, without blunting the respiratory drive and protective reflexes of the patient, may make it an optimal agent in specific cases.

Radial artery graft treatment with phenoxybenzamine is clinically safe and may reduce perioperative myocardial injury.

BACKGROUND: Phenoxybenzamine effectively reduces radial artery (RA) spasm in vitro, but clinical data supporting its use during coronary revascularization are lacking. Therefore, the purpose of this study was to evaluate the clinical safety and efficacy of RA treatment with phenoxybenzamine. METHODS: Data were collected prospectively on 698 patients who underwent coronary artery bypass grafting with a RA between 1997 and 2005. Of these, 311 patients received RA grafts incubated in 2 mg/mL phenoxybenzamine for 15 minutes, and 387 patients received RA grafts treated with verapamil and nitroglycerin (VG solution). Demographic, operative, and postoperative data were compared retrospectively using multivariate regression techniques. RESULTS: The incidence of perioperative myocardial events (defined as either low cardiac output syndrome or perioperative myocardial infarction) was significantly reduced in the phenoxybenzamine group (6.8% vs 11.9%, phenoxybenzamine vs VG solution; p = 0.03). Perioperative myocardial enzyme release, as measured by postoperative maximum creatine kinase, was also reduced in the phenoxybenzamine group (743.0 +/- 677.9 vs 937.2 +/- 1236.8 U/L, phenoxybenzamine vs VG solution; p = 0.014). After adjusting for patient and procedural factors, the use of phenoxybenzamine was independently associated with reductions in peak creatine kinase (by -343.0 +/- 136.7 U/L; p = 0.012) and peak troponin T level (by -0.50 +/- 0.19 ng/mL; p = 0.010). No differences in vasopressor support, length of stay, or other complications were observed. CONCLUSIONS: Treatment of RA grafts with phenoxybenzamine was associated with a reduction in perioperative myocardial injury and adverse cardiac events in this study population. Investigations to further evaluate the potential benefits of phenoxybenzamine in randomized settings are warranted.

Effects of off-pump versus on-pump coronary artery bypass grafting on function and viability of circulating endothelial progenitor cells.

OBJECTIVE: Off-pump coronary artery bypass grafting may result in fewer myocardial and vascular complications than on-pump. Although differences in aortic manipulations likely play a role, the systemic responses of endothelial progenitor cells to both types of operations have not been examined. We sought to examine endothelial progenitor cell characteristics after off-pump versus on-pump coronary artery bypass grafting. METHODS: Twenty patients undergoing off-pump or on-pump coronary artery bypass grafting were prospectively enrolled and had endothelial progenitor cells isolated and cultured from their peripheral blood before and 24 hours after surgery. Endothelial progenitor cells were identified by fluorescent dual lectin/low-density lipoprotein binding. Their number, phenotype characteristics, proliferation, migratory function, and viability were determined in a blinded fashion. RESULTS: Patient characteristics and numbers of grafts were equivalent. Endothelial progenitor cells had similar phenotypes between groups before and after surgery. Off-pump and on-pump coronary artery bypass grafting resulted in similar increases in endothelial progenitor cell numbers and showed equivalent proliferation activity. However, endothelial progenitor cell migratory function was higher in off-pump patients (25.3 +/- 5.0 vs 5.0 +/- 1.0 cells per high-powered field for off-pump vs on-pump coronary artery bypass grafting, respectively; P = .04). Postoperative endothelial progenitor cell viability adjusted for preoperative baseline was also higher after off-pump than on-pump coronary artery bypass grafting by 72.4% +/- 14.6% (P = .01). Endothelial progenitor cells of on-pump patients were less viable after surgery than before surgery, whereas the reverse was observed in off-pump patients. CONCLUSIONS: Both on-pump and off-pump coronary artery bypass grafting elicit mobilization of endothelial progenitor cells into the peripheral blood. On-pump coronary artery bypass grafting, however, impairs the migratory function and viability of these vascular repair cells, which are conversely preserved after off-pump surgery. Further work is necessary to determine whether the function and viability of endothelial progenitor cells correlate with vascular outcomes and whether their therapeutic modulation may one day benefit coronary artery bypass grafting patients.