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Redo sternotomy and explantation of left ventricular assist devices (LVAD) for heart transplantation (HT) involve prolonged dissection, potential injury to mediastinal structures and/or bleeding. Our study compared a complete expanded polytetrafluoroethylene (ePTFE) wrap versus minimal or no ePTFE during LVAD implantation, on outcomes of subsequent HT.Between July 2005 and July 2018, 84 patients underwent a LVAD implant and later underwent HT. Thirty patients received a complete ePTFE wrap during LVAD implantation (Group 1), and 54 patients received either a sheet of ePTFE placed in the anterior mediastinum or no ePTFE (Group 2).Baseline characteristics were similar between Groups 1 and 2. Surgeons reported subjective improvements in speed, predictability, and safety of dissection with complete ePTFE compared with minimal or no ePTFE. Time from incision to initiation of cardiopulmonary bypass (CPB) were similar between groups (97 ± 38 vs. 89 ± 29 min, p = .3). Injury to mediastinal structures during the dissection was similar between groups (10% vs. 11%, p .9). While surgeons reported less intraoperative bleeding in Group 1 (43% vs. 61%), this trend did not reach significance (p = .1). In-hospital mortality, intensive care unit length of stay and hospital length of stay were similar between both groups.In patients undergoing LVAD explant-HT, there was a trend toward reduced surgeon reported intraoperative bleeding with ePTFE placement. Despite qualitatively reported greater ease and speed of mediastinal dissection with ePTFE membrane placement, time to initiation of CPB did not differ, likely because surgeons remained cautious, allowing extra time for unanticipated difficulties.

Research regarding risks of swallow treatment suggests that patients with coronary artery disease (CAD) experience changes in heart rate/rhythm when completing the supraglottic swallow and super-supraglottic swallow. The current study evaluated cardiac function during multiple swallowing exercises in patients with dysphagia and CAD. Eligible patients had CAD and confirmed pharyngeal dysphagia from VFS and sufficient cognitive ability to follow direction. The protocol included an a priori concealed randomized order of seven swallowing exercises (supraglottic swallow, super-supraglottic swallow, Mendelsohn and Masako maneuvers, effortful swallow with and without breath hold, and jaw opening exercise). Objective measures of heart rate/rhythm, oxygen saturation, and blood pressure were compared before vs after the overall session and each exercise using the Wilcoxon signed-rank test, and McNemar's and Cochran's Q tests with alpha at 0.05 and power at 0.80. Participants were 20 adults (15 male), aged 28-88 (median 76.5 years). 90% were intubated during their hospital stay (44% 1 intubation) and 20% suffered post-op stroke. Severe dysphagia, marked by NPO status, occurred in 30% of patients. Sessions were 26 min long (mean; SD = 2.29). With few exceptions, objective measures were stable pre vs post overall and after each exercise. Potential vulnerability was noted with increased heart rate after the super-supraglottic swallow and increased arrhythmias after the effortful swallow (p 0.05 for both). The order that swallowing exercises were completed did not significantly impact cardiovascular function. Telemetry and pulse oximetry proved to be feasible tools to monitor for subtle changes in cardiovascular function during completion of swallowing exercises.

The effectiveness of in-hospital self-care patient education, delivered to patients following heart surgery, is questionable, as evidence indicates individuals are not able to absorb and/or retain information at this time. In the absence of adequate instruction, individuals will not have the relevant information to engage in specific self-care behaviors, resulting in the onset of complications and/or hospital readmissions. The purpose of this pilot study was to collect preliminary evidence to demonstrate the impact of an individualized education intervention given above and beyond usual care, delivered, at two points in time, following hospital discharge. A randomized controlled trial was used in which 34 patients were randomly assigned to one of two groups. Chi-square analyses to examine differences between groups on complications and hospital readmission rates were conducted. Findings point to the impact of the intervention in reducing the number of hospital readmissions and complications at 3 months following hospital discharge.

BACKGROUND AND AIM The P2Y12 platelet receptor inhibitor ticagrelor is widely used in patients following acute coronary syndromes or in those who have received coronary stents. Bentracimab is a monoclonal antibody-based reversal agent that is being formally evaluated in a Phase 3 clinical trial. Here, we probe the knowledge, attitudes, and practice patterns of cardiac surgeons regarding their perioperative management of ticagrelor and potential application of a ticagrelor reversal agent. METHODS A questionnaire was developed by a working group of cardiac surgeons to inquire into participants' practices and beliefs regarding ticagrelor and disseminated to practicing, Canadian-trained cardiac surgeons. RESULTS A total of 70 Canadian-trained cardiac surgeons participated. Bleeding risk was identified as the most significant consideration when surgically revascularizing ticagrelor-treated patients (90%). There is variability in the duration of withholding ticagrelor before coronary artery bypass graft procedure in a stable patient; 44.3% wait 3 days and 32.9% wait 4 days or longer. Currently, 15.7% of cardiac surgeons prophylactically give platelet transfusions and fresh frozen plasma intraoperatively following protamine infusion in patients who have recently received ticagrelor. Interestingly, 47.1% of surveyed surgeons were aware of a reversal agent for ticagrelor, 91.4% of cardiac surgeons would consider utilizing a ticagrelor reversal agent if available, and 51.4% acknowledged that the introduction of such an agent would be a major advance in clinical practice. CONCLUSIONS The present survey identified ticagrelor-related bleeding as a major concern for cardiac surgeons. Surgeons recognized the significant unmet need that a ticagrelor reversal agent would address.

Ventricular remodeling following myocardial infarction (MI) is a major cause of heart failure, a condition prevalent in older individuals. Following MI, immune cells are mobilized to the myocardium from peripheral lymphoid organs and play an active role in orchestrating repair. While the effect of aging on mouse bone marrow (BM) has been studied, less is known about how aging affects human BM cells and their ability to regulate repair processes. In this study, we investigate the effect aging has on human BM cell responses post‐MI using a humanized chimeric mouse model. BM samples were collected from middle aged (mean age 56.4 ± 0.97) and old (mean age 72.7 ± 0.59) patients undergoing cardiac surgery, CD34+/− cells were isolated, and NOD‐scid‐IL2rγnull (NSG) mice were reconstituted. Three months following reconstitution, the animals were examined at baseline or subjected to coronary artery ligation (MI). Younger patient cells exhibited greater repopulation capacity in the BM, blood, and spleen as well as greater lymphoid cell production. Following MI, CD34+ cell age impacted donor and host cellular responses. Mice reconstituted with younger CD34+ cells exhibited greater human CD45+ recruitment to the heart compared to mice reconstituted with old cells. Increased cellular responses were primarily driven by T‐cell recruitment, and these changes corresponded with greater human IFNy levels and reduced mouse IL‐1β in the heart. Age‐dependent changes in BM function led to significantly lower survival, increased infarct expansion, impaired host cell responses, and reduced function by 4w post‐MI. In contrast, younger CD34+ cells helped to limit remodeling and preserve function post‐MI., To study the effect aging has on human cell responses post‐MI, we utilized a xenograft mouse (NSG) model using BM from middle aged (Y‐CD34+) and old patients (O‐CD34+). Our results demonstrate that O‐CD34+ reconstituted mice exhibit impaired donor and host cell responses while Y‐CD34+ reconstituted mice exhibit a greater donor lymphocyte and host myeloid cell responses post‐MI. Differences in cellular responses are associated with improved cardiac function in Y‐CD34+ reconstituted mice post‐MI.

Background Cardiac repair depends on angiogenesis and cell proliferation. Previously we identified Canopy 2 (CNPY2) as a secreted angiogenic growth factor which promotes neovascularization. We investigated the role of CNPY2 in cardiac repair following myocardial infarction (MI) and the possible mediators involved using Cnpy2 knockout (KO) mice and human cardiac tissue. Methods and results Cardiac tissue from patients with end-stage heart failure had significantly lower endogenous CNPY2 expression compared to samples from control patients. CNPY2 expression in mouse hearts significantly decreased following MI. Significantly less leukocyte and endothelial cell proliferation was found in Cnpy2 KO than wild-type (WT) mice post MI which contributed to impaired angiogenesis, tissue repair, and decreased cardiac function (fractional shortening: WT: 21.1 ± 2.1% vs. KO: 16.4 ± 1.6%, p Conclusions Cardiac injury and progressive heart failure were associated with decreased CNPY2 levels in both humans and mice. Knockout of Cnpy2 resulted in up-regulation of p16INK4a which impaired cardiac function and tissue repair. These data suggest that CNPY2 is an important regulator of p16INK4a and promotes cell proliferation and tissue repair through inhibition of the p16INK4a pathway. CNPY2 treatment may offer a new approach to restore cardiac function after an MI.

Over a quarter of all heart surgery patients are readmitted to hospitals across Canada with post-operative complications experienced during the first 3 months of recovery. This may be due to the quality of existing patient education intervention. Specifically, the mode, episode, and timing of delivery of standard education programs may not be optimal in promoting self-care behaviours, resulting in the development of complications leading to increased hospital readmissions. The objectives of this preliminary descriptive study were twofold: 1) to describe the most consistent mode, episode, and timing in which education is provided to patients following heart surgery; and 2) to identify the degree to which the current educational mode and episode are correlated to readmission rates following hospital discharge. A non-experimental preliminary descriptive design was used to address the study objectives. Setting: Thirty-three patients were recruited from a cardiovascular surgical unit located within a large tertiary hospital. Method: Patients were included if they underwent heart surgery for the first time; were literate in English; cognitively oriented; and had access to a working phone at home. Point-biserial correlations were performed to identify the degree to which the characteristics of existing patient education were correlated to hospital readmission rates. Results: A statistically significant inverse relationship between episode and hospital readmission (rpb = - .49, p = .001) was noted suggesting that with reduced exposure to patient education, there is an increased likelihood for hospital readmissions. Conclusion: Increasing the number of times education is provided may reduce the number of hospital readmissions.

Randomized controlled trial (RCT) designs are standardized to control for bias and allow for replication. Conducting RCTs is generally straightforward when dealing with interventions that contain a single component, such as a drug. However, interventions that do not contain single components, such as a patient education programs, are more difficult to standardize, as they contain multiple elements, which may act independently or interdependently of each other. The purpose of this discursive clinical methods paper is to describe and explain a methodology that can be used to optimize the design of a complex intervention prior to its evaluation in a randomized control trial.

Background and Aim: The P2Y12 platelet receptor inhibitor ticagrelor is widely used in patients following acute coronary syndromes or in those who have received coronary stents. Bentracimab is a monoclonal antibody-based reversal agent that is being formally evaluated in a Phase 3 clinical trial. Here, we probe the knowledge, attitudes, and practice patterns of cardiac surgeons regarding their perioperative management of ticagrelor and potential application of a ticagrelor reversal agent. Methods: A questionnaire was developed by a working group of cardiac surgeons to inquire into participants’ practices and beliefs regarding ticagrelor and disseminated to practicing Canadian cardiac surgeons. Results: A total of 70 Canadian cardiac surgeons participated. Bleeding risk was identified as the most significant consideration when surgically revascularizing ticagrelor-treated patients (90%). There is variability in the duration of withholding ticagrelor prior to coronary artery bypass graft procedure in a stable patient; 44.3% wait 3 days and 32.9% wait 4 days or longer. Currently, 14.3% of cardiac surgeons prophylactically give platelet transfusions and/or fresh frozen plasma intraoperatively following protamine infusion in patients who have recently received ticagrelor. Interestingly, 47.1% of surveyed surgeons were aware of a reversal agent for ticagrelor, 91.4% of cardiac surgeons would consider utilizing a ticagrelor reversal agent if available, and 51.4% acknowledged that the introduction of such an agent would be a major advance in clinical practice. Conclusions: The present survey identified ticagrelor-related bleeding as a major concern for cardiac surgeons. Surgeons recognized the significant unmet need that a ticagrelor reversal agent would address.

BACKGROUND This study aims to determine the most important criteria used by Canadian cardiac surgery residency program committees (RPCs) to select applicants and compare these criteria with the perceptions of Canadian medical students interested in cardiac surgery. METHODS AND RESULTS A 50-question online survey was developed and sent to all 12 Canadian cardiac surgery RPCs. A similar 52-question online survey targeted at students interested in applying to cardiac surgery residency programs was designed and distributed broadly across Canadian medical schools. Data from both surveys were analyzed using descriptive statistics. A total of 62% (66/106) of all RPC members across the country completed the 50-question survey. Committee members from all 12 programs (range: 1-12 members/program, 9%-100% response rate/program) and 67% (8/12) of program directors participated. The average experience of participating RPC members was 3.9±2.5 years, with 20% being relatively inexperienced (≤2 years on committee) and 30% being very experienced (≥7 years on committee). Forty-one Canadian medical students (22 pre-clerks [54%], two MD/PhD students [5%], and 17 clinical clerks [41%]) participated. Committee members considered the following criteria most important when selecting candidates: clinical performance during rotation(s) at the program's institution, performance at the interview, quality of reference letters from cardiac surgeons, and completing a rotation at the target program's institution. In contrast, the following criteria were considered less important: a candidate's desire to practice in the city or province of training, having a connection to the program location, and personally knowing committee members. This pattern was consistent between Quebec and non-Quebec programs and between inexperienced and experienced RPC members. Medical students' perceptions were concordant for the most important factors but overestimated the influence of the least important factors. Prospective candidates also overestimated RPCs' expectations concerning research performance. There was a significant difference between medical students' and RPC members' perceptions of the minimum number of first-author cardiac surgery publications (1.9 vs 0.8, p=0.001), total cardiac surgery publications (3.3 vs 1.7, p CONCLUSION Canadian cardiac surgery residency programs seek applicants demonstrating clinical excellence as assessed by clerkship rotations and reference letters from colleagues, as well as solid interview performance. Medical students are aware of the importance of these factors but overemphasize non-clinical characteristics — including the minimum number of research publications — as ways to increase competitiveness.

Adequate myocardial protection is an integral part of the safe conduct of cardiac surgery. The mainstay of myocardial protection is cardioplegia. Since the concept of reversible chemically-induced cardiac arrest was first introduced in the 1950s, a number of different cardioplegic solutions have been developed. As a result, there is wide variability in clinical practice and, despite the publication of numerous comparative clinical studies, there is no clear consensus regarding the optimal strategy for myocardial protection in adult cardiac surgery. In this chapter, we briefly survey the history of myocardial protection. We describe the main types of cardioplegic solutions currently available, and discuss controversies surrounding optimal temperature and method of delivery, highlighting the advantages and limitations of various approaches. Finally, we briefly discuss the emerging evidence regarding novel strategies for myocardial protection using single-dose solutions.

Deep sternal wound infection is a rare but serious complication of cardiac operations performed through a median sternotomy. The incidence ranges from 0.75 to 1.44% in large observational studies. Staphylococcus aureus and coagulase negative Staphylococci are the most commonly encountered pathogens. Pedicled bilateral internal mammary artery harvest increases the risk of sternal wound infection, particularly in obese, diabetic patients. The diagnosis of deep sternal wound infection is essentially clinical, but computed tomography can help determine the precise location and extent of the infectious process. Intravenous antibiotics and surgical debridement is the mainstay of therapy. Sternal re-closure can be performed immediately after debridement, or following an interval of open chest management. Sternal closure is achieved either primarily (with cerclage or rigid fixation) or with the use of soft-tissue flaps. Vacuum-assisted closure therapy may improve outcomes.

BACKGROUND The benefit of mitral valve repair (MVr) over replacement in patients with severe ischemic mitral regurgitation (IMR) is still controversial. We report our early postoperative outcomes of repair versus replacement. METHODS Data were collected for patients undergoing first-time mitral valve surgery for severe IMR between 1990 and 2009 (n = 393). Patients who underwent combined procedures for papillary muscle rupture, post-infarction ventricular septal defect, endocarditis, or any previous cardiac surgery were excluded. Preoperative demographics, operative variables, and hospital outcomes were analyzed, and multivariable regression analysis was employed to identify independent predictors of hospital mortality. RESULTS Valve repair was performed in 42% (n = 164) of patients and replacement in 58% (n = 229). Patients who underwent replacement were older and had a higher prevalence of unstable angina, New York Heart Association Class IV symptoms, preoperative cardiogenic shock, preoperative myocardial infarction, peripheral vascular disease, renal failure, and urgent or emergency surgery (all p

OBJECTIVES There is an increasing proportion of patients with a previous sternotomy (PS) or durable left ventricular assist device (LVAD) undergoing heart transplantation (HT). We hypothesized that patients with LVAD support at the time of HT have a lower risk than patients with PS and may have a comparable risk to patients with a virgin chest (VC). METHODS This is a single-centre retrospective cohort study of all adults who underwent primary single-organ HT between 2002 and 2017. Multivariable Cox regression analyses were performed to compare 30-day and 1-year mortality between transplanted patients with a VC (VC-HT), a PS (PS-HT) or an LVAD explant (LVAD-HT). RESULTS Three hundred seventy-nine patients were analysed (VC-HT: 196, PS-HT: 94, LVAD-HT: 89). A larger proportion of patients in the LVAD-HT group were males (83%), had blood group O (52%), non-ischaemic aetiology (70%) and sensitization (67%). The PS-HT group had a higher frequency of patients with congenital heart disease (30%) and PSs compared to LVAD-HT patients (P CONCLUSIONS Transplants in recipients with PS-HT demonstrated increased early mortality compared to VC-HT patients. Although LVAD explant is often technically challenging, this population demonstrated similar mortality compared to those VC-HT patients. The chronic and perioperative support provided by the LVAD may play a favourable role in early patient outcomes compared to other redo sternotomy patients.

Myocardial fibrosis, resulting from ischemic injury, increases tissue resistivity in the infarct area, which impedes heart synchronous electrical propagation. The uneven conduction between myocardium and fibrotic tissue leads to dys-synchronous contraction, which progresses towards ventricular dysfunction. We synthesized a conductive poly-pyrrole-chitosan hydrogel (PPY–CHI), and investigated its capabilities in improving electrical propagation in fibrotic tissue, as well as resynchronizing cardiac contraction to preserve cardiac function. In an in vitro fibrotic scar model, conductivity increased in proportion to the amount of PPY-CHI hydrogel added. To elucidate the mechanism of interaction between myocardial ionic changes and electrical current, an equivalent circuit model was used, which showed that PPY-CHI resistance was 10 times lower, and latency time 5 times shorter, compared to controls. Using a rat myocardial infarction (MI) model, PPY-CHI was injected into fibrotic tissue 7 days post MI. There, PPY-CHI reduced tissue resistance by 30%, improved electrical conduction across the fibrotic scar by 33%, enhanced field potential amplitudes by 2 times, and resynchronized cardiac contraction. PPY-CHI hydrogel also preserved cardiac function at 3 months, and reduced susceptibility to arrhythmia by 30% post-MI. These data demonstrated that the conductive PPY-CHI hydrogel reduced fibrotic scar resistivity, and enhanced electrical conduction, to synchronize cardiac contraction.

Objective The number of adults with congenital heart disease (CHD) has increased substantially because of medical advances that are extending life expectancy beyond childhood. A historical investigation is timely not only because of this significant demographic shift, but also because stakeholder engagement is increasingly important in shaping research directions. The study questions were: From the perspective of stakeholders, what is known about the medical treatment for the adult CHD cohort in Canada and how has it changed over time? Design/methods We harnessed the use of historical research methods and conducted interviews with 21 key informants in order to articulate a contextualized understanding of the evolution of adult CHD treatment in Canada. The informants recruited were currently or previously located in and/or involved in treatment in seven provinces and two territories across Canada including patients, families, advocates, researchers, and practitioners located in disciplines that included cardiology, cardiovascular surgery, nursing, psychology, dietetics, and kinesiology. Results Alongside findings that highlighted the significant demographic shift, the findings highlight key themes related to temporal shifts in treatment, emergence of organizational structures and use of evidence, comprehensive approaches to care, and future directions. A critical finding that requires immediate attention is the significantly disproportionate resources to the number of adults living with CHD, and as a result, the real risk of premature death for this population. Conclusions The insights provided behoove the community of stakeholders to think creatively on how to draw attention to the inadequacy of resources and the unique and diverse needs of this population.

Background: Surgical aortic root enlargement (ARE) during aortic valve replacement (AVR) allows for larger prosthesis implantation and may be an important adjunct to surgical AVR in the transcatheter valve-in-valve era. The incremental operative risk of adding ARE to AVR has not been established. We aimed to evaluate the early outcomes of patients undergoing AVR with or without ARE. Methods: From January 1990 to August 2014, 7039 patients underwent AVR (AVR+ARE, n=1854; AVR, n=5185) at a single institution. Patients with aortic dissection and active endocarditis were excluded. Mean age was 65±14 years and 63% were male. Logistic regression and propensity score matching were used to adjust for unbalanced variables in group comparisons. Results: Patients undergoing AVR+ARE were more likely to be female (46% versus 34%, P P P =0.004), urgent/emergent status (6% versus 4%, P =0.01), and worse New York Heart Association status ( P P =0.98) and also underwent concomitant cardiac procedures (AVR+ARE: 68% versus AVR: 67%, P =0.31). Mean prosthesis size implanted was slightly smaller in patients requiring AVR+ARE versus AVR (23.4±2.1 versus 24.1±2.3, P P =0.008), although when the cohort was restricted to patients undergoing isolated aortic valve replacement with or without root enlargement, mortality was not statistically different (AVR+ARE: 1.7% versus AVR: 1.1%, P =0.29). After adjustment for baseline characteristics, AVR+ARE was not associated with an increased risk of in-hospital mortality when compared with AVR (odds ratio, 1.03; 95% confidence interval, 0.75–1.41; P =0.85). Furthermore, AVR+ARE was not associated with an increased risk of postoperative adverse events. Results were similar if propensity matching was used instead of multivariable adjustments for baseline characteristics. Conclusions: In the largest analysis to date, ARE was not associated with increased risk of mortality or adverse events. Surgical ARE is a safe adjunct to AVR in the modern era.

PURPOSE OF REVIEW As ventricular assist device (VAD) therapy in patients with advanced heart failure continues to grow, experience with concomitant valvular diseases present either before or after VAD implantation continues to accrue. In this review, we discuss recent data and current practice as it pertains to the subject of concomitant valvular disease in patients requiring VADs. RECENT FINDINGS Persistent aortic valve closure has been identified as a potential contributor to aortic valve 'disuse atrophy' resulting in valve degeneration. Dilation of the aortic root may be predictive of future development of aortic insufficiency. Novel echocardiographic parameters to identify the severity of aortic insufficiency following VAD implantation may be useful for risk stratification. Concomitant repair of significant mitral regurgitation may confer benefit to pulmonary vascular resistance and right ventricular function; however, this remains controversial. Concomitant repair of significant tricuspid regurgitation has not demonstrated early postoperative benefit nor survival benefit. Atrial fibrillation has emerged as a risk factor that may predict accelerated progression of postoperative tricuspid regurgitation. SUMMARY Management of aortic insufficiency, mitral regurgitation or tricuspid regurgitation in patients requiring VADs continues to be the source of controversy. As experience accrues with varying strategies to prevent or manage these valvular lesions, our understanding of the impact of these strategies continues to evolve.

Background: The post-myocardial infarction (MI) scar interrupts electrical impulse propagation and delays regional contraction, which contributes to ventricular dysfunction. We investigated the potential of an injectable conductive biomaterial to restore scar tissue conductivity and re-establish synchronous ventricular contraction. Methods: A conductive biomaterial was generated by conjugating conductive polypyrrole (PPY) onto chitosan (CHI) backbones. Trypan blue staining of neonatal rat cardiomyocytes (CMs) cultured on biomaterials was used to evaluate the biocompatibility of the conductive biomaterials. Ca2+ imaging was used to visualize beating CMs. A cryoablation injury rat model was used to investigate the ability of PPY:CHI to improve cardiac electrical propagation in the injured heart in vivo. Electromyography was used to evaluate conductivity of scar tissue ex vivo. Results: Cell survival and morphology were similar between cells cultured on biomaterials-coated and uncoated-control dishes. PPY:CHI established synchronous contraction of two distinct clusters of spontaneously-beating CMs. Intramyocardial PPY:CHI injection into the cryoablation-induced injured region improved electrical impulse propagation across the scarred tissue and decreased the QRS interval, whereas saline- or CHI-injected hearts continued to have delayed propagation patterns and significantly reduced conduction velocity compared to healthy controls. Ex vivo evaluation found that scar tissue from PPY:CHI-treated rat hearts had higher signal amplitude compared to those from saline- or CHI-treated rat heart tissue. Conclusions: The PPY:CHI biomaterial is electrically conductive, biocompatible and injectable. It improved synchronous contraction between physically separated beating CM clusters in vitro. Intra-myocardial injection of PPY:CHI following cardiac injury improved electrical impulse propagation of scar tissue in vivo.

As support times for left ventricular assist devices (LVADs) become longer, several complications requiring device exchange may occur. To our knowledge, this is the first Canadian report regarding implantable LVAD exchange.We retrospectively reviewed the cases of consecutive, unique patients implanted with an LVAD between June 2006 and October 2015 at Toronto General Hospital.In total, 122 patients were impanted with an LVAD during the study period. Eight patients required LVAD exchange, and 1 patient had 2 replacements (9 of 122, 7.3%). There were 7 HeartMate II (HMII), 1 HVAD and 1 DuraHeart pumps exchanged. Two of these exchanges occurred early at the time of initial implant, whereas 7 occurred late (range 8-623 d). Six exchanges were made owing to pump thrombosis. Of the 3 exchanges made for other causes, 1 HMII exchange was owing to a driveline fracture, 1 DuraHeart patient had early inflow obstruction requiring exchange to HMII at the initial implant, and the third had a suspected inflow obstruction with no evidence of thrombosis at the time of the procedure. The mean support time before exchange was 225 days, and time from exchange to transplant, death or ongoing support was 245 days. Three patients were successfully bridged to transplant, and at the time of data collection 2 were supported awaiting transplant. Three patients died after a mean duration of 394.3 days (range 78-673 d) of support postreplacement. Four cases were successfully performed using a subcostal approach.Pump thrombosis is the most common cause for LVAD exchange, which can be performed with acceptable morbidity and mortality. The subcostal approach may be the preferred procedure for an HMII exchange when indicated.À mesure que la durée d'utilisation des dispositifs d'assistance ventriculaire gauche (DAVG) augmente, plusieurs complications nécessitant un remplacement du dispositif peuvent survenir. À notre connaissance, il s'agit du premier rapport canadien concernant le remplacement des DAVG implantables.Nous avons passé en revue de manière rétrospective les cas individuels consécutifs de patients à qui on a implanté un DAVG entre juin 2006 et octobre 2015 à l'Hôpital Général de Toronto.En tout, 122 patients ont reçu un DAVG pendant la période de l'étude. Huit patients ont eu besoin d'un remplacement de DAVG et 1 patient a eu besoin de 2 remplacements (9 sur 122, 7,3 %). Sept dispositifs HeartMate II (HMII), 1 dispositif HVAD et 1 dispositif DuraHeart ont été remplacés. Deux de ces remplacements sont survenus peu de temps après la pose initiale du dispositif, tandis que les 7 autres se sont produits plus tardivement (dans les 8 à 623 jours suivants). Six remplacements ont été effectués en raison d'une thrombose de la pompe. Parmi les 3 remplacements effectués pour d'autres raisons, 1 dispositif HMII a été remplacé en raison d'un bris de la ligne d'activation, 1 dispositif DuraHeart a présenté une obstruction précoce du flux entrant nécessitant la pose d'un HMII dès l'implantation initiale, et le troisième présentait une obstruction présumée du flux entrant sans signe de thrombose au moment de l'intervention. La durée moyenne d'utilisation avant le remplacement du dispositif a été de 225 jours, et l'intervalle entre le remplacement et la transplantation, le décès ou la décision de maintenir l'assistance a été de 245 jours. L'appareil a permis une transition réussie jusqu'à la transplantation chez 3 patients, et au moment de la collecte des données, 2 patients porteurs d'un DAVG étaient en attente d'une transplantation. Trois patients sont décédés après une durée moyenne de 394,3 jours (entre 78 et 673 jours) d'assistance post-remplacement. Quatre remplacements ont été effectués avec succès par une approche sous-costale.La thrombose de la pompe est la cause la plus fréquente de remplacement d'un DAVG; le remplacement peut être effectué avec des taux de morbidité et de mortalité acceptables. L'approche sous-costale serait à privilégier lorsqu'un remplacement de HMII est indiqué.

Objective: Few methods enable molecular and cellular studies of vascular aging or Type 2 diabetes (T2D). Here, we report a new approach to studying human vascular smooth muscle cell (VSMC) pathophysiology by examining VSMCs differentiated from progenitors found in skin. Approach and results: Skin-derived precursors (SKPs) were cultured from biopsies (N=164, ∼1 cm2) taken from the edges of surgical incisions of older adults (N=158; males 72%; mean age 62.7 ± 13 years) undergoing cardiothoracic surgery, and differentiated into VSMCs at high efficiency (>80% yield). The number of SKPs isolated from subjects with T2D was ∼50% lower than those without T2D (cells/g: 0.18 ± 0.03, N=58 versus 0.40 ± 0.05, N=100, P

Bicuspid aortic valve (BAV) disease is a congenital abnormality that is associated with ascending aortic aneurysm yet many of the molecular mechanisms remain unknown. To identify novel molecular mechanisms of aneurysm formation we completed microarray analysis of the proximal (severely dilated) and distal (less dilated) regions of the ascending aorta from five patients with BAV. We identified 180 differentially expressed genes, 40 of which were validated by RT-qPCR. Most genes had roles in inflammation and endothelial cell function including cytokines and growth factors, cell surface receptors and the Activator Protein 1 (AP-1) transcription factor family (FOS, FOSB and JUN) which was chosen for further study. AP-1 was differentially expressed within paired BAV aneurysmal samples (n = 8) but not Marfan patients (n = 5). FOS protein was significantly enriched in BAV aortas compared to normal aortas but unexpectedly, ERK1/2 activity, an upstream regulator of FOS was reduced. ERK1/2 activity was restored when BAV smooth muscle cells were cultured in vitro. An mRNA-miRNA network within paired patient samples identified AP-1 as a central hub of miRNA regulation. FOS knockdown in BAV SMCs increased expression of miR-27a, a stretch responsive miRNA. AP-1 and miR-27a were also dysregulated in a mouse model of aortic constriction. In summary, this study identified a central role for AP-1 signaling in BAV aortic dilatation by using paired mRNA-miRNA patient sample. Upstream analysis of AP-1 regulation showed that the ERK1/2 signaling pathway is dysregulated and thus represents a novel chain of mediators of aortic dilatation in BAV which should be considered in future studies.

Purpose Minimally invasive (MI) approaches for left ventricular assist device (LVAD) implantation has the potential to offer similar benefits to of other well-established cardiac surgery procedures. We performed a systematic review and meta-analysis to determine the potential benefits of MI LVAD implantation compared to sternotomy. Methods We searched MEDLINE and EMBASE databases for studies comparing MI continuous-flow LVAD implantation with sternotomy. Data was extracted by two independent investigators. The main outcomes were perioperative mortality and complications. Results 19 observational studies (1619 patients) with mean follow-up of 9 months were included. HeartWare was the most commonly implanted device (80%), followed by HeartMate II (6%). Serum bilirubin was lower (MD: -5.4 uM; 95%CI: ‒8.1 to -2.7; p Conclusion MI LVAD implantation led to an improved perioperative complication profile and enhanced patient recovery, potentially decreasing mid-term mortality. These are consistent with findings from other well-established MI cardiac surgical procedures. A future randomized trial could further clarify these benefits and establish this technique as a standard practice.

Background: Optimal patient recovery from open-heart surgery relies on effective discharge planning and education. However, the nature of the discharge experience has not been clearly described. Objective: The study purpose is to explore patients’ and nurses’ narrative accounts of the facilitators and barriers of heart surgery discharge. Methods: A qualitative study was employed using a narrative methodology that elicited and analyzed stories. This research was conducted in a large, urban hospital in Ontario, Canada. A total of 17 patients and nurses were recruited. Five female and 5 male patients were recruited from a preoperative clinic. Ages ranged from 37 to 80 years. Seven nurses were recruited from inpatient cardiovascular units. They had 2 to 19 years of cardiovascular nursing experience. Semistructured, narrative-based interviews were conducted. Two interviews were conducted with each patient at 1 week after discharge and at 4 to 6 weeks. One interview was conducted with each nurse. Results: Findings indicate that although the preoperative period was identified as an effective time for discharge preparation, the patient’s cognitive capacity was limited during the postoperative phase of surgery. Both nurses and patients also found that insufficient time impeded the discharge process and limited individualized discussions. The structured and standardized delivery of discharge information affected patients’ capacity to apply it to the particularities in their own lives and homes. The fostering of therapeutic relationships created a space where patients felt comfortable sharing their concerns and nurses learned more about patients and thus could better tailor the discharge approach. Conclusions: Study recommendations include group and scenario-based education in which patients and nurses brainstorm about how to apply the discharge information to the particularities of patients’ lives and homes. Provision of support needs to be bolstered during the home period, where patients have timely opportunities to discuss their concerns and questions with practitioners or possibly peers.

Background Patients with a bicuspid aortic valve (BAV) are at increased risk for progressive aortic dilation associated with extracellular matrix (ECM) degradation by matrix metalloproteinases (MMP). However, the mechanisms responsible for initiating this process are unknown. In the heart, MMP activity is regulated by micro-ribonucleic acid-17 (miR-17)–related downregulation of tissue inhibitors of metalloproteinases (TIMP); a similar process may exist in the aorta. Objectives This study sought to ascertain whether aortic matrix degradation in BAV patients progresses by miR-17–related miRNA regulation of TIMP-MMP. Methods To eliminate confounding patient-related factors, severely dilated and less dilated aortic tissue samples were collected from 12 BAV patients. Gene and protein expression levels were evaluated in paired tissue samples from the same patient and were compared to aortic samples from 16 patients with aortas that appeared to be normal. Results Gene expression analyses confirmed increased expression of miR-17–related miRNAs in less dilated compared with severely dilated tissue from the same patient or normal aortic sample. TIMP-1, -2, and -3 were significantly decreased, and MMP2 activity was significantly increased in less dilated samples, suggesting that this normal-looking tissue was in the early stages of ECM degradation. Smooth muscle cells isolated from normal or BAV aortas transfected with an miR-17 mimic had decreased TIMP-1 and -2 expression and increased MMP2 activity, whereas the opposite effects were seen with an miR-17 inhibitor, suggesting that miR-17 may control the TIMP-MMP balance in these tissues. Luciferase reporter assays demonstrated that miR-17 regulated TIMP-1 and -2 expression. Conclusions Our in vitro and in vivo studies taken together confirm that miR-17 directly regulates TIMP-1 and -2. Less dilated aortic BAV tissue may be in the initial stages of dilation under the control of miR-17–related miRNAs. New therapies that inhibit these miRNAs may prevent aortic dilation.

BACKGROUND Tricuspid annular (TA) dilation has been suggested as a more reliable marker of concomitant advanced right ventricular failure (RVF) than severity of tricuspid regurgitation (TR). Our objective was to examine the impact of TA dilation on occurrence of RVF and in-hospital mortality following left ventricular assist device (LVAD) implant. METHODS Consecutive patients undergoing implantation of a continuous-flow LVAD implant were grouped according to the presence or absence of preoperative dilated TA. Clinical characteristics, hemodynamics, and short-term postoperative outcomes were compared between groups. RVF was defined as unplanned right ventricular assist device (RVAD) or postoperative use of inotropes for >14 days. Linear and logistic regressions were used to explore associations of TA with occurrence of RVF and duration of inotrope use. RESULTS We included 69 patients who had continuous-flow LVAD implanted between 2006 and 2013 (50 ± 13 years old; 69% males; 37% ischemic etiology; 69% bridge-to-transplant LVAD; 18% INTERMACS 1-2; 48% with significant TR). RVF occurred in nine cases, and overall in-hospital mortality rate was 14%. Tricuspid valve repair was performed in ten cases. Dilated TA (OR 4.86; 95% CI 1.05-22.33; p = 0.04) was associated with RVF. In an adjusted multivariable analysis, indexed TA was an independent predictor of increased days of inotrope use (0.8-day increase in inotrope use for every 1 mm/m2 increase; p = 0.04). CONCLUSION In this cohort, TA dilation was a predictor of RVF after LVAD implant. The potential benefit of concomitant TVR in selected patients with a dilated TA undergoing LVAD implantation remains to be determined.

Cardiac repair depends on angiogenesis and cell proliferation. Previously we identified Canopy 2 (CNPY2) as a secreted angiogenic growth factor which promotes neovascularization. We investigated the role of CNPY2 in cardiac repair following myocardial infarction (MI) and the possible mediators involved using Cnpy2 knockout (KO) mice and human cardiac tissue.Cardiac tissue from patients with end-stage heart failure had significantly lower endogenous CNPY2 expression compared to samples from control patients. CNPY2 expression in mouse hearts significantly decreased following MI. Significantly less leukocyte and endothelial cell proliferation was found in Cnpy2 KO than wild-type (WT) mice post MI which contributed to impaired angiogenesis, tissue repair, and decreased cardiac function (fractional shortening: WT: 21.1 ± 2.1% vs. KO: 16.4 ± 1.6%, p .01 at day 28 post MI). RT-qPCR revealed significantly increased p16Cardiac injury and progressive heart failure were associated with decreased CNPY2 levels in both humans and mice. Knockout of Cnpy2 resulted in up-regulation of p16

Purpose Results of left atrial appendage occlusion (LAAO) in coronary artery bypass and valvular surgeries from large multicentre studies remain contradictory. No data has been presented on the outcomes of LAAO during left ventricular assist device (LVAD) implant. Therefore, we studied the effects of LAAO during LVAD implantation on postoperative risk of stroke and mortality. Methods This is a single-centre retrospective cohort study including consecutive patients who underwent LVAD implantation between October/2004 and April/2018. We performed a univariate Cox regression analysis to assess the effect of LAAO on the risk of post-operative stroke and mortality. Results Among 156 patients who underwent LVAD implantation (mean age, 52.5 [SD 12.8] years, 34 [21.8%] females), 14 (9.0%) underwent concurrent LAAO. As seen in table one, there were no significant differences in baseline characteristics except for gender (p=0.039). There were no significant differences in intraoperative identification of thrombus, stroke, or embolism between groups. Patients who received LAAO had longer bypass time (p=0.035), ICU stay (p=0.006), and days hospitalized (p=0.019) compared to those without LAAO. Median follow-up was 7 months [range 0 - 92]. A total of 23 strokes and 48 deaths were identified in our cohort and LAAO was not associated with a reduced risk of stroke (HR 1.014 [0.233 - 4.419]; p=0.985) or mortality (HR 1.209 [0.432 - 3.384]; p=0.718). Conclusion Among patients undergoing LVAD implantation, concurrent surgical LAAO was independently associated with an increase in bypass time and ICU and hospital length of stay. Furthermore, LAAO was not associated with a reduced risk of subsequent stroke and all-cause mortality. Further research including data from large registries is required to definitively determine the role of surgical LAAO during LVAD implantation.

ObjectiveTo determine the impact of the degree of hypothermia on surgical outcomes in patients undergoing repair of acute type A aortic dissection.MethodsBetween 1990 and 2010, 211 consecutive patients underwent surgical repair of type A aortic syndrome. Patients with acute type A dissection (n = 128) were included. Circulatory arrest with profound hypothermia (PH

Background: Clinical trials have shown conflicting results regarding the use of volatile anaesthesia before or after an ischaemic insult in cardiac surgical patients and its effect on myocardial injury. This may be attributable to the failure of continuing volatile agents into the early postoperative period. We hypothesised that combined volatilebased anaesthesia and postoperative sedation would decrease the extent of myocardial injury after coronary artery bypass grafting (CABG) when compared with an intravenous, propofol-based approach. This study aimed to assess the feasibility of the perioperative protocol and investigate whether volatile anaesthesia provides cardioprotection in patients undergoing CABG. Methods: Randomized, controlled trial enrolling 157 patients with preserved left ventricular function scheduled for elective or urgent on-pump CABG. Patients received either volatile- or propofol-based anaesthesia and postoperative sedation. Volatile sedation in the ICU was provided with the use of the AnaConDa ® device (Sedana Medical, Uppsala, Sweden). The primary outcome was myocardial injury measured by serial troponin measurement at the beginning of surgery, 2, 4 and 12–16 h after ICU admission. The secondary outcome was cardiac performance expressed as cardiac index (CI) and the need for inotropic and vasopressor drug support. The peak postoperative troponin level was defined as the highest level at any time in the first 16 h after surgery. Results: 127 patients completed the study protocol, 60 patients in the volatile group and 67 patients in the propofol group. Troponin levels were similar between groups at all of the measured time points. There were no differences in cardiac index or vasoactive drug support except for the immediate post- cardiopulmonary bypass (CPB) period when patients in the volatile group had low systemic vascular resistance, high CI and required more vasopressors. There was no difference in postoperative kidney function, intensive care unit discharge or hospital discharge time. Conclusions: The use of volatile-based anaesthesia and postoperative sedation did not confer any cardioprotection compared with propofol-based anaesthesia and sedation in patients who had good left ventricular function and were undergoing CABG.

Background: Dysphagia following prolonged intubation after cardiovascular (CV) surgery is common occurring in 67% of patients; however, this population’s swallowing physiology has never been prospectively evaluated using standardized methods. Hence, prior to conducting a larger study, our primary objective was to determine the feasibility of assessing swallowing physiology using instrumentation and validated interpretation methods in cardiovascular surgical patients following prolonged intubation. Method: From July to October 2011, we approached adults undergoing CV surgery at our institution who were intubated > 48 h. Those with a tracheostomy were excluded. Videofluoroscopic swallowing study (VFS) and nasendoscopy were completed within 48 h after extubation. Feasibility measurements included recruitment rate, patient participation, task completion durations, and the inter-rater reliability of VFS measures using the intraclass correlation coefficient (ICC). VFSs were interpreted using perceptual rating tools (Modified Barium Swallow Measurement Tool for Swallow Impairment™© and Penetration Aspiration Scale) and objective displacement measurements (hyoid displacement and pharyngeal constriction ratio). Results: Of the 39 patients intubated > 48 h, 16 met inclusion criteria with three enrolled and completing the VFS. All refused nasendoscopy. Across all VFSs, rating completion time ranged from 14.6 to 51.7 min per patient with ICCs for VFS scales ranging from 0.25 (95% CI − 0.10 to 0.59) to 0.99 (95% CI 0.98 to 0.99). Conclusions: This study design was not feasible as recruitment was slow, few patients participated, and no patient agreed to all procedures. We discuss necessary methodological changes and lessons learned that would generalize to future research.

We investigated the roles of stem cell factor (SCF)–c-kit and stromal derived factor-1 (SDF-1)–CXCR4 signaling axes in transmyocardial revascularization (TMR)-enhanced engraftment of transplanted bone marrow stem cells (BMSCs) in infarcted hearts. 3 weeks after LAD ligation, female Lewis rats underwent 10-channel needle-TMR, followed by daily IV injections of 1 million male donor BMSC for 5 days, either wild type (WT) or with knockdown (K/D) of c-kit or CXCR4, accomplished via a shRNA + plasmid in a lentiviral vector (N = 6/group). In our rat infarct model, 3 days after last BMSC injection, the number of BMSCs that homed into infarct was affected by both TMR and donor cell type, with greater BMSC engraftment with TMR and with WT BMSC (TMR, cell type, and interaction, P

Objective Primary coronary artery bypass grafting (CABG) is performed routinely in elderly patients with good results. However, the risk profile and outcomes of reoperative CABG in elderly patients are not well defined. Our purpose was to study the risk profile and hospital outcomes of isolated reoperative CABG in elderly patients (75 years and older) compared to isolated primary CABG in the same age group. Methods Between January 1990 and December 2010, 3483 elderly patients (age ≥ 75 years) underwent isolated CABG at our institution. Of these, 129 (3.7%) underwent reoperative CABG. Data were prospectively collected in a computerized database. Independent predictors of hospital mortality were determined by multivariable logistic regression. Results Hospital mortality was 3.2% and 8.5% (p

Following cardiovascular (CV) surgery, prolonged mechanical ventilation of >48 h increases dysphagia frequency over tenfold: 51 % compared to 3–4 % across all durations. Our primary objective was to identify dysphagia frequency following CV surgery with respect to intubation duration. Our secondary objective was to explore characteristics associated with dysphagia across the entire sample. Using a retrospective design, we stratified all consecutive patients who underwent CV surgery in 2009 at our institution into intubation duration groups defined a priori: I (≤12 h), II (>12 to ≤24 h), III (>24 to ≤48 h), and IV (>48 h). Eligible patients were >18 years old who survived extubation following coronary artery bypass alone or cardiac valve surgery. Patients who underwent tracheotomy were excluded. Pre-, peri-, and postoperative patient variables were extracted from a pre-existing database and medical charts by two blinded reviewers. Disagreements were resolved by consensus. Across the entire sample, multivariable logistic regression analysis determined independent predictors of dysphagia. Across the entire sample, dysphagia frequency was 5.6 % (51/909) but varied by group: I, 1 % (7/699); II, 8.2 % (11/134); III, 16.7 % (6/36); and IV, 67.5 % (27/40). Across the entire sample, the independent predictors of dysphagia included intubation duration in 12-h increments (p < 0.001; odds ratio [OR] 1.93, 95 % confidence interval [CI] 1.63–2.29) and age in 10-year increments (p = 0.004; OR 2.12, 95 % CI 1.27–3.52). Patients had a twofold increase in their odds of developing dysphagia for every additional 12 h with endotracheal intubation and for every additional decade in age. These patients should undergo post-extubation swallow assessments to minimize complications.