Mechanical circulatory support in the context of coronary artery bypass grafting.

PURPOSE OF REVIEW: With the continuous innovation in mechanical circulatory support as an option for the management of patients in cardiogenic shock from myocardial infarction, it is important to understand the current evidence and recommendations for the use of these devices for patients who require or underwent coronary artery bypass surgery. RECENT FINDINGS: The use of mechanical circulatory support (MCS) in patients with cardiogenic shock who require or underwent coronary artery bypass surgery has not been well studied. Observational studies have shown that the use of intra-aortic balloon pump or percutaneous ventricular assist devices prior to revascularization lead to better survival. Extracorporeal membrane oxygenation (ECMO) still carries significant risk of mortality and complications; the use of additional MCS devices for left ventricular unloading during ECMO improves outcomes. SUMMARY: MCS will continue to play an important role in coronary artery surgery patients. Multidisciplinary Cardiac Shock Team can assist in proper patient selection and device choice, whereas prospective clinical trials are required to provide evidence-based guidance towards the management of these patients.

Aortic dissection following heart transplantation.

A 75-year-old male with a previous orthotopic heart transplantation performed 28 years ago was incidentally discovered to have an asymptomatic chronic type A aortic dissection. Catheter-induced dissection during coronary angiography was believed to be the culprit factor. Aortic root replacement and aortic valve reconstruction were successfully performed.

Anticoagulation strategies for left ventricular assist devices.

PURPOSE OF REVIEW: Pump thrombosis can be a devastating complication in patients with a left ventricular assist device (LVAD). Treatment options with intravenous anticoagulation can lead to further complications. The present review discusses the current antithrombotic and anticoagulation strategies following LVAD implantation and during suspected pump thrombosis. RECENT FINDINGS: Recently, a significant increase in pump thrombosis (HeartMate II) at 3 months after LVAD implantation starting in March 2011 has been observed. This observation is likely multifaceted; however, recent changes in perioperative anticoagulation, accepting lower target international normalized ratios and lack of heparin bridging may play a substantial role. The International Society for Heart and Lung Transplantation published guidelines surrounding LVAD anticoagulation and management options in the setting of pump thrombosis. SUMMARY: Recommendations for thromboprophylaxis in patients with LVADs are scarce. The International Society for Heart and Lung Transplantation has put together minimum criteria for perioperative anticoagulation; however, this is on the basis of poor level of evidence (observational studies and expert opinion). Ultimately, clinicians will need to individualize the intensity and timing of anticoagulation following LVAD implantation to ensure adequate thromboprophylaxis while simultaneously minimizing bleeding.

Operative mortality with coronary artery bypass graft: where do we stand in 2015?

PURPOSE OF REVIEW: Coronary artery bypass graft (CABG) surgery has evolved and become much safer since its inception. This article outlines recent strategies in optimizing CABG mortality. RECENT FINDINGS: Improving operative mortality around CABG relates to five components. These include the role of relevant quality indicators; improved CABG techniques, such as multiple arterial grafting with less manipulation of the aorta; improvements in cardiopulmonary bypass; refinements in cardiac anaesthesia along with postoperative care; and the development of centres of excellence. SUMMARY: The development of advanced surgical revascularization techniques raises the question as to whether CABG expertise should be considered a sub-specialty of cardiac surgery. An expert CABG surgeon should be able to appropriately utilize several different revascularization techniques to adjust the operation to the patient, rather than the contrary.

Factors affecting recruitment into psychiatry: a canadian experience.

OBJECTIVE: There is a projected shortage of psychiatrists in Canada in forthcoming years. This study assessed factors in medical school education that are associated with students selecting psychiatry first and matching as a discipline. METHOD: The Canadian Organization of Undergraduate Psychiatry Educators (COUPE) conducted telephone interviews and sent e-mail questionnaires to the 17 medical schools across Canada; all schools provided data for 2012. Relevant data were obtained from the Canadian Resident Matching Service. Statistics were performed using v12 STATA program, and significance was set at a p value of <0.05. RESULTS: Medical student enrollment ranged from 54 to 266 students (mean = 158 ± 16). Of these students, 4.9 ± 0.6 % ranked psychiatry as their first choice for residency. Final match results yielded similar numbers at 5.0 ± 0.6 %. Ten out of 17 programs filled all psychiatry residency positions, whereas the remaining 7 programs had vacancy rates from 5 to 100 % (mean = 43.4 ± 15.1 %). Medical students were exposed to an average of 2.8 ± 0.5 pre-clerkship psychiatry weeks and 6.2 ± 0.3 clerkship weeks. Linear regression analysis demonstrated that the percentage of graduating medical students entering a psychiatry residency program could be predicted from the number of weeks of pre-clerkship exposure (p = 0.01; R(2) = 0.36) but not from the number of clerkship weeks (p = 0.74). CONCLUSIONS: This study indicates that the duration of pre-clerkship exposure to psychiatry predicts the number of students selecting psychiatry as their first choice as a discipline. Thus, increasing the duration of pre-clerkship exposure may increase the enrollment of medical students into psychiatry.

Hybrid approach for coronary artery revascularization: where do we stand?

PURPOSE OF REVIEW: Recently, hybrid coronary artery revascularization (HCAR), combining the benefits of both percutaneous coronary intervention and coronary artery bypass graft surgery (CABG) while minimizing their respective shortcomings, has been developed. This review is aimed to explore and discuss recent clinical outcomes and patient selection, and comment on surgical approaches for HCAR. RECENT FINDINGS: Current forms of HCAR include off-pump mini-sternotomy or on-pump full sternotomy CABG [left internal mammary artery (LIMA)-to-left anterior descending artery(LAD) CABG followed by drug-eluting stents (DES) to non-LAD territories], robotic-assisted off-pump HCAR (robotic LIMA-to-LAD CABG and DES to non-LAD territories), and off-pump mini-thoracotomy single-vessel small thoracotomy (LIMA-to-LAD CABG), all of which have reported acceptable early to mid-term patency rates and freedom from major cardiac and cerebrovascular adverse events. As long-term effectiveness compared with conventional CABG remains to be demonstrated, especially in patients with diabetes and patients with higher SYNTAX scores, appropriate discussion between the 'Heart Team' and patient is needed prior to HCAR. SUMMARY: HCAR presents an attractive alternative option for treating patients with multivessel coronary artery disease because it maximizes the clear survival benefits of LIMA-LAD grafting, improves quality assurance with completion angiography, and allows quicker patient recovery; furthermore, patients avoid the negative systemic inflammatory effects of cardiopulmonary bypass and delayed healing after sternotomy.

An update on mechanical circulatory support for heart failure therapy.

PURPOSE OF REVIEW: This article aims to review contemporary studies that utilized mechanical circulatory support (MCS) in the treatment of heart failure and to elaborate on prospective mechanical alternatives. RECENT FINDINGS: There is a growing need for a well-tolerated, durable and effective MCS option in patients with refractory heart failure. In previous years, the primary indication for MCS therapy supported bridge to transplantation. These early left ventricular assist devices (LVADs) suffered significant adverse events, thereby limiting their prolonged use. With the introduction of newer continuous flow LVADs, with lower morbidity, neurological events, pump failure and the expanded indication use (i.e. destination therapy), the overall number of implanted patients has grown. SUMMARY: There has been a dramatic advancement of durability found in the second and third-generation, continuous flow LVADs, along with improved survival rates in patients receiving these devices for destination therapy. MCS may soon become the treatment option of choice in refractory heart failure patients, especially with further evolution of less invasive approaches, smaller designs, and energy sources.

Endovascular treatment for cerebral septic embolic stroke.

This case demonstrates an alternative approach to cerebral revascularization by performing both intravascular mechanical thrombectomy and local injection of thrombolytics that may reduce mortality, bleeding, and the diminished quality of life experienced by patients following an acute septic embolic stroke.

A Case Report of an Isolated Cardiac Metastasis in a Patient with Esophageal Carcinoma.

A 76-year-old Caucasian male presented with syncope, intermittent melena, anemia, and unexplained weight loss. Esophagogastroduodenoscopy revealed a friable non-obstructing esophageal tumor that appeared thickened on computed tomography (CT). Biopsies confirmed a poorly differentiated carcinoma. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (F-18 FDG PET/CT) showed intense FDG avidity with a maximum standardized uptake value (SUVmax) of 23. Although CT did not identify any lymphadenopathy or distant metastases, a mildly enhancing lobulated circumscribed mass with no internal calcification was incidentally identified in the left atrium. Cardiac magnetic resonance imaging (MRI) favored myxoma over thrombus given the signal characteristics and mild enhancement; however, F-18 FDG PET/CT showed an SUVmax of 18, more consistent with a metastasis. The cardiac mass was resected and shown to be a metastatic focus of poorly differentiated carcinoma, histologically identical to the esophageal mass. He received a single 8 Gray (Gy) fraction of urgent hemostatic radiotherapy for his primary tumor followed by palliative chemotherapy with cisplatin, capecitabine, and pembrolizumab. He was readmitted for transfusion due to recurrent bleeding from his primary tumor and given a second urgent hemostatic fraction of 8 Gy for stabilization. Systemic therapy was eventually discontinued due to declining performance status. He received consolidative palliative radiotherapy (20Gy in five fractions) but continued to deteriorate over the next three months and died in hospice, ten months from the time of his initial presentation.

Utility of a smartphone application in assessing palmar circulation prior to radial artery harvesting for coronary artery bypass grafting: rationale and design of the randomised CAPITAL iRADIAL-CABG trial.

INTRODUCTION: There is emerging evidence supporting the use of the radial artery (RA) as a preferred secondary conduit for coronary artery bypass grafting (CABG) as it is associated with higher rates of graft patency at 5 years when compared with saphenous vein grafts (SVG). The modified Allen's test (MAT) is traditionally regarded as the standard of care in the assessment of ulnar artery (UA) patency prior to RA harvesting. Unfortunately, due to high false-positive rates, a substantial number of pre-CABG patients are found to have an abnormal MAT despite normal UA patency, resulting in inappropriate exclusion from RA harvesting. The SVG is generally used in its place when this occurs, resulting in potentially lower rates of long-term graft patency. METHODS AND ANALYSIS: The CAPITAL iRADIAL-CABG trial is currently enrolling participants 18 years of age or older undergoing CABG for whom the treating physician is considering the use of an RA conduit. Eligible patients will be randomised in a 1:1 fashion to MAT or smartphone-based photoplethysmography application assessment to assess collateral palmar circulation prior to RA harvesting. The primary outcome of the trial is the use of the RA as a conduit during CABG. The primary safety outcome is postoperative palmar ischaemia as determined by clinical assessment or requirement of vascular intervention. Secondary outcomes include vascular complications, early graft failure, need for rescue percutaneous coronary intervention during the index hospitalisation and a composite cardiovascular outcome of myocardial infarction, stroke and cardiovascular death prior to discharge from hospital. A total of 236 participants are planned to be recruited. ETHICS AND DISSEMINATION: The study was approved by the Ottawa Heart Science Network Research Ethics Board (approval number 20180865-01H). The study results will be disseminated via conference presentations and peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT03810729.

Impact of atrial fibrillation on the risk of major adverse cardiac events following coronary revascularisation.

OBJECTIVE: Atrial fibrillation (AF) remains a highly prevalent arrhythmia with significant burden on morbidity and mortality. The impact of AF in the revascularised population remains incompletely described. Given the high prevalence of AF in the revascularised population, we sought to evaluate the incidence and prognosis in patients with pre-existing and new-onset AF following revascularisation. METHODS: We used the University of Ottawa Heart Institute Revascularisation Registry to identify patients who underwent revascularisation between August 2015 and March 2020, who were prospectively followed for an average of one year. We conducted a retrospective cohort study analysing the association between AF and clinical outcomes. The primary outcome of interest was 1-year major adverse cardiac events (MACE) defined as a composite of death, myocardial infarction, unplanned revascularisation and cerebrovascular accidents. Moreover, secondary outcomes include the individual components of MACE and bleeding. RESULTS: A total of 6704 patients underwent revascularisation and completed 1-year clinical follow-up. Median time to follow-up was 12.8 (IQR 11.2-15.9) months. One-year MACE occurred in 166 (21.8%) and 683 (11.5%) patients in AF and non-AF groups, respectively (adjusted HR, 1.61; 95% CI 1.29 to 2.01; p<0.0001). AF was independently predictive of 1-year mortality, myocardial infarction, unplanned revascularisation, cerebrovascular accident and bleeding. Within 1 year, 299 (4.5%) episodes of new-onset AF was observed. New-onset AF following revascularisation was also associated with 1-year MACE, mortality, myocardial infarction, cerebrovascular accident and unplanned revascularisation. CONCLUSIONS: Preprocedural and new-onset AF following revascularisation remains highly predictive 1-year MACE. AF should be considered in addition to traditional risk factors for adverse outcomes following revascularisation.

The extracellular matrix controls gap junction protein expression and function in postnatal hippocampal neural progenitor cells.

BACKGROUND: Gap junction protein and extracellular matrix signalling systems act in concert to influence developmental specification of neural stem and progenitor cells. It is not known how these two signalling systems interact. Here, we examined the role of ECM components in regulating connexin expression and function in postnatal hippocampal progenitor cells. RESULTS: We found that Cx26, Cx29, Cx30, Cx37, Cx40, Cx43, Cx45, and Cx47 mRNA and protein but only Cx32 and Cx36 mRNA are detected in distinct neural progenitor cell populations cultured in the absence of exogenous ECM. Multipotential Type 1 cells express Cx26, Cx30, and Cx43 protein. Their Type 2a progeny but not Type 2b and 3 neuronally committed progenitor cells additionally express Cx37, Cx40, and Cx45. Cx29 and Cx47 protein is detected in early oligodendrocyte progenitors and mature oligodendrocytes respectively. Engagement with a laminin substrate markedly increases Cx26 protein expression, decreases Cx40, Cx43, Cx45, and Cx47 protein expression, and alters subcellular localization of Cx30. These changes are associated with decreased neurogenesis. Further, laminin elicits the appearance of Cx32 protein in early oligodendrocyte progenitors and Cx36 protein in immature neurons. These changes impact upon functional connexin-mediated hemichannel activity but not gap junctional intercellular communication. CONCLUSION: Together, these findings demonstrate a new role for extracellular matrix-cell interaction, specifically laminin, in the regulation of intrinsic connexin expression and function in postnatal neural progenitor cells.

Retroesophageal Infracardiac Total Anomalous Pulmonary Venous Drainage.

This case report describes the management of a term baby, born cyanotic, who was preoperatively diagnosed to have an obstructed total anomalous pulmonary venous drainage (TAPVD) in association with a functionally univentricular heart. An urgent repair of the anomalous pulmonary venous drainage was done, and a modified Blalock-Taussig shunt was constructed. Intraoperative difficulties were encountered when the pulmonary venous confluence was not seen in the usual location in the posterior mediastinal space, anterior to the esophagus. This report describes the rare finding of infracardiac TAPVD that is located in the retroesophageal space.

Left Ventricular Assist Devices: How Do We Define Success?

Despite the growing acceptance of left ventricular assist device (LVAD) therapy to improve survival and quality of life in heart failure (HF) patients, uncertainties persist regarding the definition of a successful implant. We sought to define an innovative approach to assess success and subsequently compare preoperative variables affecting outcomes. From January 2007 to 2015, 278 patients underwent LVAD implantation. Median age at implant was 62 years and 81% patients were males. Indication for support was bridge-to-transplantation in 36% patients and the etiology of HF was ischemic in 49% patients. Based on clinically relevant and accepted standards, we defined successful LVAD implant as someone who was alive or transplanted at 2 years, had two or less readmissions in the first year, had no major adverse events in the first year, and had a New York Heart Association class of ≤ II at 6 months. Follow-up was obtained for a median of 1.7 years for a total of 605 patient-years-of-support. Based on our criteria, 81/278 (29%) patients were defined as having a successful implant. Univariate predictors of LVAD failure included destination therapy indication (hazard ratio [HR] = 2.11 [1.24, 3.58]), ischemic cardiomyopathy (HR = 1.73 [1.02, 2.94]), and a higher left ventricular ejection fraction (HR = 1.54 [1.07, 2.22]). After multivariable analysis, only destination therapy indication (HR = 2.2 [1.28, 3.78]) was found to be independently predictive of success failure. Despite an overall trend toward improved outcomes on device therapy, our criteria classified only one-third of patients as successful. Continued improvements in adverse event profiles, appropriate patient selection, and optimal time of implantation, together hold the key to improve outcomes after LVAD therapy.

Degenerative Mitral Regurgitation After Nonmitral Cardiac Surgery: MitraClip Versus Surgical Reconstruction.

BACKGROUND: Surgical mitral valve repair is the conventional treatment for severe degenerative mitral regurgitation (MR). MitraClip therapy has emerged as a viable option in high-risk surgical patients. We sought to compare conventional surgery to MitraClip therapy in patients with severe degenerative mitral valve prolapse (MVP) and previous cardiac interventions. METHODS: From January 2012 to May 2016, 131 patients with previous cardiac surgery and subsequent intervention for degenerative MVP were included in this analysis: 75 (57.3%) underwent surgical repair and 56 (42.7%) underwent MitraClip placement. Follow-up was available in all early survivors at median of 11 (interquartile range, 0 to 32) months for surgery and 11 (interquartile range, 3 to 21) months for MitraClip patients. RESULTS: MitraClip patients were older (75.7 ± 8.6 years of age versus 68.6 ± 13.1 of age; p < 0.001), and had higher Society of Thoracic Surgeons risk scores (5.8 ± 2.4 versus 2.7 ± 2.3; p < 0.001). Median length-of-stay was 7 (interquartile range, 5 to 11) days for surgery and 2 (interquartile range, 2 to 4) days for MitraClip patients (p < 0.001), but 30-day mortality was comparable between the 2 groups (2.7% versus 3.6%; p = 0.77). Recurrent MR (moderate or severe) was significantly higher for MitraClip patients, both at discharge (43.1% versus 5.4%; p < 0.001) and at 1-year follow-up (66.7% versus 33.3%; p = 0.02). At 1 year postintervention, freedom from mitral reintervention was significantly higher for surgical patients (100.0% versus 87.5%; p = 0.006). CONCLUSIONS: In patients with previous cardiac interventions and severe degenerative MVP, a repeat conventional surgery is safe and durable. Percutaneous MitraClip repair is effective but associated with higher risk of residual MR, and should only be considered in selected patients. Careful patient selection using a heart team approach is recommended.

Incidence of sternal wound infection after tracheostomy in patients undergoing cardiac surgery: A systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis was performed to determine whether timing or type of tracheostomy was associated with superficial or deep sternal wound infections after cardiac surgery. METHODS: All studies reporting the incidence of sternal wound infection after tracheostomy in patients undergoing cardiac surgery were collected and analyzed. Subgroup analyses determined a priori included timing of tracheostomy and type of procedure (open vs percutaneous). All analyses used the random effects model. A meta-regression analysis was performed on the proportion of sternal wound infection and number of days between tracheostomy and initial cardiac surgery. RESULTS: A total of 13 studies met inclusion criteria. The incidence of sternal wound infection across all studies reported was 7% (95% confidence interval [CI], 4-10). The percutaneous tracheostomy group had a sternal wound infection proportion of 3% (95% CI, 1-8), and the open tracheostomy group had a sternal wound infection proportion of 9% (95% CI, 5-14). The incidence of sternal wound infection with early (<14 days) (7%; 95% CI, 3-11) versus late (≥14 days) (7%; 95% CI, 4-10) tracheostomy was similar. Meta-regression demonstrated no significant relationship between incidence of sternal wound infection and number of days between tracheostomy and initial cardiac surgery (R2 = 6.13%, P = .72). Reported secondary outcomes included 30-day and 1-year mortality, which were high at 23% (95% CI, 19-28) and 63% (95% CI, 43-80), respectively. CONCLUSIONS: The incidence of sternal wound infection after tracheostomy in patients undergoing cardiac surgery remains high at 7% (95% CI, 4-10). Open or percutaneous tracheostomy after cardiac surgery is a feasible option because the incidence of sternal wound infection and short-term mortality are comparable. Moreover, the timing of tracheostomy (early or late) had comparable rates of sternal wound infection and short-term mortality.

Cardiovascular progenitor-derived extracellular vesicles recapitulate the beneficial effects of their parent cells in the treatment of chronic heart failure.

BACKGROUND: Cell-based therapies are being explored as a therapeutic option for patients with chronic heart failure following myocardial infarction. Extracellular vesicles (EV), including exosomes and microparticles, secreted by transplanted cells may orchestrate their paracrine therapeutic effects. We assessed whether post-infarction administration of EV released by human embryonic stem cell-derived cardiovascular progenitors (hESC-Pg) can provide equivalent benefits to administered hESC-Pg and whether hESC-Pg and EV treatments activate similar endogenous pathways. METHODS: Mice underwent surgical occlusion of their left coronary arteries. After 2-3 weeks, 95 mice included in the study were treated with hESC-Pg, EV, or Minimal Essential Medium Alpha Medium (alpha-MEM; vehicle control) delivered by percutaneous injections under echocardiographic guidance into the peri-infarct myocardium. functional and histologic end-points were blindly assessed 6 weeks later, and hearts were processed for gene profiling. Genes differentially expressed between control hearts and hESC-Pg-treated and EV-treated hearts were clustered into functionally relevant pathways. RESULTS: At 6 weeks after hESC-Pg administration, treated mice had significantly reduced left ventricular end-systolic (-4.20 ± 0.96 µl or -7.5%, p = 0.0007) and end-diastolic (-4.48 ± 1.47 µl or -4.4%, p = 0.009) volumes compared with baseline values despite the absence of any transplanted hESC-Pg or human embryonic stem cell-derived cardiomyocytes in the treated mouse hearts. Equal benefits were seen with the injection of hESC-Pg-derived EV, whereas animals injected with alpha-MEM (vehicle control) did not improve significantly. Histologic examination suggested a slight reduction in infarct size in hESC-Pg-treated animals and EV-treated animals compared with alpha-MEM-treated control animals. In the hESC-Pg-treated and EV-treated groups, heart gene profiling identified 927 genes that were similarly upregulated compared with the control group. Among the 49 enriched pathways associated with these up-regulated genes that could be related to cardiac function or regeneration, 78% were predicted to improve cardiac function through increased cell survival and/or proliferation or DNA repair as well as pathways related to decreased fibrosis and heart failure. CONCLUSIONS: In this post-infarct heart failure model, either hESC-Pg or their secreted EV enhance recovery of cardiac function and similarly affect cardiac gene expression patterns that could be related to this recovery. Although the mechanisms by which EV improve cardiac function remain to be determined, these results support the idea that a paracrine mechanism is sufficient to effect functional recovery in cell-based therapies for post-infarction-related chronic heart failure.