The Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE): protocol for a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Inflammation is a key mediator in the development and progression of the atherosclerotic disease process as well as its resultant complications, like myocardial infarction (MI), stroke and cardiovascular (CV) death, and is emerging as a novel treatment target. Trials involving anti-inflammatory medications have demonstrated outcome benefit in patients with known CV disease. In this regard, colchicine appears to hold great promise. However, there are potential drawbacks to colchicine use, as some studies have identified an increased risk of infection, and a non-significant trend for increased all-cause mortality. Thus, a more thorough understanding of the underlying mechanism of action of colchicine is needed to enable a better patient selection for this novel CV therapy. OBJECTIVE: The primary objective of the Canadian Study of Arterial Inflammation in Patients with Diabetes and Recent Vascular Events, Evaluation of Colchicine Effectiveness (CADENCE) trial is to assess the effect of colchicine on vascular inflammation in the carotid arteries and ascending aorta measured with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with type 2 diabetes mellitus (T2DM) or pre-diabetes who have experienced a recent vascular event (acute coronary syndrome (ACS)/MI, transient ischaemic attack (TIA) or stroke). Secondary objectives include determining colchicine's effect on inflammatory biomarkers (high-sensitivity C reactive protein (hs-CRP) and interleukin-6 (IL-6)). Additionally, we will assess if baseline inflammation imaging or biomarkers are associated with a treatment response to colchicine determined by imaging. Exploratory objectives will look at: (1) the difference in the inflammatory response to colchicine in patients with coronary events compared with patients with cerebral events; (2) the difference in the inflammatory response to colchicine in different vascular beds; (3) the relationship of FDG-PET imaging markers with serum biomarkers and (4) assessment of quality-of-life changes. METHODS AND DESIGN: CADENCE is a multicentre, prospective, randomised, double-blinded, placebo-controlled study to determine the effect of colchicine on arterial inflammation as assessed with imaging and circulatory biomarkers, specifically carotid arteries and aortic FDG uptake as well as hs-CRP and IL-6 among others. Patients with T2DM or pre-diabetes who have recently experienced a CV event (within 30-120 days after an ACS (ie, ST-elevation MI (STEMI) or non-STEMI)) or TIA/stroke with documented large vessel atherosclerotic disease will be randomised to treatment with either colchicine 0.6 mg oral daily or placebo. Participants will undergo baseline clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan of the ascending aorta and left and right carotid arteries. Patients will undergo treatment for 6 months and have repeat clinical evaluation including EQ5D assessment, blood work for inflammatory markers and FDG PET/CT scan at the conclusion of the study. The primary outcome will be the change in the maximum target to background ratio (TBRmax) in the ascending aorta (or carotid arteries) from baseline to follow-up on FDG PET/CT imaging. DISCUSSION: Colchicine is an exciting potential new therapy for CV risk reduction. However, its use is associated with side effects and greater understanding of its underlying mechanism of action is needed. Importantly, the current study will determine whether its anti-inflammatory action is an indirect systemic effect, or a more local plaque action that decreases inflammation. The results will also help identify patients who will benefit most from such therapy. TRIAL REGISTRATION NUMBER: NCT04181996.

Patient engagement in a Canadian consensus forum for heart donation after circulatory determination of death.

PURPOSE: Heart donation and transplantation following circulatory determination of death has yet to be performed in Canada. A consensus forum was held to provide expert guidance to inform policy with a comprehensive patient partner strategy. This paper describes the process used to create fulsome patient partner engagement resulting in mutually beneficial policy development in this complex area. METHODS: A wide-ranging process for involving patient partners in this area included pre-meeting education, in-meeting expert support, full participation and permission to step back if desired, and post-meeting debriefing. Following the meeting, a questionnaire was used to guide a debrief discussion with patient partners and steering committee members who co-authored this paper. RESULTS: Five key themes arose that echoed the sentiments and contributions made by patient partners, including: 1) a strong desire to improve the system, 2) gratitude and honour, 3) expert support and process, 4) simplification of complex concepts, and 5) mutual benefit expressed by patient partners and healthcare professionals. CONCLUSION: Despite the complexity of the content and the emotionally sensitive nature of discussions around deceased organ donation, a well-planned strategy to involve patient partners is important, impactful, and central to the process. This suggests a broad interprofessional audience can engage with properly prepared and supported patient partners to strengthen and focus dialogue and outputs in the development of health policy in the donation and transplant sector.

RéSUMé: OBJECTIF: Le don et la greffe cardiaque à la suite d'un décès circulatoire n'ont encore jamais été réalisés au Canada. Un forum de consensus a été organisé dans le but de formuler des recommandations spécifiques qui guideraient les politiques avec une stratégie globale incluant les patients partenaires. Cet article décrit le processus utilisé pour susciter une implication complète des patients partenaires, avec pour résultat la mise au point de politiques mutuellement bénéfiques dans ce domaine complexe. MéTHODE: Nous avons amorcé un vaste processus pour impliquer les patients partenaires dans ce domaine, processus qui a consisté en une formation préliminaire avant la rencontre, le soutien d'experts pendant la rencontre, la participation complète et la permission de se retirer du processus si désiré, et le débriefing après la rencontre. À la suite de la rencontre, un questionnaire a servi à orienter les discussions de débriefing avec les patients partenaires et les membres du comité directeur ayant collaboré à cet article. RéSULTATS: Cinq thèmes clés sont ressortis des discussions, faisant écho aux sentiments et aux contributions des patients partenaires, soit : 1) un profond désir d'améliorer le système, 2) la gratitude et l'honneur, 3) le soutien par et un processus d'experts, 4) la simplification des concepts complexes, et 5) les avantages mutuels exprimés par les patients partenaires et les professionnels de la santé. CONCLUSION: Malgré la complexité du contenu et la nature émotionnellement sensible des discussions entourant le don d'organes après décès, une stratégie bien planifiée d'implication des patients partenaires est importante, a un impact et doit être placée au centre du processus. Cela suggère qu'une vaste équipe interprofessionnelle peut s'impliquer auprès de patients partenaires bien préparés et convenablement soutenus; une telle approche permettra de renforcer et de concentrer le dialogue et les résultats lors de la mise au point de politiques de santé dans le secteur du don et de la greffe.

Transfusion Camp: a prospective evaluation of a transfusion education program for multispecialty postgraduate trainees.

BACKGROUND: The optimal method of providing transfusion medicine (TM) education has not been determined. Transfusion Camp was established in 2012 at the University of Toronto as a centrally delivered TM education program for postgraduate trainees. The impact of Transfusion Camp on knowledge, attitudes, and self-reported behavior was evaluated. METHODS: Didactic lectures (delivered locally, by webinar, or recorded) and locally facilitated team-based learning seminars were delivered over 5 days during the academic year to 8 sites: 7 in Canada and 1 in the United Kingdom. Knowledge assessment using a validated 20-question multiple-choice exam was conducted before and after Transfusion Camp. Attitudes and self-reported behavior were collected through a survey. RESULTS: Over 2 academic years (July 2016 to June 2018), 390 trainees from 16 different specialties (predominantly anesthesia, 41%; hematology, 14%; and critical care, 7%) attended at least 1 day of Transfusion Camp. The mean pretest score was 10.3 of 20 (±2.9; n = 286) compared with posttest score of 13.0 (±2.8; n = 194; p < 0.0001). Lower pretest score and greater attendance (4-5 days compared with 1-3 days) were associated with larger improvement in posttest score; delivery format, specialty, and postgraduate year were not. Trainees reported an improvement in self-rated abilities to manage TM scenarios; 95% rated TM knowledge as very or extremely important in providing patient care; and 81% indicated that they had applied learning from Transfusion Camp into clinical practice. CONCLUSIONS: Transfusion Camp increased TM knowledge, fostered a positive attitude toward TM, and enabled a self-reported positive impact on transfusion practice in postgraduate trainees. It is a novel and scalable approach to delivering TM education.

The impact of patient co-morbidities on the regenerative capacity of cardiac explant-derived stem cells.

BACKGROUND: Although patient-sourced cardiac stem cells repair damaged myocardium, the extent to which medical co-morbidities influence cardiac-derived cell products is uncertain. Therefore, we investigated the influence of atherosclerotic risk factors on the regenerative performance of human cardiac explant-derived cells (EDCs). METHODS: In this study, the Long Term Stratification for survivors of acute coronary syndromes model was used to quantify the burden of cardiovascular risk factors within a group of patients with established atherosclerosis. EDCs were cultured from human atrial appendages and injected into immunodeficient mice 7 days post-left coronary ligation. Cytokine arrays and enzyme linked immunoassays were used to determine the release of cytokines by EDCs in vitro, and echocardiography was used to determine regenerative capabilities in vivo. RESULTS: EDCs sourced from patients with more cardiovascular risk factors demonstrated a negative correlation with production of pro-healing cytokines (such as stromal cell derived factor 1α) and exosomes which had negative effects on the promotion of angiogenesis and chemotaxis. Reductions in exosomes and pro-healing cytokines with accumulating medical co-morbidities were associated with increases in production of the pro-inflammatory cytokine interleukin-6 (IL-6) by EDCs. Increased patient co-morbidities were also correlated with significant attenuation in improvements of left ventricular ejection fraction. CONCLUSIONS: The regenerative performance of the earliest precursor cell population cultured from human explant tissue declines with accumulating medical co-morbidities. This effect is associated with diminished production of pro-cardiogenic cytokines and exosomes while IL-6 is markedly increased. Predictors of cardiac events demonstrated a lower capacity to support angiogenesis and repair injured myocardium in a mouse model of myocardial infarction.

Paracrine Engineering of Human Explant-Derived Cardiac Stem Cells to Over-Express Stromal-Cell Derived Factor 1α Enhances Myocardial Repair.

First generation cardiac stem cell products provide indirect cardiac repair but variably produce key cardioprotective cytokines, such as stromal-cell derived factor 1α, which opens the prospect of maximizing up-front paracrine-mediated repair. The mesenchymal subpopulation within explant derived human cardiac stem cells underwent lentiviral mediated gene transfer of stromal-cell derived factor 1α. Unlike previous unsuccessful attempts to increase efficacy by boosting the paracrine signature of cardiac stem cells, cytokine profiling revealed that stromal-cell derived factor 1α over-expression prevented lv-mediated "loss of cytokines" through autocrine stimulation of CXCR4+ cardiac stem cells. Stromal-cell derived factor 1α enhanced angiogenesis and stem cell recruitment while priming cardiac stem cells to readily adopt a cardiac identity. As compared to injection with unmodified cardiac stem cells, transplant of stromal-cell derived factor 1α enhanced cells into immunodeficient mice improved myocardial function and angiogenesis while reducing scarring. Increases in myocardial stromal-cell derived factor 1α content paralleled reductions in myocyte apoptosis but did not influence long-term engraftment or the fate of transplanted cells. Transplantation of stromal-cell derived factor 1α transduced cardiac stem cells increased the generation of new myocytes, recruitment of bone marrow cells, new myocyte/vessel formation and the salvage of reversibly damaged myocardium to enhance cardiac repair after experimental infarction. Stem Cells 2016;34:1826-1835.

Paracrine Engineering of Human Cardiac Stem Cells With Insulin-Like Growth Factor 1 Enhances Myocardial Repair.

BACKGROUND: Insulin-like growth factor 1 (IGF-1) activates prosurvival pathways and improves postischemic cardiac function, but this key cytokine is not robustly expressed by cultured human cardiac stem cells. We explored the influence of an enhanced IGF-1 paracrine signature on explant-derived cardiac stem cell-mediated cardiac repair. METHODS AND RESULTS: Receptor profiling demonstrated that IGF-1 receptor expression was increased in the infarct border zones of experimentally infarcted mice by 1 week after myocardial infarction. Human explant-derived cells underwent somatic gene transfer to overexpress human IGF-1 or the green fluorescent protein reporter alone. After culture in hypoxic reduced-serum media, overexpression of IGF-1 enhanced proliferation and expression of prosurvival transcripts and prosurvival proteins and decreased expression of apoptotic markers in both explant-derived cells and cocultured neonatal rat ventricular cardiomyocytes. Transplant of explant-derived cells genetically engineered to overexpress IGF-1 into immunodeficient mice 1 week after infarction boosted IGF-1 content within infarcted tissue and long-term engraftment of transplanted cells while reducing apoptosis and long-term myocardial scarring. CONCLUSIONS: Paracrine engineering of explant-derived cells to overexpress IGF-1 provided a targeted means of improving cardiac stem cell-mediated repair by enhancing the long-term survival of transplanted cells and surrounding myocardium.

Hyperglycemia inhibits cardiac stem cell-mediated cardiac repair and angiogenic capacity.

BACKGROUND: The impact of diabetes mellitus on the cardiac regenerative potential of cardiac stem cells (CSCs) is unknown yet critical, given that individuals with diabetes mellitus may well require CSC therapy in the future. Using human and murine CSCs from diabetic cardiac tissue, we tested the hypothesis that hyperglycemic conditions impair CSC function. METHODS AND RESULTS: CSCs cultured from the cardiac biopsies of patients with diabetes mellitus (hemoglobin A1c, 10±2%) demonstrated reduced overall cell numbers compared with nondiabetic sourced biopsies (P=0.04). When injected into the infarct border zone of immunodeficient mice 1 week after myocardial infarction, CSCs from patients with diabetes mellitus demonstrated reduced cardiac repair compared with nondiabetic patients. Conditioned medium from CSCs of patients with diabetes mellitus displayed a reduced ability to promote in vitro blood vessel formation (P=0.02). Similarly, conditioned medium from CSCs cultured from the cardiac biopsies of streptozotocin-induced diabetic mice displayed impaired angiogenic capacity (P=0.0008). Somatic gene transfer of the methylglyoxal detoxification enzyme, glyoxalase-1, restored the angiogenic capacity of diabetic CSCs (diabetic transgenic versus nondiabetic transgenic; P=0.8). Culture of nondiabetic murine cardiac biopsies under high (25 mmol/L) glucose conditions reduced CSC yield (P=0.003), impaired angiogenic (P=0.02) and chemotactic (P=0.003) response, and reduced CSC-mediated cardiac repair (P<0.05). CONCLUSIONS: Diabetes mellitus reduces the ability of CSCs to repair injured myocardium. Both diabetes mellitus and preconditioning CSCs in high glucose attenuated the proangiogenic capacity of CSCs. Increased expression of glyoxalase-1 restored the proangiogenic capacity of diabetic CSCs, suggesting a means of reversing diabetic CSC dysfunction by interfering with the accumulation of reactive dicarbonyls.

Resident cardiac stem cells and their role in stem cell therapies for myocardial repair.

Despite advances in treatment, heart failure remains one of the top killers in Canada. This recognition motivated a new research focus to harness the fundamental repair properties of the human heart. Since then, cardiac stem cells (CSCs) have emerged as a promising cell candidate to regenerate damaged hearts. The rationale of this approach is simple with ex vivo amplification of CSCs from clinical-grade biopsies, followed by delivery to areas of injury, where they engraft and regenerate the heart. In this review we will summarize recent advances and discuss future developments in CSC-mediated cardiac repair to treat the growing number of Canadians living with and dying from heart failure.

The effect of encapsulation of cardiac stem cells within matrix-enriched hydrogel capsules on cell survival, post-ischemic cell retention and cardiac function.

Transplantation of ex vivo proliferated cardiac stem cells (CSCs) is an emerging therapy for ischemic cardiomyopathy but outcomes are limited by modest engraftment and poor long-term survival. As such, we explored the effect of single cell microencapsulation to increase CSC engraftment and survival after myocardial injection. Transcript and protein profiling of human atrial appendage sourced CSCs revealed strong expression the pro-survival integrin dimers αVß3 and α5ß1- thus rationalizing the integration of fibronectin and fibrinogen into a supportive intra-capsular matrix. Encapsulation maintained CSC viability under hypoxic stress conditions and, when compared to standard suspended CSC, media conditioned by encapsulated CSCs demonstrated superior production of pro-angiogenic/cardioprotective cytokines, angiogenesis and recruitment of circulating angiogenic cells. Intra-myocardial injection of encapsulated CSCs after experimental myocardial infarction favorably affected long-term retention of CSCs, cardiac structure and function. Single cell encapsulation prevents detachment induced cell death while boosting the mechanical retention of CSCs to enhance repair of damaged myocardium.