Project description:AimsThe epidemiology of sudden cardiac death (SCD) after heart transplantation (HTx) remains imprecisely described. We aimed to assess the incidence and determinants of SCD in a large cohort of HTx recipients, compared with the general population.Methods and resultsConsecutive HTx recipients (n = 1246, 2 centres) transplanted between 2004 and 2016 were included. We prospectively assessed clinical, biological, pathologic, and functional parameters. SCD was centrally adjudicated. We compared the SCD incidence beyond the first year post-transplant in this cohort with that observed in the general population of the same geographic area (registry carried out by the same group of investigators; n = 19 706 SCD). We performed a competing risk multivariate Cox model to identify variables associated with SCD. The annual incidence of SCD was 12.5 per 1,000 person-years [95% confidence interval (CI), 9.7-15.9] in the HTx recipients cohort compared with 0.54 per 1,000 person-years (95% CI, 0.53-0.55) in the general population (P < 0.001). The risk of SCD was markedly elevated among the youngest HTx recipients with standardized mortality ratios for SCD up to 837 for recipients ≤30 years. Beyond the first year, SCD was the leading cause of death. Five variables were independently associated with SCD: older donor age (P = 0.003), younger recipient age (P = 0.001) and ethnicity (P = 0.034), pre-existing donor-specific antibodies (P = 0.009), and last left ventricular ejection fraction (P = 0.048).ConclusionHTx recipients, particularly the youngest, were at very high risk of SCD compared with the general population. The consideration of specific risk factors may help identify high-risk subgroups.
Project description:Heart transplantation (HTx) is the ultimate treatment for end-stage heart failure. The number of patients on waiting lists for heart transplants, however, is much higher than the number of available organs. The shortage of donor hearts is a serious concern since the population affected by heart failure is constantly increasing. Furthermore, the long-term success of HTx poses some challenges despite the improvement in the management of the short-term complications and in the methods to limit graft rejection. Myocardial injury occurs during transplantation. Injury initiated in the donor as result of brain or cardiac death is exacerbated by organ procurement and storage, and is ultimately amplified by reperfusion injury at the time of transplantation. The innate immune system is a mechanism of first-line defense against pathogens and cell injury. Innate immunity is activated during myocardial injury and produces deleterious effects on the heart structure and function. Here, we briefly discuss the role of the innate immunity in the initiation of myocardial injury, with particular focus on the Toll-like receptors and inflammasome, and how to potentially expand the donor population by targeting the innate immune response.
Project description:Normothermic regional perfusion (NRP) allows assessment of therapeutic interventions prior to donation after circulatory death transplantation. Sodium-3-hydroxybutyrate (3-OHB) increases cardiac output in heart failure patients and diminishes ischemia-reperfusion injury, presumably by improving mitochondrial metabolism. We investigated effects of 3-OHB on cardiac and mitochondrial function in transplanted hearts and in cardiac organoids. Donor pigs (n = 14) underwent circulatory death followed by NRP. Following static cold storage, hearts were transplanted into recipient pigs. 3-OHB or Ringer's acetate infusions were initiated during NRP and after transplantation. We evaluated hemodynamics and mitochondrial function. 3-OHB mediated effects on contractility, relaxation, calcium, and conduction were tested in cardiac organoids from human pluripotent stem cells. Following NRP, 3-OHB increased cardiac output (P < 0.0001) by increasing stroke volume (P = 0.006), dP/dt (P = 0.02) and reducing arterial elastance (P = 0.02). Following transplantation, infusion of 3-OHB maintained mitochondrial respiration (P = 0.009) but caused inotropy-resistant vasoplegia that prevented weaning. In cardiac organoids, 3-OHB increased contraction amplitude (P = 0.002) and shortened contraction duration (P = 0.013) without affecting calcium handling or conduction velocity. 3-OHB had beneficial cardiac effects and may have a potential to secure cardiac function during heart transplantation. Further studies are needed to optimize administration practice in donors and recipients and to validate the effect on mitochondrial function.
Project description:Cardiac arrhythmias are a primary contributor to sudden cardiac death, a major unmet medical need. Because right ventricular (RV) dysfunction increases the risk for sudden cardiac death, we examined responses to RV stress in mice. Among immune cells accumulated in the RV after pressure overload-induced by pulmonary artery banding, interfering with macrophages caused sudden death from severe arrhythmias. We show that cardiac macrophages crucially maintain cardiac impulse conduction by facilitating myocardial intercellular communication through gap junctions. Amphiregulin (AREG) produced by cardiac macrophages is a key mediator that controls connexin 43 phosphorylation and translocation in cardiomyocytes. Deletion of Areg from macrophages led to disorganization of gap junctions and, in turn, lethal arrhythmias during acute stresses, including RV pressure overload and β-adrenergic receptor stimulation. These results suggest that AREG from cardiac resident macrophages is a critical regulator of cardiac impulse conduction and may be a useful therapeutic target for the prevention of sudden death.
Project description:Background:Organ transplantation is considered the best treatment for end-stage organ failure. However, the lack of available organs for transplantation and the increasing number of patients waiting for transplants are primary issues facing the transplant community. Thus, developing strategies to increase the number of donors, especially for liver transplantation, has become a priority. The use of organs acquired from donors who suffered cardiac related deaths has increased the pool of potential liver donors. However, donation after cardiac death (DCD) livers increases the risk of primary graft dysfunction. Methods:In the current study, we conducted transcriptome sequencing using livers from a DCD rat to assess the short-term feasibility and functional efficacy of DCD livers. RNA sequencing (RNAseq) data showed that the liver transcriptome varied greatly in rat livers subjected to 15 minutes of cardiac arrest. Results:The livers used in the current study had a significant loss of normal function before transplantation. Functional and network analyses consistently indicated that transcription and translation processes were inhibited after approximately 15 minutes of cardiac arrest. Moreover, the transcriptomic sequencing data provides significant insight for identifying functional genes and testing additional biological questions in DCD liver transplantation in future studies.
Project description:We evaluated whether combined heart and liver transplant (H+LTx) can protect the heart graft from the development of cardiac allograft vasculopathy using coronary three-dimensional (3D) volumetric intravascular ultrasound (IVUS).From 2004 to 2009, we identified 24 isolated heart transplant (HTx) and 10 H+LTx recipients in whom two coronary 3D IVUS studies were performed 1 year apart. Baseline 3D IVUS was performed at 0.22 (0.17-1.16) years after transplantation, with follow-up 3D IVUS exams performed after baseline exam (0.96 [0.83-1.08]).Rate of plaque volume and plaque index (plaque volume/vessel volume) progression was attenuated in the H+LTx group (0.3±1.1 vs. 1.5±2.9 mm/mm; P=0.08 and 0.01±0.03 vs. 0.1±0.1; P=0.004, respectively). Rejection burden was much lower in the H+LTx patients. Outcome analysis in 66 consecutive patients (56 HTx and 10 H+LTx) was performed irrespective of performance of second coronary IVUS. H+LTx was associated with reduced rate of cardiac events (P=0.04), which remained significant when adjusted for the difference in the primary etiology for heart disease (P=0.05).Our preliminary serial 3D coronary IVUS data show that H+LTx attenuates cardiac allograft vasculopathy by decreasing the rate of plaque volume and plaque index progression and improves coronary-related outcomes. Because of the small numbers and the differences in etiology of heart disease, our data should be interpreted cautiously, and larger clinical trials would be required to recommend H+LTx for improved coronary remodeling.
Project description:Understanding the seminal complications leading to death after pediatric cardiac surgical procedures may provide opportunities to reduce mortality. This study analyzed all deaths at two pediatric cardiac surgical programs and developed a method to identify the seminal complications and modes of death.Trained nurses abstracted all cases of in-hospital mortality meeting inclusion criteria from each site over 5 years (2008 to 2012). Complication definitions were consistent with those of a multicenter clinical registry. An adjudication committee assigned a seminal complication in each case (the complication initiating the cascade of events leading to death). Seminal complications were grouped into categories to designate "mode of death." The epidemiology of seminal complications and of mode of death was described.In 191 subjects, low cardiac output syndrome (71% of all subjects), cardiac arrest (52%), and arrhythmia (48%) were the most common complications. The committee assigned low cardiac output syndrome (30%), failure to separate from bypass (16%), and cardiac arrest (12%) most frequently as seminal complications. Seminal complications occurred a median 2 hours (interquartile range [IQR], 0 to 35 hours) postoperatively. Patients experienced a median of seven (IQR, 3 to 12) additional complications before death at a median of 15 days (IQR, 4 to 46). Systemic circulatory failure was the most common mode of death (51%), followed by inadequate pulmonary blood flow (13%) and cardiac arrest (12%).Seminal complications occurred early postoperatively, and systemic circulatory failure was the most common mode of death. Our classification system is likely scalable for subsequent multicenter analysis to understand cause-specific mortality variation across hospitals and to drive quality improvement.
Project description:The aim of the present article was to systematically review the ethics of surgical innovation and introduce the components of the learning health care system to guide future research and debate on surgical innovation.Although the call for evidence-based practice in surgery is increasingly high on the agenda, most surgeons feel that the format of the randomized controlled trial is not suitable for surgery. Innovation in surgery has aspects of, but should be distinguished from both research and clinical care and raises its own ethical challenges.To answer the question "What are the main ethical aspects of surgical innovation?", we systematically searched PubMed and Embase. Papers expressing an opinion, point of view, or position were included, that is, normative ethical papers.We included 59 studies discussing ethical aspects of surgical innovation. These studies discussed 4 major themes: oversight, informed consent, learning curve, and vulnerable patient groups. Although all papers addressed the ethical challenges raised by surgical innovation, surgeons hold no uniform view of surgical innovation, and there is no agreement on the distinction between innovation and research. Even though most agree to some sort of oversight, they offer different alternatives ranging from the formation of new surgical innovation committees to establishing national registries. Most agree that informed consent is necessary for innovative procedures and that surgeons should be adequately trained to assure their competence to tackle the learning curve problem. All papers agree that in case of vulnerable patients, alternatives must be found for the informed consent procedure.We suggest that the concept of the learning health care system might provide guidance for thinking about surgical innovation. The underlying rationale of the learning health care system is to improve the quality of health care by embedding research within clinical care. Two aspects of a learning health care system might particularly enrich the necessary future discussion on surgical innovation: integration of research and practice and a moral emphasis on "learning activities." Future research should evaluate whether the learning health care system and its adjacent moral framework provides ethical guidance for evidence-based surgery.
Project description:This study sought to assess the effect of the addition of coronary artery bypass grafting (CABG) to medical therapy on mode of death in heart failure.Although CABG therapy is widely used in ischemic cardiomyopathy patients, there are no prospective clinical trial data on mode of death.The STICH (Surgical Treatment for Ischemic Heart Failure ) trial compared the strategy of CABG plus medical therapy to medical therapy alone in 1,212 ischemic cardiomyopathy patients with reduced ejection fraction. A clinical events committee adjudicated deaths using pre-specified definitions for mode of death.In the STICH trial, there were 462 deaths over a median follow-up of 56 months. The addition of CABG therapy tended to reduce cardiovascular deaths (hazard ratio [HR]: 0.83; 95% confidence interval [CI]: 0.68 to 1.03; p = 0.09) and significantly reduced the most common modes of death: sudden death (HR: 0.73; 95% CI: 0.54 to 0.99; p = 0.041) and fatal pump failure events (HR: 0.64; 95% CI: 0.41 to 1.00; p = 0.05). Time-dependent estimates indicate that the protective effect of CABG principally occurred after 24 months in both categories. Deaths post-cardiovascular procedures were increased in CABG patients (HR: 3.11; 95% CI: 1.47 to 6.60), but fatal myocardial infarction deaths were lower (HR: 0.07; 95% CI: 0.01 to 0.57). Noncardiovascular deaths were infrequent and did not differ between groups.In the STICH trial, the addition of CABG to medical therapy reduced the most common modes of death: sudden death and fatal pump failure events. The beneficial effects were principally seen after 2 years. Post-procedure deaths were increased in patients randomized to CABG, whereas myocardial infarction deaths were decreased.
Project description:Introduction: Inherited cardiovascular diseases are an important cause of sudden cardiac death (SD). The use of risk scores identify high risk patients who would benefit from an implantable cardioverter-defibrillators (ICDs). The development of automated devices for out-of-hospital cardiac arrest improves early resuscitation. The objective of the study is to quantify prevented SD and the neurological recovery of patients with inherited cardiovascular diseases. Methods: Two hundred fifty-seven cases of SD (age 42 ± 18 years, 79.4% men) of non-ischemic cardiac cause were prospectively collected during the study period (2009-17). Fifty three (20.6%) had a resuscitated cardiac arrest (RCA) (age 40 ± 18 years, 64.2% male). Epidemiological, clinical and autopsy aspects were analyzed. Prevented SD was defined as a combination of RCA and appropriate ICD therapy cases. Results: An autopsy was performed in 157/204 (77.0%) cases who died. There were 19 (12.1%) cases with a negative autopsy. The diagnosis of cardiomyopathy and channelopathy was 58.0 and 18.7%, respectively. Female sex and confirmed or suspected channelopathy were associated with successful resuscitation. The percentage of prevented SD remained low during the study period (mean 35.6%). 60.4% of RCA cases presented good neurological outcome. There was no association between neurological recovery and therapeutic hypothermia, but there was association with time of resuscitation (min). Conclusion: A fifth part of non-ischemic cardiac arrests were resuscitated. Female sex and channelopathies were more prevalent among RCA. Two thirds of RCA had a good neurological recovery.