Predicting heart failure outcomes by integrating breath-by-breath measurements from cardiopulmonary exercise testing and clinical data through a deep learning survival neural network.

Aims: Mathematical models previously developed to predict outcomes in patients with heart failure (HF) generally have limited performance and have yet to integrate complex data derived from cardiopulmonary exercise testing (CPET), including breath-by-breath data. We aimed to develop and validate a time-to-event prediction model using a deep learning framework using the DeepSurv algorithm to predict outcomes of HF. Methods and results: Inception cohort of 2490 adult patients with high-risk cardiac conditions or HF underwent CPET with breath-by-breath measurements. Potential predictive features included known clinical indicators, standard summary statistics from CPETs, and mathematical features extracted from the breath-by-breath time series of 13 measurements. The primary outcome was a composite of death, heart transplant, or mechanical circulatory support treated as a time-to-event outcomes. Predictive features ranked as most important included many of the features engineered from the breath-by-breath data in addition to traditional clinical risk factors. The prediction model showed excellent performance in predicting the composite outcome with an area under the curve of 0.93 in the training and 0.87 in the validation data sets. Both the predicted vs. actual freedom from the composite outcome and the calibration of the prediction model were excellent. Model performance remained stable in multiple subgroups of patients. Conclusion: Using a combined deep learning and survival algorithm, integrating breath-by-breath data from CPETs resulted in improved predictive accuracy for long-term (up to 10 years) outcomes in HF. DeepSurv opens the door for future prediction models that are both highly performing and can more fully use the large and complex quantity of data generated during the care of patients with HF.

Induction therapy in heart transplantation: A systematic review and network meta-analysis for developing evidence-based recommendations.

INTRODUCTION: Induction therapy (IT) utility in heart transplantation (HT) remains contested. Commissioned by a clinical-practice guidelines panel to evaluate the effectiveness and safety of IT in adult HT patients, we conducted this systematic review and network meta-analysis (NMA). METHODS: We searched for studies from January 2000 to October 2022, reporting on the use of any IT agent in adult HT patients. Based on patient-important outcomes, we performed frequentist NMAs separately for RCTs and observational studies with adjusted analyses, and assessed the certainty of evidence using the GRADE framework. RESULTS: From 5156 publications identified, we included 7 RCTs and 12 observational studies, and report on two contemporarily-used IT agents-basiliximab and rATG. The RCTs provide only very low certainty evidence and was uninformative of the effect of the two agents versus no IT or one another. With low certainty in the evidence from observational studies, basiliximab may increase 30-day (OR 1.13; 95% CI 1.06-1.20) and 1-year (OR 1.11; 95% CI 1.02-1.22) mortality compared to no IT. With low certainty from observational studies, rATG may decrease 5-year cardiac allograft vasculopathy (OR .82; 95% CI .74-.90) compared to no IT, as well as 30-day (OR .85; 95% CI .80-.92), 1-year (OR .87; 95% CI .79-.96), and overall (HR .84; 95% CI .76-.93) mortality compared to basiliximab. CONCLUSION: With low and very low certainty in the synthetized evidence, these NMAs suggest possible superiority of rATG compared to basiliximab, but do not provide compelling evidence for the routine use of these agents in HT recipients.

Online resources as a source of information for exercise and physical activity in solid organ transplant recipients.

Introduction: Exercise training post-transplant has been shown to improve physical function and quality of life in solid organ transplant (SOT) recipients. Online resources in the form of websites and videos are commonly used to provide education and instruction on exercise and physical activity in SOT; however, the content and quality of these online resources has not been evaluated. Methods: The first 200 websites and videos identified on Google and YouTube using the English search term "exercise and physical activity in solid organ transplantation" were analyzed. Website and video content was evaluated based on 25 key components of exercise and physical activity in SOT as described in established exercise program recommendations. Website and video quality was determined using DISCERN, Global Quality Scale (GQS), and Patient Education Materials and Assessment Tool (PEMAT; threshold for which material is deemed understandable or actionable is >70%). Parametric and non-parametric tests were used to assess website and video characteristics, content, and quality metrics. Results: Forty-nine unique SOT websites (n = 15) and videos (n = 34) were identified, with the two most common categories being foundation/advocacy organizations and scientific resources. The average reading grade level of websites was 13 ± 3. Website and video content scores varied significantly (websites 11.3 ± 6.4; videos 8.4 ± 5.3). DISCERN total score and GQS score were low (median range for DISCERN 2.5-3.0; median for GQS 2.0 for both websites and videos, out of 5). PEMAT understandability and actionability scores were also low across websites and videos (mean range 57%-67% and 47%-65%, respectively). Foundation/advocacy websites had higher content and quality scores compared to scientific organizations and news/media articles. Conclusions: To our knowledge, this is the first comprehensive assessment of online content and quality of website and video resources on physical activity and exercise in adult SOT recipients. There were a limited number of online English patient-directed resources related to physical activity in SOT, most of which only partly captured items outlined in consensus exercise program recommendations and were of low quality and understandability and actionability. This work provides important insight to the English-speaking transplant community on the current state of online exercise health information and provides future direction for resource development.

GRADE concept paper 8: judging the certainty of discrimination performance estimates of prognostic models in a body of validation studies.

BACKGROUND: Prognostic models incorporate multiple prognostic factors to estimate the likelihood of future events for individual patients based on their prognostic factor values. Evaluating these models crucially involves conducting studies to assess their predictive performance, like discrimination. Systematic reviews and meta-analyses of these validation studies play an essential role in selecting models for clinical practice. METHODS: In this paper, we outline 3 thresholds to determine the target for certainty rating in the discrimination of prognostic models, as observed across a body of validation studies. RESULTS AND CONCLUSION: We propose 3 thresholds when rating the certainty of evidence about a prognostic model's discrimination. The first threshold amounts to rating certainty in the model's ability to classify better than random chance. The other 2 approaches involve setting thresholds informed by other mechanisms for classification: clinician intuition or an alternative prognostic model developed for the same disease area and outcome. The choice of threshold will vary based on the context. Instead of relying on arbitrary discrimination cut-offs, our approach positions the observed discrimination within an informed spectrum, potentially aiding decisions about a prognostic model's practical utility.

Use of induction therapy post-heart transplantation: Clinical practice recommendations based on systematic review and network meta-analysis of evidence.

BACKGROUND: The use of induction therapy (IT) agents in the early post-heart transplant period remains controversial. The following recommendations aim to provide guidance on the use of IT agents, including Basiliximab and Thymoglobulin, as part of routine care in heart transplantation (HTx). METHODS: We recruited an international, multidisciplinary panel of 15 stakeholders, including patient partners, transplant cardiologists and surgeons, nurse practitioners, pharmacists, and methodologists. We commissioned a systematic review on benefits and harms of IT on patient-important outcomes, and another on patients' values and preferences to inform our recommendations. We used the GRADE framework to summarize our findings, rate certainty in the evidence, and develop recommendations. The panel considered the balance between benefits and harms, certainty in the evidence, and patient's values and preferences, to make recommendations for or against the routine post-operative use of Thymoglobulin or Basiliximab. RESULTS: The panel made recommendations on three major clinical problems in HTx: (1) We suggest against the routine post-operative use of Basiliximab compared to no IT, (2) we suggest against the routine use of Thymoglobulin compared to no IT, and (3) for those patients for whom IT is deemed desirable, we suggest for the use of Thymoglobulin as compared to Basiliximab. CONCLUSION: This report highlights gaps in current knowledge and provides directions for clinical research in the future to better understand the clinical utility of IT agents in the early post heart transplant period, leading to improved management and care.

Drug levels after sirolimus initiation and short-term outcomes in ambulatory heart transplantation recipients.

INTRODUCTION: We evaluated the effect of relative changes in combined tacrolimus and sirolimus (drug) levels, following sirolimus initiation, on outcomes in ambulatory heart transplantation (HTx) recipients. METHODS: We performed a retrospective analysis of HTx recipients who received tacrolimus, followed by sirolimus initiation, any time after HTx. We calculated the relative change in combined drug levels 1-month post-sirolimus initiation, relative to tacrolimus levels pre-initiation, and categorized patients into decreased (≥15% decrease), stable (<15% decrease to <15% increase), or increased (≥15% increase) groups. We compared, across the three groups, changes in post-initiation estimated glomerular filtration rate (eGFR) and left ventricular ejection fraction (LVEF) using one-way ANOVA and Sidák's post-hoc analysis, as well as the individual and composite outcomes of new donor specific antibodies (DSA), acute cellular rejection (ACR), and all-cause mortality using Fisher's exact test. RESULTS: Amongst 99 HTx recipients included, the median age was 53 years, time to sirolimus initiation was 1.5 years post-HTx, and pre-sirolimus eGFR was 52 mL/min/1.73 m2 . Nine patients had decreased, 15 stable, and 75 increased, relative combined drug levels. Relative change in eGFR was significantly higher in patients with decreased levels compared to patients with increased levels at 6 months post-initiation (P < .05), but this was not sustained at 12 months. There were no differences in LVEF change or in individual and composite risks for developing DSA, ACR, and all-cause mortality at 12 months across the groups. CONCLUSION: Post-sirolimus initiation, a relative decrease in combined drug levels, compared to increased levels, was associated with temporarily improved renal function.

GRADE guidance 36: updates to GRADE's approach to addressing inconsistency.

OBJECTIVES: To update previous Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidance by addressing inconsistencies and interpreting subgroup analyses. STUDY DESIGN AND SETTING: Using an iterative process, we consulted with members of the GRADE working group through multiple rounds of written feedback and discussions at GRADE working group meetings. RESULTS: The guidance complements previous guidance with clarification in two areas: (1) assessing inconsistency and (2) assessing the credibility of possible effect modifiers that might explain inconsistency. Specifically, the guidance clarifies that inconsistency refers to variability in results, not in study characteristics; that inconsistency assessment for binary outcomes requires consideration of both relative and absolute effects; how to decide between narrower and broader questions in systematic reviews and guidelines; that, with the same evidence, ratings of inconsistency may differ depending on the target of certainty rating; and how GRADE inconsistency ratings relate to a statistical measure of inconsistency I2 depending on the context in which one views results. The second part of the guidance illustrates, based on a worked example, the use of the instrument to assess the credibility of effect modification analyses. The guidance explains the stepwise process of moving from a subgroup analysis to assessing the credibility of effect modification and, if found credible, to subgroup-specific effect estimates and GRADE certainty ratings. CONCLUSION: This updated guidance addresses specific conceptual and practical issues that systematic review authors frequently face when considering the degree of inconsistency in estimates of treatment effects across studies.

Patients with fulminant myocarditis supported with veno-arterial extracorporeal membrane oxygenation: a systematic review and meta-analysis of short-term mortality and impact of risk factors.

Fulminant myocarditis (FM) may lead to cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Results of effectiveness studies of VA-ECMO have been contradictory. We evaluated the aggregate short-term mortality after VA-ECMO and predictive factors in patients with FM. We systematically searched in electronic databases (February 2022) to identify studies evaluating short-term mortality (defined as mortality at 30 days or in-hospital) after VA-ECMO support for FM. We included studies with 5 or more patients published after 2009. We assessed the quality of the evidence using the QUIPS and GRADE tools. Mortality was pooled using random effect models. We performed meta-regression to explore heterogeneity based on a priori defined factors. We included 54 observational studies encompassing 2388 FM patients supported with VA-ECMO. Median age was 41 years (25th to 75th percentile 37-47), and 50% were female. The pooled short-term mortality was 35% (95% CI 29-40%, I2 = 69%; moderate certainty). By meta-regression, studies with younger populations showed lower mortality. Female sex, receiving a biopsy, cardiac arrest, left ventricular unloading, and earlier recruitment time frame, did not explain heterogeneity. These results remained consistent regardless of continent and the risk of bias category. In individual studies, low pH value, high lactate, absence of functional cardiac recovery on ECMO, increased burden of malignant arrhythmia, high peak coronary markers, and IVIG use were identified as independent predictors of mortality. When conventional therapies have failed, especially in younger patients, cardiopulmonary support with VA-ECMO should be considered in the treatment of severe FM.

Hemodynamic reserve predicts early right heart failure after LVAD implantation.

BACKGROUND: Early right heart failure (RHF) remains a major source of morbidity and mortality after left ventricular assist device (LVAD) implantation, yet efforts to predict early RHF have proven only modestly successful. Pharmacologic unloading of the left ventricle may be a risk stratification approach allowing for assessment of right ventricular and hemodynamic reserve. METHODS: We performed a multicenter, retrospective analysis of patients who had undergone continuous-flow LVAD implantation from October 2011 to April 2020. Only those who underwent vasodilator testing with nitroprusside during their preimplant right heart catheterization were included (n = 70). Multivariable logistic regression was used to determine independent predictors of early RHF as defined by Mechanical Circulatory Support-Academic Research Consortium. RESULTS: Twenty-seven patients experienced post-LVAD early RHF (39%). Baseline clinical characteristics were similar between patients with and without RHF. Patients without RHF, however, achieved higher peak stroke volume index (SVI) (30.1 ± 8.8 vs 21.7 ± 7.4 mL/m2; p < 0.001; AUC: 0.78; optimal cut-point: 22.1 mL/m2) during nitroprusside administration. Multivariable analysis revealed that peak SVI was significantly associated with early RHF, demonstrating a 16% increase in risk of early RHF per 1 ml/m2 decrease in SVI. A follow up cohort of 10 consecutive patients from July 2020 to October 2021 resulted in all patients being categorized appropriately in regards to early RHF versus no RHF according to peak SVI. CONCLUSION: Peak SVI with nitroprusside administration was independently associated with post-LVAD early RHF while resting hemodynamics were not. Vasodilator testing may prove to be a strong risk stratification tool when assessing LVAD candidacy though additional prospective validation is needed.

Impact of serial measurements of tricuspid annular plane systolic excursion on mortality and morbidity after heart transplantation.

The impact of right ventricular (RV) dysfunction on long-term post-HTx outcomes remains uncertain. We assessed the impact of serial measurements of Tricuspid Annular Plane Systolic Excursion (TAPSE) on post-HTx mortality and morbidity. This two-center retrospective cohort study included consecutive adult HTx recipients (2000-2017). We used multivariable extended hazard regression models to evaluate the association between TAPSE and left ventricular ejection fraction (LVEF), entered as time-dependent variables, and all-cause mortality, cardiac allograft vasculopathy (CAV), acute cellular rejection (ACR), and chronic kidney disease (CKD). TAPSE was modelled using cubic splines. We included 485 HTx recipients (9461 TAPSE measurements), median (25th- 75th percentile) 19 (10-27) mm; median age was 52 (41-59) years, and 71.3% were male. During a follow-up of 6.7 (3.0-10.8) years, 92 patients died, 225 had ACR >2R, 234 CAV, and 91 CKD. By multivariable analysis, for each 1-mm decrease in patients with a TAPSE value <15mm, mortality increased by 22% (P<.001). For the average HTx recipient with a TAPSE of 15mm, 10mm, and 6mm, 1-year mortality was 3%, 7%, and 17%, and 5-year mortality was 8%, 20%, and 43%, respectively. Reduced TAPSE was significantly associated with increased CAV but notACR and CKD. A decrease in TAPSE below 15mm represents clinically significant graft dysfunction, warranting close monitoring.

Predictors of Mortality in Patients Treated with Veno-Arterial ECMO for Cardiogenic Shock Complicating Acute Myocardial Infarction: a Systematic Review and Meta-Analysis.

BACKGROUND: Mortality for patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock (CS) complicating acute myocardial infarction (AMI) remains high. This meta-analysis aims to identify factors that predict higher risk of mortality after VA-ECMO for AMI. METHODS: We meta-analyzed mortality after VA-ECMO for CS complicating AMI and the effect of factors from systematically selected studies published after 2009. RESULTS: 72 studies (10,276 patients) were included with a pooled mortality estimate of 58 %. With high confidence in estimates, failure to achieve TIMI III flow and left main culprit were identified as factors associated with higher mortality. With low-moderate confidence, older age, high BMI, renal dysfunction, increasing lactate, prothrombin activity < 50%, VA-ECMO implantation after revascularization, and non-shockable ventricular arrythmias were identified as factors associated with mortality. CONCLUSION: These results provide clinicians with a framework for selecting patients for VA-ECMO for CS complicating AMI.

Association between routine measures of graft function and mortality in heart transplant recipients.

OBJECTIVE: To date, long-term graft dysfunction, an important cause of death after heart transplantation, has been defined as a left ventricular ejection fraction (LVEF) of ≤40% or right atrial pressure (RAP) of ≥15 mm Hg. Empirical associations between measures of cardiac function and mortality post-transplant remain, however, unestablished. METHODS: We conducted a retrospective two-centre cohort study of consecutive adults who underwent heart transplant between 2002 and 2017. We evaluated the association between LVEF and RAP and mortality, including rejection and cardiac allograft vasculopathy as additional time-dependent covariates using Cox proportional hazard models. We applied restricted cubic splines to both LVEF and RAP. RESULTS: Of 590 eligible heart transplant recipients, of whom 72% were male with a mean age of 49 years, 410 received their transplant at Toronto General Hospital and 180 at Rigshospitalet. We observed a 5% absolute risk increase for 1-year mortality, from 11% to 16%, when the LVEF dropped to 53% (HR 1.71 for LVEF of 53% compared with 60%, 95% CI 1.36 to 2.14) or when the RAP increased to 12 mm Hg (HR 1.49 for RAP of 12 mm Hg compared with 5 mm Hg, 95% CI 1.04 to 2.13). CONCLUSION: In this study, we observed that small changes in graft function at any time post-transplant are associated with an increased mortality. Our results suggest that the current definition of graft dysfunction may underestimate patient risk of adverse outcomes.

Prognostic value of blood pressure in ambulatory heart failure: a meta-analysis and systematic review. Ambulatory blood pressure predicts heart failure prognosis.

Previous primary studies have explored the association between blood pressure (BP) and mortality in ambulatory heart failure (HF) patients reporting varying and contrasting associations. The aim is to determine the pooled BP prognostic value and explore potential reasons for between-study inconsistency. We searched Medline, Cochrane, EMBASE and CINAHL from January 2005 to October 2018 for studies with ≥ 50 events (mortality and/or hospitalization) and included BP in a multivariable model in ambulatory HF patients. We pooled hazard ratios (random effects model) for systolic BP (SBP) or diastolic BP (DBP) effect on mortality and/or hospitalization risk. We used a priori defined sub-group analyses to explore heterogeneity and GRADE approach to assess the certainty of the evidence. Seventy-one eligible articles (239,467 screened) at low to moderate risk of bias included 235,752 participants. Higher SBP was associated with reduced all-cause mortality (HR 0.93, 95%CI 0.91-0.95, I2 = 87.13%, moderate certainty), all-cause hospitalization events (HR 0.91, 95%CI 0.88-0.93, I2 = 44.4%, high certainty) and their composite endpoint (HR 0.93 per 10 mmHg, 95%CI 0.91-0.94, I2 = 86.3%, high certainty). DBP did not demonstrate a statistically significant effect for all outcomes. The association strength was significantly weaker in studies following patients with either LVEF > 40%, higher average SBP (> 130 mmHg), increasing age and diabetes. All other a priori subgroup hypotheses did not explain between study differences. Higher ambulatory SBP is associated with reduced risk of all-cause mortality and hospitalization. Patients with lower BP and reduced LVEF are in a high-risk group of developing adverse events with moderate certainty of evidence.

GRADE concept paper 2: Concepts for judging certainty on the calibration of prognostic models in a body of validation studies.

BACKGROUND: Prognostic models combine several prognostic factors to provide an estimate of the likelihood (or risk) of future events in individual patients, conditional on their prognostic factor values. A fundamental part of evaluating prognostic models is undertaking studies to determine whether their predictive performance, such as calibration and discrimination, is reproduced across settings. Systematic reviews and meta-analyses of studies evaluating prognostic models' performance are a necessary step for selection of models for clinical practice and for testing the underlying assumption that their use will improve outcomes, including patient's reassurance and optimal future planning. METHODS: In this paper, we highlight key concepts in evaluating the certainty of evidence regarding the calibration of prognostic models. RESULTS AND CONCLUSION: Four concepts are key to evaluating the certainty of evidence on prognostic models' performance regarding calibration. The first concept is that the inference regarding calibration may take one of two forms: deciding whether one is rating certainty that a model's performance is satisfactory or, instead, unsatisfactory, in either case defining the threshold for satisfactory (or unsatisfactory) model performance. Second, inconsistency is the critical GRADE domain to deciding whether we are rating certainty in the model performance being satisfactory or unsatisfactory. Third, depending on whether one is rating certainty in satisfactory or unsatisfactory performance, different patterns of inconsistency of results across studies will inform ratings of certainty of evidence. Fourth, exploring the distribution of point estimates of observed to expected ratio across individual studies, and its determinants, will bear on the need for and direction of future research.

Cardiac Sarcoidosis: A Clinical Overview.

Cardiac sarcoidosis (CS) with clinical manifestation occurs in about 5-8% of patients with sarcoidosis. CS may be clinically suspected by the presence of ventricular arrhythmia, conduction abnormalities, and heart failure (HF). However, 20%-25% of patients may present with silent CS, having asymptomatic cardiac involvement. The diagnosis of CS is based on findings from nuclear studies, cardiac magnetic resonance, and extra-cardiac tissue biopsy. Due to the inflammatory nature of the disease, immunosuppressive medications are a cornerstone of therapy. The treatment also includes recommended HF medical therapies. Since CS patients are at risk of sudden cardiac death resulting from progression of cardiac dysfunction or the presence of scar originating from fatal arrhythmias, implantable cardioverter-defibrillators should be considered, with special indication beyond accepted recommendations in HF. In CS, the extent of left ventricular dysfunction is the most important mortality predictor. Heart transplant or mechanical circulatory support may represent life saving strategies in selective CS patients.

A 2020 Environmental Scan of Heart Failure Clinics in Ontario.

BACKGROUND: Multidisciplinary heart failure (HF) clinics decrease hospital admission rates and healthcare use, while improving patient outcomes. To understand the contemporary availability of HF clinics in Ontario, Canada, and the services provided, we performed an environmental scan of physician-led and nurse practitioner (NP)-led HF clinics. METHODS: Between November, 2019 and February 2020, we identified Ontario HF clinics led by physicians or NPs. Following an invitation, we conducted a semi-structured interview to evaluate the services offered and qualitatively compared our findings to the results of the 2010 Ontario provincial survey. RESULTS: The number of HF clinics (36 vs 34 in 2010) and physicians (157 vs 143 in 2010) have not changed since the 2010 survey. Of the 36 clinics we identified, 30 participated in our interview (22 physician-led and 8 NP-led). Twenty-five clinics (83%) were hospital-based, of which 9 (30%) were part of an academic institution. Comparisons of our findings to the 2010 study on 30 clinics show an approximately 3-fold increase (P <0.001) in both median annual and new patient visits. As previously reported, the clinics varied in services offered, but trended toward an increased availability of onsite echocardiography, exercise-stress testing, and nuclear cardiology. CONCLUSIONS: Compared to the survey performed a decade ago, the number of HF clinics and physicians have not changed, and the services provided remain heterogenous. However, the increased number of patients served suggests a greater demand for these clinics. Improving the accessibility of these clinics and standardizing the service model are critical to improving patient outcomes.

CONTEXTE: Les cliniques multidisciplinaires d'insuffisance cardiaque (IC) diminuent les taux d'hospitalisations et l'utilisation des soins de santé, tout en améliorant les résultats pour les patients. Pour connaître l'offre actuelle de cliniques d'IC en Ontario, au Canada, et les services qui y sont dispensés, nous avons effectué une analyse contextuelle des cliniques d'IC dirigées par des médecins ou par des infirmières praticiennes. MÉTHODOLOGIE: Entre novembre 2019 et février 2020, nous avons recensé des cliniques d'IC dirigées par des médecins ou des infirmières praticiennes en Ontario. Après avoir fait parvenir une invitation à ces professionnels de la santé, nous avons mené des entrevues semi-structurées afin d'évaluer les services offerts et avons, de façon qualitative, comparé nos résultats à ceux de l'enquête provinciale menée en 2010 en Ontario. RÉSULTATS: Le nombre de cliniques d'IC (36 contre 34 en 2010) et de médecins (157 contre 143 en 2010) n'a pas changé depuis l'enquête de 2010. Parmi les 36 cliniques recensées, 30 ont participé à nos entrevues (22 dirigées par des médecins et huit dirigées par des infirmières praticiennes). Vingt-cinq (83 %) des cliniques étaient situées en milieu hospitalier, dont neuf (30 %) qui faisaient partie d'un établissement d'enseignement. Les comparaisons de nos résultats à ceux de l'étude de 2010 sur 30 cliniques montrent que le nombre annuel médian de visites et le nombre de visites par de nouveaux patients ont tous deux triplé (p < 0,001). Comme il a déjà été mentionné, les services offerts étaient différents d'une clinique à l'autre, mais la tendance allait vers une augmentation des services d'échocardiographie, d'épreuves à l'effort et de cardiologie nucléaire offerts sur place. CONCLUSIONS: Par rapport aux résultats de l'enquête réalisée il y a 10 ans, le nombre de cliniques d'IC et de médecins n'a pas changé, et les services fournis demeurent hétérogènes. Toutefois, la hausse du nombre de patients desservis semble indiquer une hausse de la demande pour ces cliniques. Une meilleure accessibilité à ces cliniques et une uniformisation du modèle de services sont essentielles à l'amélioration des résultats pour les patients.

Predicting Survival After VA-ECMO for Refractory Cardiogenic Shock: Validating the SAVE Score.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used increasingly to support patients who are in cardiogenic shock. Due to the risk of complications, prediction models may aid in identifying patients who would benefit most from VA-ECMO. One such model is the Survival After Veno-Arterial Extracorporeal Membrane Oxygenation (SAVE) score. Therefore, we wanted to validate the utility of the SAVE score in a contemporary cohort of adult patients. METHODS: Retrospective data were extracted from electronic health records of 120 patients with cardiogenic shock supported with VA-ECMO between 2011 and 2018. The SAVE score was calculated for each patient to predict survival to hospital discharge. We assessed the SAVE score calibration by comparing predicted vs observed survival at discharge. We assessed discrimination with the area under the receiver operating curve using logistic regression. RESULTS: A total of 45% of patients survived to hospital discharge. Survivors had a significantly higher mean SAVE score (-9.3 ± 4.1 in survivors vs -13.1 ± 4.4, respectively; P = 0.001). SAVE score discrimination was adequate (c = 0.77; 95% confidence interval 0.69-0.86; P < 0.001). SAVE score calibration was limited, as observed survival rates for risk classes II-V were higher in our cohort (II: 67% vs 58%; III: 78% vs 42%; IV: 61% vs 30%; and V: 29% vs 18%). CONCLUSIONS: The SAVE score underestimates survival in a contemporary North American cohort of adult patients with cardiogenic shock. Its inaccurate performance could lead to denying ECMO support to patients deemed to be too high risk. Further studies are needed to validate additional predictive models for patients requiring VA-ECMO.

CONTEXTE: L'oxygénation extracorporelle veino-artérielle (ECMO-VA) est de plus en plus utilisée comme assistance pour les patients qui sont en choc cardiogène. En raison du risque de complications, des modèles de prédiction peuvent aider à déterminer quels patients bénéficieraient le plus d'une ECMO-VA. Le score SAVE (Survival After Veno-Arterial Extracorporeal Membrane Oxygenation) est un modèle de ce genre. Par conséquent, nous voulions valider l'utilité du score SAVE dans une cohorte contemporaine de patients adultes. MÉTHODOLOGIE: Des données rétrospectives ont été extraites de dossiers médicaux électroniques de 120 patients atteints d'un choc cardiogène ayant reçu une ECMO-VA entre 2011 et 2018. Le score SAVE a été calculé pour chaque patient afin de prédire la survie au congé de l'hôpital. Nous avons évalué la calibration du score SAVE en comparant la survie prédite au moment du congé et la survie observée. Nous avons évalué la discrimination par l'aire sous la courbe opérationnelle chez le receveur en faisant appel à la régression logistique. RÉSULTATS: Au total, 45 % des patients ont survécu au congé de l'hôpital. Les survivants affichaient un score SAVE moyen considérablement plus élevé (­9,3 ± 4,1 chez les survivants vs ­13,1 ± 4,4; p = 0,001). La discrimination par le score SAVE était adéquate (c = 0,77; intervalle de confiance à 95 % : 0,69 à 0,86; p < 0,001). La calibration du score SAVE était limitée, car les taux pour les classes de risque II à V étaient plus élevés dans notre cohorte (II : 67 % vs 58 %; III : 78 % vs 42 %; IV : 61 % vs 30 %; et V : 29 % vs 18 %). CONCLUSIONS: Le score SAVE sous-estime la survie dans une cohorte nord-américaine contemporaine de patients adultes atteints d'un choc cardiogène. L'inexactitude de ses résultats pourrait faire en sorte qu'une assistance par ECMO serait refusée à des patients jugés comme présentant un risque élevé. D'autres études sont nécessaires pour valider d'autres modèles de prédiction pour les patients ayant besoin d'une ECMO-VA.

Application of the heart failure meta-score to predict prognosis in patients with cardiac resynchronization defibrillators.

BACKGROUND: The Heart Failure (HF) Meta-score may be useful in predicting prognosis in patients with primary prevention cardiac resynchronization defibrillators (CRT-D) considering the competing risk of appropriate defibrillator shock versus mortality. METHODS: Data from 648 consecutive patients from two centers were used for the evaluation of the performance of the HF Meta-score. The primary endpoint was mortality and the secondary endpoint was time to first appropriate implantable cardioverter-defibrillator (ICD) shock or death without prior appropriate ICD shock. Fine-Gray model was used for competing risk regression analysis. RESULTS: In the entire cohort, 237 patients died over a median follow-up of 5.2 years. Five-year cumulative incidence of mortality ranged from 12% to 53%, for quintiles 1 through 5 of the HF Meta-score, respectively (log-rank P < 0.001). Compared with the lowest quintile, mortality risk was higher in the highest quintile (HR 6.9; 95%CI 3.7-12.8). The HF Meta-score had excellent calibration, accuracy, and good discrimination in predicting mortality (C-statistic 0.76 at 1-year and 0.71 at 5-year). The risk of death without appropriate ICD shock was higher in risk quintile 5 compared to quintile 1 (sub HR 5.8; 95%CI 3.1-11.0, P < 0.001). CONCLUSIONS: Our study demonstrated a good ability of the HF Meta-score to predict survival in HF patients treated with CRT-D as primary prevention. The HF Meta-score proved to be useful in identifying a subgroup with a significantly poor prognosis despite a CRT-D.

Redo sternotomy versus left ventricular assist device explant as risk factors for early mortality following heart transplantation.

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 < 0.001). PS-HT and LVAD-HT patients required a longer bypass time (P < 0.001) and showed a greater estimated blood loss (P < 0.001). Postoperatively, LVAD-HT required haemodialysis more frequently than the VC-HT group (P = 0.031). Multivariable analyses found that PS-HT patients had increased 30-day mortality compared to VC-HT [hazard ratio (HR) 2.63, 95% confidence interval (CI) 1.15-6.01; P = 0.022] while LVAD-HT did not (HR 2.17, 95% CI 0.96-4.93; P = 0.064). At 1-year, neither PS-HT nor LVAD-HT groups were significantly associated with increased mortality compared to VC-HT. 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.

Evaluation of a Heart Failure Telemonitoring Program Through a Microsimulation Model: Cost-Utility Analysis.

BACKGROUND: Heart failure (HF) is a major public health issue in Canada that is associated with high prevalence, morbidity, and mortality rates and high financial and social burdens. Telemonitoring (TM) has been shown to improve all-cause mortality and hospitalization rates in patients with HF. The Medly program is a TM intervention integrated as standard of care at a large Canadian academic hospital for ambulatory patients with HF that has been found to improve patient outcomes. However, the cost-effectiveness of the Medly program is yet to be determined. OBJECTIVE: This study aims to conduct a cost-utility analysis of the Medly program compared with the standard of care for HF in Ontario, Canada, from the perspective of the public health care payer. METHODS: Using a microsimulation model, individual patient data were simulated over a 25-year time horizon to compare the costs and quality-adjusted life years (QALYs) between the Medly program and standard care for patients with HF treated in the ambulatory care setting. Data were sourced from a Medly Program Evaluation study and literature to inform model parameters, such as Medly's effectiveness in reducing mortality and hospitalizations, health care and intervention costs, and model transition probabilities. Scenario analyses were conducted in relation to HF severity and TM deployment models. One-way deterministic effectiveness analysis and probabilistic sensitivity analysis were performed to explore the impact on the results of uncertainty in model parameters. RESULTS: The Medly program was associated with an average total cost of Can $102,508 (US $77,626) per patient and total QALYs of 5.51 per patient compared with the average cost of Can $97,497 (US $73,831) and QALYs of 4.95 per patient in the Standard Care Group. This led to an incremental cost of Can $5011 (US $3794) and incremental QALY of 0.566, resulting in an incremental cost-effectiveness ratio of Can $8850 (US $6701)/QALY. Cost-effectiveness improved in relation to patients with advanced HF and with deployment models in which patients used their own equipment. Baseline and alternative scenarios consistently showed probabilities of cost-effectiveness greater than 85% at a willingness-to-pay threshold of Can $50,000 (US $37,718). Although the results showed some sensitivity to assumptions about effectiveness parameters, the intervention was found to remain cost-effective. CONCLUSIONS: The Medly program for patients with HF is cost-effective compared with standard care using commonly reported willingness-to-pay thresholds. This study provides evidence for decision makers on the use of TM for HF, supports the use of a nurse-led model of TM that embeds clinically validated algorithms, and informs the use of economic modeling for future evaluations of early-stage health informatics technology.