Interpretable Survival Analysis for Heart Failure Risk Prediction

Survival analysis, or time-to-event analysis, is an important and widespread problem in healthcare research. Medical research has traditionally relied on Cox models for survival analysis, due to their simplicity and interpretability. Cox models assume a log-linear hazard function as well as proportional hazards over time, and can perform poorly when these assumptions fail. Newer survival models based on machine learning avoid these assumptions and offer improved accuracy, yet sometimes at the expense of model interpretability, which is vital for clinical use. We propose a novel survival analysis pipeline that is both interpretable and competitive with state-of-the-art survival models. Specifically, we use an improved version of survival stacking to transform a survival analysis problem to a classification problem, ControlBurn to perform feature selection, and Explainable Boosting Machines to generate interpretable predictions. To evaluate our pipeline, we predict risk of heart failure using a large-scale EHR database. Our pipeline achieves state-of-the-art performance and provides interesting and novel insights about risk factors for heart failure

Improving Postdischarge Outcomes in Acute Heart Failure

The global burden that acute heart failure (AHF) carries has remained unchanged over the past several decades (1). European registries (2–5) showed that 1-year outcome rates remain unacceptably high (Table 1) and confirm that hospitalization for AHF represents a change in the natural history of the disease process(6). As patients hospitalized for HF have a bad prognosis, it is crucial to utilize hospitalization as an opportunity to: 1) assess the individual components of the cardiac substrate; 2) identify and treat comorbidities; 3) identify early, safe endpoints of therapy to facilitate timely hospital discharge and outpatient follow-up; and 4) implement and begin optimization guideline-directed medical therapies (GDMTs). As outcomes are influenced by many factors, many of which are incompletely understood, a systematic approach is proposed that should start with admission and continues through post-discharge (7)

Relation of serum magnesium levels and postdischarge outcomes in patients hospitalized for heart failure (from the EVEREST Trial)

Serum magnesium levels may be impacted by neurohormonal activation, renal function, and diuretics. The clinical profile and prognostic significance of serum magnesium level concentration in patients hospitalized for heart failure (HF) with reduced ejection fraction is unclear. In this retrospective analysis of the placebo group of the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan trial, we evaluated 1,982 patients hospitalized for worsening HF with ejection fractions ≤40%. Baseline magnesium levels were measured within 48 hours of admission and analyzed as a continuous variable and in quartiles. The primary end points of all-cause mortality (ACM) and cardiovascular mortality or HF rehospitalization were analyzed using Cox regression models. Mean baseline magnesium level was 2.1 ± 0.3 mg/dl. Compared with the lowest quartile, patients in the highest magnesium level quartile were more likely to be older, men, have lower heart rates and blood pressures, have ischemic HF origin, and have higher creatinine and natriuretic peptide levels (all p <0.003). During a median follow-up of 9.9 months, every 1-mg/dl increase in magnesium level was associated with higher ACM (hazard ratio [HR] 1.77; 95% confidence interval [CI] 1.35 to 2.32; p <0.001) and the composite end point (HR 1.44; 95% CI 1.15 to 1.81; p = 0.002). However, after adjustment for known baseline covariates, serum magnesium level was no longer an independent predictor of either ACM (HR 0.94, 95% CI 0.69 to 1.28; p = 0.7) or the composite end point (HR 1.01, 95% CI 0.79 to 1.30; p = 0.9). In conclusion, despite theoretical concerns, baseline magnesium level was not independently associated with worse outcomes in this cohort. Further research is needed to understand the importance of serum magnesium levels in specific HF patient populations

Therapeutic Advances in the Management of Cardiogenic Shock

Background: Cardiogenic shock (CS) is a life-threatening state of tissue hypoperfusion, associated with a very high risk of mortality, despite intensive monitoring and modern treatment modalities. The present review aimed at describing the therapeutic advances in the management of CS. Areas of uncertainty: Many uncertainties about CS management remain in clinical practice, and these relate to the intensity of invasive monitoring, the type and timing of vasoactive therapies, the risk-benefit ratio of mechanical circulatory support (MCS) therapy, and optimal ventilation mode. Furthermore, most of the data are obtained from CS in the setting of acute myocardial infarction (AMI), although for non-AMI-CS patients, there are very few evidences for etiological or MCS therapies. Data sources: The prospective multicentric acute heart failure registries that specifically presented characteristics of patients with CS, distinct to other phenotypes, were included in the present review. Relevant clinical trials investigating therapeutic strategies in post-AMI-CS patients were added as source information. Several trials investigating vasoactive medications and meta-analysis providing information about benefits and risks of MCS devices were reviewed in this study. Therapeutic advances: Early revascularization remains the most important intervention for CS in settings of AMI, and in patients with multivessel disease, recent trial data recommend revascularization on a "culprit-lesion-only" strategy. Although diverse types of MCS devices improve hemodynamics and organ perfusion in patients with CS, results from almost all randomized trials incorporating clinical end points were inconclusive. However, development of new algorithms for utilization of MCS devices and progresses in technology showed benefit in selected patients. A major advance in the management of CS is development of concept of regional CS centers based on the level of facilities and expertise. The modern systems of care with CS centers used as hubs integrated with emergency medical systems and other referee hospitals have the potential to improve patient outcomes. Conclusions: Additional research is needed to establish new triage algorithms and to clarify intensity and timing of pharmacological and mechanical therapies

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p&lt;0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (&lt;1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (&lt;1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

Recurrent Headaches in Children: An Epidemiological Survey of Two Middle Schools in Inner City Chicago

Objectives: The aim of this study was to longitudinally evaluate the epidemiological characteristics of headaches in a school-based, community setting and to determine the impact of headache symptoms on the health of children. Methods: After institutional review board approval, a prospective cohort study was conducted at two Chicago public schools for a period of 6 months. Members of the research team surveyed both schools weekly for headache and other pain symptoms. The students rated each pain symptom on a 5-point scale from 0 ("not at all") to 4 ("a whole lot"). Demographic information was collected at the time of enrollment, and all participants were asked to complete age-appropriate and validated pediatric surveys to assess the severity of concurrent somatic complaints, anxiety symptoms, functional limitations, and quality of life issues. Results: Of the participating children, 89.5% reported at least one headache during the study period. Females experienced more frequent headaches compared with males (P < 0.05). Children reporting headaches had a significantly increased risk of experiencing other troubling somatic symptoms (P < 0.05). Headache severity showed a moderate correlation with increased feelings of anxiety, functional disability, and a diminished quality of life (P < 0.05). Conclusions: School-aged children commonly experience headaches. Children experiencing headaches are more likely to report other somatic symptoms, feelings of anxiety, functional limitations, and quality of life impairments