Left Ventricular Systolic Dysfunction in Patients Diagnosed With Hypertrophic Cardiomyopathy During Childhood: Insights From the SHaRe Registry.

BACKGROUND: The development of left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM) is rare but serious and associated with poor outcomes in adults. Little is known about the prevalence, predictors, and prognosis of LVSD in patients diagnosed with HCM as children. METHODS: Data from patients with HCM in the international, multicenter SHaRe (Sarcomeric Human Cardiomyopathy Registry) were analyzed. LVSD was defined as left ventricular ejection fraction <50% on echocardiographic reports. Prognosis was assessed by a composite of death, cardiac transplantation, and left ventricular assist device implantation. Predictors of developing incident LVSD and subsequent prognosis with LVSD were assessed using Cox proportional hazards models. RESULTS: We studied 1010 patients diagnosed with HCM during childhood (<18 years of age) and compared them with 6741 patients with HCM diagnosed as adults. In the pediatric HCM cohort, median age at HCM diagnosis was 12.7 years (interquartile range, 8.0-15.3), and 393 (36%) patients were female. At initial SHaRe site evaluation, 56 (5.5%) patients with childhood-diagnosed HCM had prevalent LVSD, and 92 (9.1%) developed incident LVSD during a median follow-up of 5.5 years. Overall LVSD prevalence was 14.7% compared with 8.7% in patients with adult-diagnosed HCM. Median age at incident LVSD was 32.6 years (interquartile range, 21.3-41.6) for the pediatric cohort and 57.2 years (interquartile range, 47.3-66.5) for the adult cohort. Predictors of developing incident LVSD in childhood-diagnosed HCM included age <12 years at HCM diagnosis (hazard ratio [HR], 1.72 [CI, 1.13-2.62), male sex (HR, 3.1 [CI, 1.88-5.2), carrying a pathogenic sarcomere variant (HR, 2.19 [CI, 1.08-4.4]), previous septal reduction therapy (HR, 2.34 [CI, 1.42-3.9]), and lower initial left ventricular ejection fraction (HR, 1.53 [CI, 1.38-1.69] per 5% decrease). Forty percent of patients with LVSD and HCM diagnosed during childhood met the composite outcome, with higher rates in female participants (HR, 2.60 [CI, 1.41-4.78]) and patients with a left ventricular ejection fraction <35% (HR, 3.76 [2.16-6.52]). CONCLUSIONS: Patients with childhood-diagnosed HCM have a significantly higher lifetime risk of developing LVSD, and LVSD emerges earlier than for patients with adult-diagnosed HCM. Regardless of age at diagnosis with HCM or LVSD, the prognosis with LVSD is poor, warranting careful surveillance for LVSD, especially as children with HCM transition to adult care.

Quantifying and Interpreting the Prediction Accuracy of Models for the Time of a Cardiovascular Event-Moving Beyond C Statistic: A Review.

Importance: For personalized or stratified medicine, it is critical to establish a reliable and efficient prediction model for a clinical outcome of interest. The goal is to develop a parsimonious model with fewer predictors for broad future application without compromising predictability. A general approach is to construct various empirical models via individual patients' specific baseline characteristics/biomarkers and then evaluate their relative merits. When the outcome of interest is the timing of a cardiovascular event, a commonly used metric to assess the adequacy of the fitted models is based on C statistics. These measures quantify a model's ability to separate those who develop events earlier from those who develop them later or not at all (discrimination), but they do not measure how closely model estimates match observed outcomes (prediction accuracy). Metrics that provide clinically interpretable measures to quantify prediction accuracy are needed. Observations: C statistics measure the concordance between the risk scores derived from the model and the observed event time observations. However, C statistics do not quantify the model prediction accuracy. The integrated Brier Score, which calculates the mean squared distance between the empirical cumulative event-free curve and its individual patient's counterparts, estimates the prediction accuracy, but it is not clinically intuitive. A simple alternative measure is the average distance between the observed and predicted event times over the entire study population. This metric directly quantifies the model prediction accuracy and has often been used to evaluate the goodness of fit of the assumed models in settings other than survival data. This time-scale measure is easier to interpret than the C statistics or the Brier score. Conclusions and Relevance: This article enhances our understanding of the model selection/evaluation process with respect to prediction accuracy. A simple, intuitive measure for quantifying such accuracy beyond C statistics can improve the reliability and efficiency of the selected model for personalized and stratified medicine.

Link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure and cardiovascular death.

AIMS: Left ventricular (LV) systolic deformation is altered early in the ventricular disease process despite normal LV ejection fraction (LVEF). These alterations seem to be characterized by decreased global longitudinal strain (GLS) and augmented global circumferential strain (GCS). This study aimed to investigate the link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure (HF) and cardiovascular death (CD). METHODS AND RESULTS: The study sample was based on the prospective cohort study the 5th Copenhagen City Heart Study (2011-15). All participants were examined with echocardiography following a pre-defined protocol. A total of 2874 participants were included. Mean age was 53±18 years and 60% were female. During a median follow-up of 3.5 years, a total of 73 developed HF/CD. A U-shaped relationship between GCS and HF/CD was observed. LVEF significantly modified the association between GCS and HF/CD (P for interaction <0.001). The optimal transition point for the effect modification was LVEF < 50%. In multivariable Cox regressions, increasing GCS was significantly associated with HF/CD in participants with LVEF ≥ 50% (hazard ratio [HR]=1.12 [95% confidence interval (CI): 1.02; 1.23] per 1% increase), while decreasing GCS was associated with a higher risk of HF/CD in individuals with LVEF < 50% [HR=1.18 (95% CI: 1.05; 1.31) per 1% decrease]. CONCLUSIONS: The prognostic utility of GCS is modified by LVEF. In participants with normal LVEF, higher GCS was associated with increased risk of HF/CD, while the opposite was observed in participants with abnormal LVEF. This observation adds important information to our understanding of the pathophysiological evolution of myocardial deformation in cardiac disease progression.

Subclinical Risk Factors for Heart Failure With Preserved and Reduced Ejection Fraction Among Black Adults.

Importance: Sparse data exist regarding the contributions of subclinical impairments in cardiovascular and noncardiovascular function to incident heart failure (HF) with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF) among Black US residents, limiting understanding of the etiology of HF subtypes. Objectives: To identify subclinical cardiovascular and noncardiovascular risk factors associated with HFrEF and HFpEF in Black US residents. Design, Setting, and Participants: This cohort study used cross-sectional and time-to-event analysis with data from the community-based Jackson Heart Study (JHS), a longitudinal cohort study with baseline data collected from 2000 to 2004 (visit 1) and 10-year follow-up for incident HF. Black US residents from the Jackson, Mississippi, metropolitan area enrolled in JHS; those with prevalent HF, with moderate or greater aortic or mitral valve diseases on visit 1, who died before 2005, and who had missing HF status on follow-up were excluded. The analysis included 4361 participants and was performed between June 2020 to August 2021. Exposures: Quantitative measures of cardiovascular (left ventricular mass index [LVMI], left ventricular ejection fraction [LVEF], left atrial [LA] diameter, and pulse pressure) and noncardiovascular (percent predicted forced expiration volume in 1 second [FEV1 (percent predicted)], estimated glomerular filtration rate (eGFR), waist circumference, and hemoglobin A1c [HbA1c] level) organ function. Main Outcomes and Measures: Incident HF, HFrEF, and HFpEF over 10-year follow-up. Results: The 4361 participants had a mean (SD) age of 54 (13); 2776 (64%) were women; and there were 163 HFpEF and 146 HFrEF events. In multivariable models incorporating measures reflecting each organ system, factors associated with incident HFpEF included greater LA diameter (hazard ratio [HR], 1.23; 95% CI, 1.03-1.47; P = .02), higher pulse pressure (HR, 1.23; 95% CI, 1.05-1.44; P = .009), lower FEV1 (percent predicted) (HR, 1.22; 95% CI, 1.04-1.43; P = .02), lower eGFR (HR, 1.43; 95% CI, 1.19-1.72; P < .001), higher HbA1c level (HR, 1.25; 95% CI, 1.07-1.45; P = .005), and higher waist circumference (HR, 1.41; 95% CI, 1.18-1.69; P < .001). Factors associated with incident HFrEF included greater LVMI (HR, 1.25; 1.07-1.46; P = .005), lower LVEF (HR, 1.65; 95% CI, 1.42-1.91; P < .001), lower FEV1 (percent predicted) (HR, 1.19; 95% CI, 1.00-1.42; P = .047), and lower eGFR (HR, 1.27; 95% CI, 1.04-1.55; P = .02). Conclusions and Relevance: In this community-based cohort study of Black US residents, subclinical impairments in cardiovascular and noncardiovascular organ function were differentially associated with risk of incident HFpEF and HFrEF.

Practical Recommendations on Quantifying and Interpreting Treatment Effects in the Presence of Terminal Competing Risks: A Review.

IMPORTANCE: In a comparative trial, the time to a clinical event is often a key end point. However, the occurrence of a terminal event, such as death or premature study discontinuation, may preclude observation of this outcome. Although various methods for handling competing risks are available, no specific recommendations have been made for scenarios encountered in practice, especially when the terminal event profiles of the study arms are dissimilar. Moreover, appropriate methods for a desirable outcome, such as live hospital discharge, have seldom been discussed. OBSERVATIONS: Several of the most commonly used methods are reviewed. The first regards the terminal event as censoring and applies standard survival analysis to the event of interest. The between-group difference is usually summarized by the cause-specific hazard ratio. This summary measure is inappropriate when the new therapy markedly prolongs time to the terminal event. Moreover, the corresponding Kaplan-Meier curve for the end point of interest is uninterpretable. The second method is to use the cumulative incidence curve, which is the probability of experiencing the event of interest by each time point, acknowledging that patients who have died will never experience the event. However, the resulting pseudo hazard ratio is difficult to interpret. With a proper alternative summary measure, this approach works well for a desirable outcome but may not for an undesirable outcome. The third method focuses on the event-free survival time by combining information from occurrences of the terminal event and the event of interest simultaneously. This clinically interpretable method naturally accounts for differences in terminal event rates when comparing treatments with respect to the time to an undesirable outcome. CONCLUSIONS AND RELEVANCE: This article enhances our understanding of each method's advantages and shortcomings and assists practitioners in choosing appropriate methods for handling competing risk problems in practice.

Quantifying Treatment Effects in Trials with Multiple Event-Time Outcomes.

BACKGROUND: Data on the occurrence times of multiple outcomes, reflecting the temporal profile of disease burden/progression, have been used to estimate treatment effects in various recent randomized trials. Most procedures for analyzing these data require specific model assumptions. When the assumptions are not met, the results may be misleading. Robust, model-free procedures for study design and analysis that enable clinically meaningful interpretations are warranted. METHODS: For each treatment group, we constructed and summarized the estimated mean cumulative count of events over time by the area under the curve (AUC), which can be interpreted as the mean total event-free time lost from multiple undesirable outcomes. A higher curve, and resulting larger AUC, implies a worse treatment. The treatment effect is quantified by the ratio and/or difference of AUCs. The timing and occurrence of recurrent heart failure hospitalizations (HFHs) and cardiovascular (CV) death from Prospective Comparison of ARNI with ARB Global Outcomes in HF with Preserved Ejection Fraction (PARAGON-HF), comparing sacubitril/valsartan with valsartan, are presented for illustration. We also discuss the design of future studies on the basis of the proposed method. RESULTS: With 48 months of follow-up, estimated AUCs, representing the total event-free time lost to HFHs and CV death, were 11.3 and 13.1 event-months for sacubitril/valsartan and valsartan, respectively. The ratio of these AUCs was 0.86 (95% confidence interval, 0.75 to 1.00; P=0.049), a 14% reduction of disease burden favoring combination therapy. A future study, similar to PARAGON-HF, designed using the new proposal would require fewer patients would than a conventional time-to-first-event analysis. CONCLUSIONS: The proposed method is robust and model-free and provides a clinically interpretable, time-scale summary of the treatment effect. (Funded by National Institutes of Health.).

The 3A3B score: The simple risk score for heart failure with preserved ejection fraction - A report from the CHART-2 Study.

BACKGROUND: Few simple risk models, without echocardiography have been developed for patients with heart failure (HF) and preserved left ventricular ejection fraction (LVEF) (HFpEF). METHODS: To develop a risk score to predict all-cause death for HFpEF patients, we examined 1277 HF patients with LVEF ≥50% and BNP ≥100 pg/ml in the CHART-2 Study, a large-scale prospective cohort study for HF in Japan. We selected the optimal subset of covariates for the score with Cox proportional hazard models and random survival forests (RSF). RESULTS: During the median 5.7-year follow-up, 576 deaths occurred. Cox models and RSF analyses consistently indicated age ≥75 years, albumin <3.7 g/dl, anemia, BMI <22 kg/m2, BNP ≥300 pg/ml (or NT-proBNP ≥1400 pg/ml), and BUN ≥25 mg/dl, as the important 6 prognostic variables. Incorporating these 6 variables, we developed a scoring system (3A3B score, with 2 points given to age ≥75 years and 1 point to the others based on the hazard ratios. The discrimination ability of the risk score was excellent (c-index 0.708). Regarding model goodness-of-fit, the overall gradient in 5-year risk was well captured by the score. The predictive accuracy of the 3A3B score was confirmed in the external validation cohorts from the TOPCAT trial (N = 835, c-index 0.652) and the ASIAN-HF registry (N = 170, c-index 0.741). CONCLUSIONS: We developed a simple risk score to predict long-term prognosis of HFpEF patients. The 3A3B score, comprising 6 commonly available parameters in daily practice, has potential utility in the risk stratification and management of HFpEF patients.

Spironolactone and Resistant Hypertension in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Recent evidence suggests that the mineralocorticoid receptor antagonist spironolactone should be the preferred fourth-line antihypertensive treatment in resistant hypertension (RHTN). Whether spironolactone improves blood pressure (BP) control in heart failure with preserved ejection fraction (HFpEF) and RHTN is unknown. METHODS: We identified patients with RHTN, defined as baseline systolic blood pressure (SBP) between 140 and 160 mm Hg on 3 or more medications, in the Americas cohort of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial, in which patients with HFpEF were randomized to spironolactone vs. placebo. We evaluated the effects of spironolactone vs. placebo on BP reduction in this group and related this to the primary composite outcome of death from cardiovascular causes, aborted cardiac arrest, or hospitalization for heart failure. RESULTS: We identified 403 participants in the Americas with RHTN. Compared to people without RHTN, those with RHTN were more frequently women, non-White, diabetics, with a higher left ventricular ejection fraction and body mass index, and a lower hemoglobin concentration. In the RHTN group, spironolactone resulted in a decrease of SBP: -6.1 (-8.9, -3.3); P < 0.001 and diastolic BP: -2.9 (-4.6, -1.2); P = 0.001 mm Hg during the first 8 months. BP became controlled after 4 weeks in 63% of patients receiving spironolactone vs. 46% receiving placebo (P = 0.003), with similar responses at 8 weeks, 4 and 8 months. Patients with RHTN derived similar overall benefit from spironolactone on the primary outcomes as those without. CONCLUSIONS: In HFpEF patients with RHTN, spironolactone lowered BP substantially and was associated with similar benefit as those without RHTN. CLINICAL TRIALS REGISTRATION: Trial Number NCT00094302 (ClinicalTrials.gov identifier).