B-type natriuretic peptide and risk of sudden death in patients with hypertrophic cardiomyopathy

Effect of Mavacamten in Women Compared With Men With Obstructive Hypertrophic Cardiomyopathy: Insights From EXPLORER-HCM

BACKGROUND

Compared with men, women with hypertrophic cardiomyopathy (HCM) have a higher incidence of heart failure and worse outcomes. We investigated baseline clinical and echocardiographic characteristics and response to mavacamten among women compared with men in the EXPLORER-HCM study (Clinical Study to Evaluate Mavacamten [MYK-461] in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy).

METHODS

A prespecified post hoc analysis of sex from the blinded, randomized EXPLORER-HCM trial of mavacamten versus placebo in symptomatic patients with obstructive HCM was performed. Baseline characteristics were compared with t tests for continuous variables (expressed as mean values) and χ2 tests for categorical variables. Prespecified primary, secondary, and exploratory end points and echocardiographic measurements from baseline to end of treatment (week 30) were analyzed with ANCOVA for continuous end points and a generalized linear model with binomial distribution for binary end points, with adjustment for each outcome's baseline value, New York Heart Association class, β-blocker use, and ergometer type.

RESULTS

At baseline, women (n=102) were older (62 years versus 56 years; P<0.0001), had lower peak oxygen consumption (16.7 mL·kg-1·min-1 versus 21.3 mL·kg-1·min-1; P<0.0001), were more likely to be assigned New York Heart Association class III (42% versus 17%; P<0.0001), had worse health status (Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score 64 versus 75; P<0.0001), and had higher baseline plasma NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels (1704 ng/L versus 990 ng/L; P=0.004) than men (n=149). After 30 weeks of mavacamten treatment, similar improvements were observed in women and men in the primary composite end point (percentage difference on mavacamten versus placebo, 22% versus 19%, respectively; P=0.759) and in the secondary end points of change in postexercise left ventricular outflow tract gradient (-42.4 mm Hg versus -33.6 mm Hg; P=0.348), change in peak oxygen consumption (1.2 mL·kg-1·min-1 versus 1.6 mL·kg-1·min-1; P=0.633), and percentage achieving ≥1 New York Heart Association class improvement (41% versus 28%; P=0.254). However, women had greater improvement in health status (Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score 14.8 versus 6.1; P=0.026) and in the exploratory end point of NT-proBNP levels (-1322 ng/L versus -649 ng/L; P=0.0008).

CONCLUSIONS

Although at baseline women with symptomatic obstructive HCM enrolled in EXPLORER-HCM were older and had worse heart failure and health status than men, treatment with mavacamten resulted in similar improvements in the primary and most secondary EXPLORER-HCM end points and greater improvements in health status and NT-proBNP.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03470545.

International Consensus on Differential Diagnosis and Management of Patients With Danon Disease: JACC State-of-the-Art Review

Danon disease is a rare X-linked autophagic vacuolar cardioskeletal myopathy associated with severe heart failure that can be accompanied with extracardiac neurologic, skeletal, and ophthalmologic manifestations. It is caused by loss of function variants in the LAMP2 gene and is among the most severe and penetrant of the genetic cardiomyopathies. Most patients with Danon disease will experience symptomatic heart failure. Male individuals generally present earlier than women and die of either heart failure or arrhythmia or receive a heart transplant by the third decade of life. Herein, the authors review the differential diagnosis of Danon disease, diagnostic criteria, natural history, management recommendations, and recent advances in treatment of this increasingly recognized and extremely morbid cardiomyopathy.

Updated risk assessments for sudden cardiac death in hypertrophic cardiomyopathy patients with implantable cardioverter-defibrillator

Hypertrophic cardiomyopathy (HCM) is a genetic disease associated with a risk of malignant ventricular tachyarrhythmias and sudden cardiac death (SCD). Assessment of the SCD risk is crucial for its clinical management, and there has been considerable interest in developing risk stratification strategies. An implantable cardioverter-defibrillator (ICD) is a life-saving treatment for patients with HCM who are at a high-risk of ventricular tachyarrhythmias and SCD. However, a substantial number of ICD recipients experience adverse effects arising from inappropriate device therapy and implant-related complications. This has led to numerous investigations of the risk of SCD and the indications for ICD implantation. American guidelines were recently updated to include new risk markers, including left ventricular systolic dysfunction, apical aneurysm, and extensive late gadolinium enhancement, while European guidelines recommend individualized estimated 5-year SCD risk assessment models. Studies evaluating other risk factors for SCD in patients with HCM have also been published. Drawing on recent guidelines and publications on clinical risk factors, we focus this review on updated risk assessments for SCD with ICD therapy in patients with HCM.

Circulating Biomarkers in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is the most common genetic heart disease. Biomarkers, molecules measurable in the blood, could inform the clinician by aiding in diagnosis, directing treatment, and predicting outcomes. We present an updated review of circulating biomarkers in hypertrophic cardiomyopathy representing key pathologic processes including wall stretch, myocardial necrosis, fibrosis, inflammation, hypertrophy, and endothelial dysfunction, in addition to their clinical significance.

Trends in Sudden Death Following Admission for Acute Heart Failure

Few studies on sudden death (SD) after admission for acute heart failure (AHF) have been published. A total of 1,664 patients with AHF were enrolled in this study, and 1,261 patients who were successfully followed up during the first year after admission were analyzed. The primary end point was SD, which was defined as out-of-hospital cardiac arrest. The median follow-up period from admission was 1,008 days (range 408 to 2,132). In total, 505 patients (40.0%) died: 341 (67.5%) died of cardiovascular causes and 55 (10.9%) died of other causes. Of the 505 who died, 80 (15.8%) experienced SD. The proportion of SDs increased in the later phases of follow-up (0 to 1 year, 10.3%; 1 to 2 years, 18.0%; 2 to 5 years, 18.8%; ≥5 years, 28.2%; p <0.001). A multivariate logistic regression model showed that younger age was independently associated with SD (60 to 69 years: odds ratio 2.249, 95% confidence interval 1.060 to 4.722; <60 years: odds ratio 3.863, 95% confidence interval 1.676 to 8.905). Kaplan-Meier curves showed that the incidence of cardiovascular death was highest during the acute phase, whereas the incidence of SD increased gradually over the entire follow-up period. In conclusion, the incidence of SD was surprisingly high in patients with AHF, accounting for 16% of long-term mortality. The proportion of SDs increased during the very late follow-up phases.

What Aspects of Phenotype Determine Risk for Sudden Cardiac Death in Pediatric Hypertrophic Cardiomyopathy?

Sudden cardiac death due to hypertrophic cardiomyopathy (HCM), is the most common autopsy-proven cause of unexpected medical death in children after infancy. This mode of death is preventable by implantation of an internal cardiac defibrillator (ICD), a procedure that has considerable morbidity in childhood patients, and even mortality. Since HCM is an inheritable disease (usually autosomal dominant, occasionally recessive), family screening may identify subjects at risk. This review summarizes published studies carried out to identify which phenotypic markers are important risk factors in childhood patients with HCM and reviews the performance of existing risk-stratification algorithms (HCM Risk-Kids, PRIMaCY) against those of single phenotypic markers. A significant proportion of HCM-patients diagnosed in childhood are associated with RASopathies such as Noonan syndrome, but a knowledge gap exists over risk stratification in this patient group. In conclusion, pediatric risk-stratification algorithms for sudden cardiac death perform better in children than adult HCM risk-stratification strategies. However, current multivariable algorithms overestimate risk substantially without having high sensitivity, and remain ‘a work in progress’. To include additional phenotypic parameters that can be reproducibly measured such as ECG-markers, e.g., ECG risk score (which has high sensitivity and negative predictive value), tissue Doppler diastolic function measurements, and quantification of myocardial scarring on cardiac magnetic resonance imaging, has the potential to improve risk-stratification algorithms. Until that work has been achieved, these are three factors that the clinician can combine with the current algorithm-calculated per cent risk, in order better to assess risk.

Risk factors of sudden cardiac death in hypertrophic cardiomyopathy

PURPOSE OF REVIEW

Hypertrophic cardiomyopathy (HCM) is one of the leading causes of sudden cardiac death (SCD) in younger people and athletes. It is crucial to identify the risk factors for SCD in individuals with HCM. This review, based on recent systematic literature studies, will focus on the risk factors for SCD in patients with HCM.

RECENT FINDINGS

An increasing number of studies have further explored the risk factors for SCD in patients with HCM, and new risk markers have emerged accordingly. In addition, more accurate SCD risk estimation and stratification methods have been proposed and continuously improved.

SUMMARY

The identification of independent risk factors for HCM-related SCD would likely contribute to risk stratification. However, it is difficult to predict SCD with absolute certainty, as the annual incidence of SCD in adult patients with HCM is approximately 1%. The review discusses the established risk factors, such as a family history of SCD, unexplained syncope and some new risk factors. Taken together, the findings of this review demonstrate that there is a need for further research on individual risk factors and that SCD risk stratification in HCM patients remains a clinical challenge.

Study on Risk Factors for Death from Cardiomyopathy and Effectiveness of Health Information Management

Objective

To explore risk factors for death from cardiomyopathy and the effectiveness of health information management (HIM).

Methods

A total of 80 patients with cardiomyopathy admitted in ICU of our hospital (January 2016–January 2020) were selected as study subjects, and the clinical data of the patients were retrospectively analyzed. The patients were divided into the survival group (n = 72) and the death group (n = 14) according to the treatment outcome. Then, according to the management mode, the survival group was further equally divided into the conventional group and the HIM group to investigate the influence of risk factors on prognosis of patients with cardiomyopathy and the effectiveness of HIM.

Results

No significant difference was found in baseline body mass, myocardial enzymes, troponin, infection factors, history of heart disease, and gender between the survival group and the death group (P > 0.05). Compared with the survival group, the patients of the death group were older (P < 0.05), LVEF of the death group was obviously lower (P < 0.05), and the scores of APACHE II and SOFA of the death group were obviously higher (P < 0.05). Further logistic regression analysis of the univariate factors influencing the risk of death from cardiomyopathy led to the conclusion that LVEF was an independent risk factor for death in patients with cardiomyopathy. LVEF below 24.69% examined by echocardiography had a high predictive value, with a sensitivity of 98.6% and a specificity of 78.6%. No obvious difference was found in general data between the conventional group and the HIM group (P > 0.05). Compared with the conventional group, the disease remission rate, complication rate, awareness rate of health knowledge, ICU length of stay, and scores of self-management efficacy of the HIM group were obviously better (P < 0.05). No significant difference was found in 5-year mean survival rate between the conventional group and the HIM group (P > 0.05).

Conclusion

Older age, lower LVEF, and higher scores of APACHE II and SOFA are all risk factors for death from cardiomyopathy. Lower LVEF is an independent risk factor, and LVEF below 24.69% is an important indicator of increased risk of death. Moreover, HIM can effectively improve short-term treatment efficacy but has little effect on the long-term survival rate.

Implantation of ventricular assist devices in hypertrophic cardiomyopathy with left ventricular systolic dysfunction

Aims

The outcomes of patients with hypertrophic cardiomyopathy with left ventricular systolic dysfunction (HCM‐LVSD) undergoing left ventricular assist device (LVAD) implantation remain unclear. We retrospectively evaluated the clinical impact of LVAD implantation on clinical outcomes, including haemodynamics and brain natriuretic peptide (BNP) levels, in patients with HCM‐LVSD, in comparison with those with dilated cardiomyopathy (DCM).

Methods and results

In this retrospective, single‐centre, observational study conducted in Japan, the medical records of patients who underwent LVAD implantation in the National Cerebral and Cardiovascular Center between 2011 and 2020 were reviewed. We enrolled 96 patients with DCM (average age: 43.5 years; 73 men) and 24 patients with HCM‐LVSD (average age: 48.3 years; 16 men). The HCM‐LVSD group had smaller left ventricles with thicker ventricular walls than the DCM group, which became more prominent after LVAD implantation. Preoperatively, BNP values were comparable between both groups; however, 3 months post‐implantation, they were significantly higher in the HCM‐LVSD group. Pulmonary artery pulsatility index, right ventricular stroke work index, and cardiac index were lower, and right atrial pressure was higher, in the HCM‐LVSD group, suggesting subclinical impairment of right ventricular function. The HCM‐LVSD group demonstrated equivalent outcomes, including overall survival, cerebrovascular accidents, right ventricular failure, LVAD‐related infections, arrhythmia, and aortic insufficiency, post‐implantation.

Conclusions

Despite a decreased right ventricular function with higher BNP values, patients with HCM‐LVSD and DCM showed comparable outcomes post‐LVAD implantation.

Sex Differences in Time-Dependent Changes in B-Type Natriuretic Peptide in Hypertrophic Cardiomyopathy

Background: Female sex is reported to be associated with poor prognosis in hypertrophic cardiomyopathy (HCM). The plasma B-type natriuretic peptide (BNP) concentration is a prognostic predictor in HCM. However, the effect of sex on BNP concentrations remains unclear among HCM patients.

Methods and Results: Patient records in the Clinical Personal Records of HCM national database of the Japanese Ministry of Health, Labour and Welfare from 2009 to 2014 were analyzed. Of 3,570 HCM patients, 611 in whom BNP concentrations were assessed at both baseline and the 2-year follow-up were included in this analysis. The mean age was 60.4 years and 254 (41.6%) patients were female. Median (interquartile range) BNP concentrations were higher in females than males at both baseline (320.3 [159.0–583.1] vs. 182.8 [86.1–363.9] pg/mL; P<0.001) and the 2-year follow-up (299.2 [147.0–535.3] vs. 161.0 [76.2–310.0] pg/mL; P<0.001). Female sex was associated with higher natural log-transformed BNP at the 2-year follow-up regardless of clinical characteristics, including echocardiographic findings and BNP concentrations at baseline (coefficient 0.31; 95% confidence interval 0.13–0.48; P<0.001). Cubic spline analysis showed that, among patients with high BNP concentrations at baseline, females had higher BNP concentrations at the 2-year follow-up than males.

Conclusions: In HCM, female sex was associated with higher BNP concentrations than male sex, independent of clinical characteristics, including BNP concentrations at baseline.

Risk Prediction Models and Scores in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) has historically been linked with sudden cardiac death (SCD). Currently, it is well established that only a subset of patients is at the highest risk stratum for such a catastrophic event. Detection of patients belonging to this high-risk category can allow for timely defibrillator implantation, changing the natural history of HCM. Inversely, device implantation in patients deemed at low risk leads to an unnecessary burden of device complications with no apparent protective benefit. Previous studies have identified a series of markers, now considered established risk factors, with genetic testing and newer imaging allowing for the detection of novel, highly promising indices of increased risk for SCD. Despite the identification of a number of risk factors, there is noticeable discrepancy in the utility of such factors for risk stratification between the current American and European guidelines. We sought to systematically review the data available on these two approaches, presenting their rationale and respective predictive capacity, also discussing the potential of novel markers to augment the precision of currently used risk stratification models for SCD in HCM.

Left intraventricular pressure gradient in hypertrophic cardiomyopathy patients receiving implantable cardioverter-defibrillators for primary prevention

Background

Conventional risk factors for sudden cardiac death (SCD) justify primary prevention through implantable cardioverter-defibrillator (ICD) implantation in hypertrophic cardiomyopathy (HCM) patients. However, the positive predictive values for these conventional SCD risk factors are low. Left ventricular outflow tract obstruction (LVOTO) and midventricular obstruction (MVO) are potential risk modifiers for SCD. The aims of this study were to evaluate whether an elevated intraventricular pressure gradient (IVPG), including LVOTO or MVO, is a potential risk modifier for SCD and ventricular arrhythmias requiring ICD interventions in addition to the conventional risk factors among HCM patients receiving ICDs for primary prevention.

Methods

We retrospectively studied 60 HCM patients who received ICDs for primary prevention. An elevated IVPG was defined as a peak instantaneous gradient ≥ 30 mmHg at rest, as detected by continuous-wave Doppler echocardiography. The main outcome was a composite of SCD and appropriate ICD interventions, which were defined as an antitachycardia pacing or shock therapy for ventricular tachycardia or fibrillation. The Cox proportional hazards model was used to assess the relationships between risk factors and the occurrence of SCD and appropriate ICD interventions.

Results

Thirty patients met the criteria of elevated IVPG (50%). During the median follow-up period of 66 months, 2 patients experienced SCD, and 10 patients received appropriate ICD interventions. Kaplan–Meier curves showed that the incidence of the main outcome was higher in patients with an IVPG ≥ 30 mmHg than in those without an IVPG ≥ 30 mmHg (log-rank P = 0.03). There were no differences in the main outcome between patients with LVOTO and patients with MVO. The combination of nonsustained ventricular tachycardia (NSVT) and IVPG ≥ 30 mmHg was found to significantly increase the risk of the main outcome (HR 6.31, 95% CI 1.36–29.25, P = 0.02). Five patients experienced ICD implant-related complications.

Conclusions

Our findings showed that a baseline IVPG ≥ 30 mmHg was associated with an increased risk of experiencing SCD or appropriate ICD interventions among HCM patients who received ICDs for primary prevention. Combined with NSVT, which is a conventional risk factor, a baseline IVPG ≥ 30 mmHg may be a potential modifier of SCD risk in HCM patients.

B-type natriuretic peptide and outcome in patients with apical hypertrophic cardiomyopathy

BACKGROUND

Although elevated B-type natriuretic peptide (BNP) levels predict outcome in patients with hypertrophic cardiomyopathy (HCM), the association between BNP levels and outcome in patients with the apical phenotype of HCM remains unclear. We evaluated the impact of elevated BNP levels on outcome in a cohort of apical HCM patients.

METHODS

Among 432 HCM patients, 144 with an apical phenotype were examined. Plasma BNP levels were measured at the time of the initial evaluation.

RESULTS

The median (interquartile range) BNP level at initial evaluation in these patients was 188.5 (72.0-334.4) pg/mL. During a median follow-up period of 9.5 years, 34 patients experienced HCM-related adverse outcomes, including 2 patients with sudden death, 5 with appropriate implantable defibrillator shocks, 3 with stroke-related death, 8 with non-fatal stroke, and 16 with heart failure hospitalization. Receiver operating characteristic (ROC) curve analysis of the prognostic value of BNP for the combined endpoint gave an area under the ROC curve of 0.756, and optimal BNP cut-off point of 226.0pg/mL. Patients with high BNP levels (≥226.0pg/mL) were at significantly greater risk of the combined endpoint (log-rank p<0.001) than patients with low BNP levels. Multivariable analysis that included BNP levels and potential confounders showed that high BNP levels were an independent determinant of the combined endpoint (adjusted hazard ratio: 3.71; p=0.002).

CONCLUSIONS

Measuring BNP may help stratify the risk of HCM-related adverse outcome in apical HCM patients.

Classic and Novel Biomarkers as Potential Predictors of Ventricular Arrhythmias and Sudden Cardiac Death

Sudden cardiac death (SCD), most often induced by ventricular arrhythmias, is one of the main reasons for cardiovascular-related mortality. While coronary artery disease remains the leading cause of SCD, other pathologies like cardiomyopathies and, especially in the younger population, genetic disorders, are linked to arrhythmia-related mortality. Despite many efforts to enhance the efficiency of risk-stratification strategies, effective tools for risk assessment are still missing. Biomarkers have a major impact on clinical practice in various cardiac pathologies. While classic biomarkers like brain natriuretic peptide (BNP) and troponins are integrated into daily clinical practice, inflammatory biomarkers may also be helpful for risk assessment. Indeed, several trials investigated their application for the prediction of arrhythmic events indicating promising results. Furthermore, in recent years, active research efforts have brought forward an increasingly large number of “novel and alternative” candidate markers of various pathophysiological origins. Investigations of these promising biological compounds have revealed encouraging results when evaluating the prediction of arrhythmic events. To elucidate this issue, we review current literature dealing with this topic. We highlight the potential of “classic” but also “novel” biomarkers as promising tools for arrhythmia prediction, which in the future might be integrated into clinical practice.

Prognostic Implications of Point-of-Care and Serial B-type Natriuretic Peptide Levels in Patients With Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HC) is a heterogenous disease with a variable clinical course. Predictors of long-term adverse cardiovascular events are needed. Our objectives were to determine the long-term prognostic value of a single and serial point of care (POC) B-type natriuretic-peptide (BNP) measurements in HC. One hundred and eleven ambulatory patients with HC (mean age 53 ± 16 years) were prospectively recruited over a 2-year period (2004 to 2006). A clinical assessment, comprehensive echocardiogram, and a POC BNP level was obtained at baseline and at a 1- to 2-year follow-up. They were subsequently followed for the occurrence of major adverse cardiac events (MACE). The median baseline BNP concentration was 114 pg/ml (range 5.3 to 1550 pg/ml). During a mean follow-up of 6.2 ± 3.4 years, 42 patients (38%) had a MACE. In a multivariable Cox model including clinical and echocardiographic predictors, logBNP (HR 4.30; 95% confidence interval 1.97 to 9.37, p <0.001) and left ventricualr ejection fraction (LVEF) (HR 0.96; 95% confidence interval 0.94 to 0.99, p = 0.011) remained significant predictors of MACE. Nested models demonstrated incremental prognostic value of logBNP for MACE (chi-square increased from 4.3 to 22.8, p <0.01) over clinical and echocardiographic factors. Patients with persistently elevated BNP (>100 pg/ml) at baseline and at the second visit were at a higher risk of developing MACE during follow-up (5-year MACE-free survival of 0.91 (SE 0.06) vs 0.45 (SE 0.09), p <0.001). In conclusion, POC BNP levels in patients with HC were predictive of long-term MACE and had independent and incremental value. Patients with persistently elevated BNP levels were at a higher risk of MACE.