Importance Current risk prediction guidelines for hypertrophic cardiomyopathy predict only sudden cardiac death and are imperfect, leading to avoidable deaths and unnecessary implantable cardioverter defibrillators. Objective To combine prospectively collected clinical history, imaging, genetic, and biomarker data to improve risk prediction of adverse events in hypertrophic cardiomyopathy. Design, Setting, and Participants A total of 2750 patients with hypertrophic cardiomyopathy were prospectively enrolled in the registry-based study from 44 sites in North America and Europe with expertise in hypertrophic cardiomyopathy and cardiac magnetic resonance (CMR) imaging. Participants were enrolled from April 1, 2014, to April 7, 2017. Exposures Patients underwent a health history questionnaire, blood sampling for biomarkers and genotyping, and contrast-enhanced CMR. Patients were followed up yearly by telephone and through records review regarding event documentation. Main Outcomes and Measures The predefined composite adjudicated primary end point was time to first event for hypertrophic cardiomyopathy–related deaths; nonfatal sustained ventricular arrhythmias (VAs) requiring cardioversion or defibrillation; and left ventricular (LV) assist device implant or heart transplant. A secondary end point was a composite of sudden cardiac death and nonfatal VA events. The elastic-net method identified the most important predictors. Cox proportional hazards regression assessed associations with time to the first end point. Results Of the 2750 prospectively enrolled patients, 2698 (98%) had analyzable data after 9 were excluded because they had hypertrophic cardiomyopathy phenocopies and 43 withdrew. Of these remaining patients, 1919 (71%) were male, mean age was 50 years (SD, 11 years), and 423 (16%) were from underrepresented racial and minority groups. The mean follow-up was 6.9 years (SD, 2.1 years). The primary event model in 104 patients included LV scar as a percentage of LV mass by late gadolinium enhancement (LGE%; hazard ratio [HR], 1.86; 95% CI, 1.58-2.20; P < .001), LV mass index (HR, 1.09; 95% CI, 1.01-1.17; P = .03), LV end-systolic volume index (HR, 1.28; 95% CI, 1.12-1.46; P < .001 ), all per 10-unit increase, history of heart failure at study entry (HR, 2.89; 95% CI, 1.75-4.77; P < .001), and log N-terminal pro–B-type natriuretic peptide (NT-proBNP; HR, 1.41; 95% CI, 1.17-1.70; P < .001) level per log unit, (C index for all, 0.77). An LGE percentage of the LV mass of 9% or higher substantially increased the primary composite event rate ( P = .001). The secondary sudden cardiac death and VA risk factor model (in 69 patients) included LGE%, LV mass index, LV ejection fraction, and log(NT-proBNP) (C index, 0.76). Conclusions and Relevance These results provide prospective evidence for incorporating cardiac magnetic resonance and NT-proBNP in the evaluation of patients with hypertrophic cardiomyopathy. Trial Registration ClinicalTrials.gov Identifier: NCT01915615
0395 Effects of Insomnia and Rest-Activity on Hospitalizations and Emergency Department Visits in People with Stable Heart Failure
Abstract Introduction People with heart failure (HF) have frequent hospitalizations, and emergency department (ED) visits. We examined the effects of insomnia and rest-activity rhythms (RARs) on time to hospitalizations and ED visits after controlling for other known risk factors among participants in a randomized controlled trial of cognitive behavioral therapy for insomnia compared to heart failure self-management education (attention control). Methods The analysis included 168 HF patients who had available medical records for dates of hospitalization, ED visit, transplant, and death from a randomized clinical trial for insomnia of people with HF and insomnia. The known risk factors included age, sex, New York Heart Association (NYHA) Class, ejection fraction, and comorbid conditions. We used the insomnia severity index (ISI) and evaluated the strength of RAR using the ratio of the amplitude to the MESOR estimated with cosinor analysis with activity counts from a wrist-actigraph worn for at least five consecutive days. Cox proportional hazard models were used to examine insomnia and the RAR metrics with the known risk factors on time to first hospitalization, ED visit, transplant, and death. Results Eighty-five (50.1%) had at least one hospitalization, and ninety-one (54.2%) participants had an ED visit. Approximately 42% of the participants were admitted to the hospital due to cardiac events. Older age, male sex, higher NYHA, and greater comorbidity were associated with earlier hospitalization or ED visits. After controlling for those risk factors, stronger RAR was associated with later time to hospitalization, and ED visit with hazard ratios (HRs) of 0.26 (95% CI=[0.07, 0.91]) and 0.25 (95% CI=[0.07, 0.89]); higher insomnia severity (ISI ≥22) was associated with shorter time to ED visits, with an HR of 2.28 (95% CI=[1.19, 4.38]). Conclusion In addition to known demographic and clinical risk factors, insomnia severity and RAR predict hospitalizations and ED visits in people with HF. Further research is necessary to assess the biological mechanism of the associations and examine whether the effects of the risk factors could be modified by improving insomnia severity and RAR in people with HF. Support (if any) This study was financially supported by grants R01NR016191 and P20NR014126 from NIH/NINR.
Abstract 9544: Physical Activity in Individuals With Hypertrophic Cardiomyopathy: Baseline Data From the Prospective "Lifestyle and Exercise in Hcm" (live-hcm) Study
Introduction: Safety of vigorous exercise for individuals with appropriately-treated HCM remains debated. Physical activity practices in this population have not been described. The objective of this report is to describe physical activity pattern in HCM patients. Long term follow up which is ongoing will determine safety of vigorous exercise. Methods: The NIH-funded LIVE-HCM study prospectively enrolled individuals age 8-60 years with clinically overt HCM or patients with a positive genetic test for sarcomeric HCM. Participants (or parents, for children) answered surveys describing activity patterns. Vigorous exercise was defined as > 6 METS for > 60 hours per year. Clinical and demographic data were derived from medical record review. Results: Among 1798 participants, 745 (41%) reported exercising vigorously, including 296 competitive athletes, with 59 at high-school or college varsity level, 770 (43%) were exercising at moderate, and 283 (16%) at low levels. Of those working, 6% described jobs more active than walking, including 16 in protective services, and 11 in sports/coaching. Clinical/demographic data including imaging characteristics and treatments, are shown in Table, and were mostly similar amongst the exercise-groups. Conclusions: Many patients with HCM are engaged in vigorous exercise including competitive athletics. Prospective follow-up of this cohort is ongoing. Comparison of arrhythmic outcomes outcomes in vigorous exercisers vs moderate/low level exercisers will help determine the safety of exercise in HCM patients.
Abstract 17141: Mavacamten Improves Left Ventricular Relaxation and Compliance in Obstructive Hypertrophic Cardiomyopathy Through Direct Myosin Modulation
Introduction: Obstructive hypertrophic cardiomyopathy (oHCM) consists of a constellation of LV hypercontractility, LV outflow tract obstruction (LVOTO), and impaired relaxation, often resulting in dyspnea and reduced exercise capacity. In healthy dogs, the novel myosin modulator mavacamten (MAVA), decreased LV hypercontractility and improved compliance. In the PIONEER-HCM clinical study, improvements in post-exercise LVOT gradient, exercise capacity, and symptoms were reported. To examine whether MAVA could also limit residual myosin-actin cross-bridges during diastole, and improve LV compliance, its effects on diastolic indices were evaluated. Methods: In PIONEER-HCM, an open-label, multi-site, prospective study, oHCM subjects received MAVA for 12 weeks at either 10-20 mg/d (n = 11, Cohort A; 10 completed) or at 2-5 mg/d (n = 10, Cohort B). Echo-Doppler indices of LV filling and relaxation were compared at baseline to week 12. The p-values are from Wilcoxon signed rank tests, evaluating the distribution of within-subject 12-wk changes from baseline around a null of zero. Results: MAVA reduced hypercontractility in a dose-dependent fashion, with relief of LVOTO in all subjects achieving plasma MAVA concentration >350 ng/ml (data previously reported). There was also an increase in mitral annular velocity during early diastole (e’ lat ). There was a concomitant reduction in E/e’ lat and increase in LV end-diastolic volume (LVEDV) consistent with improved LV compliance (Table). MAVA improved dyspnea score with a trend towards reduction in NT-proBNP. Conclusions: Administration of MAVA is associated with improvement in measures of myocardial relaxation (e’ lat ) and compliance in parallel with reduction in LVOT gradient. These findings are consistent with preclinical findings reported in healthy dogs and support additional evaluation of MAVA in patients with obstructive or non-obstructive HCM.
Abstract 17067: MAVERICK-HCM: Phase 2 Randomized, Multi-Center, Double-Blind, Placebo-Controlled Concentration-Guided Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Non-Obstructive Hypertrophic Cardiomyopathy
Introduction: Hypertrophic cardiomyopathy (HCM) carries substantial lifelong morbidity. Mutations in sarcomeric proteins that lead to HCM cause excess contractility, poor relaxation, and inefficient energy utilization. Although obstructive physiology is a prominent feature of disease, approximately 30% of HCM patients experience symptoms in the context of non-obstructive HCM (nHCM). Management options are extremely limited with little other than cardiac transplantation to offer severely affected patients. Mavacamten (MAVA), a first-in-class small molecule, is a selective modulator of cardiac myosin that inhibits the cardiac myosin ATPase to reversibly attenuate cardiac contractility. In addition to its effects on contractility, MAVA has been shown to improve LV compliance in preclinical and clinical studies. The Phase 2 MAVERICK-HCM study is designed to evaluate safety and tolerability, and to provide pilot data on the effects of MAVA on biomarkers, cardiac function, and exercise capacity in nHCM. Methods: This double-blind study will enroll 60 individuals with nHCM (Left ventricular outflow tract gradient <30 mmHg; resting or provoked), NYHA Class II or III, and LVEF ≥55%. Subjects will be randomized 1:1:1 to one of two target plasma drug concentrations (Group 1: ~200 ng/mL and Group 2: ~500 ng/mL) or placebo for 16 weeks. The starting dose of MAVA is 5 mg, with one-step dose titration at Week 6 based on plasma drug concentration. Predefined criteria, including LVEF, will guide study drug discontinuation if indicated. Cardiopulmonary exercise testing will be performed at baseline and Week 16 to assess the impact on exercise capacity. The primary endpoint is the frequency and severity of treatment-emergent adverse events. The study design also includes multiple secondary endpoints including echocardiographic measures of diastolic function, NT-proBNP levels, patient reported outcomes, and physical activity by wearable accelerometer. An independent data monitoring committee will oversee safety. Conclusions: MAVERICK-HCM is testing a novel therapy to improve symptom burden in nHCM; a patient cohort currently lacking effective treatment. By targeting a core molecular mechanism of disease, MAVA has the potential to alter natural history.
Abstract 15324: Mavacamten Favorably Impacts Key Pathophysiologic Processes in Obstructive Hypertrophic Cardiomyopathy: Results From the EXPLORER-HCM Study
Introduction: Obstructive hypertrophic cardiomyopathy (oHCM) is characterized by dynamic LV outflow tract (LVOT) obstruction resulting from ventricular hypertrophy and mitral valve systolic anterior motion (SAM), and by elevated left ventricular (LV) filling pressures, all of which result in a significant morbidity despite medical therapy. Mavacamten (Mava) is a novel inhibitor of cardiac myosin that significantly reduces LVOT gradients in oHCM, noted initially in the phase 2 PIONEER and more recently in the phase 3 EXPLORER-HCM studies. Additional echocardiographic analyses were performed to investigate the effect of Mava on focused measures of cardiac structure and function in oHCM. Methods: EXPLORER-HCM (NCT03470545) was a multicenter, double-blind, placebo-controlled, phase 3 study that randomized symptomatic oHCM patients (LV ejection fraction ≥55% and resting and/or provoked LVOT gradient ≥50 mmHg) 1:1 to Mava vs placebo for 30 weeks. Echocardiograms were performed serially every 2-4 weeks over 30 weeks. Results: In total, 251 patients with oHCM were enrolled and 244 patients completed the study (mean age 58.5; 40.6% female). Compared to placebo, 30-week treatment with Mava led to significant reductions in LA volume index (-7.5 ml/m 2 , p<0.0001), lateral E/e’ (-3.8, p<0.0001), septal E/e’ (-3.4, p<0.0001), and LV mass index (-15.5 g/m 2 , p<0.0001) ( Table ). Significantly more Mava-treated patients achieved resolution of mitral valve SAM compared to placebo (80.9% vs 34.0% of patients; difference of 46.8%; p<0.0001) and mitral regurgitation (MR) (9.0% vs 0.0% of patients; difference of 9.0%; p=0.0006). Conclusions: Treatment with Mava for 30 weeks led to improvement in LV hypertrophy and markers of left-sided filling pressures (LA volume and E/e’). Furthermore, Mava treatment was associated with reduction of SAM and MR. These findings suggest that Mava has beneficial effects on several adverse pathophysiologic processes that are hallmarks of oHCM.
Mavacamten Favorably Impacts Cardiac Structure in Obstructive Hypertrophic Cardiomyopathy
Background: Obstructive hypertrophic cardiomyopathy (oHCM) is characterized by unexplained left ventricular (LV) hypertrophy associated with dynamic LV outflow tract obstruction. Current medical therapies are nonspecific and have limited efficacy in relieving symptoms. Mavacamten is a first-in-class targeted inhibitor of cardiac myosin, which has been shown to reduce LV outflow tract obstruction, improve exercise capacity, and relieve symptoms of oHCM in the PIONEER-HCM phase 2 study. Methods: EXPLORER-HCM is a multicenter, phase 3, randomized, double-blind, placebo-controlled trial to investigate the efficacy and safety of mavacamten in treating symptomatic oHCM. Eligible adults with oHCM and New York Heart Association Functional Class II or III are randomized 1:1 to receive once-daily, oral mavacamten, or matching placebo for 30 weeks. The primary composite functional end point is clinical response at week 30 compared to baseline defined as either (1) an increase in peak oxygen consumption ≥1.5 mL/kg/min and reduction of at least one New York Heart Association class; or (2) an improvement of ≥3.0 mL/kg/min in peak oxygen consumption with no worsening of New York Heart Association class. Secondary end points include change in postexercise LV outflow tract gradient, New York Heart Association class, peak oxygen consumption, and patient-reported outcomes assessed by the Kansas City Cardiomyopathy Questionnaire and a novel HCM-specific instrument. Exploratory end points aim to characterize the effect of mavacamten on multiple aspects of oHCM pathophysiology. Conclusions: EXPLORER-HCM is a phase 3 trial in oHCM testing a first-in-class, targeted strategy of myosin inhibition to improve symptom burden and exercise capacity through reducing LV outflow tract obstruction. Results of this trial will provide evidence to support the first disease-specific treatment for HCM. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03470545.
228Long-term safety and effectiveness of mavacamten in symptomatic obstructive hypertrophic cardiomyopathy (oHCM) patients (pts): update from PIONEER open-label extension (PIONEER-OLE) study
Abstract Background In a phase 2 PIONEER-HCM study, pts with symptomatic, obstructive hypertrophic cardiomyopathy (oHCM) showed improvement in left ventricular outflow tract (LVOT) obstruction, exercise capacity, and symptoms after 12 wk of treatment with the novel myosin modulator, mavacamten (Mava). Purpose To examine the long-term safety and effectiveness of Mava in PIONEER-OLE study Methods PIONEER-OLE (NCT03496168) is an ongoing 2-y multicenter study for adults with symptomatic oHCM who completed PIONEER-HCM (NCT02842242). The starting dose of Mava is 5 mg/d with titration at wk 6 to an individualized therapeutic dose (5, 10, or 15 mg). Evaluations are at wk 4, 6, 8, 12 and every 12 wk thereafter to monitor LV ejection fraction (LVEF), LVOT gradient, New York Heart Association (NYHA) class, NT-proBNP, drug concentration, and safety. Results 13 pts (mean age, 57.8 y; 9 male; 12 on beta-blockers) were enrolled. Mean baseline LVOT obstruction and LVEF, and wk 12 changes from baseline, were similar to those in PIONEER-HCM (Table). Mava significantly reduced resting and provoked LVOT gradients and NT-proBNP at wk 12 and 24 compared with baseline (P<0.004). Of 10 pts who reached wk 24, 8 reported improvement in NYHA class (1 improved Class III to II; 7 improved Class II to I), and 2 pts remained Class II. Mava has been well tolerated up to 40 wk; 31 adverse events (AEs; 22 mild, 5 moderate) were reported in 8 pts; 1 pt had 3 severe and 1 serious AE (cholangiocarcinoma); all AEs were unrelated to study drug. Results from PIONEER-OLE Parameter PIONEER-HCMa PIONEER-OLE Baseline Wk 12 Baselineb Wk 12 Change at Wk 12 Wilcoxon Signed Wk 24 Change at Wk 24 Wilcoxon Signed Mean ± SD Mean ± SD Mean ± SD Mean ± SD Mean ± SD Rank Mean ± SD Mean ± SD Rank (n=13) (n=13) (n=13)c (n=12)c (n=12)c P value (n=10)c (n=10)c P value LVOT Rest gradient, mmHg 69.7±53.9 27.8±31.3 67.3±42.8 12.0±5.4 −57.9±43.2 0.0005 10.5±4.8 −66.6±42.4 0.0020 LVOT Valsalva gradient, mmHg 93.7±55.6 36.8±37.5 89.9±30.7 (n=12) 23.6±20.0 −66.4±35.3 (n=11) 0.0020 21.1±11.5 −67.3±33.5 (n=9) 0.0039 LVEF, % 73.0±5.6 64.6±10.5 72.0±4.9 67.6±7.2 −4.4±5.5 0.0269 68.2±6.5 −3.2±3.3 0.0195 NT-proBNP, pg/mL 1601.3±2782 (n=12) 684±980 1836±2886 181±211 −1759±2789 0.0005 170±225 −2128±3104 0.0039 Data extraction date January 24, 2019. aCombined results shown for pts from PIONEER-HCM originally in cohort A (n=5) and cohort B (n=8). bBaseline in PIONEER-OLE occurred 6–18 months after completion of PIONEER-HCM. cNumber of pts with data available for analysis, unless otherwise specified. Conclusion Despite management with current therapies, pts enrolled in PIONEER-OLE with similar levels of obstruction and hypercontractility as in PIONEER-HCM. In this longest observation period, Mava significantly reduced obstruction (LVOT gradient) in pts with oHCM beyond standard HCM therapy, while maintaining normal LVEF and improving symptoms. Acknowledgement/Funding MyoKardia
Mavacamten Treatment for Obstructive Hypertrophic Cardiomyopathy