Exercise Testing to Unmask Latent LVOT Obstruction in a Highly Symptomatic Patient With Hypertrophic Cardiomyopathy.

Rest imaging in hypertrophic cardiomyopathy may underestimate or miss left ventricular outflow tract obstruction, leading to suboptimal management decisions that negatively affect symptomatic patients. The 2024 hypertrophic cardiomyopathy guidelines describe exercise stress testing as an important tool to determine overall exercise tolerance and latent, exercise-provoked left ventricular outflow tract obstruction.

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, ß-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.

In ischemic LV dysfunction, adding PCI to medical therapy did not reduce a composite of death or aborted sudden death.

SOURCE CITATION: Perera D, Morgan HP, Ryan M, et al; REVIVED-BCIS2 Investigators. Arrhythmia and death following percutaneous revascularization in ischemic left ventricular dysfunction: prespecified analyses from the REVIVED-BCIS2 trial. Circulation. 2023;148:862-871. 37555345.

Cardiac Remodeling in Subclinical Hypertrophic Cardiomyopathy: The VANISH Randomized Clinical Trial.

Importance: Valsartan has shown promise in attenuating cardiac remodeling in patients with early-stage sarcomeric hypertrophic cardiomyopathy (HCM). Genetic testing can identify individuals at risk of HCM in a subclinical stage who could benefit from therapies that prevent disease progression. Objective: To explore the potential for valsartan to modify disease development, and to characterize short-term phenotypic progression in subclinical HCM. Design, Setting, and Participants: The multicenter, double-blind, placebo-controlled Valsartan for Attenuating Disease Evolution in Early Sarcomeric Hypertrophic Cardiomyopathy (VANISH) randomized clinical trial was conducted from April 2014 to July 2019 at 17 sites in 4 countries (Brazil, Canada, Denmark, and the US), with 2 years of follow-up. The prespecified exploratory VANISH cohort studied here included sarcomere variant carriers with subclinical HCM and early phenotypic manifestations (reduced E' velocity, electrocardiographic abnormalities, or an increased left ventricular [LV] wall thickness [LVWT] to cavity diameter ratio) but no LV hypertrophy (LVH). Data were analyzed between March and December 2022. Interventions: Treatment with placebo or valsartan (80 mg/d for children weighing <35 kg, 160 mg/d for children weighing ≥35 kg, or 320 mg/d for adults aged ≥18 years). Main Outcomes and Measures: The primary outcome was a composite z score incorporating changes in 9 parameters of cardiac remodeling (LV cavity volume, LVWT, and LV mass; left atrial [LA] volume; E' velocity and S' velocity; and serum troponin and N-terminal prohormone of brain natriuretic peptide levels). Results: This study included 34 participants, with a mean (SD) age of 16 (5) years (all were White). A total of 18 participants (8 female [44%] and 10 male [56%]) were randomized to valsartan and 16 (9 female [56%] and 7 male [44%]) were randomized to placebo. No statistically significant effects of valsartan on cardiac remodeling were detected (mean change in composite z score compared with placebo: -0.01 [95% CI, -0.29 to 0.26]; P = .92). Overall, 2-year phenotypic progression was modest, with only a mild increase in LA volume detected (increased by 3.5 mL/m2 [95% CI, 1.4-6.0 mL/m2]; P = .002). Nine participants (26%) had increased LVWT, including 6 (18%) who developed clinically overt HCM. Baseline LA volume index (LAVI; 35 vs 28 mL/m2; P = .01) and average interventricular septum thickness (8.5 vs 7.0 mm; P = .009) were higher in participants who developed HCM. Conclusions and Relevance: In this exploratory cohort, valsartan was not proven to slow progression of subclinical HCM. Minimal changes in markers of cardiac remodeling were observed, although nearly one-fifth of patients developed clinically overt HCM. Transition to disease was associated with greater baseline interventricular septum thickness and LAVI. These findings highlight the importance of following sarcomere variant carriers longitudinally and the critical need to improve understanding of factors that drive disease penetrance and progression. Trial Registration: ClinicalTrials.gov Identifier: NCT01912534.

In severe tricuspid regurgitation, tricuspid TEER improved QoL more than medical therapy at 1 y.

SOURCE CITATION: Sorajja P, Whisenant B, Hamid N, et al; TRILUMINATE Pivotal Investigators. Transcatheter repair for patients with tricuspid regurgitation. N Engl J Med. 4 Mar 2023. [Epub ahead of print]. 36876753.

DAPT de-escalation from ticagrelor to clopidogrel 1 mo after PCI for acute MI reduced net clinical events at 1 y.

SOURCE CITATION: Kim CJ, Park MW, Kim MC, et al. Unguided de-escalation from ticagrelor to clopidogrel in stabilised patients with acute myocardial infarction undergoing percutaneous coronary intervention (TALOS-AMI): an investigator-initiated, open-label, multicentre, non-inferiority, randomised trial. Lancet. 2021;398:1305-16. 34627490.

Syndrome of Reversible Cardiogenic Shock and Left Ventricular Ballooning in Obstructive Hypertrophic Cardiomyopathy.

Background Cardiogenic shock from most causes has unfavorable prognosis. Hypertrophic cardiomyopathy (HCM) can uncommonly present with apical ballooning and shock in association with sudden development of severe and unrelenting left ventricular (LV) outflow obstruction. Typical HCM phenotypic features of mild septal thickening, outflow gradients, and distinctive mitral abnormalities differentiate these patients from others with Takotsubo syndrome, who have normal mitral valves and no outflow obstruction. Methods and Results We analyzed 8 patients from our 4 HCM centers with obstructive HCM and abrupt presentation of cardiogenic shock with LV ballooning, and 6 cases reported in literature. Of 14 patients, 10 (71%) were women, aged 66±9 years, presenting with acute symptoms: LV ballooning; depressed ejection fraction (25±5%); refractory systemic hypotension; marked LV outflow tract obstruction (peak gradient, 94±28 mm Hg); and elevated troponin, but absence of atherosclerotic coronary disease. Shock was managed with intravenous administration of phenylephrine (n=6), norepinephrine (n=6), ß-blocker (n=7), and vasopressin (n=1). Mechanical circulatory support was required in 8, including intra-aortic balloon pump (n=4), venoarterial extracorporeal membrane oxygenation (n=3), and Impella and Tandem Heart in 1 each. In refractory shock, urgent relief of obstruction by myectomy was performed in 5, and alcohol ablation in 1. All patients survived their critical illness, with full recovery of systolic function. Conclusions When cardiogenic shock and LV ballooning occur in obstructive HCM, they are marked by distinctive anatomic and physiologic features. Relief of obstruction with targeted pharmacotherapy, mechanical circulatory support, and myectomy, when necessary for refractory shock, may lead to survival and normalization of systolic function.

Valsartan in early-stage hypertrophic cardiomyopathy: a randomized phase 2 trial.

Hypertrophic cardiomyopathy (HCM) is often caused by pathogenic variants in sarcomeric genes and characterized by left ventricular (LV) hypertrophy, myocardial fibrosis and increased risk of heart failure and arrhythmias. There are no existing therapies to modify disease progression. In this study, we conducted a multi-center, double-blind, placebo-controlled phase 2 clinical trial to assess the safety and efficacy of the angiotensin II receptor blocker valsartan in attenuating disease evolution in early HCM. In total, 178 participants with early-stage sarcomeric HCM were randomized (1:1) to receive valsartan (320 mg daily in adults; 80-160 mg daily in children) or placebo for 2 years ( NCT01912534 ). Standardized changes from baseline to year 2 in LV wall thickness, mass and volumes; left atrial volume; tissue Doppler diastolic and systolic velocities; and serum levels of high-sensitivity troponin T and N-terminal pro-B-type natriuretic protein were integrated into a single composite z-score as the primary outcome. Valsartan (n = 88) improved cardiac structure and function compared to placebo (n = 90), as reflected by an increase in the composite z-score (between-group difference +0.231, 95% confidence interval (+0.098, +0.364); P = 0.001), which met the primary endpoint of the study. Treatment was well-tolerated. These results indicate a key opportunity to attenuate disease progression in early-stage sarcomeric HCM with an accessible and safe medication.

Transradial Access for High-Risk Percutaneous Coronary Intervention: Implications of the Risk-Treatment Paradox.

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Evaluation of Mavacamten in Symptomatic Patients With Nonobstructive Hypertrophic Cardiomyopathy.

BACKGROUND: Patients with nonobstructive hypertrophic cardiomyopathy (nHCM) often experience a high burden of symptoms; however, there are no proven pharmacological therapies. By altering the contractile mechanics of the cardiomyocyte, myosin inhibitors have the potential to modify pathophysiology and improve symptoms associated with HCM. OBJECTIVES: MAVERICK-HCM (Mavacamten in Adults With Symptomatic Non-Obstructive Hypertrophic Cardiomyopathy) explored the safety and efficacy of mavacamten, a first-in-class reversible inhibitor of cardiac-specific myosin, in nHCM. METHODS: The MAVERICK-HCM trial was a multicenter, double-blind, placebo-controlled, dose-ranging phase II study in adults with symptomatic nHCM (New York Heart Association functional class II/III), left ventricular ejection fraction (LVEF) ≥55%, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥300 pg/ml. Participants were randomized 1:1:1 to mavacamten at a pharmacokinetic-adjusted dose (targeting plasma levels of 200 or 500 ng/ml), or placebo for 16 weeks, followed by an 8-week washout. Initial dose was 5 mg daily with 1 dose titration at week 6. RESULTS: Fifty-nine participants were randomized (19, 21, 19 patients to 200 ng/ml, 500 ng/ml, placebo, respectively). Their mean age was 54 years, and 58% were women. Serious adverse events occurred in 10% of participants on mavacamten and in 21% participants on placebo. Five participants on mavacamten had reversible reduction in LVEF ≤45%. NT-proBNP geometric mean decreased by 53% in the pooled mavacamten group versus 1% in the placebo group, with geometric mean differences of -435 and -6 pg/ml, respectively (p = 0.0005). Cardiac troponin I (cTnI) geometric mean decreased by 34% in the pooled mavacamten group versus a 4% increase in the placebo group, with geometric mean differences of -0.008 and 0.001 ng/ml, respectively (p = 0.009). CONCLUSIONS: Mavacamten, a novel myosin inhibitor, was well tolerated in most subjects with symptomatic nHCM. Furthermore, treatment was associated with a significant reduction in NT-proBNP and cTnI, suggesting improvement in myocardial wall stress. These results set the stage for future studies of mavacamten in this patient population using clinical parameters, including LVEF, to guide dosing. (A Phase 2 Study of Mavacamten in Adults With Symptomatic Non-Obstructive Hypertrophic Cardiomyopathy [MAVERICK-HCM]; NCT03442764).

Improving Care Pathways for Acute Coronary Syndrome: Patients Undergoing Percutaneous Coronary Intervention.

Acute coronary syndrome (ACS) admissions are common and costly. The association between comprehensive ACS care pathways, outcomes, and costs are lacking. From 434,172 low-risk, uncomplicated ACS patients eligible for early discharge (STEMI 35%, UA/NSTEMI 65%) from the Premier database, we identified ACS care pathways, by stratifying low-risk, uncomplicated STEMI and UA/NSTEMI patients by access site for PCI (trans-radial intervention [TRI] vs transfemoral intervention [TFI]) and by length of stay (LOS). Associations with costs and outcomes (death, bleeding, acute kidney injury, and myocardial infarction at 1-year) were tested using hierarchical, mixed-effects regression, and projections of cost savings with change in care pathways were obtained using modeling. In low-risk uncomplicated STEMI patients, compared with TFI and LOS ≥3 days, a strategy of TRI with LOS <3 days and TFI with LOS <3 days were associated with cost savings of $6,206 and $4,802, respectively. Corresponding cost savings for UA/NSTEMI patients were $7,475 and $6,169, respectively. These care-pathways did not show an excess risk of adverse outcomes. We estimated that >$300 million could be saved if prevalence of the TRI with LOS <3 days and TFI with LOS <3 days strategies are modestly increased to 20% and 70%, respectively. In conclusion, we demonstrate the potential opportunity of cost savings by repositioning ACS care pathways in low-risk and uncomplicated ACS patients, toward transradial access and a shorter LOS without an increased risk of adverse outcomes.

The Evolving Landscape of Impella Use in the United States Among Patients Undergoing Percutaneous Coronary Intervention With Mechanical Circulatory Support.

BACKGROUND: Impella was approved for mechanical circulatory support (MCS) in 2008, but large-scale, real-world data on its use are lacking. Our objective was to describe trends and variations in Impella use, clinical outcomes, and costs across US hospitals in patients undergoing percutaneous coronary intervention (PCI) treated with MCS (Impella or intra-aortic balloon pump). METHODS: From the Premier Healthcare Database, we analyzed 48 306 patients undergoing PCI with MCS at 432 hospitals between January 2004 and December 2016. Association analyses were performed at 3 levels: time period, hospital, and patient. Hierarchical models with propensity adjustment were used for association analyses. We examined trends and variations in the proportion of Impella use, and associated clinical outcomes (in-hospital mortality, bleeding requiring transfusion, acute kidney injury, stroke, length of stay, and hospital costs). RESULTS: Among patients undergoing PCI treated with MCS, 4782 (9.9%) received Impella; its use increased over time, reaching 31.9% of MCS in 2016. There was wide variation in Impella use across hospitals (>5-fold variation). Specifically, among patients receiving Impella, there was a wide variation in outcomes of bleeding (>2.5-fold variation), and death, acute kidney injury, and stroke (all ≈1.5-fold variation). Adverse outcomes and costs were higher in the Impella era (years 2008-2016) versus the pre-Impella era (years 2004-2007). Hospitals with higher Impella use had higher rates of adverse outcomes and costs. After adjustment for the propensity score, and accounting for clustering of patients by hospitals, Impella use was associated with death: odds ratio, 1.24 (95% CI, 1.13-1.36); bleeding: odds ratio, 1.10 (95% CI, 1.00-1.21); and stroke: odds ratio, 1.34 (95% CI, 1.18-1.53), although a similar, nonsignificant result was observed for acute kidney injury: odds ratio, 1.08 (95% CI, 1.00-1.17). CONCLUSIONS: Impella use is rapidly increasing among patients undergoing PCI treated with MCS, with marked variability in its use and associated outcomes. Although unmeasured confounding cannot be ruled out, when analyzed by time periods, or at the hospital level or the patient level, Impella use was associated with higher rates of adverse events and costs. More data are needed to define the appropriate role of MCS in patients undergoing PCI.