A Phase 1 Dose-Escalation Study of the Cardiac Myosin Inhibitor Aficamten in Healthy Participants

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Certain genetic hypertrophic cardiomyopathies may result from hypercontractility of cardiac muscle, caused by pathogenic variants in genes encoding proteins of the cardiac sarcomere.

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Aficamten (formerly CK-3773274) is a small-molecule selective inhibitor of the cardiac myosin ATPase, which reduces the contractility of cardiomyocytes in vitro and decreases measures of ventricular contractility in animal studies.

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In this first-in-human, phase 1 study in healthy adults, aficamten was well tolerated; adverse events were generally mild and comparable in frequency to those seen with placebo.

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Aficamten demonstrated dose-proportional pharmacokinetics with a half-life of 75 to 85 hours.

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Pharmacodynamically active doses of aficamten decreased left ventricular ejection fraction from baseline in a concentration-dependent manner, informing the design of a phase 2 trial in patients with hypertrophic cardiomyopathy.

This phase 1, randomized, double-blind, placebo-controlled study of aficamten (formerly CK-3773274) in healthy adults identified a pharmacologically active range of doses and exposures. At doses that were pharmacologically active (single doses of ≤50 mg or daily dosing of ≤10 mg for 14 or 17 days), aficamten appeared to be safe and well tolerated. Adverse events were generally mild and no more frequent than with placebo. Pharmacokinetic assessments showed dose proportionality over the range of single doses administered, and pharmacokinetics were not affected by administration with food or in otherwise healthy individuals with a cytochrome P450 2D6 poor metabolizer phenotype. (A Single and Multiple Ascending Dose Study of CK-3773274 in Health Adult Subjects; NCT03767855)

A Glimpse Into the Future of Transcatheter Interventional Heart Failure Therapies

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HF affects millions of patients every year, adding a significant financial burden to global health care systems.

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This review discusses the role of novel transcatheter-based therapies for the management of HF.

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Ongoing clinical trials will provide answers on the potential clinical benefits of these technologies in HF outcomes.

Chronic heart failure is one of the most debilitating chronic conditions affecting millions of people and adding a significant financial burden to health care systems worldwide. Despite the significant therapeutic advances achieved over the last decade, morbidity and mortality remain high. Multiple catheter-based interventional therapies targeting different physiological and anatomical targets are already under different stages of clinical investigation. The present paper provides a technical overview of the most relevant catheter-based interventional therapies under clinical investigation.

Left ventricular vortex analysis by high-frame rate blood speckle tracking echocardiography in healthy children and in congenital heart disease

Background

High-frame rate blood speckle tracking (BST) echocardiography is a new technique for the assessment of intracardiac flow. The purpose of this study was to evaluate the characteristics of left ventricular (LV) vortices in healthy children and in those with congenital heart disease (CHD).

Methods

Characteristics of LV vortices were analyses based on 4-chamber BST images from 118 healthy children (median age 6.84 years, range 0.01-17 years) and 43 children with CHD (median age 0.99 years, range 0.01-14 years). Both groups were compared after propensity matching. Multiple linear regression was used to identify factors that independently influence vortex characteristics.

Results

Feasibility of vortex imaging was 93.7% for healthy children and 95.6% for CHD. After propensity matching, there were no overall significant differences in vortex distance to apex, distance to interventricular septum (IVS), height, width, sphericity index, or area. However, multiple regression analysis revealed significant associations of LV morphology with vortex characteristics. Furthermore, CHD involving LV volume overload and CHD involving LV pressure overload were both associated with vortices localized closer to the IVS.

Conclusions

LV vortex analysis using high-frame rate BST echocardiography is feasible in healthy children and in those with CHD. As they are associated with LV morphology and are modified in some types of CHD, vortices might yield diagnostic and prognostic value. Future studies are warranted to establish applications of vortex imaging in the clinical setting.

Intramyocardial Transplantation of Human iPS Cell-Derived Cardiac Spheroids Improves Cardiac Function in Heart Failure Animals

The severe shortage of donor hearts hampered the cardiac transplantation to patients with advanced heart failure. Therefore, cardiac regenerative therapies are eagerly awaited as a substitution. Human induced pluripotent stem cells (hiPSCs) are realistic cell source for regenerative cardiomyocytes. The hiPSC-derived cardiomyocytes are highly expected to help the recovery of heart. Avoidance of teratoma formation and large-scale culture of cardiomyocytes are definitely necessary for clinical setting. The combination of pure cardiac spheroids and gelatin hydrogel succeeded to recover reduced ejection fraction. The feasible transplantation strategy including transplantation device for regenerative cardiomyocytes are established in this study.

Cardiac Versus Renal Response to Volume Expansion in Preclinical Systolic Dysfunction With PDEV Inhibition and BNP

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In preclinical systolic dysfunction, defined as left ventricular systolic dysfunction with no heart failure signs or symptoms, impairment in cardiorenal response to volume expansion may lead to symptomatic heart failure. Rescue of this impaired process in preclinical disease may prevent development of symptomatic heart failure.

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In preclinical systolic dysfunction, inhibition of phosphodiesterase-V in combination with exogenous B-type natriuretic peptide administration results in improved cardiac function but worsened renal function in response to acute volume expansion.

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Future studies are needed to further define the physiological effects and long-term outcomes of phosphodiesterase-V inhibition and exogenous BNP administration. Understanding the cardiorenal effects and outcomes of combination phosphodiesterase-V with exogenous B-type natriuretic peptide may affect the clinical management of patients with preclinical systolic dysfunction and renal dysfunction.

Impaired cardiorenal response to acute saline volume expansion in preclinical systolic dysfunction (PSD) may lead to symptomatic heart failure. The objective was to determine if combination phosphodiesterase-V inhibition and exogenous B-type natriuretic peptide (BNP) administration may enhance cardiorenal response. A randomized double-blinded, placebo-controlled study was conducted in 21 subjects with PSD and renal dysfunction. Pre-treatment with tadalafil and subcutaneous BNP resulted in improved cardiac function, as evidenced by improvement in ejection fraction, left atrial volume index, and left ventricular end-diastolic volume. However, there was reduced renal response with reduction in renal plasma flow, glomerular filtration rate, and urine flow. (Tadalafil and Nesiritide as Therapy in Pre-clinical Heart Failure; NCT01544998)

First-in-Man Study of a Cardiac Extracellular Matrix Hydrogel in Early and Late Myocardial Infarction Patients

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A first-in-man clinical trial was completed with VentriGel, an extracellular matrix hydrogel derived from decellularized porcine myocardium, in post–MI patients.

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Results from the trial support the safety and feasibility of transendocardial injection of VentriGel in post–MI patients with left ventricular dysfunction.

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Although the study was not designed to evaluate efficacy, there were suggestions of improvements including increases in 6-min walk test distance and decreases in New York Heart Association functional class across the entire cohort of patients.

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Improvements in left ventricular remodeling were mainly observed in patients who were treated >1-year post–MI as opposed to <1 year.

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Results from the trial warrant further evaluation in larger randomized, controlled clinical trials.

This study evaluated the safety and feasibility of transendocardial injections of VentriGel, a cardiac extracellular matrix hydrogel, in early and late post–myocardial infarction (MI) patients with left ventricular (LV) dysfunction. VentriGel was delivered in 15 patients with moderate LV dysfunction (25% ≤ LV ejection fraction ≤ 45%) who were between 60 days to 3 years post-MI and were revascularized by percutaneous coronary intervention. The primary endpoints were incidence of adverse events and abnormal clinical laboratory results. This first-in-man study established the safety and feasibility of delivering VentriGel in post-MI patients, thus warranting further evaluation in larger, randomized clinical trials.

Association of Cardiac Structure and Function With Neurocognition in Hispanics/Latinos: The Echocardiographic Study of Latinos

Objective

To study the associations of comprehensive measures of cardiac structure and function with multidimensional neurocognitive measures.

Patients and Methods

The Echocardiographic Study of Latinos is a population-based cohort of Hispanic/Latino adults older than 45 years enrolled from October 1, 2011, through June 30, 2014. Neurocognitive measures included Word Fluency (WF), Brief-Spanish English Verbal Learning Test (B-SEVLT), and Digit Symbol Substitution Test. The B-SEVLT included B-SEVLT-recall and B-SEVLT-sum. Echocardiographic measures included cardiac structure, systolic and diastolic function, and myocardial strain. Multivariable regression models were fit using survey statistics and sampling probabilities.

Results

A total of 1794 participants (mean age, 56±0.5 years; 56% women) were included in the analysis. In the adjusted model, higher left ventricular mass index was associated with lower B-SEVLT-sum and Digit Symbol Substitution Test scores. Left ventricular systolic dysfunction was associated with lower WF scores. Abnormal left ventricular geometry was associated with lower B-SEVLT-sum scores. Higher relative wall thickness was associated with B-SEVLT-recall and B-SEVLT-sum scores. Mitral annular relaxation velocities were associated with lower B-SEVLT-recall, B-SEVLT-sum, and WF scores. Higher mitral inflow to annular early diastolic velocity ratio was associated with lower B-SEVLT-recall and B-SEVLT-sum scores. Diastolic dysfunction was associated with lower B-SEVLT-sum scores. Finally, lower global longitudinal strain was associated with lower WF scores.

Conclusion

Alterations in cardiac structure, systolic and diastolic function, and myocardial strain were associated with worse neurocognitive function. Further study is needed to determine the mechanisms (ie, impairment of cerebral flow and silent brain infarctions) mediating these heart-brain associations.

Septal rebound stretch as predictor of echocardiographic response to cardiac resynchronization therapy

Aim

Septal rebound stretch (SRSsept) reflects an inefficient deformation of the septum during systole and is a potential new echocardiographic tool to predict response to Cardiac Resynchronization Therapy (CRT). However, there are only limited data on the potential predictive value of SRSsept on echocardiographic response. We evaluated the predictive value of SRSsept on echocardiographic response to CRT in a large population.

Methods and results

A total of 138 consecutive patients with functional class II–IV heart failure who underwent CRT were studied. Echocardiography was performed at baseline and after a mean follow-up period of 22 ± 8 months. Echocardiographic response to CRT was defined as a reduction in LV end-systolic volume ≥ 15%. Receiver operating characteristic curve analysis was performed to define the optimal cut-off value for SRSsept. Multivariable analyses were performed to adjust for potential confounders.

Mean age was 68 ± 8 years (30% female). Mean baseline LV ejection fraction was 26 ± 7%, 51% had ischemic etiology. LBBB or LBBB like morphology was present in 95% of patients. Mean SRSsept was 4.4 ± 3.2%, 56% of patients had SRSsept ≥ 4%. Ninety six patients (70%) were echocardiographic responders. Baseline SRSsept was significantly higher in responders compared to non-responders (5.1 ± 3.2 vs 3.0 ± 2.7, P < 0.001). The optimal cut-off value for SRSsept to predict response to CRT was 4.0%. After both univariate (OR 3.74, 95% CI 1.72–8.10) and multivariate analyses (OR 3.71, 95% CI 1.49–9.2), baseline SRSsept > 4% independently predicted the response to CRT.

Conclusions

Baseline septal rebound stretch is independently associated with echocardiographic response to CRT.

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Septal rebound stretch was used to predict response to CRT in patient who underwent CRT-D implantation.

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Echocardiographic response to CRT was defined as a reduction in LV end-systolic volume ≥ 15%.

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Baseline SRSsept was significantly higher in echocardiographic responders compared to non-responders to CRT.

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The optimal cut-off value for SRSsept was 4%.

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Baseline septal rebound stretch was independently associated with echocardiographic response to CRT.