Inotropic therapies in heart failure and cardiogenic shock: an educational review

Jean D, Malinowski J, DeBenedetto M, Moebius D, Payette J, Vargas R, Yeoman J, Motani A, Reagan J, Malik FI, Morgan BP. Discovery of Nelutroctiv (CK-136), a Selective Cardiac Troponin Activator for the Treatment of Cardiovascular Diseases Associated with Reduced Cardiac Contractility

Cardiac myosin activation has been shown to be a viable approach for the treatment of heart failure with reduced ejection fraction. Here, we report the discovery of nelutroctiv (CK-136), a selective cardiac troponin activator intended for patients with cardiovascular conditions where cardiac contractility is reduced. Discovery of nelutroctiv began with a high-throughput screen that identified compound 1R, a muscle selective cardiac sarcomere activator devoid of phosphodiesterase-3 activity. Optimization of druglike properties for 1R led to the replacement of the sulfonamide and aniline substituents which resulted in improved pharmacokinetic (PK) profiles and a reduced potential for human drug-drug interactions. In vivo echocardiography assessment of the optimized leads showed concentration dependent increases in fractional shortening and an improved pharmacodynamic window compared to myosin activator CK-138. Overall, nelutroctiv was found to possess the desired selectivity, a favorable pharmacodynamic window relative to myosin activators, and a preclinical PK profile to support clinical development.

Canadian Cardiovascular Society 2023 Guidelines on the Fitness to Drive

Cardiovascular conditions are among the most frequent causes of impairment to drive, because they might induce unpredictable mental state alterations via diverse mechanisms like myocardial ischemia, cardiac arrhythmias, and vascular dysfunction. Accordingly, health professionals are often asked to assess patients' fitness to drive (FTD). The Canadian Cardiovascular Society previously published FTD guidelines in 2003-2004; herein, we present updated FTD guidelines. Because there are no randomized trials on FTD, observational studies were used to estimate the risk of driving impairment in each situation, and recommendations made on the basis of Canadian Cardiovascular Society Risk of Harm formula. More restrictive recommendations were made for commercial drivers, who spend longer average times behind the wheel, use larger vehicles, and might transport a larger number of passengers. We provide guidance for individuals with: (1) active coronary artery disease; (2) various forms of valvular heart disease; (3) heart failure, heart transplant, and left ventricular assist device situations; (4) arrhythmia syndromes; (5) implantable devices; (6) syncope history; and (7) congenital heart disease. We suggest appropriate waiting times after cardiac interventions or acute illnesses before driving resumption. When short-term driving cessation is recommended, recommendations are on the basis of expert consensus rather than the Risk of Harm formula because risk elevation is expected to be transient. These recommendations, although not a substitute for clinical judgement or governmental regulations, provide specialists, primary care providers, and allied health professionals with a comprehensive list of a wide range of cardiac conditions, with guidance provided on the basis of the level of risk of impairment, along with recommendations about ability to drive and the suggested duration of restrictions.

The carbon monoxide prodrug oCOm-21 increases Ca2+ sensitivity of the cardiac myofilament

Patients undergoing cardiopulmonary bypass procedures require inotropic support to improve hemodynamic function and cardiac output. Current inotropes such as dobutamine, can promote arrhythmias, prompting a demand for improved inotropes with little effect on intracellular Ca2+ flux. Low-dose carbon monoxide (CO) induces inotropic effects in perfused hearts. Using the CO-releasing pro-drug, oCOm-21, we investigated if this inotropic effect results from an increase in myofilament Ca2+ sensitivity. Male Sprague Dawley rat left ventricular cardiomyocytes were permeabilized, and myofilament force was measured as a function of -log [Ca2+ ] (pCa) in the range of 9.0-4.5 under five conditions: vehicle, oCOm-21, the oCOm-21 control BP-21, and levosimendan, (9 cells/group). Ca2+ sensitivity was assessed by the Ca2+ concentration at which 50% of maximal force is produced (pCa50 ). oCOm-21, but not BP-21 significantly increased pCa50 compared to vehicle, respectively (pCa50 5.52 vs. 5.47 vs. 5.44; p < 0.05). No change in myofilament phosphorylation was seen after oCOm-21 treatment. Pretreatment of cardiomyocytes with the heme scavenger hemopexin, abolished the Ca2+ sensitizing effect of oCOm-21. These results support the hypothesis that oCOm-21-derived CO increases myofilament Ca2+ sensitivity through a heme-dependent mechanism but not by phosphorylation. Further analyses will confirm if this Ca2+ sensitizing effect occurs in an intact heart.

Current Approaches to Worsening Heart Failure: Pathophysiological and Molecular Insights

Worsening heart failure (WHF) is a severe and dynamic condition characterized by significant clinical and hemodynamic deterioration. It is characterized by worsening HF signs, symptoms and biomarkers, despite the achievement of an optimized medical therapy. It remains a significant challenge in cardiology, as it evolves into advanced and end-stage HF. The hyperactivation of the neurohormonal, adrenergic and renin-angiotensin-aldosterone system are well known pathophysiological pathways involved in HF. Several drugs have been developed to inhibit the latter, resulting in an improvement in life expectancy. Nevertheless, patients are exposed to a residual risk of adverse events, and the exploration of new molecular pathways and therapeutic targets is required. This review explores the current landscape of WHF, highlighting the complexities and factors contributing to this critical condition. Most recent medical advances have introduced cutting-edge pharmacological agents, such as guanylate cyclase stimulators and myosin activators. Regarding device-based therapies, invasive pulmonary pressure measurement and cardiac contractility modulation have emerged as promising tools to increase the quality of life and reduce hospitalizations due to HF exacerbations. Recent innovations in terms of WHF management emphasize the need for a multifaceted and patient-centric approach to address the complex HF syndrome.

Predicting the Length of Stay of Cardiac Patients Based on Pre-Operative Variables-Bayesian Models vs. Machine Learning Models

Length of stay (LoS) prediction is deemed important for a medical institution's operational and logistical efficiency. Sound estimates of a patient's stay increase clinical preparedness and reduce aberrations. Various statistical methods and techniques are used to quantify and predict the LoS of a patient based on pre-operative clinical features. This study evaluates and compares the results of Bayesian (simple Bayesian regression and hierarchical Bayesian regression) models and machine learning (ML) regression models against multiple evaluation metrics for the problem of LoS prediction of cardiac patients admitted to Tabba Heart Institute, Karachi, Pakistan (THI) between 2015 and 2020. In addition, the study also presents the use of hierarchical Bayesian regression to account for data variability and skewness without homogenizing the data (by removing outliers). LoS estimates from the hierarchical Bayesian regression model resulted in a root mean squared error (RMSE) and mean absolute error (MAE) of 1.49 and 1.16, respectively. Simple Bayesian regression (without hierarchy) achieved an RMSE and MAE of 3.36 and 2.05, respectively. The average RMSE and MAE of ML models remained at 3.36 and 1.98, respectively.

Impact of levosimendan on efficacy and renal function in acute heart failure according to renal function: A perspective, multi-center, real-world registry

Objective

Acute heart failure (AHF) is associated with high mortality. Levosimendan, an inodilator, has proved to increase cardiac output and exert renoprotective effect in AHF. Our aim was to investigate the efficacy and renoprotective effects of levosimendan in patients with AHF and different renal function.

Methods

This is a prospective, observational, multi-center registry. Patients admitted with AHF between June 2020 and May 2022 and treated with levosimendan during the hospital stay were included. Baseline characteristics, laboratory tests, electrocardiogram (ECG), chest X-ray, echocardiography, and treatment were collected. A 5-point Likert scale was used to document patients' baseline dyspnea. The estimated glomerular filtration rate (eGFR) was calculated by means of the Modification of Diet in Renal Disease equation. After levosimendan infusion, patients underwent assessment of degree of dyspnea, and levels of brain-type natriuretic peptide (BNP) /N-terminal pro-BNP (NT-pro BNP), and eGFR repeatedly.

Results

Among 789 AHF patients who received levosimendan treatment in this study, 33.0 % were female, mean age was 64.9 ± 16.8 years, and mean eGFR was 72.6 ± 32.5 ml/min/m². The mean score of dyspnea was 3.0 ± 1.0 using 5-point Likert scale before levosimendan infusion. Dyspnea improved in 68.7% patients at 6h after infusion of levosimendan, and in 79.5% at 24 h. Lower eGFR was associated with lower efficacy rate after 6h infusion (71.7, 70.7, 65.2, and 66.0%, respectively) and after 24 h infusion (80.5, 81.4, 76.2, and 77.8%, respectively). The levels of BNP or NT-pro BNP were also decreased after levosimendan treatment, and in each eGFR category. Levels of eGFR increased from baseline (72.6 ± 32.5 ml/min/m²) to 12–24h (73.8 ± 33.5 ml/min/m²) and 24–72h (75.0 ± 33.4 ml/min/m²) after starting treatment (p < 0.001). However, the eGFR levels increased only in patients with eGFR lower than 90.0 ml/min/m².

Conclusions

In AHF patients who received levosimendan, degree of dyspnea and levels of BNP or NT-pro BNP were significantly improved, especially in patients with higher eGFR levels. However, levosimendan infusion increase eGFR only in AHF patients with renal dysfunction.

Veno-Arterial Extracorporeal Membrane Oxygenation Rescue in a Patient With Pulmonary Hypertension Presenting for Revision Total Hip Arthroplasty: A Case Report and Narrative Review

Patients with pulmonary hypertension (PH) are at an increased risk of perioperative morbidity and mortality when undergoing non-cardiac surgery. We present a case of a 57-year-old patient with severe PH, who developed cardiac arrest as the result of right heart failure, undergoing a revision total hip arthroplasty under combined spinal epidural anesthesia. Emergent veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) was undertaken as rescue therapy during the pulmonary hypertensive crisis and a temporizing measure to provide circulatory support in an intensive care unit (ICU). We present a narrative review on perioperative management for patients with PH undergoing non-cardiac surgery. The review goes through the updated hemodynamic definition, clinical classification of PH, perioperative morbidity, and mortality associated with PH in non-cardiac surgery. Pre-operative assessment evaluates the type of surgery, the severity of PH, and comorbidities. General anesthesia (GA) is discussed in detail for patients with PH regarding the benefits of and unsubstantiated arguments against GA in non-cardiac surgery. The literature on risks and benefits of regional anesthesia (RA) in terms of neuraxial, deep plexus, and peripheral nerve block with or without sedation in patients with PH undergoing non-cardiac surgery is reviewed. The choice of anesthesia technique depends on the type of surgery, right ventricle (RV) function, pulmonary artery (PA) pressure, and comorbidities. Given the differences in pathophysiology and mechanical circulatory support (MCS) between the RV and left ventricle (LV), the indications, goals, and contraindications of VA-ECMO as a rescue in cardiopulmonary arrest and pulmonary hypertensive crisis in patients with PH are discussed. Given the significant morbidity and mortality associated with PH, multidisciplinary teams including anesthesiologists, surgeons, cardiologists, pulmonologists, and psychological and social worker support should provide perioperative management.

HDAC Inhibition Regulates Cardiac Function by Increasing Myofilament Calcium Sensitivity and Decreasing Diastolic Tension

We recently established a large animal model that recapitulates key clinical features of heart failure with preserved ejection fraction (HFpEF) and tested the effects of the pan-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). SAHA reversed and prevented the development of cardiopulmonary impairment. This study evaluated the effects of SAHA at the level of cardiomyocyte and contractile protein function to understand how it modulates cardiac function. Both isolated adult feline ventricular cardiomyocytes (AFVM) and left ventricle (LV) trabeculae isolated from non-failing donors were treated with SAHA or vehicle before recording functional data. Skinned myocytes were isolated from AFVM and human trabeculae to assess myofilament function. SAHA-treated AFVM had increased contractility and improved relaxation kinetics but no difference in peak calcium transients, with increased calcium sensitivity and decreased passive stiffness of myofilaments. Mass spectrometry analysis revealed increased acetylation of the myosin regulatory light chain with SAHA treatment. SAHA-treated human trabeculae had decreased diastolic tension and increased developed force. Myofilaments isolated from human trabeculae had increased calcium sensitivity and decreased passive stiffness. These findings suggest that SAHA has an important role in the direct control of cardiac function at the level of the cardiomyocyte and myofilament by increasing myofilament calcium sensitivity and reducing diastolic tension.

Basic mechanisms in cardiogenic shock: part 1-definition and pathophysiology

Cardiogenic shock mortality rates remain high despite significant advances in cardiovascular medicine and the widespread uptake of mechanical circulatory support systems. Except for early invasive angiography and percutaneous coronary intervention of the infarct-related artery, the most widely used therapeutic measures are based on low-quality evidence. The grim prognosis and lack of high-quality data warrant further action. Part 1 of this two-part educational review defines cardiogenic shock and discusses current treatment strategies. In addition, we summarize current knowledge on basic mechanisms in the pathophysiology of cardiogenic shock, focusing on inflammation and microvascular disturbances, which may ultimately be translated into diagnostic or therapeutic approaches to improve the outcome of our patients.

Effect of ICD/CRT-D Implantation on Adverse Events and Readmission Rate in Patients with Chronic Heart Failure (CHF)

Objective

To explore the effect of implantable cardioverter defibrillator/cardiac resynchronization therapy defibrillator (ICD/CRT-D) implantation on adverse events and the readmission rate in patients with chronic heart failure (CHF).

Methods

Sixty patients with CHF treated in our hospital from April 2019 to July 2021 were enrolled. The patients were randomly assigned into the control group and study group. The control group received routine intervention, and the study group received remote management with ICD/CRT-D implantation.

Results

First of all, we compared the general data of the two groups. There was no significant difference in LVEF, NYHA grade, concomitant disease, and history of arrhythmia (P > 0.05). Secondly, we compared the end-point events. In the study group, 5 cases of heart failure were readmitted, 0 cases died, and 4 cases were admitted to hospital with arrhythmia and ICD events, with a total incidence of 30.0%, while in the control group, 12 cases were rehospitalized with heart failure, 3 cases died, 25 cases were admitted with arrhythmia and ICD events, and the total incidence rate was 56.67% (P < 0.05). In terms of the readmission rate of patients with heart failure in grade NYHAII and grade III, among the patients with grade NYHAII, the number of patients with heart failure less than once in the study group was higher compared to that in the control group and the number of patients with heart failure ≥ once in the study group was lower compared to that in the control group (P < 0.05). Among the patients with grade NYHAIII, the number of patients with heart failure less than once in the study group was higher compared to that in the control group and the number of patients with heart failure ≥ once in the study group was lower compared to that in the control group. There exhibited no significant difference in the data (P > 0.05). Considering the occurrence of VT and VF events, the study team reported that 14 patients recorded a total of 276 ventricular arrhythmias: 261 ventricular tachycardia and 15 ventricular fibrillations. Among them, 24 VT (9.2%) and 4 VF (26.7%) were determined to be misrecognition of the equipment. A total of 178 ventricular arrhythmias were recorded in 13 patients in the control group, including 152 ventricular tachycardia and 26 ventricular fibrillations. Among them, 10 VT (6.6%) and 8 VF (30.8%) were determined as misrecognition of the device. In regard to the treatment results of the two groups, after admission to the hospital for radio frequency, ablation, and adjustment of drug treatment to reprogram control, the patients did not reappear to have CRT-D misidentification and misdischarged. Finally, we compared the diagnosis time of VT/VE events. The time from VT/VE events to diagnosis in 14 patients in the study group was 2.55 ± 1.41 days, and that in 13 patients in the control group was 37.32 ± 15.31 days. The discovery of ICD events in the study group was significantly earlier compared to that in the routine follow-up group (P < 0.05). This gives doctors enough time to assess the patient's condition and determine a further diagnosis and treatment plan.

Conclusion

Using ICD/CRT-D implantation to remotely monitor patients with CHF, through remote monitoring of the 24-hour average heart rate and the heart rate at rest and patient activity and other parameters and early intervention, the readmission rate caused by the deterioration of heart failure can be reduced. Compared with routine follow-up, remote monitoring significantly reduced the diagnosis time of VT/VE events.