Inappropriate Underdosing of Direct Oral Anticoagulants in Atrial Fibrillation Patients: Results from the START2-AF Registry.

Background: Direct oral anticoagulants (DOACs) are recommended for stroke prevention in non-valvular atrial fibrillation (NVAF) patients. We aimed to describe the prevalence of inappropriate DOACs dose prescription in the START2-AF Registry, the outcomes according to the appropriateness of the dosage, and the factors associated with inappropriate dose prescription. Methods: Patients' demographics and clinical data were prospectively collected as electronic files in an anonymous form on the website of the START2-Registry; DOACs dosage was determined to be appropriate when prescribed according to the European Heart Rhythm Association Guidelines. Results: We included 5943 NVAF patients on DOACs; 2572 (46.3%) were female patients. The standard dose (SD) was prescribed to 56.9% of patients and the low dose (LD) was prescribed to 43.1% of patients; 38.9% of all NVAF patients received an inappropriate LD DOAC and 0.3% received inappropriate SD. Patients treated with LD DOAC had a significantly higher rate of all bleedings (RR 1.5; 95% CI 1.2-2.0), major bleedings (RR 1.8; 95% CI 1.3-1.7), and mortality (RR 2.8; 95% CI 1.9-4.1) with respect to patients treated with SD DOAC. No difference was found among patients treated with appropriate and inappropriate LD regarding bleeding, thrombotic, and mortality rates. Age, body weight <60 kg, and renal failure were significantly associated with inappropriate LD DOAC prescription. Conclusions: Inappropriate LD DOACs in NVAF patients is not associated with a reduction in bleeding risk, nor with an increased thrombotic risk. Instead, it is associated with higher mortality rate, suggesting that, in clinical practice, underdosing is preferred for patients at particularly high risk for adverse events.

Machine learning approach for prediction of outcomes in anticoagulated patients with atrial fibrillation.

BACKGROUND: The accuracy of available prediction tools for clinical outcomes in patients with atrial fibrillation (AF) remains modest. Machine Learning (ML) has been used to predict outcomes in the AF population, but not in a population entirely on anticoagulant therapy. METHODS AND AIMS: Different supervised ML models were applied to predict all-cause death, cardiovascular (CV) death, major bleeding and stroke in anticoagulated patients with AF, processing data from the multicenter START-2 Register. RESULTS: 11078 AF patients (male n = 6029, 54.3%) were enrolled with a median follow-up period of 1.5 years [IQR 1.0-2.6]. Patients on Vitamin K Antagonists (VKA) were 5135 (46.4%) and 5943 (53.6%) were on Direct Oral Anticoagulants (DOAC). Using Multi-Gate Mixture of Experts, a cross-validated AUC of 0.779 ± 0.016 and 0.745 ± 0.022 were obtained, respectively, for the prediction of all-cause death and CV-death in the overall population. The best ML model outperformed CHA2DSVA2SC and HAS-BLED for all-cause death prediction (p < 0.001 for both). When compared to HAS-BLED, Gradient Boosting improved major bleeding prediction in DOACs patients (0.711 vs. 0.586, p < 0.001). A very low number of events during follow-up (52) resulted in a suboptimal ischemic stroke prediction (best AUC of 0.606 ± 0.117 in overall population). Body mass index, age, renal function, platelet count and hemoglobin levels resulted the most important variables for ML prediction. CONCLUSIONS: In AF patients, ML models showed good discriminative ability to predict all-cause death, regardless of the type of anticoagulation strategy, and major bleeding on DOAC therapy, outperforming CHA2DS2VASC and the HAS-BLED scores for risk prediction in these populations.

Ex Vivo Antiplatelet Effects of Oral Anticoagulants.

BACKGROUND: The impact of non-vitamin K antagonist oral anticoagulants (NOACs) on platelet function is still unclear. We conducted a comprehensive ex vivo study aimed at assessing the effect of the four currently marketed NOACs on platelet function. METHODS: We incubated blood samples from healthy donors with concentrations of NOACs (50, 150 and 250 ng/mL), in the range of those achieved in the plasma of patients during therapy. We evaluated generation of thrombin; light transmittance platelet aggregation (LTA) in response to adenosine diphosphate (ADP), thrombin receptor-activating peptide (TRAP), human γ-thrombin (THR) and tissue factor (TF); generation of thromboxane (TX)B2; and expression of protease-activated receptor (PAR)-1 and P-selectin on the platelet surface. RESULTS: All NOACs concentration-dependently reduced thrombin generation compared with control. THR-induced LTA was suppressed by the addition of dabigatran at any concentration, while TF-induced LTA was reduced by factor-Xa inhibitors. ADP- and TRAP-induced LTA was not modified by NOACs. TXB2 generation was reduced by all NOACs, particularly at the highest concentrations. We found a concentration-dependent increase in PAR-1 expression after incubation with dabigatran, mainly at the highest concentrations, but not with FXa inhibitors; P-selectin expression was not changed by any drugs. CONCLUSIONS: Treatment with the NOACs is associated with measurable ex vivo changes in platelet function, arguing for antiplatelet effects beyond the well-known anticoagulant activities of these drugs. There are differences, however, among the NOACs, especially between dabigatran and the FXa inhibitors.

Digital droplet PCR versus quantitative PCR for lipoprotein (a) kringle IV type 2 repeat polymorphism genetic characterization.

BACKGROUND: Lipoprotein(a) [Lp(a)] level variability, related to atherothrombotic risk increase, is mainly attributed to LPA gene, encoding apolipoprotein(a), with kringle IV type 2 (KIV2) copy number variation (CNV) acting as the primary genetic determinant. Genetic characterization of Lp(a) is in continuous growth; nevertheless, the peculiar structural characteristics of this variant constitute a significant challenge to the development of effective detection methods. The aim of the study was to compare quantitative real-time PCR (qPCR) and digital droplet PCR (ddPCR) in the evaluation of KIV2 repeat polymorphism. METHODS: We analysed 100 subjects tested for cardiovascular risk in which Lp(a) plasma levels were assessed. RESULTS: Correlation analysis between CNV values obtained with the two methods was slightly significant (R = 0.413, p = 0.00002), because of the wider data dispersion in qPCR compared with ddPCR. Internal controls C1, C2 and C3 measurements throughout different experimental sessions revealed the superior stability of ddPCR, which was supported by a reduced intra/inter-assay coefficient of variation determined in this method compared to qPCR. A significant inverse correlation between Lp(a) levels and CNV values was confirmed for both techniques, but it was higher when evaluated by ddPCR than qPCR (R = -0.393, p = 0.000053 vs R = -0.220, p = 0.028, respectively). When dividing subjects into two groups according to 500 mg/L Lp(a) cut-off value, a significantly lower number of KIV2 repeats emerged among subjects with greater Lp(a) levels, with stronger evidence in ddPCR than in qPCR (p = 0.000013 and p = 0.001, respectively). CONCLUSIONS: Data obtained support a better performance of ddPCR in the evaluation of KIV2 repeat polymorphism.

Impact of pregnancy on the natural history of women with hypertrophic cardiomyopathy.

AIMS: Whether pregnancy is a modifier of the long-term course and outcome of women with hypertrophic cardiomyopathy (HCM) is unknown. We assessed the association of pregnancy with long-term outcomes in HCM women. METHODS AND RESULTS: Retrospective evaluation of women with HCM from 1970 to 2021. Only women with pregnancy-related information (pregnancy present or absent) and a follow-up period lasting ≥1 year were included. The peri-partum period was defined as -1 to 6 months after delivery. The primary endpoint was a composite for major adverse cardiovascular events [MACE: cardiovascular death, sudden cardiac death, appropriate defibrillator shock and heart failure (HF) progression]. Overall, 379 (58%) women were included. There were 432 pregnancies in 242 (63%) patients. In 29 (7.6%) cases, pregnancies (n = 39) occurred after HCM diagnosis. Among these, three carrying likely pathogenic sarcomeric variants suffered MACEs in the peri-partum period. At 10 ± 9 years of follow-up, age at diagnosis [hazard ratio (HR) 1.034, 95% confidence interval (CI) 1.018-1.050, P < 0.001] and New York Heart Association (NYHA) class (II vs. I: HR 1.944, 95% CI 0.896-4.218; III vs. I: HR 5.291, 95% CI 2.392-11.705, P < 0.001) were associated with MACE. Conversely, pregnancy was associated with reduced risk (HR 0.605; 95% CI 0.380-0.963, P = 0.034). Among women with pregnancy, multiple occurrences did not modify risk. CONCLUSIONS: Pregnancy is not a modifier of long-term outcome in women with HCM and mostly occurs before a cardiac diagnosis. Most patients tolerate pregnancy well and do not show a survival disadvantage compared to women without. Pregnancy should not be discouraged, except in the presence of severe HF symptoms or high-risk features.

Hypertrophic cardiomyopathy (HCM) is the most common genetic disorder of the myocardium and is characterized by important gender-related differences: women are typically 5 years older than men at diagnosis, over half are diagnosed >50 years of age and consistently show greater propensity than men for heart failure (HF)-related complications and adverse outcome. Whether pregnancy is a modifier of the long-term course and outcome of women with HCM is unknown. In this study, pregnancy was not a modifier of long-term outcome in women with HCM. In particular: At 10 ± 7 years, most patients tolerated pregnancy well and did not show a survival disadvantage compared to women without pregnancies. Only baseline heart failure symptoms and age were associated with adverse outcome.Pregnancy should not be discouraged, except in the presence of severe HF symptoms or high-risk features. Nevertheless, cardio-obstetric counselling and close supervision are key in all instances, particularly in the peri-partum period.

LDL-cholesterol target levels achievement in high-risk patients: An (un)expected gender bias.

BACKGROUND AND AIMS: Lowering low-density lipoprotein cholesterol (LDL-C) is the cornerstone of cardiovascular disease prevention. Collection of epidemiological data is crucial for monitoring healthcare appropriateness. This analysis aimed to evaluate the proportion of high-risk patients who achieved guidelines recommended LDL-C goal, and explore the predictors of therapeutic failure, with a focus on the role of gender. METHODS AND RESULTS: Health administrative and laboratory data from seven Local Health Districts in Tuscany were collected for residents aged ≥45 years with a history of major adverse cardiac or cerebrovascular event (MACCE) and/or type 2 diabetes mellitus (T2DM) from January 1, 2019, to January 1, 2021. The study aimed to assess the number of patients with optimal levels of LDL-C (<55 mg/dl for patients with MACCE and <70 mg/dl for patients with T2DM without MACCE). A cohort of 174 200 individuals (55% males) was analyzed and it was found that 11.6% of them achieved the target LDL-C levels. Female gender was identified as an independent predictor of LDL-C target underattainment in patients with MACCE with or without T2DM, after adjusting for age, cardiovascular risk factors, comorbidities, and district area (adjusted-IRR 0.58 ± 0.01; p < 0.001). This result was consistent in subjects without lipid-lowering therapies (adjusted-IRR 0.56 ± 0.01; p < 0.001). CONCLUSION: In an unselected cohort of high-risk individuals, females have a significantly lower probability of reaching LDL-C recommended targets. These results emphasize the need for action to implement education for clinicians and patients and to establish clinical care pathways for high-risk patients, with a special focus on women.

The Role of Extracellular Matrix and Inflammation in the Stratification of Bleeding and Thrombotic Risk of Atrial Fibrillation on Oral Anticoagulant Therapy: Insights from Strat-Af Study.

In anticoagulated atrial fibrillation (AF) patients, the validity of models recommended for the stratification of the risk ratio between benefits and hemorrhage risk is limited. We hypothesize that both circulating and neuroimaging-based markers might improve the prediction of bleeding and thrombotic risk in anticoagulated AF patients. The Strat-AF study is an observational, prospective, single-center study enrolling 170 patients with AF; recruited patients are evaluated by means of a comprehensive protocol, with clinical, cerebral magnetic resonance imaging and circulating biomarkers assessment. The main outcome is the evaluation of cerebral microangiopathy related to the levels of circulating biomarkers of inflammation and extracellular matrix (ECM) remodeling. At multivariate logistic regression analysis adjusted for age, sex, CHA2DS2-VASc, HAS-BLED and type of anticoagulant, matrix metalloproteinases (MMP)-2 levels were significantly and positively associated with the presence of cerebral microbleeds (CMBs). A significant association between MMP-2, tissue inhibitor of metalloproteinases (TIMP)-1,-2,-4 levels and white matter hyperintensity was also found. Concerning the small vessel disease (SVD) score, MMP-2 and TIMP-1,-2 levels were associated with the presence of two and three or more signs of SVD, whereas TIMP-4 levels were associated with the presence of three signs of SVD with respect to patients with no instrumental signs of SVD. As regarding the presence of enlarged perivascular spaces (EPVS), a significant association was found for high levels of interleukin (IL)-8 and TIMP 1-2-3. These results demonstrate that patients with AF have evidence of impaired ECM degradation, which is an independent risk factor for thrombotic complications of AF patients on oral anticoagulant therapy. The incorporation of these markers in the prognostic schemes might improve their clinical capability in predicting stroke risk and thrombotic complications.

Pathophysiological and Molecular Basis of the Side Effects of Ticagrelor: Lessons from a Case Report.

Ticagrelor is currently considered a first-line choice in dual antiplatelet therapy (DAPT) following revascularization of acute coronary syndrome (ACS). However, its use is correlated with an increased incidence of two side effects, dyspnea and bradyarrhythmias, whose molecular mechanisms have not yet been defined with certainty and, consequently, neither of the therapeutic decisions they imply. We report the case of a patient with acute myocardial infarction treated with ticagrelor and aspirin as oral antithrombotic therapy after primary percutaneous coronary intervention (PCI), manifesting in a significant bradyarrhythmic episode that required a switch of antiplatelet therapy. Starting from this case report, this article aims to gather the currently available evidence regarding the molecular mechanisms underlying these side effects and propose possible decision-making algorithms regarding their management in clinical practice.

Incidence of stroke in patients with hypertrophic cardiomyopathy in stable sinus rhythm during long-term monitoring.

INTRODUCTION: Patients with hypertrophic cardiomyopathy (HCM) are at increased risk of stroke, but the incidence and factors associated with cardioembolic events in HCM patients without atrial fibrillation (AF) remain unresolved. We determined the incidence of stroke in patients in sinus rhythm (SR) monitored with a cardiac implantable electronic device (CIED). METHODS: All consecutive patients diagnosed with HCM and referred to CIED implantation with >16 years at diagnosis and ≥ 1 year follow-up post CIED implantation were retrospectively reviewed. Severe LA dilatation was defined as ≥48 mm. Patients were stratified by rhythm as: Pre-existing AF (AF present prior to CIED); De novo AF (AF present after CIED implantation); SR: no episodes of AF. RESULTS: Of 1651 patients, 185 (11.2%) implanted with a CIED were included (57% men, age: 54 ± 17 years). Baseline, pre-existing AF was present in 73 (39%) patients. Ischemic stroke was reported in 19 (10.3%, 1.78%/year) patients and was similar across the three groups (2.3%/year vs 1.1%/year vs 0.6%/year in patients in SR vs pre-existing AF vs de novo AF, respectively, p = 0.235). In SR patients, a LAD≥48 mm posed the greatest risk of stroke (Hazard Ratio: 10.03,95% Confidence-Interval 2.79-16.01). At Cox multivariable analysis, after adjustment for oral anticoagulation, LA was independently associated with stroke while rhythm was not. CONCLUSIONS: in HCM patients with CIED long-term monitoring and no prior history of AF, stroke rates were similar in those with de novo AF or stable SR. Severe LA dilatation was a powerful risk factor, irrespective of AF.

Monitoring antiplatelet therapy: where are we now?

Single antiplatelet therapy represents the cornerstone of thrombosis prevention in atherosclerotic cardiovascular disease. Dual antiplatelet therapy (DAPT), consisting of aspirin plus a P2Y 12 inhibitor, is the standard of care for patients with acute coronary syndrome or undergoing both coronary and peripheral percutaneous interventions. Recent data suggest the efficacy of DAPT also after minor stroke. In this setting, a large body of evidence has documented that genetic and acquired patients' characteristics may affect the magnitude of platelet inhibition induced by antiplatelet agents. The implementation of tools allowing the identification and prediction of platelet inhibition has recently been shown to improve outcomes, leading to an optimal balance between antithrombotic efficacy and bleeding risk. We are therefore clearly moving towards tailored antiplatelet therapy. The aim of this paper is to summarize the available evidence on the evaluation of platelet inhibition in patients with coronary, peripheral, or cerebrovascular atherosclerosis. We will here focus on antiplatelet therapy based on both aspirin and P2Y 12 inhibitors. In addition, we provide practical insights into the clinical settings in which it appears reasonable to implement antiplatelet therapy monitoring.

Paradoxical prolongation of QT interval during exercise in patients with hypertrophic cardiomyopathy: cellular mechanisms and implications for diastolic function.

Aims: Ventricular cardiomyocytes from hypertrophic cardiomyopathy (HCM) patient hearts show prolonged action potential duration (APD), impaired intracellular Ca2+ homeostasis and abnormal electrical response to beta -adrenergic stimulation. We sought to determine whether this behaviour is associated with abnormal changes of repolarization during exercise and worsening of diastolic function, ultimately explaining the intolerance to exercise experienced by some patients without obstruction. Methods and results: Non-obstructive HCM patients (178) and control subjects (81) underwent standard exercise testing, including exercise echocardiography. Ventricular myocytes were isolated from myocardial samples of 23 HCM and eight non-failing non-hypertrophic surgical patients. The APD shortening in response to high frequencies was maintained in HCM myocytes, while ß-adrenergic stimulation unexpectedly prolonged APDs, ultimately leading to a lesser shortening of APDs in response to exercise. In HCM vs. control subjects, we observed a lesser shortening of QT interval at peak exercise (QTc: +27 ± 52 ms in HCM, -4 ± 50 ms in controls, P < 0.0001). In patients showing a marked QTc prolongation (>30 ms), the excessive shortening of the electrical diastolic period was linked with a limited increase of heart-rate and deterioration of diastolic function at peak effort. Conclusions: Abnormal balance of Ca2+- and K+-currents in HCM cardiomyocytes determines insufficient APD and Ca2+-transient shortening with exercise. In HCM patients, exercise-induced QTc prolongation was associated with impaired diastolic reserve, contributing to the reduced exercise tolerance. Our results support the idea that severe electrical cardiomyocyte abnormalities underlie exercise intolerance in a subgroup of HCM patients without obstruction.

Strength of clinical indication and therapeutic impact of the implantable cardioverter defibrillator in patients with hypertrophic cardiomyopathy.

BACKGROUND: The implantable cardioverter defibrillator(ICD) has revolutionized the management of patients with hypertrophic cardiomyopathy (HCM) at risk of sudden cardiac death (SCD). However, the identification of ideal candidates remains challenging. We aimed to describe the long-term impact of the ICD for primary prevention in patients with HCM based on stringent (high SCD risk) vs lenient indications (need for pacing/personal choice). METHODS: Data from two Italian HCM Cardiomyopathy Units were retrospectively analyzed. Only patients >1 follow-up visits were divided into two groups according to ICD candidacy:stringent (high SCD risk) and lenient (need for pacing, patients' choice, physician advice despite lack of high SCD risk). Major cardiac events (composite of appropriate shock/intervention and SCD) was the primary endpoint. A safety endpoint was defined as a composite of inappropriate shocks and device-related complications. RESULTS: Of 2009 patients, 252(12.5%) received an ICD, including 27(1.3%) in secondary prevention and 225(11.2%) in primary prevention (age at implantation 49 ± 16 years; men 65.3%). Among those in primary prevention, 167(74.2%) had stringent, while 58(25.8%) had lenient indications. At 5 ± 4 years, only stringent ICD patients experienced major cardiac events (2.84%/year, 5-year cumulative incidence: 8.1%, 95%CI [3.5-14.1%]). ICD-related complications were similar across stringent and lenient subgroups. However, patients implanted >60 years had a significantly higher risk of adverse events. CONCLUSION: One third of ICD recipients with HCM in primary prevention received a lenient implantation and had no appropriate intervention. ICD implantation due to systematic upgrade in patients requiring pacing and increased risk perception may offer little advantage and increase complication rates.

"Tailored" antiplatelet bridging therapy with cangrelor: moving toward personalized medicine.

In the setting of patients with indication to receive dual antiplatelet therapy undergoing surgery or invasive procedures, the risk of perioperative cardiac ischemic events, particularly stent thrombosis, is high, because surgery has a prothrombotic effect and antiplatelet therapy is withdrawn in order to avoid bleeding complications. Cangrelor, an intravenous P2Y12 receptor antagonist, has been tested in a randomized trial as a "bridge" to cardiac surgery from discontinuation of oral P2Y12 receptor antagonists. Thus, a consensus document extended its off-label use in this setting and before non-cardiac surgery. Currently, despite the implementation of a standardized bridging protocol with cangrelor, a residual risk of adverse outcome mainly due to bleeding events, still persist during the perioperative phase.Accordingly, a personalized management driven by platelet reactivity serial measurements and careful assessment of ischemic and bleeding risks has potential to optimize outcomes and costs as compared to a standardized bridging protocol, based on average pharmacodynamic data of oral P2Y12 inhibitors.While specific indications for bridging have been extensively addressed in the aforementioned consensus statement, the aim of the present document is the proposal of a "tailored" clinical decision-making algorithm inspired to the principle of personalized medicine dealing with complex clinical scenarios.

MitraClip implantation in real-world: clinical relevance of different patterns of left ventricular remodeling.

OBJECTIVE: The role of left ventricular (LV) volumes and ejection fraction (EF) in the selection of patients for the MitraClip procedure remains matter of debate. The goal of this study is to assess the pattern of LV remodeling and its clinical implications after MitraClip procedures, and to evaluate the role of LV ejection fraction (EF) in patient selection. METHODS: Complete echocardiography was performed before, at discharge, 1,6, and 12-months in 45 patients treated with MitraClip for severe mitral regurgitation (MR) [age 78.2 ± 8.3 yrs, NYHA 3.74 ± 0.44, EF 36.5 ± 12.8%]. From baseline to 6-month, reverse and adverse LV-R were defined as a ≥15% decrease in LV end-systolic volume and a ≥10% increase in LV end-systolic volume, respectively. RESULTS: At 6-month, sustained reduction of MR ≤ 2 was observed in all patients, but two; reverse, adverse, and no LV-R occurred in 51% (N = 23), 18% (N = 8), and 31% (N = 14) of patients, respectively. Baseline LV end-diastolic volume was an independent predictor of reverse LV-R [P = 0.004], whereas EF was not. During follow-up (17.5 ± 9.3 months) period, 50% of adverse/no LV-R patients were free of the composite endpoint (mortality and hospitalization for heart failure) compared to 95.7% of reverse LV-R patients (P = 0.006). In Cox analysis, adverse LV-R and adverse/no LV-R were associated with composite endpoint with adjusted hazard ratios of 5.6 (95% CI 1.65-19.00) and 10.08 (95% CI 1.29-78.6), respectively. CONCLUSION: After MitraClip implantation, sustained adverse or no LV-R occurred in one-in-two patients and was associated with poor prognosis. Large LV volumes may help us to avoid the futility of the procedure.

Pathophysiology and Treatment of Hypertrophic Cardiomyopathy: New Perspectives.

PURPOSE OF REVIEW: We provide a state of the art of therapeutic options in hypertrophic cardiomyopathy (HCM), focusing on recent advances in our understanding of the pathophysiology of sarcomeric disease. RECENT FINDINGS: A wealth of novel information regarding the molecular mechanisms associated with the clinical phenotype and natural history of HCM have been developed over the last two decades. Such advances have only recently led to a number of controlled randomized studies, often limited in size and fortune. Recently, however, the allosteric inhibitors of cardiac myosin adenosine triphosphatase, countering the main pathophysiological abnormality associated with HCM-causing mutations, i.e. hypercontractility, have opened new management perspectives. Mavacamten is the first drug specifically developed for HCM used in a successful phase 3 trial, with the promise to reach symptomatic obstructive patients in the near future. In addition, the fine characterization of cardiomyocyte electrophysiological remodelling has recently highlighted relevant therapeutic targets. Current therapies for HCM focus on late disease manifestations without addressing the intrinsic pathological mechanisms. However, novel evidence-based approaches have opened the way for agents targeting HCM molecular substrates. The impact of these targeted interventions will hopefully alter the natural history of the disease in the near future.

Mavacamten, a Novel Therapeutic Strategy for Obstructive Hypertrophic Cardiomyopathy.

PURPOSE OF REVIEW: Pharmacological treatment options for hypertrophic cardiomyopathy (HCM) are currently limited and comprise non-disease specific therapies such as ß-blockers, non-dihydropyridine calcium channel blockers, and disopyramide. These agents that offer a variable degree of symptomatic relief, often suboptimal, are often limited by side-effects and fail to address the key molecular abnormalities of the disease. RECENT FINDINGS: Mavacamten is a novel, first-in-class, allosteric inhibitor of cardiac myosin ATPase, which reduces actin-myosin cross-bridge formation, thereby reducing myocardial contractility and improving myocardial energetic consumption in experimental HCM models. Following a successful Phase 2 study, the recently published phase III, placebo-controlled, randomized EXPLORER-HCM trial demonstrated the efficacy and safety of mavacamten in reducing left ventricular outflow tract obstruction and ameliorating exercise capacity, New York Heart Association functional class and health status in patients with obstructive HCM. Mavacamten represents the first agent specifically developed for HCM successfully tested in a Phase III trial, to be registered soon for clinical use, representing a radical change of paradigm in the pharmacological treatment of HCM.

Emerging Medical Treatment for Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a common myocardial disease characterized by otherwise unexplained left ventricular hypertrophy. The main cause of disabling symptoms in patients with HCM is left ventricular outflow tract (LVOT) obstruction. This phenomenon is multifactorial, determined both by anatomical and functional abnormalities: myocardial hypercontractility is believed to represent one of its major determinants. The anatomical anomalies are targeted by surgical interventions, whereas attenuating hypercontractility is the objective of old and new drugs including the novel class of allosteric myosin inhibitors. This review summarizes the current treatment modalities and discusses the emerging therapeutical opportunities focusing on the recently developed cardiac myosin ATPase inhibitors Mavacamten and CK-274. Novel surgical and interventional approaches are also discussed.

Heparin induced thrombocytopenia: position paper from the Italian Society on Thrombosis and Haemostasis (SISET).

Heparin induced thrombocytopenia (HIT) is a rare immune mediated adverse drug reaction occurring after exposure to heparin. It is a serious and potentially fatal condition, which may be associated with the development of arterial or venous thrombotic events. Although known for many years, HIT is still often misdiagnosed. Pre- test clinical probability, screening for anti-PF4/heparin antibodies and documentation of their platelet activating capacity are the cornerstones of diagnosis. However, both clinical algorithms and test modalities have limited predictive values and limited diffusion so that the diagnosis and management is challenging in the clinical practice. For this reason, there is an unmet need for novel rational non-anticoagulant therapies based on the pathogenesis of HIT.The present paper reports the position of the Italian Society on Haemostasis and Thrombosis (SISET) in order to increase awareness of HIT among clinicians and other health care professionals and to provide information on the most appropriate management.