Joe-Elie Salem

Pharmacology and mechanisms of action of new oral anticoagulants

The new oral anticoagulants are announced as an important therapeutic revolution, particularly after their approval by authorities for stroke prevention in atrial fibrillation. However, the pharmacology of these new drugs is not homogeneous. In this review, we summarize the main pharmacological characteristics of the new direct anti‐Xa and anti‐IIa agents.

Modeling susceptibility to drug-induced long QT with a panel of subject-specific induced pluripotent stem cells

A large number of drugs can induce prolongation of cardiac repolarization and life-threatening cardiac arrhythmias. The prediction of this side effect is however challenging as it usually develops in some genetically predisposed individuals with normal cardiac repolarization at baseline. Here, we describe a platform based on a genetically diverse panel of induced pluripotent stem cells (iPSCs) that reproduces susceptibility to develop a cardiotoxic drug response. We generated iPSC-derived cardiomyocytes from patients presenting in vivo with extremely low or high changes in cardiac repolarization in response to a pharmacological challenge with sotalol. In vitro, the responses to sotalol were highly variable but strongly correlated to the inter-individual differences observed in vivo. Transcriptomic profiling identified dysregulation of genes (DLG2, KCNE4, PTRF, HTR2C, CAMKV) involved in downstream regulation of cardiac repolarization machinery as underlying high sensitivity to sotalol. Our findings offer novel insights for the development of iPSC-based screening assays for testing individual drug reactions. DOI: http://dx.doi.org/10.7554/eLife.19406.001

Complex Influence of Gonadotropins and Sex Steroid Hormones on QT Interval Duration

CONTEXT QT interval duration is longer in women than in men. Sex steroid hormones have inconsistently been suggested to explain this difference. The implication of gonadotropins has never been studied. OBJECTIVE We report here the combined influence of sex steroid hormones and gonadotropins on QT interval duration in healthy subjects and patients with congenital adrenal hyperplasia (CAH) as a model of T and progesterone overexpression. DESIGN AND PATIENTS Eighty-four CAH patients (58 women) and 84 healthy subjects matched and paired for sex and age were prospectively included. Circulating concentrations of 17-OH-progesterone, progesterone, T, estradiol, FSH, and LH were measured concomitantly to the recording of a digitized electrocardiogram. RESULTS QTcFridericia (QTcF) was shorter in women with CAH than in control women (404 ± 2 vs 413 ± 2.1 milliseconds; P ≤ .001). 17-OH-progesterone, progesterone, the progesterone/estradiol ratio, and total T were higher in women with CAH than in female controls (P < .05), whereas FSH was lower (P ≤ .05). According to multivariable analysis in all women, the progesterone/estradiol ratio (β = -0.33) and FSH levels (β = 0.34) were related to QTcF (r = 0.5; P < .0001), with no influence of CAH or healthy status. QTcF was not different between CAH (404.7 ± 3.7 milliseconds) or healthy men (396 ± 2.8 milliseconds). For men, QTcF (r = 0.48; P < .01) was negatively related to free T (β = -0.29) and positively to FSH levels (β = 0.34). CONCLUSION Cardiac repolarization is influenced by complex interactions between sex steroid hormones and gonadotropins, depending on gender. Our results indicate that the progesterone/estradiol ratio in women, T in men, and FSH in both genders are major determinants of ventricular repolarization with opposite effects on QTc interval.

Effect of intracoronary administration of AAV1/SERCA2a on ventricular remodelling in patients with advanced systolic heart failure: results from the AGENT-HF randomized phase 2 trial

Restoration of sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) activity through gene transfer improved cardiac function in experimental and pilot studies in humans with heart failure. The AGENT‐HF (NCT01966887) trial investigated the impact of adeno‐associated virus (AAV1)/SERCA2a on ventricular remodelling using multimodality non‐invasive cardiac imaging.

Influence of steroid hormones on ventricular repolarization

QT interval prolongation, corrected for heart rate (QTc), either spontaneous or drug-induced, is associated with an increased risk of torsades de pointes and sudden death. Women have longer QTc than men and are at higher risk of torsades de pointes, particularly during post-partum and the follicular phase. Men with peripheral hypogonadism have longer QTc than healthy controls. The role of the main sex steroid hormones has been extensively studied with inconsistent findings. Overall, estradiol is considered to promote QTc lengthening while progesterone and testosterone shorten QTc. New findings suggest more complex regulation of QTc by sex steroid hormones involving gonadotropins (i.e. follicle-stimulating hormone), the relative concentrations of sex steroid hormones (which depends on gender, i.e., progesterone/estradiol ratio in women). Aldosterone, another structurally related steroid hormone, can also prolong ventricular repolarization in both sex. Better understanding of pathophysiological hormonal processes which may lead to increased susceptibility of women (and possibly hypogonadic men) to drug-induced arrhythmia may foster preventive treatments (e.g. progesterone in women). Exogenous hormonal intake might offer new therapeutic opportunities or, alternatively, increase the risk of torsades de pointes. Some exogenous sex steroids may also have paradoxical effects on ventricular repolarization. Lastly, variations of QTc in women linked to the menstrual cycle and sex hormone fluctuations are generally ignored in regulatory thorough QT studies. Investigators and regulatory agencies promoting inclusion of women in thorough QT studies should be aware of this source of variability especially when studying drugs over several days of administration.

Assessment of right ventricular dysfunction predictors before the implantation of a left ventricular assist device in end-stage heart failure patients using echocardiographic measures (ARVADE): Combination of left and right ventricular echocardiographic variables

BACKGROUND Right ventricular failure (RVF) is a major cause of morbidity and mortality in left ventricular assist device (LVAD) recipients. OBJECTIVES To identify preoperative echocardiographic predictors of post-LVAD RVF. METHODS Data were collected for 42 patients undergoing LVAD implantation in Germany. RVF was defined as the need for placement of a temporary right ventricular assist device or the use of inotropic agents for 14 days. Data for RVF patients were compared with those for patients without RVF. A score (ARVADE) was established with independent predictors of RVF by rounding the exponentiated regression model coefficients to the nearest 0.5. RESULTS RVF occurred in 24 of 42 LVAD patients. Univariate analysis identified the following measurements as RVF risk factors: basal right ventricular end-diastolic diameter (RVEDD), minimal inferior vena cava diameter, pulsed Doppler transmitral E wave (Em), Em/tissue Doppler lateral systolic velocity (SLAT) ratio and Em/tissue Doppler septal systolic velocity (SSEPT) ratio. Em/SLAT≥18.5 (relative risk [RR] 2.78, 95% confidence interval [CI] 1.38-5.60; P=0.001), RVEDD≥50 mm (RR 1.97, 95% CI 1.21-3.20; P=0.008) and INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) level 1 (RR 1.74, 95% CI 1.04-2.91; P=0.04) were independent predictors of RVF. An ARVADE score>3 predicted the occurrence of post-implantation RVF with a sensitivity of 89% and a specificity of 74%. CONCLUSION The ARVADE score, combining one clinical variable and three echocardiographic measurements, is potentially useful for selecting patients for the implantation of an assist device.

Platelet reactivity in human immunodeficiency virus infected patients on dual antiplatelet therapy for an acute coronary syndrome: the EVERE2ST-HIV study

Aim To explore platelet reactivity on dual antiplatelet therapy (DAPT) of acute coronary syndrome (ACS) patients infected with HIV. Methods and results Acute coronary syndrome patients infected with HIV (n = 80) were matched to ACS patients without HIV (n = 160) on age, sex, diabetes, and DAPT (aspirin 100%, clopidogrel 68%, prasugrel 31%, ticagrelor 1%). Platelet reactivity was evaluated after ACS (>30 days) by measuring residual platelet aggregation (RPA) to aspirin and to P2Y12 inhibitors with light transmission aggregometry (LTA), VerifyNow aspirin assay (ARU), and P2Y12 assay (PRU) and with the VASP platelet reactivity index (VASP-PRI). Proportion of patients with high residual platelet reactivity (HPR) was evaluated. HIV-infected ACS patients had higher levels of platelet reactivity in response to P2Y12 inhibitors (RPA: 23.8 ± 2.7% vs. 15.3 ± 1.3%; P = 0.001; PRU: 132 ± 10 vs. 107.4 ± 6.6; P = 0.04; and VASP-PRI: 45.2 ± 2.6% vs. 32.0 ± 2.0%; P < 0.001) and to aspirin (RPA: 3.6 ± 1.5% vs. 0.4 ± 0.1%; P = 0.004 and ARU: 442 ± 11 vs. 407 ± 5; P = 0.002) compared with non-HIV. HIV-infection was independently associated with increased platelet reactivity regardless of the test used (RPA: P = 0.005; PRU: P < 0.001 and VASP-PRI: P < 0.001) and a higher proportion of HPR (OR = 7.6; P < 0.001; OR = 2.06; P = 0.06; OR = 2.91; P = 0.004, respectively) in response to P2Y12 inhibitors. Similar results were found with aspirin. Protease inhibitors use was associated with increased platelet reactivity and higher rate of HPR. Conclusions Acute coronary syndrome patients infected with HIV have increased levels of platelet reactivity and higher prevalence of HPR to P2Y12 inhibitors and aspirin than non-HIV patients. These results could provide potential explanations for the observed increase risk of recurrent ischemic events in the HIV-infected population.

Impact of inodilator drugs on echocardiographic assessments of left ventricular filling pressure in patients with decompensated end-stage heart failure*.

Objectives:We investigated the impact of inodilators on the accuracy of E/e′ ratio as a surrogate for pulmonary artery occlusion pressure in patients with decompensated end-stage systolic heart failure. Setting:The ratio of early diastolic transmitral flow velocity to tissue Doppler mitral annular early diastolic velocity, E/e′, and pulmonary artery occlusion pressure have been shown to be correlated. The validity of E/e′ for predicting pulmonary artery occlusion pressure in patients with decompensated end-stage systolic heart failure was recently challenged, but the influence of inodilators was not taken into account, despite the reported influence of these drugs on left ventricular relaxation properties. Patients and Intervention:Invasive hemodynamic monitoring and echocardiographic data were collected prospectively from 39 patients with decompensated end-stage systolic heart failure (92% male), aged 56 ± 13 years. These patients had dilated ventricles with a low cardiac index (1.9 ± 0.6 L/min/m2) and high pulmonary artery occlusion pressure (22 ± 8 mm Hg), and 90% required inodilator support during hospitalization. Measurements and Main Results:The correlation between septal E/e′ and pulmonary artery occlusion pressure was good for examinations in the absence of inodilators (n = 21) (r = 0.7; p < 0.001), but no correlation was found when inodilators were used (n = 31). Lateral and mean E/e′ were poorly correlated with pulmonary artery occlusion pressure, if at all, in both cases. Conclusions:By modifying ventricular relaxation properties and the influence of filling pressure on e′, inodilator agents severely impair the correlation between E/e′ and pulmonary artery occlusion pressure in patients with decompensated end-stage systolic heart failure.

GENomE wide analysis of sotalol-induced IKr inhibition during ventricular REPOLarization, “GENEREPOL study”: Lack of common variants with large effect sizes

Many drugs used for non-cardiovascular and cardiovascular purposes, such as sotalol, have the side effect of prolonging cardiac repolarization, which can trigger life-threatening cardiac arrhythmias by inhibiting the potassium-channel IKr (KCNH2). On the electrocardiogram (ECG), IKr inhibition induces an increase in QTc and Tpeak-Tend (TpTe) interval and a decrease of T wave maximal amplitude (TAmp). These changes vary markedly between subjects, suggesting the existence of predisposing genetic factors. 990 healthy individuals, prospectively challenged with an oral 80mg sotalol dose, were monitored for changes in ventricular repolarization on ECG between baseline and 3 hours post dosing. QTc and TpTe increased by 5.5±3.5% and 15±19.6%, respectively, and TAmp decreased by 13.2±15.5%. A principal-component analysis derived from the latter ECG changes was performed. A random subsample of 489 individuals were subjected to a genome-wide-association analysis where 8,306,856 imputed single nucleotide polymorphisms (SNPs) were tested for association with QTc, TpTe and TAmp modulations, as well their derived principal-components, to search for common genetic variants associated with sotalol-induced IKr inhibition. None of the studied SNPs reached the statistical threshold for genome-wide significance. This study supports the lack of common variants with larger effect sizes than one would expect based on previous ECG genome-wide-association studies. Clinical trial registration: ClinicalTrials.gov NCT00773201

Anticancer drug-induced cardiac rhythm disorders: Current knowledge and basic underlying mechanisms

ABSTRACT Significant advances in cancer treatment have resulted in decreased cancer related mortality for many malignancies with some cancer types now considered chronic diseases. Despite these improvements, there is increasing recognition that many cancer patients or cancer survivors can develop cardiovascular diseases, either due to the cancer itself or as a result of anticancer therapy. Much attention has focused on heart failure; however, other cardiotoxicities, notably cardiac rhythm disorders, can occur without underlying cardiomyopathy. Supraventricular tachycardias occur in cancer patients treated with cytotoxic chemotherapy (anthracyclines, gemcitabine, cisplatin and alkylating‐agents) or kinase‐inhibitors (KIs) such as ibrutinib. Ventricular arrhythmias, with a subset of them being torsades‐de‐pointes (TdP) favored by QTc prolongation have been reported: this may be the result of direct hERG‐channel inhibition or a more recently‐described mechanism of phosphoinositide‐3‐kinase inhibition. The major anticancer drugs responsible for QTc prolongation in this context are KIs, arsenic trioxide, anthracyclines, histone deacetylase inhibitors, and selective estrogen receptor modulators. Anticancer drug‐induced cardiac rhythm disorders remain an underappreciated complication even by experienced clinicians. Moreover, the causal relationship of a particular anticancer drug with cardiac arrhythmia occurrence remains challenging due in part to patient comorbidities and complex treatment regimens. For example, any cancer patient may also be diagnosed with common diseases such as hypertension, diabetes or heart failure which increase an individuals arrhythmia susceptibility. Further, anticancer drugs are generally usually used in combination, increasing the challenge around establishing causation. Thus, arrhythmias appear to be an underappreciated adverse effect of anticancer agents and the incidence, significance and underlying mechanisms are now being investigated.