Optimal Medical Therapy for Stable Ischemic Heart Disease: Focus on Anti-anginal Therapy.

Chronic coronary disease (CCD) is a major cause of morbidity and mortality worldwide. The most common symptom of CCD is exertional angina pectoris, a discomfort in the chest that commonly occurs during activities of daily life. Patients are dismayed by recurring episodes of angina and seek medical help in preventing or minimizing episodes. Angina occurs when the coronary arteries are unable to supply sufficient blood flow to the cardiac muscle to meet the metabolic needs of the left ventricular myocardium. While lifestyle changes and aggressive risk factor modification play a critical role in the management of CCD, management of angina usually requires pharmacologic therapy. Medications such as beta-blockers, calcium channel blockers, nitrates, ranolazine, and others ultimately work to improve the mismatch between myocardial blood flow and metabolic demand. This manuscript briefly describes the pathophysiologic basis for symptoms of angina, and how currently available anti-anginal therapies contribute to preventing or minimize the occurrence of angina.

Efficacy of nicorandil and ranolazine in prevention of contrast-induced nephropathy in patients with mild-to-moderate renal dysfunction: a randomized controlled trial.

INTRODUCTION: Contrast-induced nephropathy (CIN) is a common complication after percutaneous coronary intervention (PCI). There is conflicting evidence regarding efficacy of nicorandil in CIN prevention. With respect to ranolazine, there is physiological possibility as well as data in animal study regarding its protective effect against CIN; there is, however, no human data till date. AIM AND OBJECTIVES: To assess the efficacy of nicorandil and ranolazine in preventing CIN. The secondary endpoint was to measure difference in postprocedure acute kidney injury (AKI) incidence across groups. Also, patients were followed up till 6 months for major adverse events. MATERIAL AND METHODS: This single-center randomized controlled study included 315 patients of coronary artery disease with mild-to-moderate renal dysfunction undergoing elective PCI. Eligible patients were assigned to either nicorandil (n = 105), ranolazine (n = 105) or control group (n = 105) in 1 : 1 : 1 ratio by block randomization. All enrolled patients were given intravenous sodium chloride at rate of 1.0 mL/kg/h (0.5 mL/kg/h for patients with left ventricular ejection fraction <45%) from 6 h before procedure till 12 h after procedure. Iso-osmolar contrast agent (iodixanol) was used for all patients. In addition to hydration, patients in nicorandil group received oral nicorandil (10 mg, 3 times/d) and those in ranolazine group received oral ranolazine (1000 mg, 2 times/d) 1 day before procedure and for 2 days after PCI. Patients in control group received only hydration. RESULTS: Total number of CIN was 34 (10.7%), which included 19 (18.1%) in control, 8 (7.6%) in nicorandil and 7 (6.6%) in ranolazine group. There was significant association of CIN reduction across groups ( P  = 0.012). On pairwise comparison also, there was significant benefit across control and ranolazine as well as control and nicorandil ( P  < 0.025). There was numerically higher incidence of AKI in controls; the difference, however, did not reach statistical significance after applying Bonferroni correction ( P  = 0.044). Over 6-month follow-up, adverse events were similar across groups. CONCLUSION: While this study adds to existing literature that supports role for nicorandil in CIN prevention, the efficacy of ranolazine in protecting against CIN has been demonstrated in humans for the first time.

Association between Ranolazine, Ischemic Preconditioning, and Cardioprotection in Patients Undergoing Scheduled Percutaneous Coronary Intervention.

Background and Objectives: Remote ischemic preconditioning (RIPC) has demonstrated efficacy in protecting against myocardial ischemia-reperfusion injury when applied before percutaneous coronary revascularization. Ranolazine, an anti-ischemic drug, has been utilized to minimize ischemic events in chronic angina patients. However, there is a lack of trials exploring the combined effects of ranolazine pretreatment and RIPC in patients undergoing percutaneous coronary interventions (PCIs). Materials and Methods: The present study is a prospective study which enrolled 150 patients scheduled for nonemergent percutaneous coronary revascularization. Three groups were formed: a control group undergoing only PCIs, an RIPC group with RIPC applied to either upper limb before the PCI (preconditioning group), and a group with RIPC before the PCI along with prior ranolazine treatment for stable angina (ranolazine group). Statistical analyses, including ANOVAs and Kruskal-Wallis tests, were conducted, with the Bonferroni correction for type I errors. A repeated-measures ANOVA assessed the changes in serum enzyme levels (SGOT, LDH, CRP, CPK, CK-MB, troponin I) over the follow-up. Statistical significance was set at p < 0.05. Results: The ranolazine group showed (A) significantly lower troponin I level increases compared to the control group for up to 24 h, (B) significantly lower CPK levels after 4, 10, and 24 h compared to the preconditioning group (p = 0.020, p = 0.020, and p = 0.019, respectively) and significantly lower CPK levels compared to the control group after 10 h (p = 0.050), and (C) significantly lower CK-MB levels after 10 h compared to the control group (p = 0.050). Conclusions: This study suggests that combining RIPC before scheduled coronary procedures with ranolazine pretreatment may be linked to reduced ischemia induction, as evidenced by lower myocardial enzyme levels.

Myocardial energy balance and metabolism as causes of myocardial ischemia.

The current approach to myocardial ischemia has been influenced by the misconception of a close link between ischemia and coronary atherosclerotic obstructions. Recent guidelines have, however, acknowledged the multifactorial nature of this condition, with an identifiable cause present in less than half of angina patients, and a large fraction with angina of unknown origin. Because of this background, focusing on cardiac energy metabolim offers new opportunities to manage myocardial ischemia even when its cause is unknown.

ChaMP-CMD: A Phenotype-Blinded, Randomized Controlled, Cross-Over Trial.

BACKGROUND: Angina with nonobstructive coronary arteries is a common condition for which no effective treatment has been established. We hypothesized that the measurement of coronary flow reserve (CFR) allows identification of patients with angina with nonobstructive coronary arteries who would benefit from anti-ischemic therapy. METHODS: Patients with angina with nonobstructive coronary arteries underwent blinded invasive CFR measurement and were randomly assigned to receive 4 weeks of amlodipine or ranolazine. After a 1-week washout, they crossed over to the other drug for 4 weeks; final assessment was after the cessation of study medication for another 4 weeks. The primary outcome was change in treadmill exercise time, and the secondary outcome was change in Seattle Angina Questionnaire summary score in response to anti-ischemic therapy. Analysis was on a per protocol basis according to the following classification: coronary microvascular disease (CMD group) if CFR<2.5 and reference group if CFR≥2.5. The study protocol was registered before the first patient was enrolled (International Standard Randomised Controlled Trial Number: ISRCTN94728379). RESULTS: Eighty-seven patients (61±8 years of age; 62% women) underwent random assignment (57 CMD group and 30 reference group). Baseline exercise time and Seattle Angina Questionnaire summary scores were similar between groups. The CMD group had a greater increment (delta) in exercise time than the reference group in response to both amlodipine (difference in delta, 82 s [95% CI, 37-126 s]; P<0.001) and ranolazine (difference in delta, 68 s [95% CI, 21-115 s]; P=0.005). The CMD group reported a greater increment (delta) in Seattle Angina Questionnaire summary score than the reference group in response to ranolazine (difference in delta, 7 points [95% CI, 0-15]; P=0.048), but not to amlodipine (difference in delta, 2 points [95% CI, -5 to 8]; P=0.549). CONCLUSIONS: Among phenotypically similar patients with angina with nonobstructive coronary arteries, only those with an impaired CFR derive benefit from anti-ischemic therapy. These findings support measurement of CFR to diagnose and guide management of this otherwise heterogeneous patient group.

Sex-Related Differences in Ventricular Tachyarrhythmia Events in Patients With Implantable Cardioverter-Defibrillator and Prior Ventricular Tachyarrhythmias.

BACKGROUND: Data on the risk of ventricular tachycardia (VT), ventricular fibrillation (VF), and death by sex in patients with prior VT/VF are limited. OBJECTIVES: This study aimed to assess sex-related differences in implantable cardioverter-defibrillator (ICD)-treated VT/VF events and death in patients implanted for secondary prevention or primary prevention ICD indications who experienced VT/VF before enrollment in the RAID (Ranolazine Implantable Cardioverter-Defibrillator) trial. METHODS: Sex-related differences in the first and recurrent VT/VF requiring antitachycardia pacing or ICD shock and death were evaluated in 714 patients. RESULTS: There were 124 women (17%) and 590 men observed during a mean follow-up of 26.81 ± 14.52 months. Compared to men, women were at a significantly lower risk of VT/VF/death (HR: 0.67; P = 0.029), VT/VF (HR: 0.68; P = 0.049), VT/VF treated with antitachycardia pacing (HR: 0.59; P = 0.019), and VT/VF treated with ICD shock (HR: 0.54; P = 0.035). The risk of recurrent VT/VF was also significantly lower in women (HR: 0.35; P < 0.001). HR for death was similar to the other endpoints (HR: 0.61; P = 0.162). In comparison to men, women presented with faster VT rates (196 ± 32 beats/min vs 177 ± 30 beats/min, respectively; P = 0.002), and faster shock-requiring VT/VF rates (258 ± 56 beats/min vs 227 ± 57 beats/min, respectively; P = 0.30). There was a significant interaction for the risk of VT/VF by race (P = 0.013) with White women having significantly lower risk than White men (HR: 0.36; P < 0.001), whereas Black women had a similar risk to Black men (HR: 1.06; P = 0.851). CONCLUSIONS: Women with a history of prior VT/VF experienced a lower risk recurrent VT/VF requiring ICD therapy when compared to men. Black Women had a risk similar to men, whereas the lower risk for VT/VF in women was observed primarily in White women. (Ranolazine Implantable Cardioverter-Defibrillator Trial; NCT01215253).

Anti-ischemic and pleiotropic effects of ranolazine in chronic coronary syndromes.

The vast majority of antianginal drugs decrease heart rate and or blood pressure levels or the inotropic status of the left ventricle to decrease myocardial oxygen consumption (MVO2) and thus anginal symptoms. Ranolazine presents a completely different mechanism of action, which reduces the sodium-dependent calcium overload inhibiting the late sodium current. Current European Society of Cardiology (ESC) guidelines for the management of angina in patients with chronic coronary symptoms recommend the use of several drugs such as ranolazine, b-blockers, calcium channel blockers, long-acting nitrates, ivabradine, nicorandil and trimetazidine for angina relief. However, ranolazine, in addition to symptom relief properties, is an antianginal drug showing favorable effects in decreasing the arrhythmic burden and in ameliorating the glycemic profile of these patients. In this review, we summarize the available data regarding the antianginal and pleiotropic effects of this drug.

Effect of Voltage-Gated Sodium Channel Inhibitors on the Metastatic Behavior of Prostate Cancer Cells: A Meta-Analysis.

<b>Background and Objective:</b> Functional Voltage-Gated Sodium Channels (VGSCs) are expressed in metastatic prostate cancer (PCa) cells. A number of <i>in vitro</i> studies have evaluated the effect of functional VGSC expression on the metastatic cell behavior of PCa cells. This study aimed to evaluate the effect of VGSC inhibition on metastatic cell behavior in PCa cells by meta-analysis. <b>Materials and Methods:</b> Meta-analysis was performed on data taken from 13 publications that examined the effect of VGSC inhibitors on the metastatic cell behavior of metastatic PCa cells expressing functional VGSCs. The measure of effect was calculated according to the random effects model using mean differences and presented with a forest plot graph. Heterogeneity was checked using the Cochran's Q Test (Chi-square statistic) and the I² test statistic. In order to evaluate the objectivity, the funnels-plot graph was used. <b>Results:</b> The g value showing the effect size was calculated as 4.49 (95% CI = 5.35-3.62) in the experiments where Tetrodotoxin (TTX) was used, which has a very high specificity for VGSCs but is not licensed for clinical use. In experiments using licensed inhibitors Lamotrigine, Oxcarbazepine, Phenytoin, Ranolazine, Riluzole and Lidocaine, the g value was 1.37 (95 % CI = 2.02-0.71). Suppression of metastatic cell behavior in both subgroups is statistically significant (p<0.00001). <b>Conclusion:</b> Meta-analysis confirmed that VGSCs are an enhancing factor in the metastasis of PCa cells. The VGSCs appear to be an important target in the diagnosis and development of new treatment options in PCa.

Anti-inflammatory reprogramming of microglia cells by metabolic modulators to counteract neurodegeneration; a new role for Ranolazine.

Microglia chronic activation is a hallmark of several neurodegenerative diseases, including the retinal ones, possibly contributing to their etiopathogenesis. However, some microglia sub-populations have anti-inflammatory and neuroprotective functions, thus making arduous deciphering the role of these cells in neurodegeneration. Since it has been proposed that functionally different microglia subsets also rely on different metabolic routes, we hypothesized that modulating microglia metabolism might be a tool to enhance their anti-inflammatory features. This would have a preventive and therapeutic potential in counteracting neurodegenerative diseases. For this purpose, we tested various molecules known to act on cell metabolism, and we revealed the anti-inflammatory effect of the FDA-approved piperazine derivative Ranolazine on microglia cells, while confirming the one of the flavonoids Quercetin and Naringenin, both in vitro and in vivo. We also demonstrated the synergistic anti-inflammatory effect of Quercetin and Idebenone, and the ability of Ranolazine, Quercetin and Naringenin to counteract the neurotoxic effect of LPS-activated microglia on 661W neuronal cells. Overall, these data suggest that using the selected molecules -also in combination therapies- might represent a valuable approach to reduce inflammation and neurodegeneration while avoiding long term side effects of corticosteroids.

The Role of Ranolazine in Heart Failure-Current Concepts.

Heart failure is a complex clinical syndrome with a detrimental impact on mortality and morbidity. Energy substrate utilization and myocardial ion channel regulation have gained research interest especially after the introduction of sodium-glucose co-transporter 2 inhibitors in the treatment of heart failure. Ranolazine or N-(2,6-dimethylphenyl)-2-(4-[2-hydroxy-3-(2-methoxyphenoxy) propyl] piperazin-1-yl) acetamide hydrochloride is an active piperazine derivative which inhibits late sodium current thus minimizing calcium overload in the ischemic cardiomyocytes. Ranolazine also prevents fatty acid oxidation and favors glycose utilization ameliorating the "energy starvation" of the failing heart. Heart failure with preserved ejection fraction is characterized by diastolic impairment; according to the literature ranolazine could be beneficial in the management of increased left ventricular end-diastolic pressure, right ventricular systolic dysfunction and wall shear stress which is reflected by the high natriuretic peptides. Fewer data is evident regarding the effects of ranolazine in heart failure with reduced ejection fraction and mainly support the control of the sodium-calcium exchanger and function of sarcoendoplasmic reticulum calcium adenosine triphosphatase. Ranolazine's therapeutic mechanisms in myocardial ion channels and energy utilization are documented in patients with chronic coronary syndromes. Nevertheless, ranolazine might have a broader effect in the therapy of heart failure and further mechanistic research is required.

Improvement of Vascular Insulin Sensitivity by Ranolazine.

Ranolazine (RN) is a drug used in the treatment of chronic coronary ischemia. Different clinical trials have shown that RN behaves as an anti-diabetic drug by lowering blood glucose and glycosylated hemoglobin (HbA1c) levels. However, RN has not been shown to improve insulin (IN) sensitivity. Our study investigates the possible facilitating effects of RN on the actions of IN in the rabbit aorta. IN induced vasodilation of the abdominal aorta in a concentration-dependent manner, and this dilatory effect was due to the phosphorylation of endothelial nitric oxide synthase (eNOS) and the formation of nitric oxide (NO). On the other hand, IN facilitated the vasodilator effects of acetylcholine but not the vasodilation induced by sodium nitroprusside. RN facilitated all the vasodilatory effects of IN. In addition, IN decreased the vasoconstrictor effects of adrenergic nerve stimulation and exogenous noradrenaline. Both effects were in turn facilitated by RN. The joint effect of RN with IN induced a significant increase in the ratio of p-eNOS/eNOS and pAKT/AKT. In conclusion, RN facilitated the vasodilator effects of IN, both direct and induced, on the adrenergic system. Therefore, RN increases vascular sensitivity to IN, thus decreasing tissue resistance to the hormone, a key mechanism in the development of type II diabetes.

Metabolic rewiring induced by ranolazine improves melanoma responses to targeted therapy and immunotherapy.

Resistance of melanoma to targeted therapy and immunotherapy is linked to metabolic rewiring. Here, we show that increased fatty acid oxidation (FAO) during prolonged BRAF inhibitor (BRAFi) treatment contributes to acquired therapy resistance in mice. Targeting FAO using the US Food and Drug Administration-approved and European Medicines Agency-approved anti-anginal drug ranolazine (RANO) delays tumour recurrence with acquired BRAFi resistance. Single-cell RNA-sequencing analysis reveals that RANO diminishes the abundance of the therapy-resistant NGFRhi neural crest stem cell subpopulation. Moreover, by rewiring the methionine salvage pathway, RANO enhances melanoma immunogenicity through increased antigen presentation and interferon signalling. Combination of RANO with anti-PD-L1 antibodies strongly improves survival by increasing antitumour immune responses. Altogether, we show that RANO increases the efficacy of targeted melanoma therapy through its effects on FAO and the methionine salvage pathway. Importantly, our study suggests that RANO could sensitize BRAFi-resistant tumours to immunotherapy. Since RANO has very mild side-effects, it might constitute a therapeutic option to improve the two main strategies currently used to treat metastatic melanoma.

The antianginal ranolazine fails to improve glycaemia in obese liver-specific pyruvate dehydrogenase deficient male mice.

AIMS: Recent studies have demonstrated that stimulating pyruvate dehydrogenase (PDH, gene Pdha1), the rate-limiting enzyme of glucose oxidation, can reverse obesity-induced non-alcoholic fatty liver disease (NAFLD), which can be achieved via treatment with the antianginal ranolazine. Accordingly, our aim was to determine whether ranolazine's ability to mitigate obesity-induced NAFLD and hyperglycaemia requires increases in hepatic PDH activity. METHODS: We generated liver-specific PDH-deficient (Pdha1Liver-/- ) mice, which were provided a high-fat diet for 12 weeks to induce obesity. Pdha1Liver-/- mice and their albumin-Cre (AlbCre ) littermates were randomized to treatment with either vehicle control or ranolazine (50 mg/kg) once daily via oral gavage during the final 5 weeks, following which we assessed glucose and pyruvate tolerance. RESULTS: Pdha1Liver-/- mice exhibited no overt phenotypic differences (e.g. adiposity, glucose tolerance) when compared to their AlbCre littermates. Of interest, ranolazine treatment improved glucose tolerance and mildly reduced hepatic triacylglycerol content in obese AlbCre mice but not in obese Pdha1Liver-/- mice. The latter was independent of changes in hepatic mRNA expression of genes involved in regulating lipogenesis. CONCLUSIONS: Liver-specific PDH deficiency is insufficient to promote an NAFLD phenotype. Nonetheless, hepatic PDH activity partially contributes to how the antianginal ranolazine improves glucose tolerance and alleviates hepatic steatosis in obesity.

Chronic testosterone deficiency increases late inward sodium current and promotes triggered activity in ventricular myocytes from aging male mice.

Clinical studies suggest low testosterone levels are associated with cardiac arrhythmias, especially in later life. We investigated whether chronic exposure to low circulating testosterone promoted maladaptive electrical remodeling in ventricular myocytes from aging male mice and determined the role of late inward sodium current (INa,L) in this remodeling. C57BL/6 mice had a gonadectomy (GDX) or sham surgery (1 mo) and were aged to 22-28 mo. Ventricular myocytes were isolated; transmembrane voltage and currents were recorded (37°C). Action potential duration at 70 and 90% repolarization (APD70 and APD90) was prolonged in GDX compared with sham myocytes (APD90, 96.9 ± 3.2 vs. 55.4 ± 2.0 ms; P < 0.001). INa,L was also larger in GDX than sham (-2.4 ± 0.4 vs. -1.2 ± 0.2 pA/pF; P = 0.002). When cells were exposed to the INa,L antagonist ranolazine (10 µM), INa,L declined in GDX cells (-1.9 ± 0.5 vs. -0.4 ± 0.2 pA/pF; P < 0.001) and APD90 was reduced (96.3 ± 14.8 vs. 49.2 ± 9.4 ms; P = 0.001). GDX cells had more triggered activity (early/delayed afterdepolarizations, EADs/DADs) and spontaneous activity than sham. EADs were inhibited by ranolazine in GDX cells. The selective NaV1.8 blocker A-803467 (30 nM) also reduced INa,L, decreased APD and abolished triggered activity in GDX cells. Scn5a (NaV1.5) and Scn10a (NaV1.8) mRNA was increased in GDX ventricles, but only NaV1.8 protein abundance was increased in GDX compared with sham. In vivo studies showed QT prolongation and more arrhythmias in GDX mice. Thus, triggered activity in ventricular myocytes from aging male mice with long-term testosterone deficiency arises from APD prolongation mediated by larger NaV1.8- and NaV1.5-associated currents, which may explain the increase in arrhythmias.NEW & NOTEWORTHY Older men with low testosterone levels are at increased risk of developing cardiac arrhythmias. We found aged mice chronically exposed to low testosterone had more arrhythmias and ventricular myocytes had prolonged repolarization, abnormal electrical activity, larger late sodium currents, and increased expression of NaV1.8 sodium channels. Drugs that inhibit late sodium current or NaV1.8 channels abolished abnormal electrical activity and shortened repolarization. This suggests the late sodium current may be a novel target to treat arrhythmias in older testosterone-deficient men.

Bayesian Network Meta-analysis of Randomized Controlled Trials on the Efficacy of Antiarrhythmics in the Pharmacological Cardioversion of Paroxysmal Atrial Fibrillation.

PURPOSE: Since atrial fibrillation (AF) is one of the major arrhythmias managed in hospitals worldwide, it has a major impact on public health. The guidelines agree on the desirability of cardioverting paroxysmal AF episodes. This meta-analysis aims to answer the question of which antiarrhythmic agent is most effective in cardioverting a paroxysmal AF. MATERIALS AND METHODS: A systematic review and Bayesian network meta-analysis, searching MEDLINE, Embase, and CINAHL, were performed, including randomized controlled trials (RCTs) enrolling a population of unselected adult patients with a paroxysmal AF that compared at least two pharmacological regimes to restore the sinus rhythm or a cardioversion agent against a placebo. The main outcome was efficacy in restoring sinus rhythm. RESULTS: Sixty-one RCTs (7988 patients) were included in the quantitative analysis [deviance information criterion (DIC) 272.57; I2 = 3%]. Compared with the placebo, the association verapamil-quinidine shows the highest SUCRA rank score (87%), followed by antazoline (86%), vernakalant (85%), tedisamil at high dose (i.e., 0.6 mg/kg; 80%), amiodarone-ranolazine (80%), lidocaine (78%), dofetilide (77%), and intravenous flecainide (71%). Taking into account the degree of evidence of each individual comparison between pharmacological agents, we have drawn up a ranking of pharmacological agents from the most effective to the least effective. CONCLUSIONS: In comparing the antiarrhythmic agents used to restore sinus rhythm in the case of paroxysmal AF, vernakalant, amiodarone-ranolazine, flecainide, and ibutilide are the most effective medications. The verapamil-quinidine combination seems promising, though few RCTs have studied it. The incidence of side effects must be taken into account in the choice of antiarrhythmic in clinical practice. CLINICAL TRIAL REGISTRATION: PROSPERO: International prospective register of systematic reviews, 2022, CRD42022369433 (Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022369433 ).

Ranolazine exhibits anti-inflammatory and antioxidant activities in H9c2 cardiomyocytes.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of ranolazine on hypoxia-inducible factor-1α (HIF-1α) and oxidative stress in H9c2 cardiomyocyte cells. MATERIALS AND METHODS: We have assessed the effects of increasing concentrations of methotrexate (MTX) and ranolazine on proliferation of H9c2 rat cardiomyocyte cells by MTT assay. Malondialdehyde (MDA) protein oxidation [advanced oxidation protein products (AOPPs)], lipid hydroperoxide (LOOH) and xanthine oxidase (XO) activity as oxidative stress markers and HIF-1α levels increased and total thiol (T-SH), catalase (CAT) activity and total antioxidant capacity (TAC) antioxidant capacity markers decreased in MTX-treated cells compared to control cells. RESULTS: Oxidative stress markers decreased, and antioxidant capacity markers increased in cells treated with ranolazine alone compared to control cells. For all parameters, we showed that the levels of oxidant, antioxidant markers and HIF-1α in cells treated with MTX and ranolazine together reached the level of the control group, and ranolazine reversed the oxidative damage caused by MTX. CONCLUSIONS: The cell viability increased the levels of oxidant and prooxidant markers and decreased the levels of antioxidant markers decreased in H9c2 cardiomyocytes induced by oxidative stress. These results suggest that ranolazine may protect the cardiomyocytes from MTX-induced oxidative damage. The effects of ranolazine could result from its antioxidant properties.

Cost-utility of Ranolazine for Chronic Stable Angina Pectoris: Systematic Review and Meta-analysis.

PURPOSE: Ranolazine is used to treat stable angina pectoris, the most common symptom of ischemic heart disease. Appropriate management of chronic stable angina pectoris is essential from both a clinical and an economic view point. METHODS: This systematic review and meta-analysis adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included cost-utility analyses, which compared ranolazine with other standard treatments for treating stable angina pectoris. The search was conducted in PubMed, EMBASE, and Scopus databases. A random-effects model based on the DerSimonian and Laird method was used to pool the incremental net benefit reported in purchasing power parity adjusted US dollars. The modified economic evaluation checklist was used to assess the risk of bias. FINDINGS: The pooled results from 7 selected studies with a time horizon of 1 year show that add-on ranolazine was significantly cost-effective compared with standard treatment, with a pooled incremental net benefit of US$1335 (95% CI, 500 to 2169) but with substantial heterogeneity (I2 = 79.46%). On subgroup analysis, ranolazine was cost-effective from the payers' perspective (US$1975; 95% CI, 1042 to 2908; I2 = 69.23) but not from a societal perspective (US$297; 95% CI, -241 to 715; I2 = 0%)]. There was limited evidence from lower economies. IMPLICATIONS: Pooled evidence suggests that add-on ranolazine therapy is cost-effective for chronic stable angina pectoris up to a 1-year time horizon. There is a lacuna of evidence from low- and middle-income countries and on long-term cost-effectiveness. The current evidence synthesis may provide a macroeconomic point of view for policy makers regarding the direction of ranolazine's cost-effectiveness for evidence-informed policy-making. PROSPERO identifier: CRD42022332454.

Ranolazine exerts atrial antiarrhythmic effects in a rat model of monocrotaline-induced pulmonary hypertension.

Atrial arrhythmias are a hallmark of heart diseases. The antiarrhythmic drug ranolazine with multichannel blocker properties is a promising agent to treat atrial arrhythmias. We therefore used the rat model of monocrotaline-induced pulmonary-hypertension to assess whether ranolazine can reduce the incidence of ex vivo atrial arrhythmias in isolated right atrium. Four-week-old Wistar rats were injected with 50 mg/kg of monocrotaline, and isolated right atrium function was studied 14 days later. The heart developed right atrium and right ventricular hypertrophy, and the ECG showed an increased P wave duration and QT interval, which are markers of the disease. Moreover, monocrotaline injection caused enhanced chronotropism and faster kinetics of contraction and relaxation in isolated right atrium. Additionally, in a concentration-dependent manner, ranolazine showed chronotropic and ionotropic effects upon isolated right atrium, with higher potency in the control when compared with experimental model. Using a burst pacing protocol, the isolated right atrium from the monocrotaline-treated animals was more susceptible to develop arrhythmias, and ranolazine was able to attenuate the phenotype. Thus, we concluded that the rat model of monocrotaline-induced pulmonary-hypertension develops right atrium remodelling, which increased the susceptibility to present ex vivo atrial arrhythmias, and the antiarrhythmic drug ranolazine ameliorated the phenotype.

Modulation of post-pacing action potential duration and contractile responses on ventricular arrhythmogenesis in chloroquine-induced long QT syndrome.

BACKGROUND: Excitation-contraction (E-C) coupling, the interaction of action potential duration (APD) and contractility, plays an essential role in arrhythmogenesis. We aimed to investigate the arrhythmogenic role of E-C coupling in the right ventricular outflow tract (RVOT) in the chloroquine-induced long QT syndrome. METHODS: Conventional microelectrodes were used to record electrical and mechanical activity simultaneously under electrical pacing (cycle lengths from 1000-100 ms) in rabbit RVOT tissue preparations before and after chloroquine with and without azithromycin. KB-R7943 (a Na+-Ca2+ exchanger [NCX] inhibitor), ranolazine (a late sodium current inhibitor), or MgSO4 were used to assess their pharmacological responses in the chloroquine-induced long QT syndrome. RESULTS: Sequential infusion of chloroquine and chloroquine plus azithromycin triggered ventricular tachycardia (VT) (33.7%) after rapid pacing compared to baseline (6.7%, p = 0.004). There were greater post-pacing increases of the first occurrence of contractility (ΔContractility) in the VT group (VT vs. non-VT: 521.2 ± 50.5% vs. 306.5 ± 26.8%, p < 0.001). There was no difference in the first occurrence of action potential at 90% repolarization (ΔAPD90) (VT vs. non-VT: 49.7 ± 7.4 ms vs. 51.8 ± 13.1 ms, p = 0.914). Pacing-induced VT could be suppressed to baseline levels by KB-R7943 or MgSO4. Ranolazine did not suppress pacing-induced VT in chloroquine-treated RVOT. ΔContractility was reduced by KB-R7943 and MgSO4, but not by ranolazine. CONCLUSION: ΔContractility (but not ΔAPD) played a crucial role in the genesis of pacing-induced VT in the long QT tissue model, which can be modulated by NCX (but not late sodium current) inhibition or MgSO4.