Beneficial effects of trimetazidine treatment on exercise tolerance and B-type natriuretic peptide and troponin T plasma levels in patients with stable ischemic cardiomyopathy

Effects of trimetazidine on heart failure with reduced ejection fraction and associated clinical outcomes: a systematic review and meta-analysis

BACKGROUND

Despite maximal treatment, heart failure (HF) remains a major clinical challenge. Besides neurohormonal overactivation, myocardial energy homoeostasis is also impaired in HF. Trimetazidine has the potential to restore myocardial energy status by inhibiting fatty acid oxidation, concomitantly enhancing glucose oxidation. Trimetazidine is an interesting adjunct treatment, for it is safe, easy to use and comes at a low cost.

OBJECTIVE

We conducted a systematic review to evaluate all available clinical evidence on trimetazidine in HF. We searched Medline/PubMed, Embase, Cochrane CENTRAL and ClinicalTrials.gov to identify relevant studies.

METHODS

Out of 213 records, we included 28 studies in the meta-analysis (containing 2552 unique patients), which almost exclusively randomised patients with HF with reduced ejection fraction (HFrEF). The studies were relatively small (median study size: N=58) and of short duration (mean follow-up: 6 months), with the majority (68%) being open label.

RESULTS

Trimetazidine in HFrEF was found to significantly reduce cardiovascular mortality (OR 0.33, 95% CI 0.21 to 0.53) and HF hospitalisations (OR 0.42, 95% CI 0.29 to 0.60). In addition, trimetazidine improved (New York Heart Association) functional class (mean difference: -0.44 (95% CI -0.49 to -0.39), 6 min walk distance (mean difference: +109 m (95% CI 105 to 114 m) and quality of life (standardised mean difference: +0.52 (95% CI 0.32 to 0.71). A similar pattern of effects was observed for both ischaemic and non-ischaemic cardiomyopathy.

CONCLUSIONS

Current evidence supports the potential role of trimetazidine in HFrEF, but this is based on multiple smaller trials of varying quality in study design. We recommend a large pragmatic randomised clinical trial to establish the definitive role of trimetazidine in the management of HFrEF.

Metabolic mechanisms in physiological and pathological cardiac hypertrophy: new paradigms and challenges

Cardiac metabolism is vital for heart function. Given that cardiac contraction requires a continuous supply of ATP in large quantities, the role of fuel metabolism in the heart has been mostly considered from the perspective of energy production. However, the consequence of metabolic remodelling in the failing heart is not limited to a compromised energy supply. The rewired metabolic network generates metabolites that can directly regulate signalling cascades, protein function, gene transcription and epigenetic modifications, thereby affecting the overall stress response of the heart. In addition, metabolic changes in both cardiomyocytes and non-cardiomyocytes contribute to the development of cardiac pathologies. In this Review, we first summarize how energy metabolism is altered in cardiac hypertrophy and heart failure of different aetiologies, followed by a discussion of emerging concepts in cardiac metabolic remodelling, that is, the non-energy-generating function of metabolism. We highlight challenges and open questions in these areas and finish with a brief perspective on how mechanistic research can be translated into therapies for heart failure.

Trimetazidine Affects Mitochondrial Calcium Uniporter Expression to Restore Ischemic Heart Function via Reactive Oxygen Species/NFκB Pathway Inhibition

ABSTRACT

Studies have demonstrated the roles of trimetazidine beyond being an antianginal agent in ischemic heart disease (IHD) treatment associated with mechanisms of calcium regulation. Our recent studies revealed that mitochondrial calcium uniporter (MCU, the pore-forming unit responsible for mitochondrial calcium entrance) inhibition provided cardioprotective effects for failing hearts. Because trimetazidine and MCU are associated with calcium homeostasis, we hypothesized that trimetazidine may affect MCU to restore the failing heart function. In the present study, we tested this hypothesis in the context of cardiac ischemia in vivo and in vitro. The IHD model was established in male C57BL/6 mice followed by trimetazidine administration intraperitoneally at 20 mg/kg q.o.d for 8 weeks. In vitro studies were performed in a hypoxia model using primary rat neonate cardiomyocytes. The mice survival outcomes and heart function, pathohistologic, and biological changes were analyzed. The results demonstrated that trimetazidine treatment resulted in longer life spans and heart function improvement accompanied by restoration of mitochondrial calcium levels and increase in ATP production via MCU down-regulation. Studies in vitro further showed that trimetazidine treatment and MCU inhibition decreased reactive oxygen species (ROS) production, inhibited the NFκB pathway, and protected the cardiomyocytes from hypoxic injury, and vice versa. Thus, the present study unveils a unique mechanism in which trimetazidine is involved in ameliorating the ischemic failing heart via MCU down-regulation and the following mitochondrial calcium homeostasis restoration, ROS reduction, and cardiomyocyte protection through NFκB pathway inhibition. This mechanism provides a novel explanation for the treatment effects of trimetazidine on IHD.

Targeting Myocardial Substrate Metabolism in the Failing Heart: Ready for Prime Time?

PURPOSE OF REVIEW

We review the clinical benefits of altering myocardial substrate metabolism in heart failure.

RECENT FINDINGS

Modulation of cardiac substrates (fatty acid, glucose, or ketone metabolism) offers a wide range of therapeutic possibilities which may be applicable to heart failure. Augmenting ketone oxidation seems to offer great promise as a new therapeutic modality in heart failure. The heart has long been recognized as metabolic omnivore, meaning it can utilize a variety of energy substrates to maintain adequate ATP production. The adult heart uses fatty acid as a major fuel source, but it can also derive energy from other substrates including glucose and ketone, and to some extent pyruvate, lactate, and amino acids. However, cardiomyocytes of the failing heart endure remarkable metabolic remodeling including a shift in substrate utilization and reduced ATP production, which account for cardiac remodeling and dysfunction. Research to understand the implication of myocardial metabolic perturbation in heart failure has grown in recent years, and this has raised interest in targeting myocardial substrate metabolism for heart failure therapy. Due to the interdependency between different pathways, the main therapeutic metabolic approaches include inhibiting fatty acid uptake/fatty acid oxidation, reducing circulating fatty acid levels, increasing glucose oxidation, and augmenting ketone oxidation.

BSCL2/Seipin deficiency in hearts causes cardiac energy deficit and dysfunction via inducing excessive lipid catabolism

BACKGROUND

Heart failure (HF) is one of the leading causes of death worldwide and is associated with cardiac metabolic perturbations. Human Type 2 Berardinelli-Seip Congenital Lipodystrophy (BSCL2) disease is caused by mutations in the BSCL2 gene. Global lipodystrophic Bscl2^-/- mice exhibit hypertrophic cardiomyopathy with reduced cardiac steatosis. Whether BSCL2 plays a direct role in regulating cardiac substrate metabolism and/or contractile function remains unknown.

METHODS

We generated mice with cardiomyocyte-specific deletion of Bscl2 (Bscl2^cKO ) and studied their cardiac substrate utilisation, bioenergetics, lipidomics and contractile function under baseline or after either a treatment regimen using fatty acid oxidation (FAO) inhibitor trimetazidine (TMZ) or a prevention regimen with high-fat diet (HFD) feeding. Mice with partial ATGL deletion and cardiac-specific deletion of Bscl2 were also generated followed by cardiac phenotyping.

RESULTS

Different from hypertrophic cardiomyopathy in Bscl2^-/- mice, mice with cardiac-specific deletion of Bscl2 developed systolic dysfunction with dilation. Myocardial BSCL2 deletion led to elevated ATGL expression and FAO along with reduced cardiac lipid contents. Cardiac dysfunction in Bscl2^cKO mice was independent of mitochondrial dysfunction and oxidative stress, but associated with decreased metabolic reserve and ATP levels. Importantly, cardiac dysfunction in Bscl2^cKO mice could be partially reversed by FAO inhibitor TMZ, or prevented by genetic abolishment of one ATGL allele or HFD feeding. Lipidomic analysis further identified markedly reduced glycerolipids, glycerophospholipids, NEFA and acylcarnitines in Bscl2^cKO hearts, which were partially normalised by TMZ or HFD.

CONCLUSIONS

We identified a new form of cardiac dysfunction with excessive lipid utilisation which ultimately causes cardiac substrate depletion and bioenergetics failure. Our findings also uncover a crucial role of BSCL2 in controlling cardiac lipid catabolism and contractile function and provide novel insights into metabolically treating energy-starved HF using FAO inhibitor or HFD.

Efficacy of trimetazidine - an inhibitor of free fatty acids oxidation in the treatment of patients with stable angina pectoris and heart failure

Aim      To evaluate efficacy of modified-release trimetazidine (TMZ) included into the standard therapy for patients with stable angina and chronic heart failure (CHF) as a part of a subgroup analysis in the PERSPECTIVE study.Material and methods  The study included 806 patients: group 1 (n=691), patients receiving a standard therapy and modified-release TMZ (TMZ group); and group 2 (n=115), patients receiving a standard therapy (control group). Total duration of the study was 12 months.Results In the TMZ group, the weekly number of angina attacks decreased by 41.9% (p<0.0001) in 2 months and by 69.6 % (from baseline, р<0.0001) in 12 months, and the frequency of nitroglycerine dosing decreased by 40.8 % (р<0.0001) and 67.7 % (р<0.0001), respectively. In the control group, the respective values did not change. In the TMZ group compared to the control group, the QT interval was shorter (7.9 %; р<0.05), the left ventricular (LV) end-systolic dimension was reduced (13.4 %; р<0.01), interventricular septal thickness and LV posterior wall thickness were decreased (9.5 %; р<0.01 and 12.2 %; р<0.01, respectively), and the ejection fraction was increased (11.4; р<0.05). Following the TMZ treatment, the leukocyte count in peripheral blood was decreased (5.3 %; р<0.01) and the serum concentration of high-sensitivity C-reactive protein was decreased (30.7 %; р<0.01) vs. increases of these indexes in the control group (17.9 %; р<0.05 and 17.8 %; р<0.05, respectively). The proportion of patients hospitalized for exacerbation of CHF or angina for 12 months was 8.6 % in the TMZ group and 15.7 % in the control group (p=0,001).Conclusion      In patients with stable angina and CHF, inclusion of modified-release TMZ into the standard therapy decreases the number of angina attacks, reduces the activity of inflammatory factors, and improves the course of disease.

Trimetazidine in Heart Failure

Heart failure is a systemic syndrome caused by multiple pathological factors. Current treatments do not have satisfactory outcomes. Several basic studies have revealed the protective effect of trimetazidine on the heart, not only by metabolism modulation but also by relieving myocardial apoptosis, fibrosis, autophagy, and inflammation. Clinical studies have consistently indicated that trimetazidine acts as an adjunct to conventional treatments and improves the symptoms of heart failure. This review summarizes the basic pathological changes in the myocardium, with an emphasis on the alteration of cardiac metabolism in the development of heart failure. The clinical application of trimetazidine in heart failure and the mechanism of its protective effects on the myocardium are carefully discussed, as well as its main adverse effects. The intention of this review is to highlight this treatment as an effective alternative against heart failure and provide additional perspectives for future studies.

Modulatory Effects of Chinese Herbal Medicines on Energy Metabolism in Ischemic Heart Diseases

Ischemic heart disease (IHD), a major global public health problem, is associated with high morbidity and mortality. Although the very best of modern approaches have proven effective in reducing morbidity and mortality, the poor prognosis of patients with IHD remains a major clinical concern. Cardiac energy metabolism is increasingly recognized as having a role in the pathogenesis of IHD, inducing metabolic substrate alterations, mitochondrial dysfunction, impaired function of the mitochondrial electron transport chain, and deprivation of cardiac energy. Factors involved in cardiac energy metabolism provide potential therapeutic targets for the treatment of IHD. Chinese herbal medicines (CHMs) have a long history of use in the prevention and treatment of cardiovascular diseases with multi-component, multi-target, and multi-signaling. Increasing evidence suggests that Chinese herbal medicines may improve myocardial ischemia through modulating cardiac energy metabolism. Here, we describe the possible targets and pathways of cardiac energy metabolism for CHMs, and appraise the modulatory effects of CHMs on energy metabolism in IHD. Especially, this review focuses on summarizing the metabolic effects and the underlying mechanisms of Chinese herbal medicines (including herbs, major bioactive components, and formulas) in IHD. In addition, we also discuss the current limitations and the major challenges for research investigating the use of CHMs in the treatment of cardiovascular diseases.

AMPK: a therapeutic target of heart failure-not only metabolism regulation

Heart failure (HF) is a serious disease with high mortality. The incidence of this disease has continued to increase over the past decade. All cardiovascular diseases causing dysfunction of various physiological processes can result in HF. AMP-activated protein kinase (AMPK), an energy sensor, has pleiotropic cardioprotective effects and plays a critical role in the progression of HF. In this review, we highlight that AMPK can not only improve the energy supply in the failing heart by promoting ATP production, but can also regulate several important physiological processes to restore heart function. In addition, we discuss some aspects of some potential clinical drugs which have effects on AMPK activation and may have value in treating HF. More studies, especially clinical trials, should be done to evaluate manipulation of AMPK activation as a potential means of treating HF.

Meta-analysis of trimetazidine treatment for cardiomyopathy

To explore the effect of trimetazidine (TMZ) in cardiomyopathy treatment. Literatures, related with TMZ treatment for cardiomyopathy, were retrieved between 1990 and February 2018 in the Pubmed, Embase, and Cochrane Library systems. Cardiopulmonary exercise testing [resting heart rate (RHR), peak heart rate (PHR), peak systolic blood pressure (PSBP), and resting systolic blood pressure (RSBP)] and echocardiographic results [left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), systolic wall thickening score index (SWTSI), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD)] were merged to detect the publication bias. Total 898 patients with cardiomyopathy were divided into two groups: TMZ-treated group (n=456) and control group (n=442). There was no difference in the improvement of cardiomyopathy between the TMZ and control group. No publication bias was shown for PHR (t= 0.9791, P=0.5067). There were significant differences in LVEF, LVESV, SWTSI, LVESD, and LVEDD between the TMZ group and the control group. TMZ-treatment significantly increased the level of LVEF (95% confidence interval (CI): 5.46-7.84, P<0.001), and reduced the level of LVESV (95% CI: -18.73 to -7.77, P<0.001), SWTSI (95% CI: -0.47 to -0.15, Z = -3.85, P=0.001), LVESD (95% CI: -1.09 to -0.08, P<0.001), and LVEDD (95% CI: -0.55 to -0.26, P=0.023). There was no publication bias except for LVEDV (t = 2.5456, P=0.0438). TMZ is effective for cardiomyopathy treatment and worth to popularize in clinic.

Trimetazidine protects against myocardial ischemia/reperfusion injury by inhibiting excessive autophagy

Trimetazidine (TMZ) has been demonstrated to have protective effects against myocardial ischemia/reperfusion (MI/R) injury. In the present study, we investigated the effects and the underlying mechanisms of TMZ on autophagy during MI/R in vivo and in vitro. In the in vivo study, an animal model of MI/R was induced by coronary occlusion. TMZ (20 mg/kg/day) protected the rat hearts from MI/R-induced heart failure by increasing ejection fraction and fractional shortening and decreasing end-systolic volume, end-diastolic volume, left ventricular (LV) internal diameter at systole, and LV internal diameter at diastole; it alleviated myocardial injury and oxidative stress by decreasing LDH, creatine kinase MB isoenzyme, ROS, and MDA levels and increasing SOD and glutathione peroxidase levels in plasma. TMZ also reduced myocardial infarct size and apoptosis. Moreover, TMZ markedly inhibited MI/R-induced autophagy by decreasing the protein and messenger RNA levels of LC3-II, Beclin1, ATG5, and ATG7 and the number of autophagosomes and by involving the AKT/mTOR pathway. Further, in the in vitro experiments, H9c2 cells were incubated with TMZ (40 μM) to explore the direct effects of TMZ following exposure to hypoxia and reoxygenation (H/R). TMZ increased cell viability and the concentration of intracellular SOD and inhibited H/R-induced cell apoptosis and ROS production. Moreover, TMZ decreased the number of autophagosomes and autophagy-related protein expression; it also upregulated p-AKT and p-mTOR expression. In addition, TMZ augmented Bcl-2 protein expression and diminished Bax protein expression, the Bax/Bcl-2 rate, and cleaved caspase-3 level. However, these effects on H9c2 cells were notably abolished by the PI3K inhibitor LY294002. In conclusion, our results showed that TMZ inhibited I/R-induced excessive autophagy and apoptosis, which was, at least partly, mediated by activating the AKT/mTOR pathway.

KEY MESSAGES

TMZ improved cardiac function, alleviated myocardial injury and oxidative stress, and reduced the myocardial infarct area and apoptosis. TMZ inhibited MI/R-induced myocardial autophagy, H/R-induced H9c2 cell apoptosis, and autophagy flux. The effect of TMZ on autophagy was repressed by LY294002. TMZ protected against MI/R injury by inhibiting excessive autophagy via activating the AKT/mTOR pathway.

Metabolic Modulation of Cardiac Metabolism in Heart Failure

Heart failure (HF) is associated with metabolic changes that cause a progressive impairment of cardiac and skeletal muscle high-energy phosphate production. As a consequence of the impaired cardiac metabolism, other processes are activated in the failing heart that further exacerbate the progression of HF. The reduced production of high-energy phosphates has important implications for both systole and diastole in HF with both preserved and reduced left ventricular function. The aim of this review is to summarise the state-of-the-art on metabolic therapy in HF with a particular focus on trimetazidine. Metabolic agents optimise cardiac substrate metabolism without exerting negative haemodynamic effects. In particular, as studies with metabolic agents modulating cardiac metabolism have consistently demonstrated, this approach is effective in improving symptoms, functional capacity and prognosis in people with HF when added to optimal medical therapy. Therefore, the modulation of cardiac metabolism is an important therapeutic approach to the treatment of HF, especially in patients where it is of ischaemic or metabolic origin. Although further studies are needed, metabolic agents might be a new, effective strategy for the treatment of HF.

Effects of trimetazidine on interleukin-2 and interleukin-8 concentrations in patients with coronary artery disease

Trimetazidine (TMZ) exhibits metabolic and cardioprotective effects. The aim of this study was to assess the effects of TMZ on interleukin-2 (IL-2) and interleukin-8 (IL-8) serum concentrations in 156 patients with stable coronary artery disease. They underwent a treadmill exercise test (TET) before and after 3 months of TMZ treatment. IL-2 and IL-8 concentrations were determined before and after each TET. Before treatment, TET did not influence IL-2 concentrations, whereas IL-8 concentrations increased. TMZ treatment led to a decrease in IL-2 concentrations before TET, as well as it prevented the increase of IL-8 following the second TET. Obtained results confirmed the improvement in TET performance during TMZ treatment and they revealed a significant influence of TMZ on IL-2 and IL-8 concentrations both before and after TET. These changes may reflect potential anti-inflammatory effects of TMZ.

Metabolic manipulation in dilated cardiomyopathy: Assessing the role of trimetazidine

OBJECTIVES

To study the role of metabolic modulator (trimetazidine: TMZ) in dilated cardiomyopathy (DCM). Optimizing altered substrate metabolism in heart failure (HF) with metabolic modulators allows more efficacious energy production from glucose than from free fatty acids.

METHODS

100 patients of DCM (47.7 years, NYHA class 2.17, LVEF 27.3%) were randomized to TMZ (20mg tid, n=50) vs conventional therapy (n=50). Functional status, BNP and various echocardiographic parameters were assessed at 3-6 months.

RESULTS

At 3 months, TMZ group had significantly improved NYHA class (2.25 vs 1.85), 6min walk test (349.7 vs 402m), LVD-36 score (25.5 vs 21) and BNP (744.7 vs 248.3pg/ml), all p 0.001. Significant improvement was also seen in LV end-systolic (LVESV, 87.1±27.5 vs 78.5±24.9ml/m2, p 0.001), LV end-diastolic volumes (LVEDV, 117.6±29.3 vs 110.9±27.4ml/m2, p 0.001), LVEF (27 vs 30.9%, p 0.001) and LV wall stress (90.2±18.9 vs 71.1±13.2dyn/cm2, p 0.0001). The % change in LVESV, LVEDV, LVEF and LV wall stress was -9.5%, -5.4%, +8.4% and -21.8%. Other echo parameters also improved after 3 months of TMZ (E/A ratio 1.9 vs 1.2, p=0.001, E/A VTI 2.7 vs 1.6, p=0.001, myocardial performance index, MPI 0.8 vs 0.7, p=0.0001), Tissue Doppler parameters (E/E' septal (19.7 vs 12.5, p=0.001) and E/E' lateral (13.3 vs 9.4, p=0.0001)). Patients in control group had no change in NYHA class, LVD-36 scores, LV volumes or LVEF at 3 months although BNP and LV wall stress reduced to a slight extent. Patients on TMZ had further improvement in NYHA class, walk test, BNP levels and echocardiographic parameters at 6 months.

CONCLUSIONS

Metabolic modulators (TMZ) may help in improving LV function in DCM. In this study, benefit was noted by 3 months with further improvement at 6 months.

Effects of Trimetazidine on T Wave Alternans in Stable Coronary Artery Disease

Background and Objectives

Studies reveal that the microvolt T wave alternans (MTWA) test has a high negative predictive value for arrhythmic mortality among patients with ischemic or non-ischemic cardiomyopathy. In this study, we investigate the effects of trimetazidine treatment on MTWA and several echocardiographic parameters in patients with stable coronary artery disease.

Subjects and Methods

One hundred patients (23 females, mean age 55.6±9.2 years) with stable ischemic heart disease were included in the study group. Twenty-five age- and sex-matched patients with stable coronary artery disease formed the control group. All patients were stable with medical treatment, and had no active complaints. Trimetazidine, 60 mg/day, was added to their current treatment for a minimum three months in the study group and the control group received no additional treatment. Pre- and post-treatment MTWA values were measured by 24 hour Holter testing. Left ventricular systolic and diastolic functions were assessed by echocardiography.

Results

After trimetazidine treatment, several echocardiographic parameters related with diastolic dysfunction significantly improved. MTWA has been found to be significantly improved after trimethazidine treatment (63±8 μV vs. 53±7 μV, p<0.001). Abnormal MTWA was present in 29 and 11 patients pre- and post-treatment, respectively (p< 0.001).

Conclusion

Trimetazidine improves MTWA, a non-invasive determinant of electrical instability. Moreover, several echocardiographic parameters related with left ventricular functions also improved. Thus, we can conclude that trimetazidine may be an effective agent to prevent arrhythmic complications and improve myocardial functions in patients with stable coronary artery disease.

Review of novel therapeutic targets for improving heart failure treatment based on experimental and clinical studies

Heart failure (HF) is a major public health priority due to its epidemiological transition and the world's aging population. HF is typified by continuous loss of contractile function with reduced, normal, or preserved ejection fraction, elevated vascular resistance, fluid and autonomic imbalance, and ventricular dilatation. Despite considerable advances in the treatment of HF over the past few decades, mortality remains substantial. Pharmacological treatments including β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists have been proven to prolong the survival of patients with HF. However, there are still instances where patients remain symptomatic, despite optimal use of existing therapeutic agents. This understanding that patients with chronic HF progress into advanced stages despite receiving optimal treatment has increased the quest for alternatives, exploring the roles of additional pathways that contribute to the development and progression of HF. Several pharmacological targets associated with pathogenesis of HF have been identified and novel therapies have emerged. In this work, we review recent evidence from proposed mechanisms to the outcomes of experimental and clinical studies of the novel pharmacological agents that have emerged for the treatment of HF.

The Role of Ivabradine and Trimetazidine in the New ESC HF Guidelines

The prevalence of heart failure (HF) is increasing, representing a major cause of death and disability, and a growing financial burden on healthcare systems. Despite the use of effective treatments with both drugs and devices, mortality remains high. There is therefore a need for new and effective therapeutic agents. Ivabradine is a specific sinus node inhibiting agent that was approved in 2005 by the European Medicines Agency, alone or in combination with a beta-blocker. Trimetazidine is a cytoprotective, anti-ischaemic agent established in the treatment of angina pectoris. In the 2012 European Society of Cardiology (ESC) guidelines for diagnosis and treatment of HF, ivabradine was recommended in symptomatic HF patients who are in sinus rhythm with left ventricular ejection fraction ≤35 % and heart rate higher than 70 beats per minute, despite optimal medical therapy, including maximally tolerated dose of beta-blocker. The role of trimetazidine in this setting was not mentioned. In the 2016 ESC guidelines, recommendations for ivabradine are unchanged but trimetazidine is included for the treatment of angina pectoris with HF. This article discusses the need for new therapeutic options in HF and reviews clinical evidence in support of these two therapeutic options.

Defining the role of trimetazidine in the treatment of cardiovascular disorders: some insights on its role in heart failure and peripheral artery disease

Trimetazidine is a cytoprotective drug whose cardiovascular effectiveness, especially in patients with stable ischemic heart disease, has been the source of much controversy in recent years; some have gone so far as to treat the medication as a ‘placebo drug’ whose new side effects, such as Parkinsonian symptoms, outweigh its benefits. This article is an attempt to present the recent key studies, including meta-analyses, on the use of trimetazidine in chronic heart failure, also in patients with diabetes mellitus and arrhythmia, as well as in peripheral artery disease. This paper also includes the most recent European Society of Cardiology guidelines, including those of 2013, on the use of trimetazidine in cardiovascular disease.

Is treatment with trimetazidine beneficial in patients with chronic heart failure?

BACKGROUND

Whether additional benefit can be achieved with the use of trimetazidine (TMZ) in patients with chronic heart failure (CHF) remains controversial. We therefore performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of TMZ treatment in CHF patients.

METHODS

We searched PubMed, EMBASE, and Cochrane databases through October 2013 and included 19 RCTs involving 994 CHF patients who underwent TMZ or placebo treatment. Risk ratio (RR) and weighted mean differences (WMD) were calculated using fixed or random effects models.

RESULTS

TMZ therapy was associated with considerable improvement in left ventricular ejection fraction (WMD: 7.29%, 95% CI: 6.49 to 8.09, p<0.01) and New York Heart Association classification (WMD: -0.55, 95% CI: -0.81 to -0.28, p<0.01). Moreover, treatment with TMZ also resulted in significant decrease in left ventricular end-systolic volume (WMD: -17.09 ml, 95% CI: -20.15 to -14.04, p<0.01), left ventricular end-diastolic volume (WMD: -11.24 ml, 95% CI: -14.06 to -8.42, p<0.01), hospitalization for cardiac causes (RR: 0.43, 95% CI: 0.21 to 0.91, p = 0.03), B-type natriuretic peptide (BNP; WMD: -157.08 pg/ml, 95% CI: -176.55 to -137.62, p<0.01) and C-reactive protein (CRP; WMD: -1.86 mg/l, 95% CI: -2.81 to -0.90, p<0.01). However, there were no significant differences in exercise duration and all-cause mortality between patients treated with TMZ and placebo.

CONCLUSIONS

TMZ treatment in CHF patients may improve clinical symptoms and cardiac function, reduce hospitalization for cardiac causes, and decrease serum levels of BNP and CRP.

C-Myc induced compensated cardiac hypertrophy increases free fatty acid utilization for the citric acid cycle

The protooncogene C-Myc (Myc) regulates cardiac hypertrophy. Myc promotes compensated cardiac function, suggesting that the operative mechanisms differ from those leading to heart failure. Myc regulation of substrate metabolism is a reasonable target, as Myc alters metabolism in other tissues. We hypothesize that Myc induced shifts in substrate utilization signal and promote compensated hypertrophy. We used cardiac specific Myc-inducible C57/BL6 male mice between 4-6 months old that develop hypertrophy with tamoxifen (tam) injections. Isolated working hearts and (13)Carbon ((13)C)-NMR were used to measure function and fractional contributions (Fc) to the citric acid cycle by using perfusate containing (13)C-labeled free fatty acids, acetoacetate, lactate, unlabeled glucose and insulin. Studies were performed at pre-hypertrophy (3-days tam, 3dMyc), established hypertrophy (7-days tam, 7dMyc) or vehicle control (Cont). Non-transgenic siblings (NTG) received 7-days tam or vehicle to assess drug effect. Hypertrophy was assessed by echocardiograms and heart weights. Western blots were performed on key metabolic enzymes. Hypertrophy occurred in 7dMyc only. Cardiac function did not differ between groups. Tam alone did not affect substrate contributions in NTG. Substrate utilization was not significantly altered in 3dMyc versus Cont. The free fatty acid FC was significantly greater in 7dMyc versus Cont with decreased unlabeled Fc, which is predominately exogenous glucose. Free fatty acid flux to the citric acid cycle increased while lactate flux was diminished in 7dMyc compared to Cont. Total protein levels of a panel of key metabolic enzymes were unchanged; however total protein O-GlcNAcylation was increased in 7dMyc. Substrate utilization changes for the citric acid cycle did not precede hypertrophy; therefore they are not the primary signal for cardiac growth in this model. Free fatty acid utilization and oxidation increase at established hypertrophy. Understanding the mechanisms whereby this change maintained compensated function could provide useful information for developing metabolic therapies to treat heart failure. The molecular signaling for this metabolic change may occur through O-GlcNAcylation. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism".

Nicotinamide pretreatment protects cardiomyocytes against hypoxia-induced cell death by improving mitochondrial stress

BACKGROUND/AIMS

Nicotinamide plays a protective role in hypoxia-induced cardiomyocyte dysfunction. However, the underlying molecular mechanisms remain poorly understood. The purpose of this study was to investigate these and the effect of nicotinamide pretreatment on hypoxic cardiomyocytes.

METHODS

Cultured rat cardiomyocytes were pretreated with nicotinamide, subjected to hypoxia for 6 h, and then cell necrosis and apoptosis were examined. The effects of nicotinamide pretreatment on hypoxia-induced reactive oxygen species (ROS) formation, antioxidant enzyme expression, nicotinamide adenine dinucleotide (NAD(+)) and nicotinamide adenine dinucleotide phosphate (NADP(+)) levels, adenosine triphosphate (ATP) production and mitochondrial membrane potential were tested to elucidate the underlying mechanisms.

RESULTS

Based on the findings that nicotinamide treatment decreased protein expression of receptor-interacting protein (RIP; a marker for cell necrosis) and cleaved caspase-3 (CC3; a marker for cell apoptosis) in normoxic cardiomyocytes, we found that it dramatically reduced hypoxia-induced necrosis and apoptosis in cardiomyocytes. The underlying mechanisms of these effects are associated with the fact that it increased protein expression of superoxide dismutase and catalase, increased intracellular levels of NAD(+) and ATP concentration, decreased mitochondrial ROS generation and prevented the loss of mitochondrial membrane potential.

CONCLUSION

All of these results indicate that nicotinamide pretreatment protects cardiomyocytes by improving mitochondrial stress. Our study provides a new clue for the utilization of nicotinamide in therapies for ischemic heart disease.

Additional use of trimetazidine in patients with chronic heart failure: a meta-analysis

OBJECTIVES

The aim of this meta-analysis was to evaluate the effects of additional trimetazidine (TMZ) treatment on patients with chronic heart failure (CHF).

BACKGROUND

Conflicting results currently exist on the clinical use of TMZ in CHF patients.

METHODS

PubMed, MEDLINE, EMBASE, and EBM Reviews databases were searched through November 2010 for randomized controlled trials (RCTs) assessing TMZ treatment in CHF patients. Data concerning the study design, patient characteristics, and outcomes were extracted. Risk ratio (RR) and weighted mean differences (WMD) were calculated using fixed or random effects models.

RESULTS

Sixteen RCTs involving 884 CHF patients were included. Hospitalization for cardiac causes (RR: 0.43, p = 0.03), but not all-cause mortality (RR: 0.47, p = 0.27), was reduced by TMZ treatment. Moreover, TMZ therapy was associated not only with the increase of left ventricular ejection fraction (WMD: 6.46%, p < 0.0001) and total exercise time (WMD: 63.75 seconds, p < 0.0001), but also with the decrease of New York Heart Association functional class (WMD: -0.57, p = 0.0003), left ventricular end-systolic diameter (WMD: -6.67 mm, p < 0.0001), left ventricular end-diastolic diameter (WMD: -6.05 mm, p < 0.0001), and B-type natriuretic peptide (WMD: -203.40 pg/ml, p = 0.0002).

CONCLUSIONS

Additional use of TMZ in CHF patients may decrease hospitalization for cardiac causes, improve clinical symptoms and cardiac function, and simultaneously ameliorate left ventricular remodeling.

Evaluation of trimetazidine in angina pectoris by echocardiography and radionuclide angiography: a meta-analysis of randomized, controlled trials

BACKGROUND

The objective of this meta-analysis was to evaluate the efficacy of the metabolic agent trimetazidine (TMZ) as monotherapy in the treatment of stable angina pectoris, from echocardiography and radionuclide angiography data.

HYPOTHESIS

Treatment with TMZ proved to be as effective as other first-line antianginal agents for coronary patients, and it provided additional efficacy in combination with hemodynamic agents.

METHODS

A search of the literature published between 1965 and 2008 was performed on the MEDLINE and EMBASE databases. Only randomized, controlled trials were included in this meta-analysis. Patients had to be treated for at least 2 weeks with data on the following 4 parameters at baseline and at the end of the treatment period: left ventricular ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and wall motion score index (WMSI). The quality of the trials was assessed by the Jadad score.

RESULTS

Eleven clinical studies meeting our criteria were analyzed. Results showed that TMZ significantly improved LVEF, with a mean increase of 6.88% (95% confidence interval [CI]: 5.50-8.25), and significantly reduced LVESV by 11.58 mL (95% CI: 5.79-17.37) and WMSI by 0.23 (95% CI: 0.07-0.38). Changes in LVEDV were variable. In both the long term and the short term, TMZ can improve LV function. The efficacy was unchanged in patients with diabetes mellitus.

CONCLUSIONS

This meta-analysis confirmed the efficacy of TMZ monotherapy in improving LV function compared with placebo.

Modulating fatty acid oxidation in heart failure

In the advanced stages of heart failure, many key enzymes involved in myocardial energy substrate metabolism display various degrees of down-regulation. The net effect of the altered metabolic phenotype consists of reduced cardiac fatty oxidation, increased glycolysis and glucose oxidation, and rigidity of the metabolic response to changes in workload. Is this metabolic shift an adaptive mechanism that protects the heart or a maladaptive process that accelerates structural and functional derangement? The question remains open; however, the metabolic remodelling of the failing heart has induced a number of investigators to test the hypothesis that pharmacological modulation of myocardial substrate utilization might prove therapeutically advantageous. The present review addresses the effects of indirect and direct modulators of fatty acid (FA) oxidation, which are the best pharmacological agents available to date for 'metabolic therapy' of failing hearts. Evidence for the efficacy of therapeutic strategies based on modulators of FA metabolism is mixed, pointing to the possibility that the molecular/biochemical alterations induced by these pharmacological agents are more complex than originally thought. Much remains to be understood; however, the beneficial effects of molecules such as perhexiline and trimetazidine in small clinical trials indicate that this promising therapeutic strategy is worthy of further pursuit.

Improved left and right ventricular functions with trimetazidine in patients with heart failure: a tissue Doppler study

Downregulation of glucose and fatty acid oxidation occurs in heart failure (HF). Trimetazidine reduces fatty acid oxidation and increases glucose oxidation. In this single-blind study, trimetazidine, 20 mg three times per day (n = 51) or placebo (n = 36) was added to treatment of 87 HF patients receiving optimal HF therapy. Etiology of heart failure was coronary artery disease in 35 patients (68.6%) in the trimetazidine group and 22 (62.9%) in the placebo group. Fourteen (27.5%) patients in the trimetazidine group and 11 (31.4%) patients in the placebo group had diabetes. Peak systolic velocity (Vs), and the peak early diastolic (Vd) and late diastolic (Va) velocities of various segments left and right ventricles (RV) were obtained with tissue Doppler imaging (TDI) and averaged. Patients were re-evaluated three months later. Significant increases in mean left ventricular ejection fraction (LVEF) (33.3% +/- 5.6% to 42.4% +/- 6.3%, P < 0.001 and 30.6% +/- 8.2% to 33.2% +/- 6.6%, P = 0.021) and LV and RV myocardial velocities and mitral and tricuspid annular TDI velocities were observed in both groups. However, compared to placebo, increments in LVEF (9.1% +/- 4.2% vs. 2.5% +/- 1.4%, P < 0.001) and myocardial velocities were significantly higher with trimetazidine (P < 0.001 for LV Vs, Vd, Va; P = 0.035 for RV Vd; and P < 0.001 for RV Va and Vs). Increase in LVEF with trimetazidine was significantly correlated with presence of diabetes (r = 0.524, P < 0.001). With trimetazidine LVEF increased significantly more in diabetic patients compared to nondiabetics (P < 0.001). Also, patients having both diabetes and ischemic HF tended to have greater improvement in LVEF compared to ischemic HF patients without diabetes (P = 0.063). Addition of trimetazidine to current treatment of HF, especially for those who are diabetic, may improve LV and RV functions.

Trimetazidine revisited: a comprehensive review of the pharmacological effects and analytical techniques for the determination of trimetazidine

Trimetazidine (TMZ) is an effective and well-tolerated antianginal drug that possesses protective properties against ischemia-induced heart injury. Growing interest in metabolic modulation in recent years urged an up-to-date review of the literature on TMZ. This review consists of two major sections: (1) comprehensive and critical information about the pharmacological effects, mechanism of action, pharmacokinetics, side effects, and current usage of TMZ, and (2) developments in analytical techniques for the determination of the drug in raw material, pharmaceutical dosage forms, and biological samples.