Comparison of trimetazidine with nifedipine in effort angina: a double-blind, crossover study

Regenerative therapies for myocardial infarction: exploring the critical role of energy metabolism in achieving cardiac repair

Cardiovascular diseases are the most lethal diseases worldwide, of which myocardial infarction is the leading cause of death. After myocardial infarction, in order to ensure normal blood supply to the heart, the remaining cardiomyocytes compensate for the loss of cardiomyocytes mainly by working at high capacity rather than by proliferating to produce new cardiomyocytes. This is partly due to the extremely limited ability of the adult heart to repair itself. A growing body of research suggests that the loss of cardiac regenerative capacity is closely related to metabolic shifts in energy sources. Currently, a large number of studies have focused on changes in metabolic levels before and after the proliferation window of cardiomyocytes, so it is crucial to search for relevant factors in metabolic pathways to regulate the cell cycle in cardiomyocyte progression. This paper presents a review of the role of myocardial energy metabolism in regenerative repair after cardiac injury. It aims to elucidate the effects of myocardial metabolic shifts on cardiomyocyte proliferation in adult mammals and to point out directions for cardiac regeneration research and clinical treatment of myocardial infarction.

Regulatory effects of trimetazidine in cardiac ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a tissue damage during reperfusion after an ischemic condition. I/R injury is induced by pathological cases including stroke, myocardial infarction, circulatory arrest, sickle cell disease, acute kidney injury, trauma, and sleep apnea. It can lead to increased morbidity and mortality in the context of these processes. Mitochondrial dysfunction is one of the hallmarks of I/R insult, which is induced via reactive oxygen species (ROS) production, apoptosis, and autophagy. MicroRNAs (miRNAs, miRs) are non-coding RNAs that play a main regulatory role in gene expression. Recently, there are evidence, which miRNAs are the major modulators of cardiovascular diseases, especially myocardial I/R injury. Cardiovascular miRNAs, specifically miR-21, and probably miR-24 and miR-126 have protective effects on myocardial I/R injury. Trimetazidine (TMZ) is a new class of metabolic agents with an anti-ischemic activity. It has beneficial effects on chronic stable angina by suppressing mitochondrial permeability transition pore (mPTP) opening. The present review study addressed the different mechanistic effects of TMZ on cardiac I/R injury. Online databases including Scopus, PubMed, Web of Science, and Cochrane library were assessed for published studies between 1986 and 2021. TMZ, an antioxidant and metabolic agent, prevents the cardiac reperfusion injury by regulating AMP-activated protein kinase (AMPK), cystathionine-γ-lyase enzyme (CSE)/hydrogen sulfide (H2S), and miR-21. Therefore, TMZ protects the heart against I/R injury by inducing key regulators such as AMPK, CSE/H2S, and miR-21.

Effectiveness and Tolerability of Trimetazidine 80 Mg Once Daily in Patients with Stable Angina Uncontrolled with Bisoprolol-Based Therapy: The Modus Vivendi Observational Study

Introduction

Modus Vivendi was conducted in routine clinical practice to evaluate the effect of adding trimetazidine 80 mg once daily (TMZ 80 OD) to treat patients with persistent symptoms despite treatment with background antianginal therapies including maximally tolerated bisoprolol.

Methods

This multicenter, prospective, observational, open-label, uncontrolled study recruited adult outpatients with a confirmed diagnosis of stable angina to whom physicians had decided to prescribe TMZ 80 OD. All patients were symptomatic despite treatment, including maximally tolerated doses of bisoprolol. Data on number of angina attacks, use of short-acting nitrates, and quality of life (QoL) were collected at baseline (V1) and at 1-month (V2) and 3-month (V2) follow-up visits. Two sub-analyses assessed efficacy in patients who remained on a stable bisoprolol dose throughout the study, and in patients in whom background antianginal therapy was known.

Results

A total of 1939 patients were recruited (57.2% women). The mean age was 65.6 ± 8.8 years; 73.8% had class II and 26.2% class III angina. At V1, the mean number of angina attacks per week was 6.2 ± 6.5 despite antianginal therapy including maximally tolerated bisoprolol dosage. Following the addition of TMZ 80 OD, this decreased to 3.4 ± 4.2 attacks per week at V2, and 1.6 ± 2.6 at V3 (P < 0.05 at V2 and V3), with concomitant reductions in short-acting nitrate use (P < 0.05). Significant improvements in QoL were observed throughout the study. Subgroup analyses showed that the addition of TMZ 80 OD to guideline-recommended antianginal therapy was associated with significant reductions in the mean number of weekly angina attacks and consumption of short-acting nitrates and improvements in QoL whether patients were treated with maximally tolerated bisoprolol and TMZ 80 OD alone, or maximally tolerated bisoprolol and TMZ 80 OD on top of other antianginal therapies. Treatment was well tolerated.

Conclusion

The study findings support the addition of TMZ 80 OD to bisoprolol with or without other antianginal therapies for patients with persistent angina.

Trial Registration

This study was retrospectively registered under the number ISRCTN29992579.

Trimetazidine and Bisoprolol to Treat Angina in Symptomatic Patients: Post Hoc Analysis From the CHOICE-2 Study

Introduction

Angina is the cardinal symptom of chronic coronary syndrome (CCS), which is the leading cause of death worldwide. As such, the control of angina is important. The current guidelines recommend beta blockers (BB) or calcium channel blockers to reduce angina, yet many patients with stable angina remain symptomatic. It has been suggested that combining trimetazidine (TMZ), an anti-ischemic agent, with a BB is beneficial for symptomatic patients. Bisoprolol, a BB, is often used to treat patients with CCS, yet no data are currently available regarding the efficacy of bisoprolol combined with TMZ in patients who remain symptomatic despite receiving bisoprolol.

Methods

The aim of this post-hoc analysis of the CHOICE-2 study was to evaluate the efficacy and safety of TMZ 35 mg twice daily in combination with different bisoprolol doses in symptomatic patients with stable angina patients receiving hemodynamic therapy in a real-world clinical setting.

Results

This analysis involved 221 patients (mean [± standard deviation] age 64.8 ± 8.9 years) with stable angina. The mean number of weekly angina episodes gradually fell from 6.2 ± 5.3 at inclusion (M0) to 1.5 ± 1.9 at 6 months after treatment initiation (M6) with combined TMZ–bisoprolol therapy (P < 0.001). The number of patients assessed to be angina-free increased almost sixfold from 5.4% (12/221) at M0 to 33.9% (74/221) at M6. Exercise capacity improved, as measured by walking distance, from 308 ± 207 m at M0 to 497 ± 253 m at M6 (P < 0.05). The number of patients with Canadian Cardiovascular Society class 1 angina increased by tenfold during the study, whereas those with class 3 angina decreased by threefold.

Conclusion

The TMZ–bisoprolol combination is a rapidly effective treatment for reducing the frequency of angina attacks and the use of short-acting nitrates in patients with stable angina in a real-world clinical setting. The benefits of this combination therapy was observed as early as 2 weeks after treatment initiation and the treatment was well tolerated.

Trial Registration

ISRCTN identifier: ISRCTN65209863

Trimetazidine alleviates hypoxia/reoxygenation-induced apoptosis in neonatal mice cardiomyocytes via up-regulating HMGB1 expression to promote autophagy

Previous studies demonstrated the effect of Trimetazidine (TMZ) on alleviating cardiomyocytes Hypoxia/Reoxygenation (H/R) injuries and the protective effect of autophagy on Ischemia-Reperfusion (I/R) cell injuries. However, whether the protection mechanism of TMZ was also involved in autophagy remained unclear. Our study introduces the role of HMGB1 to examine the regulation of TMZ on autophagy against cardiomyocytes H/R injuries. After cell extraction and identification through anti-α-actin staining, the cardiomyocytes were made hypoxic and reoxygenated, each for 3 h, and then treated with various concentrations of TMZ and transfected with siHMGB1. Cell viability and apoptosis were measured by the MTS method and flow cytometry, respectively. The expressions of autophagy-related factors (LC3-I, LC3-II, Beclin-1) and HMGB1 were detected by Western blot and qPCR. Lactate dehydrogenase (LDH) release was assessed by ELISA kit. The cardiomyocytes were extracted. H/R decreased the cell viability and increased the LDH level and apoptosis of cardiomyocytes. TMZ had no effect on untreated cardiomyocytes, but it reversed the adverse impact of H/R on cardiomyocytes. The expressions of LC3-II, Beclin-1, and HMGB1 and the ratio of LC3-II/LC3-I were increased in H/R-processed cardiomyocytes and further raised by TMZ pretreatment. However, siHMGB1 transfection aggravated the impact of H/R on cardiomyocytes and suppressed the protective effects of TMZ on H/R damaged cardiomyocytes by increasing the LDH level and apoptosis and reducing the viability of cardiomyocytes. Autophagy was inhibited by siHMGB1 in TMZ-pretreated and H/R-processed cardiomyocytes. TMZ protected cardiomyocytes against H/R injuries may through regulating HMGB1 to increase the impact of autophagy.

Myocardium Metabolism in Physiological and Pathophysiological States: Implications of Epicardial Adipose Tissue and Potential Therapeutic Targets

The main energy substrate of adult cardiomyocytes for their contractility are the fatty acids. Its metabolism generates high ATP levels at the expense of high oxygen consumption in the mitochondria. Under low oxygen supply, they can get energy from other substrates, mainly glucose, lactate, ketone bodies, etc., but the mitochondrial dysfunction, in pathological conditions, reduces the oxidative metabolism. In consequence, fatty acids are stored into epicardial fat and its accumulation provokes inflammation, insulin resistance, and oxidative stress, which enhance the myocardium dysfunction. Some therapies focused on improvement the fatty acids entry into mitochondria have failed to demonstrate benefits on cardiovascular disorders. Oppositely, those therapies with effects on epicardial fat volume and inflammation might improve the oxidative metabolism of myocardium and might reduce the cardiovascular disease progression. This review aims at explain (a) the energy substrate adaptation of myocardium in physiological conditions, (b) the reduction of oxidative metabolism in pathological conditions and consequences on epicardial fat accumulation and insulin resistance, and (c) the reduction of cardiovascular outcomes after regulation by some therapies.

Real-world Evidence for the Antianginal Efficacy of Trimetazidine from the Russian Observational CHOICE-2 Study

INTRODUCTION

The guidelines recommend a beta-blocker or calcium channel blocker as the first-line medication for angina, supplemented by other agents for additional symptoms. One such agent is trimetazidine (TMZ), which has been shown to reduce the frequency of anginal episodes and improve exercise performance without affecting haemodynamic parameters. However, extensive real-world evidence for its efficacy in combination with first-line therapies has been lacking.

METHODS

The aim of this large-scale, Russian, multicentre, 6-month, open-label, prospective observational study was to assess the effect of adding TMZ modified release 35 mg bid to background antianginal therapy in the real-world clinical setting.

RESULTS

The study included 896 patients: 54% women, aged 29-90 years (42.6% >65 years), 63% with class II angina, and receiving beta-blockers alone or in combination (93%). Add-on TMZ reduced angina frequency and short-acting nitrate use within 2 weeks (both p < 0.0001) regardless of background therapy and maintained this effect over 6 months. It increased the proportion of patients with class I angina sixfold while decreasing that of class 3 angina almost fourfold. It also improved walking distance and well-being at 6 months (both p < 0.0001). Treatment was well tolerated.

CONCLUSION

Add-on TMZ is a safe and rapidly effective treatment for reducing angina attacks and nitrate use in the real-world clinical setting. It also increases exercise capacity and well-being. These effects are observed within 2 weeks and persist for at least 6 months.

WITHDRAWN: Trimetazidine for stable angina

BACKGROUND

Patients with stable angina not controlled by monotherapy with nitrates, beta blockers, or calcium channel blockers are often treated with combinations of these drugs. There may be adverse effects from, or contraindications to, the use of combinations. In low risk groups, medical treatment appears to be as good an option as percutaneous transluminal coronary angioplasty in terms of averting myocardial infarction, death, or subsequent revascularization. Revascularization procedures are too costly or inaccessible for many patients in developing countries therefore effective and safe medical treatment is needed. Trimetazidine is a less well known anti-anginal drug that controls myocardial ischaemia through intracellular metabolic changes. Trimetazidine has been reported, in some studies, to be better tolerated than combined anti-anginal therapy; however it is not considered in published guidelines.

OBJECTIVES

To determine the efficacy and tolerability of trimetazidine in patients with stable angina.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS and SCISEARCH, without language restriction, from inception to October 2003. Experts in the field were contacted to locate unpublished studies.

SELECTION CRITERIA

Randomised studies comparing trimetazidine with placebo, or other anti-angina drug in adults with stable angina.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted data.

MAIN RESULTS

Twenty-three studies (1378 patients) met the inclusion criteria. There was a paucity of information about mortality, cardiovascular events and quality of life. Trimetazidine, compared with placebo, reduced the number of weekly angina attacks ( mean difference -1.44, 95% CI -2.10 to -0.79; P < 0.0001), reduced weekly nitroglycerin tablet consumption (95% CI -1.47 to -2.20, -0.73; P < 0.0001) and improved exercise time to 1 mm segment depression (P = 0.0002). Four small trials (263 patients) compared trimetazidine against other anti-anginal agents. One favoured trimetazidine over nitrates. Three tended to favour alternative regimens but with confidence intervals consistent with both major increases and decreases in frequency of angina episodes. In this subgroup, adverse events were considered in 5 trials (448 patients) and totals of 2 versus 12 drop outs due to adverse events were observed in the trimetazidine and alternative regimens respectively, but this was mostly driven by a single trial.

AUTHORS' CONCLUSIONS

Trimetazidine is effective in the treatment of stable angina compared with placebo, alone or combined with conventional anti-anginal agents. Trimetazidine may result in fewer dropouts due to adverse events. Large, long term trials comparing trimetazidine with other anti-anginal drugs assessing clinically relevant important outcomes are required to establish its role in clinical management.

The risk of cardiovascular side effects with anti-anginal drugs

INTRODUCTION

Angina pectoris is a common presenting symptom of underlying coronary artery disease or reduced coronary flow reserve. Patients with angina have impaired quality of life; and need to be treated optimally with antianginal drugs to control symptoms and improve exercise performance. A wide range of antianginal medications are approved for the treatment of angina, and often more than one class of antianginal drugs are used to adequately control the symptoms. This expert opinion highlights the likely cardiac adverse effects of available antianginal drugs, and how to minimize these in individual patients and especially during combination treatment. Areas covered: All approved antianginal drugs, including the older and newly approved medications with different mechanism of action to the older drugs as well as some of the unapproved herbal medications. The safety profiles and potential cardiac side effects of these medications when used as monotherapy or as combination therapy are discussed and highlighted. Expert opinion: Because of the different cardiac safety profiles and possible side effects, we recommend selection of initial drug or adjustment of therapy based on the resting heart rate; blood pressure, hemodynamic status; and resting left ventricular function, concomitant medications and any associated comorbidities.

Economic evaluation of trimetazidine in the management of chronic stable angina in Greece

Background

To evaluate the cost-effectiveness of trimetazidine (TMZ) as add-on therapy to standard-of-care (SoC) compared to SoC alone in patients with chronic stable angina who did not respond adequately to first line therapy with b-blockers, nitrates or calcium channel antagonists in Greece.

Methods

A Markov model with 3-month cycles and 1-year time horizon was developed to assess the comparators. The analysis was conducted from a third-party payer perspective. The clinical inputs and utility values were extracted from the published literature. Resource consumption data were obtained from local experts, using a questionnaire developed for the purpose of the study and were combined with unit cost data (in €2016) obtained from official sources. Cost effectiveness was assessed by calculating the incremental cost effectiveness ratio (ICER). Probabilistic sensitivity analysis (PSA) was performed to account for uncertainty and variation in the input parameters of the model.

Results

The analysis showed that the cost of TMZ plus SoC was €1755.57 versus €1751.76 of SoC alone. In terms of health outcomes, TMZ plus SoC was associated with 0.6650 QALYs versus 0.6562 QALYs for SoC alone. The incremental analysis resulted in an ICER of €430.67 per QALY gained. PSA revealed that the probability of TMZ plus SoC being cost-effective over SoC was 89 %, at a threshold of €34,000 per QALY gained.

Conclusion

The results indicate that TMZ as add –on treatment may be a highly cost-effective option for the symptomatic treatment of patients with chronic stable angina in Greece relative to SoC alone.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1779-6) contains supplementary material, which is available to authorized users.

Non-haemodynamic anti-anginal agents in the management of patients with stable coronary artery disease and diabetes: A review of the evidence

Patients with coronary artery disease and concomitant diabetes mellitus tend to have more extensive vessel disease than non-diabetes mellitus coronary artery disease patients, are at high risk of adverse cardiovascular events and suffer from a great anginal burden. Very few trials have specifically addressed the issue of optimal anti-anginal therapy in coronary artery disease patients who also have diabetes mellitus. Among 'classical' anti-anginal agents, recent guidelines do not specifically recommend any molecule over others; however, European Society of Cardiology guidelines acknowledge that favourable data in patients with concomitant diabetes mellitus and coronary artery disease are available for trimetazidine and ranolazine, two anti-anginal agents with a non-haemodynamic mechanism of action. The aim of this article is to review available evidence supporting the anti-anginal efficacy of these two drugs in the difficult-to-treat population of diabetes mellitus patients, including their effects on glycated haemoglobin (HbA1c), a measure of medium-term glycaemic control. Although direct head-to-head comparisons have not been performed, available evidence favours ranolazine as an effective anti-anginal agent over trimetazidine in this population. In addition, ranolazine lowers HbA1c, indicating that it may improve glycaemic control in patients with diabetes mellitus. Conversely, scanty data are available on the metabolic effects of trimetazidine in this cohort of patients. Thus, ranolazine may represent a valuable therapeutic option in stable coronary artery disease patients with diabetes mellitus.

Trimetazidine and cardioprotection: facts and perspectives

Trimetazidine (TMZ) is a metabolic agent used in cardiology for more than 40 years. Several studies assessed the cardioprotective effects of TMZ in patients with chronic coronary heart disease (CHD) as well as in patients with heart failure (HF). In light of the inclusion of TMZ in the current guidelines on the management of stable CHD, we reviewed the published literature on TMZ, focusing mainly its effects on patients with stable angina and HF. According to the published literature, there is sufficient evidence to support the addition of this agent in the treatment of symptomatic patients with stable angina.

Trimetazidine demonstrated cardioprotective effects through mitochondrial pathway in a model of acute coronary ischemia

Myocardial ischemia affects mitochondrial function leading to ionic imbalance and susceptibility to ventricular fibrillation. Trimetazidine (TMZ), a metabolic agent, is clinically used as an anti-anginal therapy. This study was conducted to compare the effect of TMZ 20 mg immediate release (IR) and TMZ 35 mg modified release (MR), two bioequivalent marketed formulations of TMZ, on cardioprotection during acute ischemia in pigs. A 4-day oral treatment with TMZ 20 mg IR (800 mg, tid) or TMZ 35 mg MR (1,400 mg, bid) had no effect on ventricular fibrillation threshold (VFT) prior to ischemia but significantly prevented the decrease in VFT observed in placebo-treated groups after a 1-min left anterior descending coronary artery occlusion. This effect occurred without modifying cardiac hemodynamic and conduction parameters. In both TMZ-treated groups, a significant reduction of the ischemic area as well as a protection of cardiomyocytes were observed. Cardiac enzymatic activity (phosphorylase, succinate dehydrogenase, ATPase) was increased in TMZ-treated groups. Both formulations preserved mitochondrial structure and improved mitochondrial function as demonstrated by a twofold increase of oxidative phosphorylation, by a reduction of reactive oxygen species (ROS) production (>30 %) and by a trend to increase the mitochondrial calcium retention capacity. In this model of ischemia, both TMZ formulations, leading to equivalent TMZ plasma exposures, demonstrated similar cardioprotective effects. This protection could be attributed to a preservation of mitochondrial structure and function, which plays a central role in ATP and ROS production and consequently could be considered as a target of cardioprotection.

Mildronate in cardiology practice – current evidence, ongoing research, and future perspectives

The review discusses the benefits and various practical aspects of the new cardioprotector mildronate use in cardiology. The latest evidence on the mildronate role in complex therapy of patients with stable angina, or patients in the rehabilitation period after myocardial infarction, is summarised.

Improvement of mechanical heart function by trimetazidine in db/db mice

AIM

To investigate the influence of trimetazidine, which is known to be an antioxidant and modulator of metabolism, on cardiac function and the development of diabetic cardiomyopathy in db/db mouse.

METHODS

Trimetazidine was administered to db/db mice for eight weeks. Cardiac function was measured by inserting a Millar catheter into the left ventricle, and oxidative stress and AMP-activated protein kinase (AMPK) activity in the myocardium were evaluated.

RESULTS

Untreated db/db mice exhibited a significant decrease in cardiac function compared to normal C57 mice. Oxidative stress and lipid deposition were markedly increased in the myocardium, concomitant with inactivation of AMPK and increased expression of peroxisome proliferator-activated receptor coactivator-1 alpha (PGC-1 alpha). Trimetazidine significantly improved systolic and diastolic function in hearts of db/db mice and led to reduced production of reactive oxygen species and deposition of fatty acid in cardiomyocytes. Trimetazidine also caused AMPK activation and reduced PGC-1 alpha expression in the hearts of db/db mice.

CONCLUSION

The data suggest that trimetazidine significantly improves cardiac function in db/db mice by attenuating lipotoxicity and improving the oxidation status of the heart. Activation of AMPK and decreased expression of PGC-1 alpha were involved in this process. Furthermore, our study suggests that trimetazidine suppresses the development of diabetic cardiomyopathy, which warrants further clinical investigation.

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.

Metabolic agents in the management of diabetic coronary patients: A new era

Modulation of myocardial free fatty acid metabolism is the key target for metabolic interventions in patients with coronary artery disease (CAD) with diabetes mellitus (DM). Because of its beneficial effects on heart metabolism at rest and on myocardial ischemia and left ventricular function, trimetazidine should be always combined with classical anti-ischemic treatment in patients with DM with CAD. We believe that, the new metabolic agents including L-carnitine, dichloroacetate, perhexiline and etomoxir will be added into our arsenal for the battle against CAD especially in patients with DM in the near future.

Trimetazidine protective effect against ischemia-induced susceptibility to ventricular fibrillation in pigs

PURPOSE

Ventricular fibrillation (VF) is a possible consequence of brief myocardial ischemia. Such a short ischemia does not provoke cell damage, but induces changes in intracellular cardiac metabolism due to diminished oxygen supply to the heart. Trimetazidine (TMZ) is a drug able to restore the metabolic balance between fatty acid and glucose oxidation in ischemic myocardial cells. The aim of this double-blind study was to investigate TMZ effect on VF in pigs during short-term ischemia.

METHODS

Ischemia was induced after thoracotomy by complete, but brief (1 min) occlusion of the left anterior descending coronary artery under electrical stimulation. The ventricular fibrillation threshold (VFT), heart rate (HR), various hemodynamic parameters and malondialdehyde (MDA) blood levels were measured before and during ischemia in two groups of eight anesthetized pigs. The mass of ischemic myocardial tissue was also evaluated.

RESULTS

No effects on either the HR or the hemodynamic parameters were observed during myocardial ischemia, whereas TMZ increased the VFT and decreased both MDA blood levels (an index of lipid peroxidation) and the ischemic area.

CONCLUSIONS

TMZ limited ischemia-induced electrical dysfunction leading to cardiac susceptibility to VF by decreasing lipid peroxidation and maintaining ionic homeostasis. TMZ could therefore provide protection against ischemia-induced VF.

Effect of free fatty acid inhibition on silent and symptomatic myocardial ischemia in diabetic patients with coronary artery disease

OBJECTIVE

Free fatty acid inhibition with trimetazidine (TMZ) improves myocardial metabolism and myocardial ischemia in patients with coronary artery disease (CAD). Because of its effect on myocardial glucose utilization TMZ may represent a therapeutic option in diabetic patients with CAD. Aim of the present study was to evaluate whether the metabolic effect of TMZ may improve episodes of myocardial ischemia in diabetic patients with CAD.

RESEARCH DESIGN AND METHODS

We assessed the effect of TMZ on 24 h ambulatory ECG monitoring (AEM) in 30 patients (22 males and 8 females, mean (SE) age 67+/-6.5 years) with NIDDM and ischemic cardiomyopathy. Patients were randomized to receive on top of standard therapy either TMZ (20 mg, tds) or placebo (tds) and were evaluated at baseline and after 6 months.

RESULTS

Patients randomized to TMZ or placebo were comparable regarding demographic data, distribution of CAD, and glicated haemoglobin levels. TMZ significantly reduced the number of episodes of transient myocardial ischemia (-24% compared to baseline, p<0.01; -27% compared to placebo, p<0.01), and Total Ischemic Burden (-28% compared to baseline, p<0.01; -29% compared to placebo, p<0.01). TMZ also significantly reduced the number of silent episodes of myocardial ischemia (-42% compared to baseline and -39% compared to placebo, p<0.01) and the time of silent myocardial ischemia/24 h (-37% compared to baseline and -35% compared to placebo, p<0.01). No significant changes in heart rate were detected between baseline, placebo and TMZ evaluations.

CONCLUSIONS

TMZ is effective in reducing silent and symptomatic episodes of transient myocardial ischemia in diabetic patients with CAD on standard anti-anginal therapy.

Trimetazidine added to combined hemodynamic antianginal therapy in patients with type 2 diabetes: a randomized crossover trial

BACKGROUND

In nondiabetic patients with stable angina, combined treatment with hemodynamic agents and trimetazidine is well-tolerated and effective in controlling ischemia. This study aims to evaluate the antiischemic and metabolic effects of trimetazidine in patients with type 2 diabetes mellitus, not eligible for revascularization, who remained symptomatic despite the use of at least 2 antianginal agents.

METHODS

A randomized, double-blind, crossover clinical trial was used. Ten patients were randomized to receive trimetazidine (20 mg, 3 times a day) or placebo for 6-week periods. At baseline and at the end of each 6-week intervention period, clinical and biochemical evaluations, exercise testing, 24-hour ambulatory blood pressure, and Holter monitoring were performed.

RESULTS

During trimetazidine therapy, patients had significant improvement on angina functional class (P < .05), with decrease in the number of weekly angina episodes (1.5 +/- 0.8 vs 0.4 +/- 0.7, P < .01), and in sublingual nitrate doses (1.4 +/- 0.7 mg vs 0.1 +/- 0.3 mg, P < .001). Time to 1-mm ST-segment depression during exercise test was increased after trimetazidine use (229 +/- 126 seconds at baseline, 276 +/- 101 seconds after placebo, and 348 +/- 145 seconds after trimetazidine, P < .001). No differences were observed between treatment periods on mean 24-hour blood pressure, heart rate, and rate-pressure product evaluated concomitantly with ambulatory blood pressure and Holter monitoring. Glycemic and lipid profiles were similar after trimetazidine and placebo use.

CONCLUSIONS

In patients with diabetes who remain symptomatic, the addition of trimetazidine improves symptoms and exercise responses without hemodynamic or metabolic changes. The present data suggest that trimetazidine may be an effective adjunct therapy for these patients, but further investigation is needed to confirm these findings.

The effects of chronic trimetazidine treatment on mechanical function and fatty acid oxidation in diabetic rat hearts

Clinical and experimental evidence suggest that increased rates of fatty acid oxidation in the myocardium result in impaired contractile function in both normal and diabetic hearts. Glucose utilization is decreased in type 1 diabetes, and fatty acid oxidation dominates for energy production at the expense of an increase in oxygen requirement. The objective of this study was to examine the effect of chronic treatment with trimetazidine (TMZ) on cardiac mechanical function and fatty acid oxidation in streptozocin (STZ)-diabetic rats. Spontaneously beating hearts from male Sprague–Dawley rats were subjected to a 60-minute aerobic perfusion period with a recirculating Krebs–Henseleit solution containing 11 mmol/L glucose, 100 μU/mL insulin, and 0.8 mmol/L palmitate prebound to 3% bovine serum albumin (BSA). Mechanical function of the hearts, as cardiac output × heart rate (in (mL/min)·(beats/min)·10–2), was deteriorated in diabetic (73 ± 4) and TMZ-treated diabetic (61 ± 7) groups compared with control (119 ± 3) and TMZ-treated controls (131 ± 6). TMZ treatment increased coronary flow in TMZ-treated control (23 ± 1 mL/min) hearts compared with untreated controls (18 ± 1 mL/min). The mRNA expression of 3-ketoacyl-CoA thiolase (3-KAT) was increased in diabetic hearts. The inhibitory effect of TMZ on fatty acid oxidation was not detected at 0.8 mmol/L palmitate in the perfusate. Addition of 1 μmol/L TMZ 30 min into the perfusion did not affect fatty acid oxidation rates, cardiac work, or coronary flow. Our results suggest that higher expression of 3-KAT in diabetic rats might require increased concentrations of TMZ for the inhibitory effect on fatty acid oxidation. A detailed kinetic analysis of 3-KAT using different concentrations of fatty acid will determine the fatty acid inhibitory concentration of TMZ in diabetic state where plasma fatty acid levels are increased.

Metabolic therapy for patients with diabetes mellitus and coronary artery disease

Patients with diabetes mellitus and ischemic heart disease more frequently develop heart failure and have a greater amount of myocardial ischemia, often silent, compared with patients without diabetes. Furthermore, patients with coronary artery disease (CAD) and diabetes or insulin resistance have altered myocardial metabolism and accelerated and diffuse atherogenesis with involvement of distal coronary segments that causes chronic hypoperfusion and hibernation. Therefore, in patients with diabetes and CAD, the ischemic metabolic changes are heightened by the metabolic changes in patients with diabetes. An important metabolic alteration in patients with diabetes is the increase in free fatty acid (FFA) concentrations and the increased skeletal muscle and myocardial FFA uptake and oxidation. The increased uptake and utilization of FFA and the reduced utilization of glucose as a source of energy during stress and ischemia contribute to the increased susceptibility of diabetic hearts to myocardial ischemia and to a greater decrease of myocardial performance for a given amount of ischemia compared with nondiabetic hearts. A therapeutic approach aimed at an improvement in cardiac metabolism through manipulations of the use of metabolic substrates should result in an improvement in myocardial ischemia and left ventricular (LV) function. The inhibition of FFA oxidation with trimetazidine improves cardiac metabolism at rest, increases cardiac resistance to ischemia, and therefore reduces the decrease of LV function caused by chronic hypoperfusion and repetitive episodes of myocardial ischemia in patients with and without diabetes. Thus, modulation of myocardial FFA metabolism should be the key target for metabolic interventions in patients with CAD with and without diabetes. In patients with diabetes, the effects of modulation of FFA metabolism should be even greater compared with those observed in patients without diabetes. Because of its effect on cardiac metabolism at rest and its effects on myocardial ischemia and LV function, trimetazidine should always be considered for the treatment of patients with diabetes with CAD with or without LV dysfunction.

A randomized clinical trial of trimetazidine, a partial free fatty acid oxidation inhibitor, in patients with heart failure

OBJECTIVES

This study sought to assess whether the long-term addition of trimetazidine to conventional treatment could improve functional class, exercise tolerance, and left ventricular function in patients with heart failure (HF).

BACKGROUND

Previous small studies have shown that trimetazidine may be beneficial in terms of left ventricular function preservation and control of symptoms in patients with post-ischemic HF.

METHODS

Fifty-five patients with HF were randomly allocated in an open-label fashion to either conventional therapy plus trimetazidine (20 mg three times daily) (28 patients) or conventional therapy alone (27 patients). Mean follow-up was 13 +/- 3 months. At study entry and at follow-up, all patients underwent exercise testing and two-dimensional echocardiography. Among the others, New York Heart Association (NYHA) functional class and ejection fraction (EF) were evaluated.

RESULTS

In the trimetazidine group, NYHA functional class significantly improved compared with the conventional therapy group (p < 0.0001). Treatment with trimetazidine significantly decreased left ventricular end-systolic volume (from 98 +/- 36 ml to 81 +/- 27 ml, p = 0.04) and increased EF from 36 +/- 7% to 43 +/- 10% (p = 0.002). On the contrary, in the conventional therapy group, both left ventricular end-diastolic and -systolic volumes increased from 142 +/- 43 ml to 156 +/- 63 ml, p = 0.2, and from 86 +/- 34 ml to 104 +/- 52 ml, p = 0.1, respectively; accordingly, EF significantly decreased from 38 +/- 7% to 34 +/- 7% (p = 0.02).

CONCLUSIONS

In conclusion, long-term trimetazidine improves functional class and left ventricular function in patients with HF. This benefit contrasts with the natural history of the disease, as shown by the decrease of EF in patients on standard HF therapy alone.

The anti-ischemic effect of trimetazidine in patients with postprandial myocardial ischemia is unrelated to meal composition

BACKGROUND

Previous studies provide evidence for a significant reduction of coronary flow reserve after ingestion of meals of different compositions. A possible role of hyperinsulinemia and increased free fatty acid levels, which are deleterious during acute myocardial ischemia and reperfusion, has been hypothesized. We assessed in patients with stable coronary disease the effects of high-fat meals (HFMs) and high-carbohydrate meals (HCMs) on ischemic threshold and stress left ventricular function on placebo and after partial fatty acid inhibition by trimetazidine (TMZ).

METHODS

Ten patients (9 men, age 68 +/- 7 years) were allocated to placebo and TMZ (40 mg TID), both administered in the 24 hours preceding testing, according to a randomized double-blind study design. All patients underwent stress (treadmill exercise testing according to the Bruce protocol) echocardiography after fasting (8 hours) and after an HFM and HCM (2 hours) either on placebo or on TMZ. Time to 1-mm ST-segment depression (time to 1 mm) and stress wall motion score index (WMSI) were evaluated.

RESULTS

An HFM did not affect exercise variables compared with fasting, whereas an HCM resulted in a reduction of the ischemic threshold (time to 1 mm from 402 +/- 141 to 292 +/- 123 seconds, P = .025). Compared with placebo, TMZ improved time to 1 mm after fasting, HFM, and HCM (432 +/- 153 vs 402 +/- 141, 439 +/- 118 vs 380 +/- 107, 377 +/- 123 vs 292 +/- 123, F(1,9) = 26.91, P = .0006). Compared with placebo, on TMZ, stress WMSI decreased from 1.55 +/- 0.25 to 1.29 +/- 0.14 after fasting, from 1.57 +/- 0.10 to 1.39 +/- 0.28 after HFM, and from 1.64 +/- 0.21 to 1.39 +/- 0.21 after HCM (F(1,9) = 37.04, P = .0002). Interestingly, stress WMSI on TMZ was never different from rest WMSI on placebo.

CONCLUSIONS

In patients with coronary disease, exercise testing after an HCM results in more severe myocardial ischemia compared with that after an HFM. The observed beneficial effects of the partial fatty acid inhibitor TMZ seem to be unrelated to meal composition and are possibly caused by the better glucose use induced by the drug.

Placebo or trimetazidine (99m)Tc tetrofosmin myocardial SPECT and low-dose dobutamine echocardiography in hibernating myocardium

BACKGROUND

Trimetazidine (TMZ) improves (99m)Tc sestamibi uptake in myocardial single photon emission tomography (SPECT). This study compared TMZ (99m)Tc tetrofosmin SPECT and low-dose dobutamine echocardiography (LDDE) as predictors of functional recovery of hibernating myocardium after coronary revascularization.

METHODS

Thirty-one patients with prior myocardial infarction and left ventricular dysfunction underwent coronary angiography, LDDE, placebo SPECT and TMZ SPECT. Echocardiographic follow-up was obtained at 2/6 months; the clinical follow-up lasted 2 years.

RESULTS

Twenty-three (74.2%) patients (195 dysfunctioning left ventricular segments) were revascularized. TMZ improved (99m)Tc tetrofosmin uptake (p = 0.0001) as well as LVEF at gated SPECT (p = 0.04). At 2-months, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated (LDDE 71.9, 78.7, 71, 79.5; placebo SPECT 66.2, 75.6, 65.4, 76.3; TMZ SPECT 79.2, 67.7, 61.6, 83.3, respectively). The specificity improved in placebo and TMZ SPECT (82.1 and 78.7%) at 6-months follow-up. Two patients (2/23) with hibernating myocardium treated with revascularization and three (3/4) treated medically died a cardiac death (p = 0.0016, log rank 12.89). None (0/4) without viability died during the 2-year follow-up (p = 0.6, log rank 0.28).

CONCLUSIONS

The addition of TMZ to (99m)Tc tetrofosmin SPECT improved diagnostic accuracy. The importance of hibernating myocardium revascularization was confirmed.

Metabolic therapy for the diabetic patients with ischaemic heart disease

Diabetic patients with ischaemic heart disease have a greater amount of myocardial ischaemia, often silent, and an increased incidence of heart failure compared to nondiabetic patients. This is the result of altered myocardial metabolism and accelerated atherogenesis with involvement of peripheral coronary segments causing chronic hypoperfusion and diffuse hybernation. In patients with diabetes mellitus and myocardial ischaemia, the metabolic changes occurring as a consequence of the mismatch between blood supply and cardiac metabolic requirements are heightened by the diabetic metabolic changes. An important metabolic alteration of diabetes is the increase in free fatty acid concentrations and increased muscular and myocardial free fatty acid uptake and oxidation. This increased uptake and utilization of free fatty acid during stress and ischaemia is responsible for the increased susceptibility of the diabetic heart to myocardial ischaemia and to a greater decrease of myocardial performance for a given amount of ischaemia compared to nondiabetic hearts. Given the metabolic alterations of the diabetic heart at rest and during episodes of myocardial ischaemia, a therapeutic approach aimed at an improvement of cardiac metabolism through manipulations of the utilization of metabolic substrates should result in an improvement of myocardial ischaemia and of left ventricular function. Modulation of myocardial free fatty acid metabolism should be the key target for metabolic interventions in patients with coronary artery disease with and without diabetes. In diabetic patients, the effects of modulation of free fatty acid metabolism should be even greater than those observed in patients without diabetes. The inhibition of FFA oxidation with trimetazidine improves cardiac metabolism at rest, decreases cardiac ischaemia and therefore prevents the decline of left ventricular function due to chronic hypoperfusion and repetitive episodes of myocardial ischaemia. Because of its effect on cardiac metabolism at rest, its effects on myocardial ischaemia and left ventricular function trimetazidine should always be considered for the treatment of diabetic patients with ischaemic heart disease with or without left ventricular dysfunction.

Effects of trimetazidine on myocardial perfusion and the contractile response of chronically dysfunctional myocardium in ischemic cardiomyopathy: a 24-month study

OBJECTIVE

The aim was to assess the long-term effect of trimetazidine on myocardial perfusion, using gated single photon emission computerized tomography (SPECT).

METHODS

200 patients (aged 54.7 +/- 12 years) with ischemic left ventricular dysfunction (LVD) and multivessel coronary artery disease were randomized to receive trimetazidine 20mg three times daily or a placebo for 24 months. At baseline and after 24 months of treatment, all patients underwent a symptom-limited cardiopulmonary exercise test concluded by the injection of (99m)Tc-MIBI (technetium-99m methoxy-isobutyl-isonitrile). Imaging of post-stress gated SPECT and resting gated SPECT were performed. Standard antianginal therapy was interrupted for 48 hours (nitrates for 6 hours) before the exercise tests and resumed immediately after testing.

RESULTS

On initial evaluation, summed stress and rest scores (SSS and SRS, respectively), systolic wall thickness (SWT), and wall motion score index (WMI), heart rate, SBP, and rate pressure product were similar at rest and peak exercise in both groups. After 24 months, 91% of patients in the trimetazidine group versus 22% in the placebo group showed a significant decrease of the frequency of anginal episodes per week (3.9 vs 5.7, p < 0.01). Weekly nitroglycerin (glyceryl trinitrate) tablet consumption was significantly lower with trimetazidine than with placebo at endpoint (2.3 +/- 0.8 vs 6.1 +/- 1.6, p < 0.01). This was supported by perfusion SPECT data. Compared with baseline values, SSS and SRS were significantly reduced with trimetazidine (from 19.8 +/- 7.7 to 11.2 +/- 6.1, p < 0.00001 and from 12.4 +/- 8.7 to 5.8 +/- 3.3, p < 0.00001, respectively). There was a nonsignificant decrease from baseline values in both SRS and SSS with placebo group (from 11.9 +/- 8.3 to 11.2 +/- 7.4 and 18.1 +/- 6.3 to 17.9 +/- 9.2, respectively). Duration of peak exercise increased significantly from baseline values with trimetazidine (from 4.6 to 5.8 minutes, p < 0.01) but not with placebo (from 5.4 to 5.8 minutes). Accordingly, mean maximum work at peak exercise improved by 1.2 metabolic equivalents with trimetazidine. This was proved by gated SPECT with an increase in SWT score of 89.5% (p < 0.00001) and in ejection fraction of 23% with trimetazidine (p < 0.001) without significant changes in hemodynamic parameters.

CONCLUSION

Trimetazidine improves ischemic attacks in patients with ischemic cardiomyopathy, clinically and objectively as seen in gated SPECT myocardial perfusion. The improvement in myocardial function with trimetazidine was not accompanied by hemodynamic changes.

Meeting the challenge of chronic ischaemic heart disease with trimetazidine

The risk of cardiovascular events in patients with diabetes is similar to that of patients with previous history of ischaemic heart disease and the prevalence of ischaemic heart disease complicating diabetic syndromes is growing rapidly. Management of ischaemic heart disease in diabetic patients remains a challenge. Therapeutic options include several antianginal agents, and mechanical removal of coronary obstructions by percutaneous transluminal coronary angioplasty, and aorto-coronary by-pass surgery. Unfortunately, all treatments are less effective in diabetic patients than in nondiabetic patients. Direct modulation of cardiac metabolic alterations associated with the diabetic syndrome appears as a promising alternative for the management of ischaemic heart disease in diabetic patients. Results obtained in anginal patients with the metabolic agent trimetazidine are consistent with this hypothesis.

Trimetazidine for stable angina

BACKGROUND

Patients with stable angina not controlled by monotherapy with nitrates, beta blockers, or calcium channel blockers are often treated with combinations of these drugs. There may be adverse effects from, or contraindications to, the use of combinations. In low risk groups, medical treatment appears to be as good an option as percutaneous transluminal coronary angioplasty in terms of averting myocardial infarction, death, or subsequent revascularization. Revascularization procedures are too costly or inaccessible for many patients in developing countries therefore effective and safe medical treatment is needed. Trimetazidine is a less well known anti-anginal drug that controls myocardial ischaemia through intracellular metabolic changes. Trimetazidine has been reported, in some studies, to be better tolerated than combined anti-anginal therapy; however it is not considered in published guidelines.

OBJECTIVES

To determine the efficacy and tolerability of trimetazidine in patients with stable angina.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS and SCISEARCH, without language restriction, from inception to October 2003. Experts in the field were contacted to locate unpublished studies.

SELECTION CRITERIA

Randomised studies comparing trimetazidine with placebo, or other anti-angina drug in adults with stable angina.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted data.

MAIN RESULTS

Twenty-three studies (1378 patients) met the inclusion criteria. There was a paucity of information about mortality, cardiovascular events and quality of life. Trimetazidine, compared with placebo, reduced the number of weekly angina attacks ( mean difference -1.44, 95% CI -2.10 to -0.79; P < 0.0001), reduced weekly nitroglycerin tablet consumption (95% CI -1.47 to -2.20, -0.73; P < 0.0001) and improved exercise time to 1 mm segment depression (P=0.0002). Four small trials (263 patients) compared trimetazidine against other anti-anginal agents. One favoured trimetazidine over nitrates. Three tended to favour alternative regimens but with confidence intervals consistent with both major increases and decreases in frequency of angina episodes. In this subgroup, adverse events were considered in 5 trials (448 patients) and totals of 2 versus 12 drop outs due to adverse events were observed in the trimetazidine and alternative regimens respectively, but this was mostly driven by a single trial.

AUTHORS' CONCLUSIONS

Trimetazidine is effective in the treatment of stable angina compared with placebo, alone or combined with conventional anti-anginal agents. Trimetazidine may result in fewer dropouts due to adverse events. Large, long term trials comparing trimetazidine with other anti-anginal drugs assessing clinically relevant important outcomes are required to establish its role in clinical management.

The acute administration of trimetazidine modified myocardial perfusion and left ventricular function in 31 patients with ischaemic ventricular dysfunction

Trimetazidine (TMZ) increases the mithocondrial oxidative metabolism and improves Tc-99m sestamibi uptake in myocardial single photon emission tomography (SPECT). The aim of this study was to evaluate whether the acute administration of TMZ improved myocardial perfusion and modified left ventricular ejection fraction (LVEF) in ischaemic left ventricular impairment.

METHODS

Thirty-one patients (23 males, age 66 years) with prior myocardial infarction (>6 months) and echocardiographic LVEF < or = 45% underwent coronary angiography, rest basal myocardial SPECT (after 3-day placebo administration) and rest TMZ myocardial SPECT [after 3-day TMZ administration (60mg/die)]. The left ventricle was analysed in 16 segments. The summed placebo score (SPS) and the summed TMZ score (STS) were calculated with a 5-point scale (from 0 = normal uptake to 4 = absent uptake) by two blinded operators. The GATED Tc-99m SPECT was always provided.

RESULTS

After TMZ administration GATED LVEF improved from 26.5+/-9.7% to 29.1+/-11.3% (p = 0.04) and left ventricular end-systolic volume (LVESV) was reduced from 90.2+/-40.7 to 85.6+/-39.2 ml/mq (p = 0.006). Similarly the addition of TMZ to myocardial SPECT significantly reduced the STS compared to SPS (21.5+/-11 vs. 26.6+/-10.5 p = 0.0001). Eleven patients (35.5%) had an echocardiographic LVEF < or = 30%; in these patients who had severe ventricular dysfunction, GATED LVEF and LVESV did not change after TMZ (20.2+/-5.7% vs. 21+/-6.9% p =0.6; 116.7+/-35.3 ml vs. 112.6+/-32.3 ml p = 0.08, respectively).

CONCLUSION

In comparison with placebo, the addition of TMZ to myocardial Tc-99m tetrofosmin SPECT improved myocardial perfusion and LVEF, reducing LVESV. These effects were lost in patients with more severe ventricular dysfunction.

Myocardial substrate metabolism in the normal and failing heart

The alterations in myocardial energy substrate metabolism that occur in heart failure, and the causes and consequences of these abnormalities, are poorly understood. There is evidence to suggest that impaired substrate metabolism contributes to contractile dysfunction and to the progressive left ventricular remodeling that are characteristic of the heart failure state. The general concept that has recently emerged is that myocardial substrate selection is relatively normal during the early stages of heart failure; however, in the advanced stages there is a downregulation in fatty acid oxidation, increased glycolysis and glucose oxidation, reduced respiratory chain activity, and an impaired reserve for mitochondrial oxidative flux. This review discusses 1) the metabolic changes that occur in chronic heart failure, with emphasis on the mechanisms that regulate the changes in the expression of metabolic genes and the function of metabolic pathways; 2) the consequences of these metabolic changes on cardiac function; 3) the role of changes in myocardial substrate metabolism on ventricular remodeling and disease progression; and 4) the therapeutic potential of acute and long-term manipulation of cardiac substrate metabolism in heart failure.

Protective effect of trimetazidine on myocardial mitochondrial function in an ex-vivo model of global myocardial ischemia

Trimetazidine is an anti-ischemic drug whose cytoprotective mechanisms are not yet fully understood (but until now mainly related to the trimetazidine-induced "metabolic shift" from lipid beta-oxidation to glucose aerobic oxidation). We studied the effect of trimetazidine on the mitochondrial function of ischemic Wistar rat hearts perfused with glucose, using a model of ex-vivo perfusion (Langendorff system). We measured the electrical potential of the mitochondrial membrane, O2 consumption by the respiratory chain, energy charges generated and the enzyme activities of the respiratory chain complexes. In this model, trimetazidine had a preferential action on the oxidative system (mainly on complex I), increasing its enzyme activity and decreasing O2 consumption after phosphorylation; this could decrease oxygen free radical production and increase mitochondrial integrity, thus allowing the maintenance of the electrical potential. These results allow us to better understand the cytoprotective effects of trimetazidine in coronary artery disease.

Estudio prospectivo en pacientes diabéticos de la efectividad y la tolerabilidad de la trimetazidina en asociación al tratamiento previo de su enfermedad coronaria. Estudio DIETRIC

INTRODUCTION AND OBJECTIVES

Diabetics frequently suffer diffuse coronary disease with difficulties for coronary artery bypass graft, which means that they require multiple medical treatment. Trimetazidine is an anti-ischemic agent that improves the myocardial metabolism and that can be especially useful in the ischemic myocardium of diabetic patients. The objective of this study is to evaluate in diabetic patients the anti-ischemic effectiveness of trimetazidine associated with regular medical treatment.

METHODS

In the DIETRIC study 580 patients with diabetes type 2 and coronary disease have been included for the assessment of antianginous effect of trimetazidine (20 mg/8 h). Basal clinical record, physical examination, laboratory evaluation, ECG and exercise test were carried out, with 6-month follow-up. In this article the clinical and exercise test response to the treatment is analyzed.

RESULTS

A reduction of angina episodes was observed (2.8 vs 0,9; p < 0.001), in addition to a reduction of the number of weekly nitroglycerin tablets (2.5 vs 0,7; p < 0.001). In the exercise test carried out at 6-month follow-up an increase in its length was observed (441 vs 391 s; p < 0.001); also an increase of the time up to the decline of ST segment (214 vs 209 s; p = 0.02); at the same time a smaller decline of ST segment occurred (1.7 vs 1,2; p < 0.001). Tolerance was excellent.

CONCLUSIONS

In this group of patients with diabetes mellitus type 2 and coronary artery disease, trimetazidine associated with regular medical treatment decreased the incidence of angina episodes and the ischemic response in the exercise test with an excellent tolerance.

Fatty acid oxidation inhibitors in the management of chronic complications of atherosclerosis

Ischemic heart disease is characterized by a modification of the normal energy balance of the heart. During and following an ischemic event, circulating fatty acids are elevated, resulting in the acceleration of fatty acid oxidation at the expense of glucose oxidation. Despite the reduction in glucose oxidation, the rate of glycolysis increases, leading to an uncoupling of glucose metabolism. This results in the accumulation of metabolic byproducts, which leads to a decrease in cardiac efficiency. A novel therapeutic strategy involves improving the efficiency of oxygen utilization by the ischemic heart by the modulation of energy metabolism. This can be achieved by a reduction in the levels of circulating fatty acids using beta-blockers, glucose-insulin-potassium infusions, and nicotinic acid. Alternatively, fatty acid oxidation can be directly inhibited using trimetazidine, ranolazine, or glucose oxidation directly activated using dichloroacetate, which significantly improves the efficiency of the heart.

Trimetazidine improves left ventricular function in diabetic patients with coronary artery disease: a double-blind placebo-controlled study

Background

Patients with diabetic cardiomyopathy have an impaired myocardial glucose handling and distal distribution of coronary atherosclerosis. Trimetazidine, an anti-ischemic metabolic agent, improves myocardial glucose utilization though inhibition of fatty acid oxidation. Aim of the present study was to evaluate whether the metabolic effect of trimetazidine on left ventricular function in patients with diabetic cardiomyopathy.

Methods

32 patients (24 males and 8 females, mean (SE) age = 67 ± 6 years) with type 2 diabetes and ischemic cardiomyopathy were randomized to receive either trimetazidine (20 mg, t.d.s.) or placebo (t.d.s.) for six months in a randomized parallel study. Patients performed an echocardiogram at baseline and after 6 months.

Results

Demographic data were comparable between the two groups. After six month baseline left ventricular end-diastolic diameters increased from 62.4 ± 1.7 to 63 ± 2.1 mm in the placebo group, while decreased from 63.2 ± 2.1 to 58 ± 1.6 mm (p < 0.01 compared to baseline) in the trimetazidine group. Compared to baseline, left ventricular ejection fraction increased by 5.4 ± 0.5% (p < 0.05) in the trimetazidine group while remained unchanged in the placebo group -2.4 ± 1.1% (NS), p < 0.01 between groups. A significant improvement in wall motion score index and in the E/A wave ratio was detected in patients treated with trimetazidine, but not in those receiving placebo.

Conclusion

in diabetic patients with ischemic heart disease trimetazidine added to standard medical therapy has beneficial effect on left ventricular volumes and on left ventricular ejection fraction compared to placebo. This effect may be related to the effect of trimetazidine upon cardiac glucose utilization.

Beneficial effects of trimetazidine in ex vivo working ischemic hearts are due to a stimulation of glucose oxidation secondary to inhibition of long-chain 3-ketoacyl coenzyme a thiolase

High rates of fatty acid oxidation in the heart and subsequent inhibition of glucose oxidation contributes to the severity of myocardial ischemia. These adverse effects of fatty acids can be overcome by stimulating glucose oxidation, either directly or secondary to an inhibition of fatty acid oxidation. We recently demonstrated that trimetazidine stimulates glucose oxidation in the heart secondary to inhibition of fatty acid oxidation. This inhibition of fatty acid oxidation was attributed to an inhibition of mitochondrial long-chain 3-ketoacyl CoA thiolase (LC 3-KAT), an enzyme of fatty acid beta-oxidation. However, the accompanying Research Commentary of MacInnes et al suggests that trimetazidine does not inhibit cardiac LC 3-KAT. This discrepancy with our data can be attributed to the reversible competitive nature of trimetazidine inhibition of LC 3-KAT. In the presence of 2.5 micromol/L 3-keto-hexadecanoyl CoA (KHCoA), trimetazidine resulted in a 50% inhibition of LC-3-KAT activity. However, the inhibition of LC 3-KAT could be completely reversed by increasing substrate (3-keto-hexadecanoyl CoA, KHCoA) concentrations to 15 micromol/L even at high concentrations of trimetazidine (100 micromol/L). The study of MacInnes et al was performed using concentrations of 3K-HCoA in excess of 16 micromol/L, a concentration that would completely overcome 100 micromol/L trimetazidine inhibition of LC 3-KAT. Therefore, the lack of inhibition of LC 3-KAT by trimetazidine in the MacInnes et al study can easily be explained by the high concentration of KHCoA substrate used in their experiments. In isolated working hearts perfused with high levels of fatty acids, we found that trimetazidine (100 micromol/L) significantly improves functional recovery of hearts subjected to a 30-minute period of global no-flow ischemia. This occurred in the absence of changes in oxygen consumption resulting in an improved increase in cardiac efficiency. Combined with our previous studies, we conclude that trimetazidine inhibition of LC 3-KAT decreases fatty acid oxidation and stimulates glucose oxidation, resulting in an improvement in cardiac function and efficiency after ischemia. The full text of this article is available online at http://www.circresaha.org.

The antianginal agent trimetazidine does not exert its functional benefit via inhibition of mitochondrial long-chain 3-ketoacyl coenzyme A thiolase

Trimetazidine acts as an effective antianginal clinical agent by modulating cardiac energy metabolism. Recent published data support the hypothesis that trimetazidine selectively inhibits long-chain 3-ketoacyl CoA thiolase (LC 3-KAT), thereby reducing fatty acid oxidation resulting in clinical benefit. The aim of this study was to assess whether trimetazidine and ranolazine, which may also act as a metabolic modulator, are specific inhibitors of LC 3-KAT. We have demonstrated that trimetazidine and ranolazine do not inhibit crude and purified rat heart or recombinant human LC 3-KAT by methods that both assess the ability of LC 3-KAT to turnover specific substrate, and LC 3-KAT activity as a functional component of intact cellular beta-oxidation. Furthermore, we have demonstrated that trimetazidine does not inhibit any component of beta-oxidation in an isolated human cardiomyocyte cell line. Ranolazine, however, did demonstrate a partial inhibition of beta-oxidation in a dose-dependent manner (12% at 100 micromol/L and 30% at 300 micromol/L). Both trimetazidine (10 micromol/L) and ranolazine (20 micromol/L) improved the recovery of cardiac function after a period of no flow ischemia in the isolated working rat heart perfused with a buffer containing a relatively high concentration (1.2 mmol/L) of free fatty acid. In summary, both trimetazidine and ranolazine were able to improve ischemic cardiac function but inhibition of LC 3-KAT is not part of their mechanism of action. The full text of this article is available online at http://www.circresaha.org.

Effect of hyperglycemia and fatty acid oxidation inhibition during aerobic conditions and demand-induced ischemia

Metabolic interventions improve performance during demand-induced ischemia by reducing myocardial lactate production and improving regional systolic function. We tested the hypotheses that 1) stimulation of glycolysis would increase lactate production and improve ventricular wall motion, and 2) the addition of fatty acid oxidation inhibition would reduce lactate production and further improve contractile function. Measurements were made in anesthetized open-chest swine hearts. Three groups, hyperglycemia (HG), HG + oxfenicine (HG + Oxf), and control (CTRL), were treated under aerobic conditions and during demand-induced ischemia. During demand-induced ischemia, HG resulted in greater lactate production and tissue lactate content but had no significant effect on glucose oxidation. HG + Oxf significantly lowered lactate production and increased glucose oxidation compared with both the CTRL and HG groups. Myocardial energy efficiency was greater in the HG and HG + Oxf groups under aerobic conditions but did not change during demand-induced ischemia. Thus enhanced glycolysis resulted in increased energy efficiency under aerobic conditions but significantly enhanced lactate production with no further improvement in function during demand-induced ischemia. Partial inhibition of free fatty acid oxidation in the presence of accelerated glycolysis increased energy efficiency under aerobic conditions and significantly reduced lactate production and enhanced glucose oxidation during demand-induced ischemia.