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.

Effects of metabolic modulation by trimetazidine on left ventricular function and phosphocreatine/adenosine triphosphate ratio in patients with heart failure

AIMS

The addition of trimetazidine to standard treatment has been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy (31P-MRS), the effects of trimetazidine on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure.

METHODS AND RESULTS

Twelve heart failure patients were randomized in a double-blind, cross-over study to placebo or trimetazidine (20 mg t.i.d.) for two periods of 90 days. At the end of each period, all patients underwent exercise testing, 2D echocardiography, and MRS. New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate-pressure product, and metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. On trimetazidine, NYHA class decreased from 3.04+/-0.26 to 2.45+/-0.52 (P = 0.005), whereas EF (34+/-10 vs. 39+/-10%, P = 0.03) and METS (from 7.44+/-1.84 to 8.78+/-2.72, P = 0.03) increased. The mean cardiac PCr/ATP ratio was 1.35+/-0.33 with placebo, but was increased by 33% to 1.80+/-0.50 (P = 0.03) with trimetazidine.

CONCLUSION

Trimetazidine improves functional class and LV function in patients with heart failure. These effects are associated to the observed trimetazidine-induced increase in the PCr/ATP ratio, indicating preservation of the myocardial high-energy phosphate levels.

Trimetazidine: a new concept in the treatment of angina. Comparison with propranolol in patients with stable angina. Trimetazidine European Multicenter Study Group

1. Trimetazidine has a direct anti-ischaemic effect on the myocardium without altering the rate x pressure product or coronary blood flow. 2. The effects of trimetazidine (20 mg three times daily) were compared with those of propranolol (40 mg three times daily) in a double-blind parallel group multicentre study in 149 men with stable angina. 3. Reproducibility of exercise performance was verified during a 3 week run-in placebo washout period. All patients had > 1 mm ST-depression on exercise test. 4. After 3 months, similar anti-anginal efficacy was observed between the trimetazidine (n = 71) and propranolol (n = 78) groups. No significant differences were observed between trimetazidine and propranolol as regards anginal attack rate per week (mean difference P-TMZ: 2; 95% CI: -4.4, 0.5) and exercise duration (mean difference P-TMZ: 0 s; 95% CI: -33, 34) or time to 1 mm ST segment depression (mean difference P-TMZ: 13 s; 95% CI: -24, 51). Heart rate and rate x pressure product at rest and at peak exercise remained unchanged in the trimetazidine group but significantly decreased with propranolol (P < 0.001 in all cases). With both drugs there was a trend to decreased ischaemic episodes in the 46% patients who experienced ambulatory ischaemia on Holter monitoring. Six patients stopped trimetazidine and 12 propranolol. Of these, five in each group were withdrawn because of deterioration in cardiovascular status. 5. The results suggest that trimetazidine and propranolol at the doses studied have similar efficacy in patients with stable angina pectoris.(ABSTRACT TRUNCATED AT 250 WORDS)

Combination treatment in stable effort angina using trimetazidine and metoprolol: results of a randomized, double-blind, multicentre study (TRIMPOL II). TRIMetazidine in POLand

AIMS

To assess the antiischaemic efficacy and tolerability of the metabolic agent trimetazidine in combination with metoprolol in patients with stable effort angina.

METHODS

This was a randomized, multicentre, double-blind, placebo-controlled parallel group study. A total of 426 male and female patients with stable, effort-induced angina and documented coronary artery disease received either placebo or trimetazidine 20 mg three times daily in addition to metoprolol 50 mg twice daily. Treadmill exercise tests were performed at weeks (-1), 0, 4 and 12.

RESULTS

After 12 weeks, there were significantly greater improvements in the metoprolol + trimetazidine group than in the metoprolol + placebo group in: time to 1 mm ST segment depression, total workload, time to onset of angina, maximum ST segment depression, mean weekly number of angina attacks, mean weekly nitrate consumption, and grade of anginal pain. There was no evidence of any development of tolerance to trimetazidine. The tolerability of trimetazidine was excellent.

CONCLUSIONS

Therapy with trimetazidine plus metoprolol produced significant improvements in exercise stress tests and the symptoms of angina relative to metoprolol alone. With its metabolic effect, devoid of any haemodynamic action, trimetazidine is useful for combination therapy in patients with stable angina insufficiently controlled by monotherapy with a beta-blocker.

Metabolic manipulation in ischaemic heart disease, a novel approach to treatment

Antianginal drugs that exert their anti-ischaemic effects primarily by altering myocardial metabolism have recently attracted attention. They have the potential to relieve symptoms in patients with refractory angina who are already on "optimal" medical therapy and have disease that is not amenable to revascularisation, making these drugs an attractive addition to therapy, particularly for the elderly population. In some cases, they may even be used as first-line treatment. These drugs increase glucose metabolism at the expense of free-fatty-acid metabolism, enhancing oxygen efficiency during myocardial ischaemia. Whilst they have been demonstrated to reduce ischaemia in several clinical trials, their use remains limited. This review aims to draw attention to these "metabolic" antianginal drugs while surveying the evidence supporting their use and mode of action. Four metabolic antianginal drugs are reviewed: perhexiline, trimetazidine, ranolazine, and etomoxir. We also discuss the metabolic actions of glucose-insulin-potassium and beta-blockers and describe myocardial metabolism during normal and ischaemic conditions. The potential of these metabolic agents may extend beyond the treatment of ischaemia secondary to coronary artery disease. They offer significant promise for the treatment of symptoms occurring due to inoperable aortic stenosis, hypertrophic cardiomyopathy, and chronic heart failure.

Short- and long-term beneficial effects of trimetazidine in patients with diabetes and ischemic cardiomyopathy

BACKGROUND

Trimetazidine (TMZ) has been shown to partially inhibit free fatty acid oxidation by shifting substrate utilization from fatty acid to glucose. The aim of this study was to assess the effects of TMZ in patients with diabetes and ischemic cardiomyopathy.

METHODS

Sixteen patients with diabetes and ischemic hypokinetic cardiomyopathy (all males) on conventional therapy were randomized to receive either placebo or TMZ (20 mg 3 times per day), each arm lasting 15 days, and then again to receive either placebo or TMZ for 2 additional 6-month periods, according to a double-blind, crossover design. At the end of each period, all patients underwent exercise testing, 2-dimensional echocardiography, and hyperinsulinemic/euglycemic clamp. Among the others, New York Heart Association class, ejection fraction, exercise time, fasting blood glucose, end-clamp M value (index of total body glucose disposal) and endothelin-1 levels were evaluated.

RESULTS

Both in the short and long term (completed by 13 patients), on TMZ compared to placebo, ejection fraction (47 +/- 7 vs 41 +/- 9 and 45 +/- 8 vs 36 +/- 8%, P <.001 for both) and M value (4.0 +/- 1.8 vs 3.3 +/- 1.6, P =.003, and 3.5 +/- 1.5 vs 2.7 +/- 1.6 mg/kg body weight/min, P <.01) increased, while fasting blood glucose (121 +/- 30 vs 136 +/- 40, P =.02 and 125 +/- 36 vs 140 +/- 43, P =.19) and endothelin-1 (8.8 +/- 3.8 vs 10.9 +/- 3.8, P <.001 and 6.2 +/- 2.4 vs 9.2 +/- 4.3 pg/mL, P =.03) decreased. In the short term, 10 patients decreased 1 class on the NYHA scale during treatment with TMZ (P =.019 vs placebo). Eight patients decreased 1 NYHA class while on long-term TMZ treatment, while on placebo 1 patient increased 1 NYHA class and none improved (P =.018 vs placebo).

CONCLUSIONS

In a short series of patients with diabetes and ischemic cardiomyopathy, TMZ improved left ventricular function, symptoms, glucose metabolism, and endothelial function. Shifting energy substrate preference away from fatty acid metabolism and toward glucose metabolism by TMZ appears an effective adjunctive treatment in patients with diabetes with postischemic cardiomyopathy.

Trimetazidine improves left ventricular function and quality of life in elderly patients with coronary artery disease

AIM

Elderly patients have an increased incidence of ischaemic dilated cardiomyopathy often related to diffuse coronary artery disease. Trimetazidine protects ischaemic myocardium by improving the myocardial energy utilisation during myocardial ischaemia. Aim of the present study was to evaluate the effects of trimetazidine on left ventricular (LV) function in elderly patients with ischaemic heart disease and reduced LV function.

METHODS

Forty seven elderly patients (40 males and 7 females, mean age 78+/-3 years) were randomised to receive, in addition to standard therapy, either trimetazidine or placebo and were evaluated by echocardiography at baseline and after 6 months.

RESULTS

Trimetazidine and placebo had no effect on either blood pressure or heart rate (SBP 2+/-5 vs 4+/-6 mmHg, DBP -1+/-6 vs 3+/-4 mmHg, HR -3+/-7 vs 5+/-9 bpm, trimetazidine and placebo compared to baseline, respectively). At the end of the study patients randomised to trimetazidine showed a significant greater left ventricular function and smaller left ventricular diastolic and systolic diameters and volume indices compared to patients receiving placebo (LVEF: 34.4+/-2.3% vs 27+/-2.8%, p<0.0001; LVEDD: 58.6+/-1.9 mm vs 64+/-1.7 mm, p<0.0001; LVESD: 44.5+/-1.1 vs 50+/-0.8 mm, p<0.0001). A significant smaller wall motion score index was detected in trimetazidine-treated patients compared to those allocated to placebo (1.24+/-0.12 vs 1.45+/-0.19, p<0.01), the percentage change in LVEF compared to baseline was also significantly greater in trimetazidine-treated patients. Diastolic function significantly improved in the trimetazidine group while it remained unchanged in the placebo group. At follow-up evaluation, patients receiving trimetazidine showed a greater improvement in angina and NYHA class than patients allocated to placebo. Quality of life significantly improved in all patients treated with trimetazidine while remained unchanged in those allocated to placebo.

CONCLUSION

In elderly patients with ischaemic cardiomyopathy trimetazidine in addition to standard medical therapy has a beneficial effect on LV systolic and diastolic function, and improves quality of life.

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

Trimetazidine has been shown to have an antianginal effect, increasing exercise capability without producing any significant change of heart rate or systolic blood pressure. The aim of this study was to compare trimetazidine efficiency to that of another classical antianginal drug. A double-blind crossover trimetazidine versus nifedipine trial was carried out in 39 male patients, mean age 58 years, with effort angina for 5 years on average, and a mean number of weekly attacks of 2.4. Thirteen patients had previous myocardial infarction. Nineteen patients received nifedipine (40 mg per day) then trimetazidine (60 mg per day), and 20 patients received the drugs in the opposite order. Each therapeutic period of 6 weeks was preceded by 1 week of washout with placebo. Drug efficacy was assessed by a bicycle exercise tolerance test, performed at the beginning and at the end of each therapeutic period, and by clinical symptoms observed with placebo or with treatment. The statistical analysis was performed according to a crossover design, with repeated measurements. The decrease of the number of weekly attacks was not significantly different with trimetazidine and nifedipine. Results on the exercise test showed no significant differences for maximum workload, the duration of exercise, ST-segment depression at peak exercise, and the time to 1-mm ST-segment depression. Heart rate and systolic blood pressure were not significantly different at rest and at peak exercise. However, the change in the rate-pressure product at the same workload differed significantly between the drugs: It decreased with nifedipine and remained unchanged with trimetazidine, indicating the difference to be in the mode of action of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Pharmacological preconditioning of mesenchymal stem cells with trimetazidine (1-[2,3,4-trimethoxybenzyl]piperazine) protects hypoxic cells against oxidative stress and enhances recovery of myocardial function in infarcted heart through Bcl-2 expression

Stem cell transplantation is a possible therapeutic option to repair ischemic damage to the heart. However, it is faced with a number of challenges including the survival of the transplanted cells in the ischemic region. The present study was designed to use stem cells preconditioned with trimetazidine (1-[2,3,4-trimethoxybenzyl]piperazine; TMZ), a widely used anti-ischemic drug for treating angina in cardiac patients, to increase the rate of their survival after transplantation. Bone marrow-derived rat mesenchymal stem cells (MSCs) were subjected to a simulated host tissue environment by culturing them under hypoxia (2% O(2)) and using hydrogen peroxide (H(2)O(2)) to induce oxidative stress. MSCs were preconditioned with 10 microM TMZ for 6 h followed by treatment with 100 microM H(2)O(2) for 1 h and characterized for their cellular viability and metabolic activity. The preconditioned cells showed a significant protection against H(2)O(2)-induced loss of cellular viability, membrane damage, and oxygen metabolism accompanied by a significant increase in HIF-1alpha, survivin, phosphorylated Akt (pAkt), and Bcl-2 protein levels and Bcl-2 gene expression. The therapeutic efficacy of the TMZ-preconditioned MSCs was evaluated in an in vivo rat model of myocardial infarction induced by permanent ligation of left anterior descending coronary artery. A significant increase in the recovery of myocardial function and up-regulation of pAkt and Bcl-2 levels were observed in hearts transplanted with TMZ-preconditioned cells. This study clearly demonstrated the potential benefits of pharmacological preconditioning of MSCs with TMZ for stem cell therapy for repairing myocardial ischemic damage.

Effects of trimetazidine on the contractile response of chronically dysfunctional myocardium to low-dose dobutamine in ischaemic cardiomyopathy

BACKGROUND

There is evidence that trimetazidine, an anti-ischaemic agent with a direct cytoprotective effect on the myocardium, is effective in stable angina. However, it is not clear whether trimetazidine can improve the mechanical efficiency of chronically dysfunctional myocardium, and whether this potentially beneficial effect can translate into improvements in left ventricular function as well as functional capacity.

METHODS

Thirty-eight patients (52.7 +/- 8 years) with post-necrotic left ventricular dysfunction (ejection fraction: 33 +/- 5%) and multivessel coronary artery disease were studied. Patients were randomized into two matched groups. Group A received trimetazidine (20 mg three times daily) for 2 months, while group B received a placebo during the same period. The usual antianginal medications were not altered during the study. At baseline and after 2 months, all patients underwent low-dose dobutamine echocardiography (5-20 microg x kg(-1) x min(-1)), and a symptom-limited cardiopulmonary exercise test.

RESULTS

On initial evaluation, systolic wall thickening score index, heart rate, systolic blood pressure and rate pressure product were similar at rest and peak dobutamine in both groups. However, at 2 months, group A patients had significant improvements in the rest and peak systolic wall thickening score index (13% and 20.7%, P<0.001) and ejection fraction (19.7% and 14.1%, P<0.001) without concomitant changes in heart rate and blood pressure. Peak VO2 was also significantly increased in patients taking trimetazidine (15%, P=0.001 vs controls).

CONCLUSIONS

In patients with ischaemic cardiomyopathy, trimetazidine improves the contractile response of chronically dysfunctional myocardium to dobutamine without haemodynamic changes. This effect was associated with improvements in left ventricular function and peak VO2.

The protective effect of trimetazidine on myocardial ischemia/reperfusion injury through activating AMPK and ERK signaling pathway

INTRODUCTION

Trimetazidine (TMZ) is an anti-anginal drug that has been widely used in Europe and Asia. The TMZ can optimize energy metabolism via inhibition of long-chain 3-ketoacyl CoA thiolase (3-KAT) in the heart, with subsequent decrease in fatty acid oxidation and stimulation of glucose oxidation. However, the mechanism by which TMZ aids in cardioprotection against ischemic injury has not been characterized. AMP-activated protein kinase (AMPK) is an energy sensor that controls ATP supply from substrate metabolism and protects heart from energy stress. TMZ changes the cardiac AMP/ATP ratio by modulating fatty acid oxidation, thereby triggering AMPK signaling cascade that contributes to the protection of the heart from ischemia/reperfusion (I/R) injury.

METHODS

The mouse model of in vivo regional ischemia and reperfusion by the ligation of the left anterior descending coronary artery (LAD) was used for determination of myocardial infarction. The infarct size was compared between C57BL/6J WT mice and AMPK kinase dead (KD) transgenic mice with or without TMZ treatment. The ex vivo working heart perfusion system was used to monitor the effect of TMZ on glucose oxidation and fatty acid oxidation in the heart.

RESULTS

TMZ treatment significantly stimulates cardiac AMPK and extracellular signal-regulated kinase (ERK) signaling pathways (p<0.05 vs. vehicle group). The administration of TMZ reduces myocardial infarction size in WT C57BL/6J hearts, the reduction of myocardial infarction size by TMZ in AMPK KD hearts was significantly impaired versus WT hearts (p<0.05). Intriguingly, the administration of ERK inhibitor, PD98059, to AMPK KD mice abolished the cardioprotection of TMZ against I/R injury. The ex vivo working heart perfusion data demonstrated that TMZ treatment significantly activates AMPK signaling and modulating the substrate metabolism by shifting fatty acid oxidation to glucose oxidation during reperfusion, leading to reduction of oxidative stress in the I/R hearts. Therefore, both AMPK and ERK signaling pathways mediate the cardioprotection of TMZ against ischemic injury. The metabolic benefits of TMZ for angina patients could be due to the activation of energy sensor AMPK in the heart by TMZ administration.

Therapeutic value of a cardioprotective agent in patients with severe ischaemic cardiomyopathy

Trimetazidine (TMZ) has been shown to have anti-ischaemic properties improving exercise tolerance without haemodynamic effects. A 6-month double-blind placebo-controlled study was carried out in 20 patients, mean age 59 +/- 6 years, to examine the benefit of adding 60 mg of TMZ vs placebo to the classical therapy, excluding those previously treated with calcium-antagonists, conversion enzyme inhibitors, vasodilators and antiplatelet agents. All patients had severe ischaemic cardiomyopathy, confirmed by coronary angiography; six were in NYHA class IV; 14 in NYHA class III; four had mild recurrent angina pectoris. assessment included clinical and biological evaluation, electrocardiography (ECG), 24-h ECG monitoring, cardiac volume evaluation with chest X-ray, left ventricular fractional shortening by echocardiography, left ventricular ejection fraction by radionuclide angiography. Baseline characteristics were similar in placebo (11 patients) and TMZ (nine patients) groups. Eighteen patients (nine in each group) were followed up for 6 months. In eight patients of the placebo group, treatment had to be modified (addition of calcium antagonists: four patients, conversion enzyme inhibitors: two patients; digitalics: one patient; diuretics: one patient). In the TMZ group, digitalic therapy was withdrawn in one patient and added in one patient (P less than 0.01). At 6 months, all TMZ group patients were free from angina; dyspnoea was improved in all TMZ patients and in only one placebo patient (P less than 0.001). Ejection fraction, increased by 9.3% in the TMZ group and decreased by 15.6% in the placebo group (P less than 0.018), CV decreased by 7% with TMZ, increased by 4% with placebo. (P = 0.034).(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic therapy in the treatment of ischaemic heart disease: the pharmacology of trimetazidine

The primary result of myocardial ischaemia is reduced oxygen consumption and adenosine triphosphate (ATP) formation in the mitochondria, and accelerated anaerobic glycolysis, lactate accumulation and cell acidosis. Classic pharmacotherapy for demand-induced ischaemia is aimed at restoring the balance between ATP synthesis and breakdown by increasing the oxygen delivery (i.e. with long acting nitrates or Ca2+ channel antagonist) or by decreasing cardiac power by reducing blood pressure and heart rate (i.e. with beta-blocker or Ca2+ channel antagonist). Animal studies show that fatty acids are the primary mitochondrial substrate during moderate severity myocardial ischaemia, and that they inhibit the oxidation of carbohydrate and drive the conversion of pyruvate to lactate. Drugs that partially inhibit myocardial fatty acid oxidation increase carbohydrate oxidation, which results in reduced lactate production and a higher cell pH during ischaemia. Trimetazidine (1-[2,3,4-trimethoxibenzyl]-piperazine) is the first and only registered drug in this class, and is available in over 90 countries world-wide. Trimetazidine selectively inhibits the fatty acid beta-oxidation enzyme 3-keto-acyl-CoA dehydrogenase (3-KAT), and is devoid of any direct haemodynamic effects. In double-blind placebo-controlled trials trimetazidine significantly improved symptom-limited exercise performance in stable angina patients when used either as monotherapy or in combination with beta-blockers or Ca2+ channel antagonists. Given available evidence, trimetazidine is an excellent alternative to classic haemodynamic agents, and is unique in its ability to reduce symptoms of angina when used in patients resistant to a haemodynamic treatment as vasodilators, beta-blockers or Ca2+ channel antagonists.

Changes in intracellular sodium and pH during ischaemia-reperfusion are attenuated by trimetazidine. Comparison between low- and zero-flow ischaemia

OBJECTIVE

The aim of this study was to investigate whether trimetazidine (TMZ; 10(-6)M), which has been shown to inhibit fatty acid oxidation, reduces the ionic imbalance induced by ischaemia and reperfusion, especially through an attenuation in intracellular changes in H(+) and Na(+).

METHODS

Isovolumic rat hearts receiving 5.5 mM glucose and 1.2 mM palmitate as metabolic substrates were exposed to zero-flow ischaemia (TI) or low-flow ischaemia (LFI - coronary flow decreased by an average of 90%) (30 min at 37 degrees C) and then reperfused. 23Na nuclear magnetic resonance (NMR) spectroscopy was used to monitor intracellular Na(+) (Na(+)(i)) and 31P NMR spectroscopy was used to monitor intracellular pH (pH(i)).

RESULTS

During LFI the major effect of TMZ was a significant reduction in intracellular acidosis, whereas during TI the main effect of TMZ was a significant reduction in Na(+)(i) gain. In addition, the further gain in Na(+)(i) that occurred during the first minutes of reperfusion following TI, and to a far lesser extent following LFI, was suppressed in TMZ-treated hearts and also suppressed when hearts were perfused without fatty acid. In both LFI and TI, TMZ-induced attenuation of ionic imbalance was associated with a significantly improved recovery of ventricular function on reperfusion, as assessed by a lower increase in diastolic pressure and an increased recovery of developed pressure.

CONCLUSION

Our data provide evidence that specific myocardial metabolic modulation plays a significant role in reducing ionic imbalance during ischaemia and reperfusion.

The use of partial fatty acid oxidation inhibitors for metabolic therapy of angina pectoris and heart failure

BACKGROUND

Partial fatty acid oxidation inhibitors have raised great interest since they are expected to counteract a dysregulated gene expression of hypertrophied cardiocytes. Some of these compounds have been developed for treating non-insulin-dependent diabetes mellitus and stable angina pectoris. A shift from fatty acid oxidation to glucose oxidation leads to a reduced gluconeogenesis and improved economy of cardiac work. An increased glucose oxidation can be achieved with the following enzyme inhibitors: etomoxir, oxfenicine, methyl palmoxirate, S-15176, metoprolol, amiodarone, perhexiline (carnitine palmitoyltransferase-1); aminocarnitine, perhexiline (carnitine palmitoyltransferase-2); hydrazonopropionic acid (carnitine-acylcarnitine translocase); MET-88 (gamma-butyrobetaine hydroxylase); 4-bromocrotonic acid, trimetazidine, possibly ranolazine (thiolases); hypoglycin (butyryl-CoA dehydrogenase); dichloroacetate (pyruvate dehydrogenase kinase). CLINICAL TRIALS with trimetazidine and ranolazine showed that this shift in substrate oxidation has an antianginal action. Etomoxir and MET-88 improved the function of overloaded hearts by increasing the density of the Ca(2+) pump of sarcoplasmic reticulum (SERCA2). The promoters of SERCA2 and alpha-myosin heavy-chain exhibit sequences which are expected to respond to transcription factors responsive to glucose metabolites and/or peroxisome proliferator-responsive element (PPAR) agonists. Further progress in elucidating novel compounds which upregulate SERCA2 expression is closely linked to the characterization of regulatory sequences of the SERCA2 promoter.

Modification of myocardial substrate use as a therapy for heart failure

Despite advances in treatment, chronic heart failure is still associated with significant morbidity and a poor prognosis. The scope for further advances based on additional neurohumoral blockade is small. Effective adjunctive therapies acting via a different cellular mechanism would, therefore, be attractive. Energetic impairment seems to contribute to the pathogenesis of heart failure. The findings from several studies have shown that the so-called metabolic agents could have potential as adjunctive therapies in heart failure. These agents cause a shift in the substrate used by the heart away from free fatty acids, the oxidation of which normally provides around 70% of the energy needed, towards glucose. The oxygen cost of energy generation is lessened when glucose is used as the substrate. In this review we aim to draw attention to the metabolic alteration in heart failure and we present evidence supporting the use of metabolic therapy in heart failure.

Efficacy and tolerability of trimetazidine in stable angina: a meta-analysis of randomized, double-blind, controlled trials

OBJECTIVE

The objective of this meta-analysis was to evaluate the efficacy and tolerance of the metabolic agent trimetazidine (TMZ), both in monotherapy and in combination with other antianginal agents, in the treatment of stable angina pectoris. A search of literature published between 1985 and 2001 was performed on computerized databases (MEDLINE and EMBASE).

METHODS

Only double-blind, randomized, controlled trials were included in this meta-analysis. Patients had to be treated for at least 2 weeks. Four parameters were selected, one clinical parameter (number of weekly angina attacks) and three ergometric parameters (time to 1 mm ST-segment depression, total work and exercise duration at peak exercise). They were evaluated at baseline and at the end of the treatment period.The quality of the trials was assessed on specific methodological criteria. Standard statistical methods, pooled odds ratio and 95% confidence intervals for subjective symptoms and pooled z and P for objective symptoms, were used.

RESULTS

Twelve clinical studies meeting our criteria were analyzed. Results showed that TMZ significantly reduced the number of weekly angina attacks in coronary patients and improved time to 1 mm segment depression and total work at peak exercise, while exercise duration at peak exercise showed a trend toward improvement (P = 0.09).

CONCLUSION

This meta-analysis confirms the efficacy of TMZ in the treatment of stable angina, compared with placebo or conventional antianginal agent, as well as in monotherapy or in combination with conventional antianginal agents. TMZ is well tolerated in monotherapy as well as in combination.

Combination treatment with trimetazidine and diltiazem in stable angina pectoris

OBJECTIVE

To assess antianginal efficacy and possible adverse haemodynamic effects of combination treatment with trimetazidine and diltiazem in patients with stable angina.

DESIGN

Double blind, randomised, placebo controlled trial of four weeks duration.

SETTING

Outpatient department of two Indian hospitals.

SUBJECTS

64 male patients with stable angina, uncontrolled on diltiazem alone.

INTERVENTIONS

Diltiazem 180 mg and trimetazidine 60 mg, or diltiazem 180 mg and placebo daily.

MAIN OUTCOME MEASURE

Change in exercise time to 1 mm ST segment depression.

RESULTS

33 patients (55%) had no exercise induced angina at 3 mm ST segment depression at inclusion in the study (silent ischaemia). Intention to treat analysis showed that of 32 patients in each treatment group, the number (%) of patients responding to trimetazidine compared to placebo was: for anginal attacks, 28 (87.5) v 15 (46.9), p < 0.001; for exercise time to 1 mm ST segment depression, 21 (65.6) v 9 (28.1), p < 0.003; for exercise time to angina, 12 (37.5) v 5 (15.6), p < 0.05; and for maximum work at peak exercise, 17 (53.1) v 8 (25), p < 0.02. Compared to placebo, there was net improvement with trimetazidine in mean anginal attacks of 4.8/ week (95% confidence interval (CI) 7.5 to 2.1; p < 0.002); in mean exercise times at 1 mm ST segment depression of 94.2 seconds (95% CI 182.8 to 5.6; p < 0.05), and at onset of angina of 113.1 seconds (95% CI 181.6 to 44.6; p < 0.02); and in mean maximum work at peak exercise of 1.4 metabolic equivalents (95% CI 2.4 to 0.3; p < 0.05).

CONCLUSIONS

Patients with stable angina uncontrolled with diltiazem had a clinically important improvement after combination treatment with trimetazidine, without adverse haemodynamic events or increased side effects.

Effect of 48-h intravenous trimetazidine on short- and long-term outcomes of patients with acute myocardial infarction, with and without thrombolytic therapy; A double-blind, placebo-controlled, randomized trial. The EMIP-FR Group. European Myocardial Infarction Project--Free Radicals

AIMS

To compare the effect of trimetazidine (TMZ) versus placebo administered during the acute phase of myocardial infarction on long- and short-term mortality.

METHODS AND RESULTS

EMIP-FR (European Myocardial Infarction Project - Free Radicals) was a prospective, double-blind, European multicentre trial in which 19 725 patients, presenting symptoms of acute myocardial infarction within the previous 24 h were randomized. Stratification was according to thrombolytic therapy (56%) or not (44%). An intravenous bolus injection of trimetazidine (40 mg) was given just before or simultaneously with thrombolysis, followed by continuous infusion (60 mg. 24 h(-1)) for 48 h. Overall, no difference was found between trimetazidine and placebo for the main end-point, short-term (35-day) mortality, (P = 0.98) in an intention-to-treat analysis. This was the result of opposing trends in the two strata. Thrombolysed patients showed a tendency towards more short-term deaths with trimetazidine, compared to placebo (trimetazidine: 11.3%, placebo: 10.5%, P = 0.15) and non-thrombolysed patients the converse (trimetazidine: 14.0%, placebo: 15.1%, P = 0.14). In a per-protocol analysis the beneficial effect of trimetazidine for non-thrombolysed patients became statistically significant (trimetazidine: 13.3%, placebo: 15.1%, P = 0.027).

CONCLUSION

Trimetazidine does not reduce mortality in patients undergoing thrombolytic therapy; however, it might have some beneficial effect for non-thrombolysed patients.

Trimetazidine in Angina Combination Therapy-The TACT Study: Trimetazidine versus Conventional Treatment in Patients with Stable Angina Pectoris in a Randomized, Placebo-Controlled, Multicenter Study

The aim of this study was to assess the efficacy and acceptability of trimetazidine (TMZ) in combination with hemodynamic agents (beta-blockers or long-acting nitrates) in 177 stable angina patients. In this randomized, placebo-controlled study (TACT: Trimetazidine in Angina Combination Therapy), stable angina patients resistant to nitrates or beta-blockers were selected. After a 1-week selection period (W0), patients who had a difference of <10% in duration between 2 positive exercise tests, defined as 1-mm ST-segment depression (STD) 80 milliseconds after J point with angina pain or 1.5 mm without pain were randomly treated with TMZ (20 mg t.i.d., n = 90) or placebo (Pbo t.i.d., n = 87) orally. A final exercise test was performed after 12 weeks of treatment (W12). The efficacy was assessed by exercise test duration, time to 1-mm STD, time to angina onset, mean number of angina attacks, mean short-acting nitrate consumption, and rate-pressure product. Differences (W12 - W0) in these parameters were analyzed using the Student t test. All statistical tests were conducted at the 5% significance level. At inclusion and during the study, 52% of patients received long-acting nitrates, and 48% were treated with a beta-blocker as monotherapy. At the beginning of the study, the TMZ and Pbo groups were statistically homogeneous with respect to all analyzed characteristics (demographic characteristics, characteristics of anamnesis, characteristics used for evaluation of antianginal therapy efficacy). For various reasons, 11 patients (7 from the Pbo group and 4 from the TMZ group) were excluded from the trial. A total of 166 patients (80 from the Pbo group and 86 from the TMZ group) completed the study in full compliance with the protocol. After 12 weeks of therapy, exercise test duration increased from 417.7 +/- 14.2 (W0) to 506.8 +/- 17.7 seconds (W12) in the TMZ group versus 435.3 +/- 14.8 (W0) to 458.9 +/- 16.2 seconds (W12) in the Pbo group (P < 0.05). Time to 1-mm STD increased from 389.0 +/- 15.3 (W0) to 479.6 +/- 18.6 seconds (W12) in the TMZ group versus 411.8 +/- 15.2 (W0) to 428.5 +/- 17.3 seconds (W12) in the Pbo group (P < 0.05). Time to onset of anginal pain increased from 417.0 +/- 16.9 (W0) to 517.3 +/- 21.0 seconds (W12) in the TMZ group versus 415.1 +/- 16.5 (W0) to 436.4 +/- 18.5 seconds (W12) in the Pbo group (P < 0.005). The mean number of anginal attacks per week decreased from 5.6 +/- 0.6 to 2.7 +/- 0.5 in the TMZ group versus 6.8 +/- 0.7 to 5.1 +/- 0.7 in the Pbo group (P < 0.05), mean consumption short-acting nitrates per week decreased from 5.2 +/- 0.9 to 2.8 +/- 0.8 in the TMZ group versus 5.5 +/- 0.8 to 4.1 +/- 0.9 in the Pbo group (NS). No change in the rate-pressure product was seen in both. The combination of trimetazidine with beta-blockers or long-acting nitrates significantly improves exercise stress test parameters and angina symptoms compared with placebo. Due to its metabolic effect, free of any hemodynamic action, trimetazidine has proven to be beneficial for combination in patients with stable angina.

Mitochondria-mediated cardioprotection by trimetazidine in rabbit heart failure

Trimetazidine (TMZ) is used successfully for treatment of ischemic cardiomyopathy, however its therapeutic potential in heart failure (HF) remains to be established. While the cardioprotective action of TMZ has been linked to inhibition of free fatty acid oxidation (FAO) via 3-ketoacyl CoA thiolase (3-KAT), additional mechanisms have been suggested. The aim of this study was to evaluate systematically the effects of TMZ on calcium signaling and mitochondrial function in a rabbit model of non-ischemic HF and to determine the cellular mechanisms of the cardioprotective action of TMZ. TMZ protected HF ventricular myocytes from cytosolic Ca(2+) overload and subsequent hypercontracture, induced by electrical and ß-adrenergic (isoproterenol) stimulation. This effect was mediated by the ability of TMZ to protect HF myocytes against mitochondrial permeability transition pore (mPTP) opening via attenuation of reactive oxygen species (ROS) generation by the mitochondrial electron transport chain (ETC) and uncoupled mitochondrial nitric oxide synthase (mtNOS). The majority of ROS generated by the ETC in HF arose from enhanced complex II-mediated electron leak. TMZ inhibited the elevated electron leak at the level of mitochondrial ETC complex II and improved impaired activity of mitochondrial complex I, thereby restoring redox balance and mitochondrial membrane potential in HF. While TMZ decreased FAO by ~15%, the 3-KAT inhibitor 4-bromotiglic acid did not provide protection against palmitic acid-induced mPTP opening, indicating that TMZ effects were 3-KAT independent. Thus, the beneficial effect of TMZ in rabbit HF was not linked to FAO inhibition, but rather associated with reduced complex II- and uncoupled mtNOS-mediated oxidative stress and decreased propensity for mPTP opening.

Trimetazidine improves endothelial dysfunction in chronic heart failure: an antioxidant effect

AIMS

To determine whether trimetazidine (TMZ) improves the endothelium-dependent relaxation (EDR) in chronic heart failure (CHF) and whether this effect is associated with its antioxidant properties.

METHODS AND RESULTS

We studied 51 patients (mean age 51.4 +/- 6 years) with CHF secondary to ischaemic cardiomyopathy (ejection fraction 32.5 +/- 4.5%). Plasma malondialdehyde (MDA) and lipid hydroperoxides (LOOHs) were measured from an antecubital vein on study entry and after a 4 week treatment with oral TMZ (20 mg tid) (group T, n = 23) or placebo (group C, n = 22) given randomly. Endothelium-dependent vasodilation of the radial artery (RA) was determined by intra-arterial infusion of acetylcholine (7.5, 15 and 30 microg/min). Patients receiving TMZ had an increased radial artery diameter (RAD) in response to each dose of acetylcholine infusion and a greater peak oxygen uptake (P < 0.01 vs. placebo). Plasma MDA and LOOHs levels were reduced at 4 weeks only in patients receiving TMZ (P < 0.001 for both vs. placebo). The improvement in ED-vasodilation was correlated with changes in peak VO(2) (r = 0.68; P = 0.0001), MDA (r = -0.61; P = 0.0002) and LOOHs (r = -0.59; P = 0.005).

CONCLUSION

TMZ improves the ED-relaxation in patients with ischaemic cardiomyopathy. The antioxidant properties of TMZ may play a role.

Effects of trimetazidine on ischemic left ventricular dysfunction in patients with coronary artery disease

We studied 15 patients with chronic coronary artery disease (13 men aged 62 +/- 8 years) undergoing dobutamine (5 to 40 microg/kg/min) echocardiography at the end of two 15-day treatment periods with placebo and trimetazidine (20 mg 3 times daily) given in random order, according to a double-blind, crossover design. Results show that trimetazidine improves resting left ventricular function and reduces the severity of dobutamine-induced ischemic myocardial dysfunction.

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.