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

Myocardial protection in man--from research concept to clinical practice

Myocardial protection aims at preventing myocardial tissue loss: (a) In the acute stage, i.e., during primary angioplasty in acute myocardial infarction. In this setup, the attenuation of reperfusion injury is the main target. As a "mechanical" means, post-conditioning has already been tried in man with encouraging results. Pharmacologic interventions that could be of promise are statins, insulin, peptide hormones, including erythropoietin, fibroblast growth factor, and many others. (b) The patient with chronic coronary artery disease offers another paradigm, with the target of avoidance of further myocyte loss through apoptosis and inflammation. Various pharmacologic agents may prove useful in this context, together with exercise and "mechanical" improvement of cardiac function with attenuation of myocardial stretch, which by itself is a noxious influence. A continuous effort toward acute and chronically preserving myocardial integrity is a concept concerning both the researcher and the clinician.

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.

iTRAQ-coupled 2D LC-MS/MS analysis on protein profile in vascular smooth muscle cells incubated with S- and R-enantiomers of propranolol: possible role of metabolic enzymes involved in cellular anabolism and antioxidant activity

Propranolol is a nonselective beta-blocker of the beta-adrenergic receptors, and the S-enantiomer is more active compared with the R-enantiomer. Clinically, it has been shown to be effective in hypermetabolic burn patients by decreasing cardiac work, protein catabolism, and lipolysis. While gene expression profiles have recently been reported in children receiving propranolol treatment, variations from one individual to another may have influenced the data analysis. Using iTRAQ-coupled 2D LC-MS/MS analysis, we report here the first study of protein profile in vascular smooth muscle cells incubated separately with the two enantiomers of propranolol. Four types of cellular proteins including metabolic enzymes, signaling molecules, cytoskeletal proteins, and those involved in DNA synthesis/protein translation displayed changes. The higher protein level of a number of enzymes involved in cellular anabolism and antioxidant activity in cells incubated with the S-enantiomer, as revealed by LC-MS/MS, was further supported by real-time PCR and Western blot analyses. Significantly, the increase in the anabolic activity associated with the higher level of metabolic enzymes was also supported by the higher intracellular concentration of the metabolic cofactor NAD+ which was a result of an increased oxidation of NADH. Our findings therefore provide molecular evidence on metabolic effect associated with propranolol treatment. The metabolic enzymes identified in our study may in turn be useful targets for future pharmaceutical interventions to reduce clinical side effects following propranolol treatment.

LC/ESI-MS method for the determination of trimetazidine in human plasma: Application to a bioequivalence study on Chinese volunteers

A rapid liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) method with good sensitivity and specificity has been developed and validated for the identification and quantification of trimetazidine in human plasma. Trimetazidine and lidocaine (internal standard) were isolated from plasma samples by protein precipitation with methanol. The chromatographic separation was accomplished on a Xterra MS C18 Column (150 mm x 4.6 mm, 5 microm particle size) with the mobile phase consisting of methanol and water (40:60, v/v) (pH 2.0, adjusted with trifluoroacetic acid), and the flow rate was set at 0.6 mL/min. Detection was performed on a single quadruple mass spectrometer by selected ion monitoring (SIM) mode (m/z 267.0 for trimetazidine and m/z 235.0 for lidocaine) with the retention time at about 3.47 and 5.05 min, respectively. The calibration curve for trimetazidine was satisfactory with regression coefficient 0.9995 over the range of 2.5-100 ng/mL in the plasma. The LOQ (S/N=10) was accordingly 2.5 ng/mL. The intra-day and inter-day precision expressed as relative standard deviation was 2.83-6.10% and 4.83-5.82%. The method was successfully applied to investigate the bioequivalence between two kinds of tablets (test versus reference product) in 19 healthy male Chinese volunteers. After a single 20 mg dose for the test and reference product, the resulting mean of major pharmacokinetic parameters such as AUC(0-24), AUC(0-infinity), Cmax, Tmax and t(1/2) of trimetazidine were (673.1+/-117.6 ng h mL(-1) versus 652.3+/-121.9 ng h mL(-1)), (717.1+/-120.9 ng h mL(-1) versus 692+/-128.6 ng h mL(-1)), (74.85+/-12.13 ng mL(-1) versus 71.93+/-14.32 ng mL(-1)), (2.312+/-0.663 h versus 2.211+/-0.608 h) and (4.785+/-0.919 h versus 4.740+/-0.823 h), respectively, indicating that these two kinds of tablets were bioequivalent in the Chinese population.

Novel therapeutic approaches to treating chronic angina in the setting of chronic ischemic heart disease

Pharmacologic therapy to alleviate symptoms in chronic angina has been enhanced by the recent approval of several novel compounds that complement the traditional approach using beta-adrenergic blocking drugs, calcium antagonists, and long-acting nitrates. In the United States, ranolazine, a drug that inhibits late I(Na), was approved for patients with chronic angina that remain symptomatic on beta-blockers, calcium antagonists, or long-acting nitrates, on the basis of an acceptable safety profile and efficacy in several randomized placebo controlled studies. A slight increase in the QT interval is observed (<10 ms on average) at the maximum approved dose of 1,000 mg twice daily. Therefore, an ECG should be acquired at baseline and during follow-up, and the drug should not be used in patients with QT prolongation or those who are on QT prolonging drugs unless longer term randomized outcome data demonstrates no excess risk. The MERLIN trial of non-ST-elevation acute coronary syndrome (NSTE ACS) randomized 6,560 patients to assess the potential benefit of ranolazine in reducing the composite endpoint of cardiovascular death, myocardial infarction, and recurrent ischemia, with results expected in 2007. In Europe, ivabradine, a drug that inhibits the hyperpolarization-activated mixed sodium/potassium inward I(f) current, which slows the rest and exercise heart rate, was approved in 2005. Ivabradine at a dose of 10 mg twice daily has been shown to have similar efficacy to amlodipine 10 mg once daily or atenolol 100 mg once daily in alleviating chronic angina symptoms. In this review, several other novel investigational approaches are presented and patient selection considerations for the most recent approved drugs for chronic angina are discussed.

Trimetazidine improves post-ischemic recovery by preserving endothelial nitric oxide synthase expression in isolated working rat hearts

OBJECTIVE

Previous investigations have consistently shown that the piperazine derivative trimetazidine (TMZ, 1-[2,3,4-trimethoxybenzil] piperazine, dihydrocloride) has cardioprotective effects in the experimental ischemia-reperfusion model. We tested the hypothesis that cardioprotective effect of TMZ is partly mediated by preservation of the endothelial barrier of the coronary microcirculation.

METHODS

Isolated Wistar rat (250-300 g) hearts were subjected to a 15 min period of global ischemia and 180 min reperfusion in the presence or absence of 1 microM TMZ. Hemodynamic parameters, heart weight, creatinekinase (CK) release and microvascular permeability (FITC-albumin extravasation) were evaluated. In addition, eNOS gene expression was estimated by rt-PCR, and eNOS protein levels were assessed by Western analysis. In order to confirm the involvement of NO in mediating the cardioprotective effects of TMZ, 30 microM N(omega)-nitro-l-arginine methylester (L-NAME), a specific inhibitor of nitric oxide synthase, was used.

RESULTS

After ischemia and reperfusion, TMZ produced a significant improvement of mechanical function associated with a reduction of CK release and FITC-albumin diffusion (P<0.001); the agent also resulted in improvement in coronary flow (at 45 min+27% vs control). The eNOS mRNA and protein levels were significantly higher in TMZ-treated hearts compared to controls. The addition of L-NAME significantly reduced the beneficial effects of TMZ on contractile function, CK release and FITC-albumin diffusion.

CONCLUSIONS

in the isolated rat heart, TMZ exerts a relevant, NO-dependent, cardioprotection against ischemia-reperfusion injury and preserves the endothelial barrier of the coronary circulation. This could contribute to explain the cardioprotective action of TMZ following ischemia and reperfusion.

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.

Structure-activity studies on the protection of Trimetazidine derivatives modified with nitroxides and their precursors from myocardial ischemia-reperfusion injury

Trimetazidine, the known anti-anginal and anti-ischemic drug, was modified by pyrroline and tetrahydropyridine nitroxides and their hydroxylamine and sterically hindered secondary amine precursors. The synthesized new compounds proved to be better superoxide scavenger molecules compared to the parent Trimetazidine in an in vitro experiment. This reactive oxygen species (ROS) scavenging activity was further supported by ischemia/reperfusion (I/R) studies on Langendorff-perfused rat hearts pretreated with Trimetazidine and with the modified Trimetazidine derivatives before ischemia. Two of the investigated compounds, containing 2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole and 4-phenyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole substituents on the piperazine ring, provided significant protection from the cardiac dysfunction caused by I/R. The protective effect could be attributed to the combined anti-ischemic and antioxidant effects.

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.

Current medical management of chronic stable angina

Severe atherosclerotic narrowing of one or more coronary arteries is responsible for myocardial ischemia and angina pectoris in most patients with stable angina. The coronary arteries of patients with stable angina also contain many more non-obstructive plaques, which are prone to rupture resulting in acute coronary syndrome (unstable angina, myocardial infarction, sudden ischemic death). Therefore, the medical management must use strategies which not only relieve symptoms and prolong angina free walking but also reduce the incidence of adverse clinical outcomes. Whether any of the approved antianginal drugs, nitrates, beta-blockers, and calcium channel blockers reduce the incidence of adverse clinical outcomes in patients with stable angina has not been studied to date. Published data shows that percutaneous coronary revascularization procedures and coronary bypass surgery are effective in relieving angina but these procedures do not reduce mortality or the incidence of myocardial infarction compared to anti-anginal drug therapy. From the available data, an initial trial of medical treatment with anti-anginal drugs and strategies to reduce adverse clinical outcomes (smoking cessation, daily aspirin, treatment of dyslipidemias and hypertension) is indicated in most patients with stable angina pectoris. The initial choice of drug will depend on the presence or absence of comorbid conditions. Patients who do not respond to medical therapy or do not wish to take anti-anginal drugs and whose life style is limited because of anginal symptoms should be offered percutaneous revascularization procedures with or without stent placement or coronary bypass surgery. New drug-coated stents hold promise but long-term data and large-scale trials assessing the continued long-term improvement in symptoms and reduction of adverse outcomes is needed before offering such devices to all patients with stable angina. Newer medical therapies such as metabolic modulators and sinus rate lowering drugs also hold promise but need further evaluation. Patients who have refractory angina despite optimal medical therapy and are not candidates for revascularization procedures may be candidates for some new techniques of enhanced external Counterpulsation, Spinal Cord Stimulation, sympathectomy or direct transmyocardial revascularization. The usefulness of these techniques, however, needs to be confirmed in large randomized trials.

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.

Effects of trimetazidine on myocardial preconditioning in anesthetized rats

Trimetazidine is a widely used anti-ischemic agent, but its effect on myocardial preconditioning in anesthetized animals has not been investigated. The aim of this study was to examine the effects of trimetazidine on ischemic preconditioning and carbachol preconditioning in anesthetized rats. Ischemic preconditioning, induced by 5-min coronary artery occlusion and 5-min reperfusion, decreased the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation during 30-min ischemia. Trimetazidine (10 mg/kg, i.v.) alone attenuated these parameters of arrhythmia. Carbachol infusion induced preconditioning with a marked depression of mean arterial blood pressure, heart rate and ventricular tachycardia. The marked reductions in parameters of arrhythmia induced by ischemic preconditioning and carbachol preconditioning were preserved in the presence of trimetazidine. Arrhythmia scores and myocardial infarct size were significantly reduced with ischemic preconditioning or carbachol preconditioning and were not inhibited by trimetazidine. These results show that trimetazidine protects the heart against ischemia-induced arrhythmias, reduces myocardial infarct size, preserves the effects of ischemic preconditioning and pharmacological preconditioning, and is able to mimic ischemic preconditioning in anesthetized rats.

Long term cardioprotective action of trimetazidine and potential effect on the inflammatory process in patients with ischaemic dilated cardiomyopathy

OBJECTIVE

To investigate the long term effects of trimetazidine in patients with dilated ischaemic cardiomyopathy. The effects of trimetazidine on left ventricular function as well as its tolerability profile and potential anti-inflammatory effects were studied.

DESIGN

61 patients were randomly assigned either to receive trimetazidine (20 mg thrice daily) in addition to their conventional treatment or to continue their usual drug treatment for 18 months. Patients were evaluated at baseline and at 6, 12, and 18 months with a clinical examination, echocardiography, and biochemical analysis (C reactive protein).

RESULTS

Trimetazidine added to the usual treatment significantly improved the patients' functional status (assessed by New York Heart Association functional class). The functional improvement of trimetazidine treated patients was associated with a significant increase in left ventricular ejection fraction (30 (6)%, 32 (8)%, 38 (7)%, and 37 (6)% v 31 (8)%, 30 (7)%, 28 (6)%, and 26 (9)% in control patients at baseline and at 6, 12, and 18 months, respectively) and with a significant effect on ventricular remodelling. C reactive protein plasma concentrations remained stable throughout the study in patients receiving trimetazidine (2.5 (1.0), 2.7 (2.0), 2.7 (3.0), and 3.0 (2.0) mg/l at baseline and at 6, 12, and 18 months, respectively) but increased significantly in the control group (2.4 (1.0), 3.4 (1.2), 6.0 (4.0), and 7.0 (5.0) mg/l, respectively). No significant adverse event or changes in clinical or biochemical parameters were detected.

CONCLUSION

Treatment with trimetazidine added to the usual treatment for up to 18 months was well tolerated and induced a functional improvement in patients with dilated cardiomyopathy. Trimetazidine treatment was associated with a significant improvement of left ventricular function and the remodelling process. Results also suggest that the inflammatory response was limited in patients treated with trimetazidine.

Comparison of trimetazidine plus sildenafil to chronic nitrates in the control of myocardial ischemia during sexual activity in patients with coronary artery disease

A large proportion of patients who have erectile dysfunction also have coronary artery disease (CAD). In these patients, nitrate therapy is a contraindication to the use of sildenafil. To assess whether the metabolic anti-ischemic agent, trimetazidine, is effective in controlling episodes of myocardial ischemia during sexual activity in patients who have CAD and use long-term nitrate therapy, we studied 38 men (57 +/- 6 years of age) who had proved CAD. Patients underwent 24-hour ambulatory electrocardiographic monitoring at baseline, after 1 week of oral nitrate therapy (20 mg 3 times a day), and after 1 week of trimetazidine (20 mg 3 times a day). Patients were asked to engage in >/=1 session of sexual intercourse during each session of ambulatory electrocardiographic monitoring. They were instructed to take sildenafil (100 mg) 1 hour before sexual intercourse performed at baseline and during therapy with trimetazidine and sildenafil or placebo (blinded) during therapy with nitrates. A decrease in total ischemic burden was observed with nitrates and trimetazidine compared with baseline (-3 +/- 1.2 episodes/patient/24 hours vs -5 +/- 1.3 episodes/patient/24 hours and -6 +/- 5 min/patient/24 hours vs -8 +/- 3 min/patient/24 hours, p <0.01 for nitrates and trimetazidine vs baseline). Trimetazidine plus sildenafil was more effective in controlling episodes of myocardial ischemia during sexual activity than nitrates alone (-45 +/- 11% vs -18 +/- 7%, p <0.04). In conclusion, in patients who have CAD, combination therapy with sildenafil and trimetazidine is more effective than nitrate therapy in the control of ischemic episodes during sexual activity, suggesting that long-term nitrate therapy may be safely switched to trimetazidine therapy when therapy for erectile dysfunction is required.

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.

Assessment of the sustained release properties of a new oral formulation of trimetazidine in pigs and dogs and confirmation in healthy human volunteers

The pharmacokinetics of immediate (IR) and modified release (MR) trimetazidine (TMZ) in dogs and pigs, have been compared under single dose conditions, then predicted at steady-state under conditions mimicking an actual human pharmacokinetic study. In both animal species, the MR tablet has demonstrated sustained release properties, as assessed by delayed time to peak and increased mean absorption times. Multiple dose simulations in dogs revealed a delayed time to peak (3.0 vs. 1.0 h), a decrease in peak plasma concentration (544 vs. 659 microg/L), an increase in trough concentrations (115 vs. 63 microg/L), a decrease in peak-trough fluctuation (141 vs. 193%), and an increase in plateau time (5.5 vs. 4.9 h). Qualitatively similar changes were simulated in pigs. These properties have then been verified in humans where a TMZ MR 35 mg b.i.d regimen did provide similar total exposure, increased plateau time (11 vs. 4 h), decreased peak-trough fluctuation (86 vs. 121%), a 31% increase in trough concentrations, and no increase in inter-individual variability as compared to a TMZ IR 20 mg t.i.d. regimen. Furthermore, the TMZ MR 35 mg b.i.d. regimen is likely to result in improved patient compliance and better patient anti-ischemic protection in the early morning.

Ischemic heart disease: metabolic approaches to management

The number of patients with coronary artery disease and its risk factors is increasing in Western nations. New treatments for these patients may soon include a class of agents known as the metabolic modulators. This group of agents consists of the partial fatty acid oxidation inhibitors trimetazidine and ranolazine, as well as dichloroacetate, which promotes carbohydrate utilization. Metabolic modulators also include the nutriceuticals L-carnitine and D-ribose. The available evidence regarding the benefits of each of these five agents is reviewed.

Anti-excitotoxic activity of trimetazidine in the retina

The purpose of this study was to investigate the mechanism of the neuroprotective activity of trimetazidine in animal retina stressed by ischemia or kainate. Flash electroretinograms were recorded in guinea pigs after ischemia, induced by an acute increase in the intraocular pressure (IOP), or after an intravitreal injection of kainate. Treatment with trimetazidine per os afforded a significant protection of the electroretinogram against the ischemic as well as the excitotoxic insult as an antioxidant (dimethylthiourea) and a nitric oxide synthase inhibitor (nitroarginine) did. The effect of the drug on the extracellular accumulation of glutamate induced by chemical ischemia was studied by incubating rat retina in vitro. Trimetazidine was able to inhibit the extracellular glutamate accumulation, which represents the first step of the excitotoxic phenomenon. Then the compound activity on the glial uptake of glutamate was studied in a rat Müller cell line (rMC-1) in culture. Chemical ischemia inhibited the active 3H-glutamate transport, an effect that was reversed by trimetazidine, at micromolar concentrations. These results demonstrate that trimetazidine which is recognized as an efficient drug against ischemic injuries, is also capable of protecting the retina against excitotoxicity by reducing ischemia-induced accumulation of glutamate due in particular to glial transporter inhibition.

Chronic angina pectoris: inadequacies of current therapy

Chronic angina is a major medical problem in the United States with more than 6 million patients affected, a number that will increase substantially because of the progressive aging of the population. The annual mortality rate for patients with chronic angina is approximately 2%, but is much higher in certain subsets of patients, particularly the elderly. Angina is also associated with major social and economic burdens. Because of poor symptom control and hemodynamic, as well as other drug side effects, angina is commonly associated with a poor quality of life. No new class of drug has been available for angina treatment in more than two decades, and current medications frequently fail to provide adequate symptom control. Thus, the majority of patients are taking two or three antianginal medications. New agents that modulate myocardial metabolism have shown antianginal efficacy, a favorable side-effect profile, and an absence of hemodynamic effects.

Trimetazidine Modified Release in???the???Treatment of Stable Angina

OBJECTIVE

To assess the clinical efficacy, safety and effects on quality of life of trimetazidine modified release (MR) in patients with stable angina.

METHODS

This large, open-label, uncontrolled study was conducted in 906 patients with stable angina in the Russian Federation. Patients were treated for 8 weeks with trimetazidine MR (35mg tablet, twice a day) in addition to their conventional therapy.

RESULTS

Overall 846 patients (516 men and 330 women) aged 58.7 +/- 9 years completed the study. During the 8-week treatment period the number of angina attacks per week decreased continuously and significantly from 11.2 +/- 0.4 to 3.6 +/- 0.2 (p < 0.0001). Concurrently, the number of short-acting nitrate tablets taken per week decreased from 11.9 +/- 0.8 to 3.4 +/- 0.2 (p < 0.0001). Patients' quality of life, assessed on the Seattle Angina Questionnaire, showed a significant improvement (p < 0.0001) for all five items evaluated: physical limitation increased from 50.7 +/- 0.7 to 61.0 +/- 0.6, angina stability improved from 57.6 +/- 0.9 to 92.5 +/- 0.7, angina frequency extended from 33.3 +/- 0.7 to 55.6 +/- 0.8, treatment satisfaction increased from 62.3 +/- 0.7 to 77.4 +/- 0.5, and disease perception improved from 36.7 +/- 0.6 to 55.5 +/- 0.7. Adverse events were reported in 2.4% of patients (22/906) during the 8 weeks of treatment. No serious adverse events were reported.

CONCLUSION

The results of this study suggest an improvement in clinical efficacy and in quality of life and a good tolerance of trimetazidine MR administered at a dose of 35mg twice a day for 8 weeks in patients with stable angina.

Trimetazidine Diminishes Fasting Glucose in Rats With Fasting Hyperglycemia: A Preliminary Study

Trimetazidine is a drug with cardioprotective properties used in coronary artery disease. Its effect has been attributed to the inhibition of the long chain fatty acids intramitochondrial transport via carnitine-palmitoyl-transferase-1. Clinical evidence supports the possibility that trimetazidine is able to improve the fasting glycemia in diabetic patients. For this reason, the objective of the present study was to determine the effect of trimetazidine on serum glucose of Sprague-Dawley rats with fasting hyperglycemia. All animals received water and food "ad libitum." Blood glucose was measured weekly to confirm fasting hyperglycemia in rats. The rats were treated for 1 month with trimetazidine (1 mg/kg), and blood samples were collected (in the fasting period) on the last day of treatment (the 30th day); and then on the 15th day posttreatment, measurements of plasma glucose were taken. Fasting plasma levels after 30 days of trimetazidine administration decreased significantly from 141.2 +/- 3.3 mg/dL (pre-drug) to 120.9 +/- 5.8 mg/dL (P<0.01). 15 days after the end of treatment, fasting plasma glucose levels (137.0 +/- 7.0 mg/dL) were close to the pretreatment levels but significantly different (P<0.05) from levels on day 30 of treatment. These data suggest that trimetazidine improved blood glucose utilization in rats with fasting hyperglycemia.

Effect of trimetazidine on exercise performance in patients with coronary artery ectasia

Coronary artery ectasia (CAE) is a rare form of coronary artery disease. It has previously been shown that nitrate derivatives induce exertional angina in patients with CAE. Furthermore, there is limited data about the effects of other anti-ischemic agents in CAE. The aim of this study was to investigate the effect of trimetazidine on exercise performance in patients with CAE. The study population consisted of 56 patients with isolated CAE (32 males, mean age: 58 +/- 9 years). The presence of myocardial ischemia was evaluated by treadmill exercise test. The exercise test was positive in 49 patients at baseline and in 27 patients during trimetazidine therapy (P < 0.01). The exercise test induced angina in all of the patients who have had a positive test result. Significant ST depressions were observed in 42 and 23 patients before and after the treatment, respectively (P < 0.01). The extent of ST depression at peak exercise was significantly lower on trimetazidine (0.9 +/- 0.5 vs 1.5 +/- 0.6 mm, P < 0.01). With trimetazidine, the exercise duration increased from 7.8 +/- 2.1 to 8.7 +/- 2.4 min (P = 0.04) and cardiac work-load also increased from 8.9 +/- 2.3 to 10.4 +/- 2.1 mets (P < 0.01). The results suggest that trimetazidine can relieve exercise-induced angina and improve exercise performance in patients with CAE.

Insulin therapy as an adjunct to reperfusion after acute coronary ischemia: a proposed direct myocardial cell survival effect independent of metabolic modulation

Reperfusion therapy has become a practical and effective strategy in the salvage of ischemic myocardium. The direct enhancement of cardiac cellular tolerance against ischemic and reperfusion injury should further improve patient outcome in acute coronary syndromes (ACS). This approach has been explored for many decades, and although we await mortality-weighted randomized clinical trials, the infusion of glucose-insulin-potassium (GIK) has shown promise in protecting post-infarct myocardium. The current dogma is that this cardioprotective effect of GIK acts via the modulation of cardiac and circulating metabolites to provide the heart with an optimal metabolic milieu to resist ischemia and reperfusion injury. This concept of metabolic modulation has gained favor in coronary heart disease, and its efficacy currently is being investigated in stable angina using the new class of partial fatty acid oxidation inhibitors, including trimetazidine and ranolazine. We contend that the mitogen insulin, itself, promotes tolerance against ischemic cell death via the activation of innate cell-survival pathways in the heart. To advance this viewpoint, we will present clinical data that support a dose-dependent effect of insulin's beneficial action in the management of acute myocardial infarction. Furthermore, we present experimental data that identify cell-survival programs that are directly activated by the administration of insulin. Finally, as intravenous insulin therapy is both labor intensive and associated with metabolic perturbations, we propose that the development of pharmaco-therapeutic agents that target downstream cell-survival insulin-activated signaling molecules may be an alternate approach to promote cardioprotection during ACS.

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.

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.

Treatment of stable angina with low dose diltiazem in combination with the metabolic agent trimetazidine

BACKGROUND

The risk/benefit of moderate to high doses of calcium antagonists in stable angina is uncertain. This study investigates the efficacy and acceptability of low dose diltiazem in combination with trimetazidine for the treatment of stable angina.

METHODS

In a 28-day, randomized, double blind study, treatment with 90 mg diltiazem in combination with 60 mg trimetazidine or placebo per day was compared in 50 patients with stable angina. The primary outcomes were time to 1-mm ST segment depression and the Duke treadmill score.

RESULTS

Of the 25 patients in each treatment group, the number (%) of patients responding to trimetazidine compared to placebo was, in time to 1-mm ST segment depression, 13 (52) versus 5 (20), P<0.05; in the Duke treadmill score, 18 (72) versus 8 (32), P<0.01; and in angina 17 (68) versus 3 (12), P<0.01. Compared to placebo there was an improvement with trimetazidine in mean exercise time to 1-mm ST segment depression of 128 s (95% confidence interval 45.0-208.5; P<0.01); in the mean Duke treadmill score of 57.4% (95% confidence interval 9.9-100; P<0.02); and in mean anginal attacks of 5.1 per week (95% confidence interval, 3.1-7.3, P<0.01).

CONCLUSION

The combination of low dose diltiazem with trimetazidine is effective with few side-effects in the symptomatic control of patients with stable angina.

Metabolic modulation and optimization of energy consumption in heart failure

Chronic heart failure (CHF) is a common and disabling syndrome with a poor prognosis. It is a major and increasing public health problem. Angiotensin-converting enzyme inhibitors, diuretics, and digitalis are the standards treatments for CHF. Other drugs, such as beta-blockers, spironolactone, calcium antagonists, vasodilators, and antiarrhythmic agents are used to counteract the progression of the syndrome or to improve the hemodynamic profile. Despite optimum treatment with neurohumoral antagonists, prognosis of CHF remains poor; the patients complain of persistent reductions in their exercise capacity and quality of life. Fatigue and shortness of breath, two common and disabling symptoms in patient with CHF, are relatively independent from hemodynamic and neuroendocrine changes, although they seem to be related to the impairment of peripheral muscle metabolism and energetic phosphate production. Therefore, CHF is a complex metabolic syndrome in which the metabolism of cardiac and peripheral muscles is impaired and novel therapeutic strategies have been aimed at positive modulation with compounds such as carnitine, trimetazidine, and ranolazine.

Myocardial cytoprotection by trimetazidine against anthracycline-induced cardiotoxicity in anticancer chemotherapy

The ability of trimetazidine (2,3,4, trimethoxybenzylpiperazine dihydrochloride, TMZ) to protect the myocardium against anthracycline (ANT)-induced cardiotoxicity during chemotherapy has been evaluated in female patients with breast cancer. A clinical trial was conducted in 61 patients subdivided into three groups: group 1 (n = 15, G1 ) treated with standard ANT protocol and cardioprotection by dexrazoxane (DEX) plus TMZ (60 mg, daily dose); group 2 (n = 22, G2) treated with ANT and cardioprotection by TMZ only; and group 3 (n = 24, G3) scheduled to receive ANT therapy and DEX. All the patients submitted to an echocardiographic evaluation of diastolic function (E wave velocity, A wave velocity, isovolumetric relaxation time [IVRT], deceleration time [DT]) at enrollment (T0), at T1 time, at T2 time, and at T3 time. After a 12-month follow-up period, the patients showed a good conservation of diastolic function both in G1 and G2 groups. No statistically significant difference was observed in E wave and A wave velocity and E/A ratio after ANT treatment. TMZ produced a cardioprotective effect, comparable to DEX protection, against subacute and chronic subclinical cardiotoxicity with no significant changes in diastolic function after 1 year of follow-up.

Assessment of anti-ischemic and antianginal effect at trough plasma concentration and safety of trimetazidine MR 35 mg in patients with stable angina pectoris: a multicenter, double-blind, placebo-controlled study

OBJECTIVE

The study aimed to assess, at trough plasma concentration, the anti-ischemic and antianginal efficacy and tolerability of trimetazidine modified release (MR) 35 mg taken twice daily by patients with stable angina pectoris.

DESIGN

This multicenter, randomized, double-blind, placebo-controlled, international study started with a run-in period of 3 weeks with atenolol 50 mg/day and placebo, followed by a 6-month treatment period with once daily atenolol 50 mg and twice daily trimetazidine MR 35 mg or placebo.

PATIENTS

The study involved 223 patients with stable angina pectoris (class II or III of the Canadian Cardiovascular Society [CCS] classification). 180 patients were analyzed in the full analysis set (FAS) following the intention to treat principle (ITT) and 167 patients were analyzed in the per protocol set (PPS). The PPS data are presented here.

INTERVENTIONS

Two exercise tolerance tests (ETTs) were performed during the run-in period in order to assess the stability of exercise tolerance before angina pectoris and significant ST segment depression. Efficacy was assessed by a third ETT performed after 8 weeks of treatment, at trough, 12 hours after the intake of the drug. Safety was evaluated over the 6-month duration of the study.

MAIN OUTCOMES MEASURES

Time to 1 mm ST segment depression.

RESULTS

Time to 1 mm ST segment depression was increased by 44 seconds more in the trimetazidine MR 35 mg group than in the placebo group (p = 0.005). A significant difference was also evidenced for the time to onset of angina pectoris (p = 0.049) and for the reason for stopping the exercise (p = 0.02). No difference between groups was found for safety parameters.

CONCLUSION

This study demonstrates the anti-ischemic and antianginal efficacy of trimetazidine MR 35 mg twice daily at trough plasma concentrations in patients with stable angina pectoris receiving atenolol 50 mg/day. Furthermore, the drug is well tolerated over 6 months.