Effects of trimetazidine on pHi regulation in the rat isolated ventricular myocyte

Trimetazidine, a metabolic modulator, attenuates silica-induced pulmonary fibrosis and decreases lactate levels and LDH activity in rats

Pulmonary fibrosis has been recently linked to metabolic dysregulation. Silica-induced pulmonary fibrosis in rats was employed by the current study to explore the effects of trimetazidine (a metabolic modulator-antianginal drug; TMZ) on silica-induced pulmonary fibrosis. Pulmonary fibrosis was induced by intranasal instillation of silica (50 mg/100 µl/rat) in TMZ versus vehicle-treated rats. Body weights of rats, weights of lungs, and wet-to-dry lung weights were determined. Various parameters were also measured in serum, bronchoalveolar lavage fluid (BALF) in addition to lung tissue homogenates. Moreover, histopathological examination of sectioned lungs for lesion score and distribution and histochemical detection of myeloperoxidase (MPO) in lung tissues were also performed. No significant differences were observed in body weight gains, lung coefficients, lung weights, and wet-to-dry lung weight in silica versus control rats. Elevated lactate levels in serum and lung homogenates were significantly attenuated by TMZ. In addition, lactate dehydrogenase activity, transforming growth factor-β, and total proteins in BALF were significantly normalized with TMZ. Moreover, TMZ significantly increased reduced glutathione and adenosine triphosphate levels and decreased nitrate/nitrite and hydroxyproline content in lungs of silica-treated rats. Histopathological examination of lungs revealed more than 56% reduction in lesion score and distribution by TMZ. MPO expression in lungs of silica-treated rats was also significantly attenuated by TMZ. TMZ attenuates silica-induced pulmonary fibrosis, an effect that could be mediated by suppressing anaerobic glycolysis-induced excessive lactate production. Regulation of oxidative stress could also play a role in TMZ-promoted protective effects.

The Effect of Trimetazidine on C-Reactive Protein, Cytokines and Adhesion Molecules in the Course of Acute Myocardial Infarction

The aim of this randomised, double-blind, placebo controlled, parallel group study was to assess the effect of trimetazidine (TMZ), a potent antiischaemic drug, on plasma C-reactive protein (C-RP), cytokine and adhesion molecule levels. The study population consists of 18 patients (16 males, 2 females, average age 56.45 ± 10.97 years) with acute myocardial infarction admitted within 6 hours after onset of symptoms and treated with streptokinase. Blood samples were taken at 3-hour intervals during the time of treatment. All patients were randomised blindly using a centralised randomisation process, between trimetazidine (40mg bolus iv. then 60mg per day for 48 hours intravenously in glucose infusion) or placebo group. Plasma C-RP level was significantly lower in TMZ group (39.5mg/ml ± 9.7 mg/ml) as compared to placebo (75.7 ± 29.4 mg/ml, p≤0.001) and peaked 28 hours later in TMZ group. Plasma interleukin 6 (IL 6) level showed a sharp peak 9 hours after the onset of the symptoms in TMZ group (116.9 ± 180.2 pg/ml vs. 45.4 ± 37.9 pg/ml) and was increased up to 30 hours after the onset of the symptoms. Plasma interleukin 1 beta (IL 1β) was also higher in TMZ group notably 21 hours after the onset of symptoms (26.4 ± 9.3 pg/ml vs. 16.2 ± 2.4 pg/ml). TMZ group showed lower plasma E-selectin levels. Plasma IL 8, TNF α and ICAM 1 levels were without statistical significant differences. The present study demonstrates a significant reduction of plasma C-reactive protein level in the course of acute myocardial infarction treated with streptokinase and intravenous trimetazidine infusion compared with the group of patients without trimetazidine treatment.

Effectiveness and safety of anti-ischemic trimetazidine in patients with stable angina pectoris and Type 2 diabetes

Aim & methods: This 6-month prospective, observational, noninterventional, open-label clinical study assessed the effectiveness/safety of trimetazidine in 737 patients with stable angina pectoris and Type 2 diabetes mellitus (OGYI/51534–1/2014). Results: Trimetazidine-based therapy was effective in stable coronary artery disease, with significant improvements from baseline (p < 0.05) in: number of angina attacks/week (2.9 ± 2.4 vs 1.1 ± 1.6), angina severity (Canadian Cardiovascular Society Classification 1.9 ± 0.8 vs 1.2 ± 0.8), exercise capacity (metabolic equivalents 6.1 ± 1.7 vs 6.5 ± 1.7), and exercise-induced myocardial ischemia (min 5.5 ± 2.5 vs 6.5 ± 2.6). Discussion: Trimetazidine treatment significantly (p < 0.05) improved glucose metabolism, lowered HbA1c (7.1 ± 1.1% vs 6.6 ± 1.0%), glucose levels (7.7 ± 2.1 mmol/l vs 6.9 ± 1.6 mmol/l) and decreased arterial stiffness (pulse wave velocity 11.2 ± 2.1 m/s vs 10.4 ± 2.2 m/s). In most patients, the tolerability of trimetazidine was rated as excellent to good, with a low incidence of adverse events.

Metabolic manipulation in dilated cardiomyopathy: Assessing the role of trimetazidine

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of sustained-release trimetazidine on chronically dysfunctional myocardium of ischemic dilated cardiomyopathy - Six months follow-up result

Background

Ischemic cardiomyopathy is a growing burden in third world countries. So far, benefits of trimetazidine in this group of patients have been suggested by clinical trials mainly conducted in Europe. We evaluated the effect of trimetazidine on ischemic dilated cardiomyopathy in our population.

Methods and results

98 patients (aged 58.5 ± 9.2 years), admitted with decompensated heart failure with previous history of MI and/or documentation of significant CAD with previous CAG, were chosen for the study. Patients were randomized into two groups – one provided with trimetazidine 35 mg sustained released tablet, twice daily and the other with a placebo, along with other conventional medications. Patients were included if they had dilated LV (LVIDd > 57 mm) and left ventricular ejection fraction (LVEF) ≤40%. After 6 months, significantly higher number of patients in trimetazidine group were in NYHA class I (22% vs. 8%, p = 0.03) and class II (56% vs. 34%, p = 0.01); higher number of patients in placebo group were in NYHA class III class IV. Anginal episodes and use of sublingual nitrate per week were significantly lower in the trimetazidine group. Left ventricular diastolic dimension (59.7 ± 5.2 vs. 65.1 ± 6.1, p = 0.001) was significantly different in the two groups as was the increase of LVEF (11% vs. 5.6%, p = 0.001). Hospitalization for worsening heart failure was significantly lower in trimetazidine group (13 vs. 22, p = 0.047).

Conclusion

Trimetazidine seems to be beneficial in patients with ischemic dilated cardiomyopathy in South Asian population and larger scale study with extended follow-up is needed.

Chronic treatment with trimetazidine after discharge reduces the incidence of restenosis in patients who received coronary stent implantation: a 1-year prospective follow-up study

BACKGROUND

The incidence of stent restenosis (SR) has risen with as more patients are being treated with drug-eluting stents (DESs). Trimetazidine has multiple favorable effects on the cardiovascular system. Here, we aimed to evaluate whether chronic treatment with trimetazidine reduced the incidence of SR.

METHODS

From January 2009 to December 2011 at Chinese PLA General Hospital, 768 patients were enrolled and randomized into the trimetazidine treatment group (TG, n = 384) and control group (CG, n = 384). After DES implantation, all patients were treated with regular medication. In the TG, trimetazidine was administrated at 20mg tid for at least 30days. All patients received follow-up angiography 9-13 months after discharge. Major adverse cardiac and cerebrovascular events (MACCEs) were recorded.

RESULTS

Six hundred thirty-five patients were included in the final analysis (TG, n = 312; CG, n = 323). SR occurred in 49 (7.7%) patients. The TG had a lower incidence of SR compared to the CG (4.2% vs. 11.1%, p = 0.001). At the 30-day follow-up, the TG exhibited a higher left ventricular ejection fraction than the CG (65.4 ± 10.7 vs. 63.1 ± 10.4, p = 0.006). The incidence of MACCEs was also lower in the TG at the 1-year follow-up (6.1% vs. 10.8%, p = 0.032). Further multivariate analysis revealed that trimetazidine treatment was a predictor for SR (OR: 0.376; 95% CI: 0.196-0.721; p = 0.003).

CONCLUSIONS

Trimetazidine treatment effectively reduced the incidence of SR and MACCEs after DES implantation at the 1-year follow-up.

Effects of trimetazidine, a partial inhibitor of fatty acid oxidation, on ventricular function and survival after myocardial infarction and reperfusion in the rat

Trimetazidine (TMZ), a partial inhibitor of fatty acid oxidation, has been effective in treating chronic angina, but its effects on the development of post-myocardial infarction (MI) left ventricular remodeling are not defined. In this study, we tested whether chronic pre-MI administration of TMZ would be beneficial during and after acute MI. Two-hundred male Wistar rats were studied in four groups: sham + TMZ diet (n = 20), sham + control diet (n = 20), MI + TMZ diet (n = 80), and MI + control diet (n = 80) splitted into one short-term and one long-term experiments. Sham surgery consisted of a thoracotomy without coronary ligation. MI was induced by coronary occlusion followed by reperfusion. Left ventricle (LV) function and remodeling were assessed by serial echocardiography throughout a 24-week post-MI period. LV remodeling was also assessed by quantitative histological analysis of post-MI scar formation at 24 weeks post-MI. During the short-term experiment, 10/80 rats died after MI, with no difference between groups (MI + control = 7/40, MI + TMZ = 3/40, P = 0.3). In the long-term experiment, the deaths occurred irregularly over the 24 weeks with no difference between groups (MI + control = 16% mortality, MI + TMZ = 17%, P = 0.8). There was no difference between groups as regard to LV ejection fraction (MI + control = 36 +/- 13%, MI + TMZ = 35 +/- 13%, P = 0.6). In this experimental model, TMZ had no effects on the post-MI occurrence of LV dysfunction or remodeling. Further investigations are warranted to assess whether the partial inhibition of fatty acid oxidation may limit the ability of the heart to respond to acute severe stress.

Trimetazidine Shortens QTc Interval in Patients With Ischemic Heart Failure

Background: Trimetazidine improves functional class and left ventricular function in patients with heart failure; however, its potential impact on QTc interval remains undefined. We analyzed the effects of trimetazidine on QTc interval in patients with ischemic heart failure. Methods: A prospective trial included 42 patients with ischemic heart failure (New York Heart Association [NYHA] 2 or 3) and reduced left ventricular ejection fraction (<55%), who were randomly allocated to conventional therapy plus trimetazidine in a modulated release formulation (35 mg twice daily; 22 patients) or conventional therapy alone (20 patients; controls). We measured QTc interval at baseline and after 1 month. Results: At baseline, QTc interval duration was similar in both groups (443 ± 41 milliseconds in trimetazidine group vs 446 ± 27 milliseconds in controls, P = .62). After 1 month, QTc interval decreased in the trimetazidine group (404 ± 36 milliseconds, P = .0002) but not in controls (452 ± 25 milliseconds, P = .74). QTc interval shortening with trimetazidine was more pronounced in patients with prolonged (>440 milliseconds) baseline QTc interval (—45 ± 38 milliseconds) than in patients with normal QTc interval (—19 ± 19 milliseconds P = .04). Significant QTc interval shortening (>20 milliseconds) was present in 14 of 22 patients (64%) in trimetazidine group compared to 3 of 20 (15%) patients in control group (P = .002). Conclusions: Trimetazidine therapy is associated with QTc interval shortening in patients with ischemic heart failure.

Trimetazidine administration minimizes myocardial damage and improves left ventricular function after percutaneous coronary intervention

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate whether the administration of trimetazidine, a piperazine derivative, to patients before and after percutaneous coronary intervention (PCI) minimizes the PCI-induced myocardial damage and improves left ventricular function 1 and 3 months after the procedure.

METHODS

Fifty-two patients hospitalized for acute coronary syndromes (ACS) were included in this study. Patients were randomized into two groups: group A (trimetazidine group; n = 27) and group B (placebo group; n = 25). All patients received conventional antianginal therapy. In addition, group A patients received oral trimetazidine 20 mg every 8 hours, starting 15 days before PCI and continuing for 3 months after the procedure. For each patient, serum troponin I and creatinine kinase (CK)-MB levels were measured before PCI, then at 6, 24, and 48 hours after the procedure; a 2D cardiac echocardiogram was performed before PCI and at 1 and 3 months after the procedure.

RESULTS

Twenty-four hours after PCI, troponin I levels were >1 ng/mL in 7 of 27 patients (26%) of group A and 11 of 25 patients (44%) in group B. Fourty-eight hours after revascularization troponin levels remained elevated in 15% of patients in group A and in 32% of patients in group B. Twenty-two percent of patients in group A had CK-MB levels >5 ng/mL, 24 hours after PCI, compared with 40% of patients in group B; four patients of group A had high CK-MB levels prior to PCI procedure. Echocardiographic measurements before revascularization revealed that 11 of 27 patients (40%) in group A had an ejection fraction <50% versus 8 of 24 patients (33%) in group B . The number of patients with an ejection fraction <50% was significantly reduced in group A compared with group B at 1 and 3 months after PCI, i.e. 11% versus 16% (p = 0.046) at 1 month and 4% versus 16% (p = 0.017) at 3 months.A significant improvement in regional wall motion was noted after treatment with trimetazidine compared with placebo. One month after PCI, inferior left ventricular (LV) wall hypokinesia had improved in 4 of 6 trimetazidine recipients and in 4 of 14 placebo recipients (p = 0.014, group A vs group B). After 3 months inferior wall hypokinesia improved in four patients in group A versus six patients in group (p = 0.05). Similarly, anterior LV wall motion improved in 3 of 11 patients in group A and in 1 of 6 patients in group B at 1 month. After 3 months anterior wall hypokinesia had improved in eight patients in group A and in two patients in group B (p = 0.04, group A vs group B).

CONCLUSION

The metabolic agent trimetazidine appears to minimize myocardial reperfusion injury during PCI and improves global and regional wall motion at 1 and 3 months after PCI. This study was limited by small patient numbers and further studies are necessary to evaluate exact mechanisms of action and clinical implications of using trimetazidine in conjunction with PCI.

Trimetazidine-induced enhancement of myocardial recovery during reperfusion: a comparative study in diabetic and non-diabetic rat hearts

BACKGROUND

Diabetes mellitus (DM) is a major predisposing factor for ischemic heart disease. Metabolic disturbances in diabetic heart including impaired myocardial glucose uptake and elevated plasma free fatty acids and increased rate of fatty acid beta-oxidation are probably important contributing factors to greater mortality. Trimetazidine (TMZ), a well-studied anti-ischemic agent, has been demonstrated to be beneficial in treatment of coronary artery disease as well as in treatment of diabetic patients. However, studies reporting the effects of the drug against global myocardial ischemia/reperfusion injury, particularly in diabetic hearts, are rare. This study was mainly aimed to investigate the cardioprotective action of TMZ against global ischemia in diabetic hearts and to compare its protective efficiency level with non-diabetics.

METHODS

Twenty streptozotocin-induced diabetic and 20 non-diabetic rats were divided into two groups each. Group I (diabetic, n = 10) and group III (non-diabetic, n = 10) rats were given saline in both pretreatment and acute treatment protocols and reserved as control groups. Group II (diabetic, n = 10) and group IV (non-diabetic, n = 10) rats were both pretreated orally with 3 mg/kg TMZ twice daily for 5 days and treated with TMZ infusion at a concentration of 10(-6) M for 30 min during the experiment. Isolated hearts from each rat were submitted to Langendorff perfusion and a period of 60 min of global ischemia following 60 min of reperfusion. Myocardial post-ischemic recovery was compared in each group using hemodynamic data (peak systolic pressure, end diastolic pressure, +dP/dt(max)), coronary flow, biochemical parameters (CK-MB, cTnT) from coronary effluent, and obtained data were statistically analyzed by both MANOVA and two-sample Hotelling's T2 tests.

RESULTS

Both hemodynamic and biochemical findings signaled a significantly enhanced myocardial recovery provided by TMZ treatment in diabetic and non-diabetic hearts as compared to non-treated hearts. Although efficiency level of TMZ on mechanical recovery was not different between diabetics and non-diabetics, the protective action of TMZ on myocardial damage measured by biochemical parameters was more evident in diabetic hearts than in non-diabetics.

CONCLUSIONS

Shifting myocardial energy metabolism away from fatty acids toward glucose oxidation and regulating transmembrane ion disturbances by TMZ can be considered as an appropriate adjunctive treatment in diabetics, especially in patients undergoing open-heart surgery who will be exposed to global myocardial ischemia.

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.

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.

Cardioprotective effects of trimetazidine: a review

The efficacy of trimetazidine, an anti-ischaemic agent, has been largely assessed and presented in the international literature through its metabolic effects, selective and specific fatty acid oxidation inhibition and lack of haemodynamic effects in stable angina pectoris. As such, trimetazidine has opened up a new class of metabolic agents that reduce fatty acid oxidation: the 3-KAT (3-ketoacyl-CoA thiolase) inhibitors. The aim of this review article is to demonstrate the cardioprotective benefits of trimetazidine, and how this can be translated into positive effects in the treatment of cardiac disorders. Trimetazidine has been assessed in several double-blind randomised studies as a treatment of ischaemic heart disease or as an agent given prior to or during percutaneous transluminal coronary angioplasty, coronary artery bypass grafting and thrombolysis to prevent or limit ischaemia/reperfusion damage in the heart. All these studies demonstrate that trimetazidine protects the heart from the deleterious consequences of ischaemia by switching cardiac metabolism from fatty acid oxidation to glucose oxidation. Study results cast no doubts on the value of the cardioprotective effects of trimetazidine and support the fact that trimetazidine has a direct anti-ischaemic effect on human myocardial cells. Trimetazidine has proven antianginal efficacy, and can be also used in other cardiac diseases with ischaemic signs.

Trimetazidine as a potential neuroprotectant in transient global ischemia in gerbils: a behavioral and histological study

The effect of Trimetazidine (TMZ) as a potential neuroprotectant against stroke was studied in the gerbil model of transient forebrain global ischemia. Animals were subjected to a 5-min period of ischemia and assessed 4 and 21 days later. Gerbils were divided into two groups: in group one, gerbils were treated with TMZ at a dose of 25 mg/kg given by intraperitoneal injection prior to ischemia. In group two, gerbils were treated with TMZ at a dose of 25 mg/kg given intraperitoneally after ischemia. Saline-injected gerbils served as controls. Histological evaluation of neuronal damage was carried out using the silver staining technique in gerbils 4 and 21 days after the start of the experimental protocol. Behavioral functions were assessed in gerbils from the 14th to the 21st day after the start of the experimental protocol using the Morris water maze test. Results obtained from this study showed no significant difference between saline treated TMZ-treated gerbils when TMZ was administered after ischemia. When TMZ was administered prior to ischemia, there was a reduction in neuronal damage although it did not reach statistical significance and a statistically significant improvement in behavior. We conclude that TMZ shows signs of promise as a neuroprotective agent, and further studies should look at pre-treatment with different doses and different times.

Acute effects of heparin administration on the ischemic threshold of patients with coronary artery disease: evaluation of the protective role of the metabolic modulator trimetazidine

OBJECTIVES

We sought to assess the effects of heparin and the potential protective effects of trimetazidine (TMZ) on exercise performance, plasma nitric oxide (NO), endothelin-1 (ET-1) and free fatty acid (FFA) release in patients with stable coronary artery disease (CAD).

BACKGROUND

Heparin has been shown to reduce the ischemic threshold in patients with CAD. Trimetazidine may affect myocardial substrate utilization by shifting energy production from FFA to glucose oxidation.

METHODS

In four consecutive days, nine patients with CAD each received one of the following four regimens: 1) one tablet of placebo the evening before and at 8 AM and 4 PM on the day of the study, 10 ml of saline in a bolus 10 min before exercise, followed by an infusion of the same preparation; 2) placebo at the same times as in the first regimen, 5,000 IU of heparin 10 min before exercise, followed by 1,000 IU/h; 3) 20 mg TMZ at the same times as in the first regimen, 5,000 IU of heparin 10 min before exercise, followed by 1,000 IU/h; or 4) TMZ at the same times as in the first regimen, 10 ml of saline 10 min before exercise, followed by an infusion of the same preparation.

RESULTS

During placebo (test 2), heparin reduced the time to 1-mm ST-segment depression and prolonged the recovery time, as compared with the results of test 1. When heparin was administered after TMZ (test 3), the time to 1-mm ST-segment depression and the recovery time were similar to those recorded during saline (test 1). Finally, compared with all study phases, TMZ during saline (test 4) prolonged the time to 1 mm. No changes in NO release were found, whereas ET-1 was decreased at peak exercise and during recovery, when the patients were receiving TMZ (tests 3 and 4). Free fatty acids increased after heparin, both with placebo and TMZ.

CONCLUSIONS

In patients with CAD, heparin reduces the ischemic threshold. Trimetazidine reduces the effects of heparin, probably by inhibiting FFA oxidation and enhancing glucose metabolism. The concomitant novel observation of reduced ET-1 release is likely to be also dependent on TMZ-induced improvement of endothelial metabolism or reduction of myocardial ischemia.

Trimetazidine limits the effects of myocardial ischaemia during percutaneous coronary angioplasty

This open-label, randomised, controlled study is aimed at assessing the effect of pre-treatment with the metabolic agent trimetazidine on the degree of ischaemia during percutaneous transluminal coronary angioplasty (PTCA). Overall 44 patients with one-vessel coronary artery stenosis (> 70%) in the medial part of the left anterior descending artery were included. One group (n = 22) was pre-treated with oral trimetazidine. The other group (n = 22) was the control. All patients (n = 44) were administered aspirin and conventional treatment. All patients underwent PTCA; stents were implanted in 11 trimetazidine patients and in seven control patients. The mean ST-segment elevation during all balloon inflations was significantly lower in the trimetazidine group than in the control group (-1.66 +/- 1.50 mm vs. 3.29 +/- 1.59 mm, p = 0.001). Maximal ST-segment elevations and mean ST elevation values during sequential balloon inflations were also significantly lower with trimetazidine (p = 0.018). The mean amplitude of the T-wave alterations during all balloon inflations was significantly lower with trimetazidine (3.09 +/- 2.39 mm vs. 6.83 +/- 4.31 mm; p = 0.001). Similarly, the maximal amplitude of the T-wave alterations was 4.50 +/- 2.90 mm with trimetazidine vs. 9.25 +/- 4.97 mm in control patients (p = 0.0005). Angina and rhythm disturbances were more frequent in the control group. Time from balloon inflation to onset of angina was 50 +/- 26.2 s with trimetazidine vs. 32 +/- 15.0 s, for control group (p = 0.03). The time to pain relief after deflation was 19.3 +/- 11.4 s with trimetazidine vs. 28.2 +/- 16.8 s (p = 0.001). Trimetazidine administered a few days before PTCA appears to be a cardioprotective agent for the prevention of myocardial ischaemia.

Influence of trimetazidine on the synthesis of complex lipids in the heart and other target organs

Trimetazidine exerts antianginal properties at the cellular level, without haemodynamic effect in clinical and experimental conditions. This cytoprotection was attributed to a decreased utilization of fatty acids for energy production, balanced by an increased incorporation in structural lipids. This study evaluated the influence of Trimetazidine on complex lipid synthesis from [2-(3)H] glycerol, in ventricular myocytes, isolated rat hearts and in vivo in the myocardium and several other tissues. In cardiomyocytes, Trimetazidine increased the synthesis of phosphatidyl-choline (+ 80%), phosphatidyl-ethanolamine (+ 210%), phosphatidyl-inositol (+ 250%) and cardiolipid (+ 100%). The common precursor diacylglycerol was also increased (+ 40%) whereas triacylglycerol was decreased (-70%). Similar results were obtained in isolated hearts with 10 microm Trimetazidine (phosphatidyl-choline + 60%, phosphatidyl-ethanolamine + 60%, phosphatidyl-inositol + 100% and cardiolipid + 50%), the last two phospholipids containing 85% of the radioactivity. At 1 microm, Trimetazidine still stimulated the phospholipid synthesis although the difference was found significant only in phosphatidyl-inositol and cardiolipid. In vivo studies (10 mg/kg per day for 7 days and 5 mg/kg, i.p. before the experiment) revealed significant changes in the intracellular lipid biosynthesis, with increased labelling of phospholipids and reduced incorporation of glycerol in nonphosphorous lipids. Trimetazidine increased the glycerol uptake from plasma to the other tissues (liver, cochlea, retina), resulting in an altered lipid synthesis. The anti-anginal properties of Trimetazidine involve a reorganisation of the glycerol-based lipid synthesis balance in cardiomyocytes, associated with an increased uptake of plasma glycerol that may contribute to explain the pharmacological properties reported in other organs.

Apoptosis in myocardial ischemia, infarction, and altered myocardial states

The work ahead necessary to develop and refine clinically useful antiapoptotic therapy in ischemic-reperfusion injury is daunting. There are many unanswered questions. What is the best method of detecting apoptosis in the cardiac myocytes? What will be the most practical method to deliver this therapy to the cardiac myocyte? Will antiapoptotic agents act selectively on affected myocytes to provide clinical efficacy? Will antiapoptotic agents be effective, or will they be limited by dose heterogeneity? If antiapoptotic is proven to have long lasting efficacy, should it be used for all patients with myocardial infarction or confined only to patients with left ventricular dysfunction. Will antiapoptotic therapy be so effective that it replaces ACE inhibitors and betablockers, or will it always be used as an adjunct to an ACE inhibitor or a betablocker? These questions lay the foundation for investigation for the next decade.

Trimetazidine. A review of its use in stable angina pectoris and other coronary conditions

The orally administered antianginal agent trimetazidine increases cell tolerance to ischaemia by maintaining cellular homeostasis. In theory, this cytoprotective activity should limit myocyte loss during ischaemia in patients with angina pectoris. Data from studies in patients with coronary artery disease indicate that, unlike the effects of other antianginals, the anti-ischaemic effects of trimetazidine 20 mg are not associated with alterations in haemodynamic determinants of myocardial oxygen consumption such as heart rate, systolic blood pressure and the rate-pressure product. Furthermore, limited evidence suggests trimetazidine may improve left ventricular function in patients with chronic coronary artery disease or ischaemic cardiomyopathy and in patients experiencing acute periods of ischaemia when undergoing percutaneous transluminal coronary angioplasty. Clinical studies have shown that oral trimetazidine 20 mg 3 times daily reduces the frequency of anginal attacks and nitroglycerin use and increases exercise capacity when used as monotherapy in patients with angina pectoris. Its clinical effects are broadly similar to those of nifedipine 40 mg/day and propranolol 120 to 160 mg/day but, unlike these agents, trimetazidine does not affect the rate-pressure product during peak exercise or at rest. Adjunctive trimetazidine 60 mg/day reduces the frequency of anginal attacks and nitroglycerin use and improves exercise capacity in patients with angina pectoris not sufficiently controlled by conventional antianginal agents. Furthermore, the drug appears to be more effective than isosorbide dinitrate 30 mg/day when used adjunctively in patients with angina pectoris poorly controlled by propranolol 120 mg/day. The tolerability profile of trimetazidine 60 mg/day was similar to that of placebo when used as add-on therapy in patients with angina pectoris insufficiently controlled by other antianginal agents and was superior to that of either nifedipine 40 mg/day or propranolol 120 to 160 mg/day when used as monotherapy. The most frequently reported adverse events in trimetazidine recipients were gastrointestinal disorders, although the incidence of these events was low.

CONCLUSIONS

Trimetazidine is an effective and well tolerated anti-ischaemic agent which, in addition to providing symptom relief and functional improvement in patients with angina pectoris, has a cytoprotective action during ischaemia. The drug is suitable for initial use as monotherapy in patients with angina pectoris and, because of its different mechanism of action, as adjunctive therapy in those with symptoms not sufficiently controlled by nitrates, beta-blockers or calcium antagonists. The role of trimetazidine in other coronary conditions has yet to be clearly established.

The pH-partition profile of the anti-ischemic drug trimetazidine may explain its reduction of intracellular acidosis

PURPOSE

The anti-ischemic drug trimetazidine (TMZ) acts by a combination of molecular mechanisms which begin to be understood. Thus, it acts in the micromolar range to significantly reduce intracellular acidification during ischemia. To search for a possible physicochemical explanation of this phenomenon, we investigated the transfer mechanisms of the various electrical forms of this dibasic drug.

METHODS

The transfer characteristics of TMZ were studied by electrochemistry at the water/1,2-dichloroethane interface. Cyclic voltammetry was used to measure the formal transfer potentials of singly and doubly protonated forms of TMZ (noted TH+ and TH(2)2+, respectively) as a function of aqueous pH, and the partition coefficient of neutral TMZ (log P(T)) was measured by two-phase titration.

RESULTS

log P(T) was measured to be 1.04 +/- 0.06, and the acid-base dissociation constants in water were deduced to be pK(w)a1 = 4.54 +/- .02 and pK(w)a2 = 9.14 +/- 0.02. The partition coefficients of TH+ and TH(2)2+ were found to be respectively log P0'TH+ = -3.78 +/- 0.16 and log P0'TH(2)2+ = -9.84 +/- 0.30, which agrees well with the charge being delocalized on two nitrogen atoms in TH+. The pH-partition profile of TMZ was then established in the form of its ionic partition diagram, which showed that the affinity of the ions for the organic phase is pH-dependent and strongly increased by the interfacial potential.

CONCLUSIONS

This behavior suggests a physicochemical mechanism whereby efflux of protonated TMZ out of an acidified cell is facilitated, in effect exporting protons to extracellular space.

Trimetazidine prevents cochlear lesions induced by intraperitoneal and perilymphatic administration of kainic acid

The protective activity of trimetazidine (TMZ) against cochlear neurotoxicity induced by intraperitoneal and intracochlear administration of kainic acid (KA) has been analyzed. The amplitude of the CAP N1 wave was significantly higher in KA rats pretreated with TMZ, independently of the administration route, than in those only treated with KA. However, CAP N1 amplitude of both TMZ pretreated and non-pretreated animals was always lesser than the N1 wave amplitude observed in the control group. The CAP N1 latency did not show any significant difference between KA and TMZ+KA groups except at high intensities of 8 and 12 kHz. As a complementary control, we have demonstrated that the intraperitoneal administration of TMZ (5 mg/kg) alone did not affect either the electrophysiological activity or the morphology of the auditory nerve. Morphological results fit well with electrophysiology. Some isolated swollen afferent fibers were observed in TMZ+KA cochleae, the swollen dendrites being sparser than in the KA only treated animals. In TMZ+KA animals, the cochlear apical coils were less affected than the basal coils. Our results are in agreement with recent clinical studies and suggest that TMZ could be an active drug on cochlear impairment linked to hypoxic-ischaemic syndromes.

Trimetazidine: potential mechanisms of action in hypertrophic cardiomyopathy

In this review we consider available information on the cardio- and cytoprotective properties and mechanism of action of trimetazidine, an antianginal drug. Two points in particular are addressed: the advantages of trimetazidine over classic drugs and its possible use for the long-term treatment of hypertrophic cardiomyopathy, described as an ischemic disorder.

Coronary artery constriction in rats: necrotic and apoptotic myocyte death

The purpose of this study was to determine whether coronary artery narrowing was associated with the activation of necrotic and apoptotic myocyte cell death in the myocardium and whether these 2 forms of cell death were restricted to the left ventricle, or involved the other portions of the heart. Coronary artery narrowing was surgically induced in rats, and the animals were killed from 45 minutes to 12 days after surgery. Myocyte apoptosis was detected by the terminal deoxynucleotidyl transferase assay, confocal microscopy, and deoxyribonucleic acid (DNA) agarose gel electrophoresis. Myocyte necrosis was identified by myosin monoclonal antibody labeling of the cytoplasm. A separate group of animals was treated with trimetazidine in an attempt to interfere with tissue injury. Coronary artery narrowing was characterized by myocyte apoptosis in the left ventricle and interventricular septum, which progressively increased from 45 minutes to 6 days. However, apoptosis was not observed at 12 days. Conversely, myocyte necrosis reached its maximum value at 1 day and was still present at 12 days. This form of cell death affected not only the left ventricular free wall and interventricular septum, but also the right ventricle. Cell necrosis markedly exceeded apoptosis at all intervals. At the peak of cell death, myocyte necrosis was 52-fold and 33-fold higher than apoptosis in the left ventricle and septum. In conclusion, necrotic myocyte cell death is the prevailing form of damage produced by coronary artery narrowing, but apoptotic cell death contributes to the loss of myocytes in the ischemic heart. Trimetazidine treatment attenuated the extent of myocardial damage produced by global ischemia.

Ionic and metabolic imbalance as potential factors of ischemia reperfusion injury

This study examined the influence of metabolic substrates on the effects of trimetazidine on functional and metabolic aspects of the ischemic reperfused heart. Isovolumic rat hearts were submitted to a 30-minute period of global mild ischemia (coronary flow decreased by an average of 70%) and then reperfused at constant preischemic coronary flow rate. Either glucose (11 mM) or glucose and palmitic acid (0.1 mM) were used as metabolic substrates. Trimetazidine (6 x 10(-7)M) markedly reduced the increase in diastolic pressure that occurred on reperfusion after the ischemic episode, whatever the exogenous substrate used. However, in those hearts that received fatty acid, the postischemic increase in diastolic pressure was abolished. Ischemia-induced increase in acyl carnitine levels-determined as indicators of fatty acid utilization by myocardial cells-was significantly decreased by trimetazidine in those hearts receiving fatty acid. Also, similar effects to those of trimetazidine on the postischemic increase in diastolic pressure and on tissue levels of acyl carnitine were obtained in the presence of dichloroacetate. Moreover, the presence of trimetazidine was associated with a reduction in the intracellular pH decrease during ischemia in those hearts receiving fatty acid. Combined with previous studies, these results suggest that an improved metabolic balance by trimetazidine may well consequently decrease the ionic imbalance after a transient period of ischemia.

Is the cytoprotective effect of trimetazidine associated with lipid metabolism?

Trimetazidine is an anti-ischemic compound devoid of hemodynamic effect, which was recently suspected to induce cardioprotection at the cellular level by a mechanism involving lipid metabolism. The effect on trimetazidine was evaluated in vivo by determination of rat cardiac fatty acid composition, and in vitro by investigation of the phospholipid metabolism in cultured rat cardiomyocytes. In rats, a 4-week trimetazidine treatment induced a significant decrease in the phospholipid content in linoleic acid, balanced by a small increase in oleic and stearic acids. These changes were not correlated with similar alterations in plasma fatty acid composition. In isolated cells, the time-dependent incorporation of labeled precursors of membrane phospholipid ([3H]inositol, [14C]ethanolamine, [14C]choline, [3H]glycerol, [14C]arachidonic acid, and [14C]linoleic acid 10 micromol/L) was compared in trimetazidine-treated cells and control cells. In trimetazidine-treated cells, arachidonic acid incorporation was increased in the phospholipid, but not in other lipid fractions. This enhanced fatty acid utilization elicited a net increase in the total arachidonic acid uptake. The incorporation of [14C] inositol in phosphatidylinositol was strongly stimulated by trimetazidine, although the uptake of inositol was not altered. The difference was significant within 30 minutes, and reached +70%(in trimetazidine-treated cells) after 150 minutes. A similar result was obtained with ethanolamine as phosphatidylethanolamine precursor, where turnover increased by 50% in trimetazidine-treated cells. Conversely, the incorporation of choline in phosphatidylcholine was not significantly affected by the presence of trimetazidine. In conclusion, trimetazidine appears to interfere with the metabolism of phospholipids in cardiac myocytes in a manner that could indicate an increased phosphatidylinositol turnover and a redirection of cytidine triphosphate (CTP) utilization toward phosphatidylethanolamine instead of phosphatidylcholine turnover. This overall phospholipid turnover increase may contribute to a reorganization of the fatty acid utilization balance in the heart, which could lead to a lowered availability of fatty acids for energy production.

Trimetazidine-induced enhancement of myocardial glucose utilization in normal and ischemic myocardial tissue: an evaluation by positron emission tomography

Trimetazidine has an anti-ischemic effect in angina pectoris. This agent has no hemodynamic effects, and its benefit is presumed to be based on a metabolic mechanism of action. A group of 33 dogs undergoing openchest left anterior descending coronary artery (LAD) ligation causing prolonged ischemia were imaged with quantitative positron emission tomography (PET) using 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) to measure regional glucose metabolic utilization (rGMU) and [11C]acetate to measure regional monoexponential washout rate constant (Kmono) for oxidative metabolism in nonrisk and ischemic-risk myocardium. A total of 20 dogs were pretreated with trimetazidine at low dose (n = 10, 1 mg/kg) and high dose (n = 10, 5 mg/kg) and compared with 13 control dogs. Microsphere-measured myocardial blood flow (mL/min/g) was measured preocclusion and repeated hourly after occlusion and expressed as a ratio of preocclusion myocardial blood flow to verify a stable level of ischemia during PET. No differences were seen in postocclusion ischemic risk/nonrisk myocardial blood flow between treatment groups (p = not significant [NS]). Preocclusion and hourly measurements of heart rate and blood pressure corrected for baseline revealed no difference in control dogs versus trimetazidine (low-dose and high-dose) groups (p = NS). 18FDG-derived rGMU (micromol/min/g) was increased in high-dose trimetazidine versus control dogs in nonrisk and ischemic risk groups, respectively (1.16+/-0.57 vs 0.51+/-0.38 and 0.43+/-0.29 vs 0.20+/-0.14; p <0.05). rGMU was increased proportionately in nonrisk and ischemic risk in all groups without significant differences when corrected for nonrisk rGMU (ischemic risk/nonrisk was 0.92+/-1.3 vs 0.64+/-0.66 vs 0.40+/-0.22 for control dogs, all trimetazidine and high-dose trimetazidine groups). Kmono (min(-1) was not altered in any group (nonrisk = 0.13+/-0.03 vs 0.13+/-0.03 vs 0.14+/-0.02 and ischemic risk = 0.18+/-0.05 vs 0.17+/-0.06 vs 0.16+/-0.06 for control dogs, all trimetazidine and high-dose trimetazidine groups, respectively; p = NS for nonrisk vs ischemic risk, between and within groups). Our data verify that trimetazidine does not alter hemodynamic porameters. It increases total glucose utilization (oxidative and glycolytic) in myocardium without preferential increase in ischemic tissue. Absence of change in total oxidative metabolism suggests increased glucose metabolism is predominantly glycolysis or an increase in glucose oxidation with similar decrease in fatty acid oxidation.

Trimetazidine increases phospholipid turnover in ventricular myocyte

Trimetazidine (TMZ) is an anti-ischemic compound devoid of hemodynamic effects. It was recently suggested to induce cardiomyocyte protection by a mechanism involving lipid metabolism. The effects of TMZ were evaluated in rats on cardiac lipid composition, and in cultured rat cardiomyocytes on phospholipid metabolism. Rats were treated with TMZ for 4 weeks, and the fatty acid compositions were determined. Treatment with TMZ induced a significant decrease in phospholipid linoleic acid, balanced by a small increase in oleic and stearic acids. These changes were not correlated to alterations in plasma fatty acid composition. Cultured ventricular myocytes were treated with TMZ, 16 and 1 before experimentation. The time-dependent incorporation of radio labelled precursors of membrane phospholipids (3-inositol, 14C-ethanolamine, 14C-choline, 14C-arachidonic acid, 10 mumol/L) was investigated. The cells were harvested 30, 60, 105 or 150 min after precursor addition. In TMZ-cells, arachidonic acid (AA) incorporation was increased in the phospholipids, but not in other lipid fractions. This increase elicited a net increase in the total AA uptake. The incorporation of 3-inositol in the phospholipids was strongly stimulated by TMZ, although the uptake of inositol was not altered. The difference was significant within 30 min, and after 150 min the phospholipid labelling in TMZ cells was higher by 70%. A similar result was obtained with ethanolamine as precursor, which turnover increased by 50% in TMZ-treated cells. Conversely, the incorporation of choline was not significantly affected by the presence of TMZ. In conclusion TMZ appears to interfere with the metabolism of phospholipids in cardiac myocytes in a manner which could indicate an increase of membrane phospholipid turnover.

Long-term therapy with trimetazidine in cardiomyopathic Syrian hamster BIO 14:6

The cardiomyopathic Syrian hamster (CMH) of the strain BIO 14:6 is a model for both cardiac and skeletal muscle abnormalities. It has reduced longevity and noticeable hypertrophy of the heart and liver. At 220 days, CMHs display a total Ca2+ overload, 1.3-1.8-fold normal and a cytosolic Ca2+ concentration 2-4-fold higher than normal. Long-term oral treatment (18 mg/kg per day) with trimetazidine (anti-ischaemic drug), from age 30 to 350 days, was more efficient than the standard Ca2+ blocker verapamil. Trimetazidine increased the median survival time of CMH by 57% and the hypertrophy disappeared. The total Ca2+ level in CMHs reverted to that of normal Syrian hamsters (F1B). The cytosolic Ca2+ overload was limited to a factor of approximately 2. Therefore, trimetazidine possesses anti-Ca2+ properties and is effective in increasing survival and decreasing the heart and liver hypertrophy of CMH. This suggests that trimetazidine may be valuable in the prevention of congestive heart failure of similar aetiology.