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

Metabolic remodelling in human heart failure

In addition to the typical abnormalities in myocardial structure and function, it is well established that the cardiac metabolism is abnormal in patients with heart failure (HF). Insulin resistance is a common co-morbidity in HF patients and also modulates cardiac metabolism in HF. The notion that an altered myocardial metabolism may contribute to the disease pathogenesis and optimizing it may serve therapeutic purposes underscores the importance of identifying the metabolic characteristics of HF patients. In this paper, the literature on the metabolic changes in human HF is reviewed, and the effects of metabolic modulators on patients with HF are discussed.

Modulating fatty acid oxidation in heart failure

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

Mitochondrial metabolic adaptation in right ventricular hypertrophy and failure

Right ventricular failure (RVF) is the leading cause of death in pulmonary arterial hypertension (PAH). Some patients with pulmonary hypertension are adaptive remodelers and develop RV hypertrophy (RVH) but retain RV function; others are maladaptive remodelers and rapidly develop RVF. The cause of RVF is unclear and understudied and most PAH therapies focus on regressing pulmonary vascular disease. Studies in animal models and human RVH suggest that there is reduced glucose oxidation and increased glycolysis in both adaptive and maladaptive RVH. The metabolic shift from oxidative mitochondrial metabolism to the less energy efficient glycolytic metabolism may reflect myocardial ischemia. We hypothesize that in maladaptive RVH a vicious cycle of RV ischemia and transcription factor activation causes a shift from oxidative to glycolytic metabolism thereby ultimately promoting RVF. Interrupting this cycle, by reducing ischemia or enhancing glucose oxidation, might be therapeutic. Dichloroacetate, a pyruvate dehydrogenase kinase inhibitor, has beneficial effects on RV function and metabolism in experimental RVH, notably improving glucose oxidation and enhancing RV function. This suggests the mitochondrial dysfunction in RVH may be amenable to therapy. In this mini review, we describe the role of impaired mitochondrial metabolism in RVH, using rats with adaptive (pulmonary artery banding) or maladaptive (monocrotaline-induced pulmonary hypertension) RVH as models of human disease. We will discuss the possible mechanisms, relevant transcriptional factors, and the potential of mitochondrial metabolic therapeutics in RVH and RVF.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Myocardial fatty acid metabolism in health and disease

There is a constant high demand for energy to sustain the continuous contractile activity of the heart, which is met primarily by the beta-oxidation of long-chain fatty acids. The control of fatty acid beta-oxidation is complex and is aimed at ensuring that the supply and oxidation of the fatty acids is sufficient to meet the energy demands of the heart. The metabolism of fatty acids via beta-oxidation is not regulated in isolation; rather, it occurs in response to alterations in contractile work, the presence of competing substrates (i.e., glucose, lactate, ketones, amino acids), changes in hormonal milieu, and limitations in oxygen supply. Alterations in fatty acid metabolism can contribute to cardiac pathology. For instance, the excessive uptake and beta-oxidation of fatty acids in obesity and diabetes can compromise cardiac function. Furthermore, alterations in fatty acid beta-oxidation both during and after ischemia and in the failing heart can also contribute to cardiac pathology. This paper reviews the regulation of myocardial fatty acid beta-oxidation and how alterations in fatty acid beta-oxidation can contribute to heart disease. The implications of inhibiting fatty acid beta-oxidation as a potential novel therapeutic approach for the treatment of various forms of heart disease are also discussed.

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

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

Metabolic modulation and cellular therapy of cardiac dysfunction and failure

At present the prevalence of heart failure rises along with aging of the population. Current heart failure therapeutic options are directed towards disease prevention via neurohormonal antagonism (β-blockers, angiotensin converting enzyme inhibitors and/or angiotensin receptor blockers and aldosterone antagonists), symptomatic treatment with diuretics and digitalis and use of biventricular pacing and defibrillators in a special subset of patients. Despite these therapies and device interventions heart failure remains a progressive disease with high mortality and morbidity rates. The number of patients who survive to develop advanced heart failure is increasing. These patients require new therapeutic strategies. In this review two of emerging therapies in the treatment of heart failure are discussed: metabolic modulation and cellular therapy. Metabolic modulation aims to optimize the myocardial energy utilization via shifting the substrate utilization from free fatty acids to glucose. Cellular therapy on the other hand has the goal to achieve true cardiac regeneration. We review the experimental data that support these strategies as well as the available pharmacological agents for metabolic modulation and clinical application of cellular therapy.

Effect of trimetazidine on quality of life in elderly patients with ischemic dilated cardiomyopathy

INTRODUCTION

Elderly patients have an increased incidence of ischemic dilated cardiomyopathy, often related to diffuse coronary artery disease. Data have been cumulated to suggest that trimetazidine improves myocardial ischemia in patients with ischemic heart disease and improves left ventricular function in elderly patients with ischemic cardiomyopathy. The purpose of the present study was to assess the effects of trimetazidine in addition to standard cardiovascular therapy on left ventricular function and quality of life (QOL) parameters in elderly patients with ischemic heart disease and reduced left ventricular function.

METHODS

Patients were randomized to receive either trimetazidine (twice daily) or placebo (twice daily) in addition to standard therapy, and were evaluated at baseline and after 6 months.

RESULTS

Forty-seven patients completed the study (40 male, seven female; mean [+/-SD] age 78+/-3.4 years). Demographic data were comparable between the two groups with respect to sex, age, and race. At 6 months there was a significant improvement in the number of angina episodes per week in the trimetazidine group (-2.3+/-1, P=0.023). The overall assessment of QOL by a visual analog scale showed an improvement in patients randomized to trimetazidine at 6 months (from 4.1+/-0.6 to 6.4+/-0.8, P<0.01) and no changes in patients randomized to placebo (from 4.3+/-0.7 to 4.2+/-0.9, P>0.05). Physical QOL, evaluated by a MacNew Quality of Life After Myocardial Infarction questionnaire (MacNewQLMI), improved in patients randomized to trimetazidine but not in those allocated to placebo (32%+/-5% vs. -1%+/-3%, P<0.01). Similar results were obtained on social QOL evaluated by MacNewQLMI with trimetazidine compared with placebo (39%+/-4% vs. -2%+/-5%, P<0.01).

CONCLUSION

In elderly patients with ischemic heart disease and reduced ventricular function, trimetazidine improves clinical condition and QOL.

Retained features of embryonic metabolism in the adult MRL mouse

The MRL mouse is an inbred laboratory strain that was derived by selective breeding in 1960 from the rapidly growing LG/J (Large) strain. MRL mice grow to nearly twice the size of other commonly used mouse strains, display uncommonly robust healing and regeneration properties, and express later onset autoimmune traits similar to Systemic Lupus Erythematosis. The regeneration trait (heal) in the MRL mouse maps to 14-20 quantitative trait loci and the autoimmune traits map to 5-8 loci. In this paper we report the metabolic and biochemical features that characterize the adult MRL mouse and distinguish it from C57BL/6 control animals. We found that adult MRL mice have retained a number of features of embryonic metabolism that are normally lost during development in other strains. These include an emphasis on aerobic glycolytic energy metabolism, increased glutamate oxidation, and a reduced capacity for fatty acid oxidation. MRL tissues, including the heart, liver, and regenerating ear hole margins, showed considerable mitochondrial genetic and physiologic reserve, decreased mitochondrial transmembrane potential (DeltaPsi(m)), decreased reactive oxygen species (ROS), and decreased oxidative phosphorylation, yet increased mitochondrial DNA and protein content. The discovery of embryonic metabolic features led us to look for cells that express markers of embryonic stem cells. We found that the adult MRL mouse has retained populations of cells that express the stem cell markers Nanog, Islet-1, and Sox2. These are present in the heart at baseline and highly induced after myocardial injury. The retention of embryonic features of metabolism in adulthood is rare in mammals. The MRL mouse provides a unique experimental window into the relationship between metabolism, stem cell biology, and regeneration.

Trimetazidine potentiates the effects of exercise training in patients with ischemic cardiomyopathy referred for cardiac rehabilitation

BACKGROUND

Patients referred for cardiac rehabilitation may take advantage from combining trimetazidine (TMZ) with exercise training (ET), as both treatments produce similar effects in the cardiovascular system. It is, however, unknown whether the combination of TMZ with ET may determine greater improvements in functional capacity and endothelial function than ET alone.

DESIGN

A randomized longitudinal controlled study.

METHODS

We studied 116 patients (97 men and 19 women, mean age 58+/-9 years) with ischemic heart disease and left ventricular dysfunction who were referred for cardiac rehabilitation. Coronary risk factors were present in 82 patients (diabetes in 28 patients). Patients were randomized into three matched groups. A group (TMZ+training, TT, n=30) received TMZ at doses of 20 mg three times daily orally for 8 weeks in addition to standard medications and underwent a supervised program of ET at 60% of oxygen uptake at peak, three times a week for 8 weeks. A group (exercise, E, n=30) completed the ET program without receiving TMZ. A control group (C, n=26) was neither exercised nor received TMZ. A fourth group (TMZ, n=30) receiving TMZ 20 mg three times daily for 8 weeks was also studied. On study entry and at 8 weeks all patients underwent echocardiography, cardiopulmonary exercise testing, and vasomotor reactivity of the brachial artery.

RESULTS

Oxygen uptake at peak was significantly increased in the TT (25%), TMZ (15.1%), and E group (15.3%) (P<0.001 TT vs. C; P<0.05 vs. TMZ and E). Left ventricular ejection fraction was also improved in TT (18.4%), TMZ (15.7%), and E (12.9%) (P<0.001 TT vs. C; P<0.05 vs. TMZ and E), as a result of reduction in end-systolic volume. The endothelium-dependent dilation was similarly improved (P<0.001 TMZ vs. C; P<0.05 vs. TMZ and E). The most significant improvements were observed in the subgroup TT with multiple risk factors.

CONCLUSION

The addition of TMZ to ET determined greater improvements in functional capacity, left ventricular ejection fraction, and endothelium-dependent dilation than TMZ or ET given alone. No differences between improvements after TMZ and E as compared with controls were observed.

Effects of trimetazidine on myocardial perfusion and left ventricular systolic function in type 2 diabetic patients with ischemic cardiomyopathy

AIMS

To determine whether short-term treatment with trimetazidine (TMZ), an antiischemic agent that directly inhibits fatty acid oxidation and results in stimulation of glucose oxidation, may improve myocardial perfusion and left ventricular systolic function in diabetic patients with ischemic cardiomyopathy.

METHODS AND RESULTS

We studied 34 clinically stable patients with type 2 diabetes mellitus (DM) and documented multivessel coronary artery disease (29 men and 5 women, mean age 54 +/- 9 years) with depressed systolic function (left ventricular ejection fraction 38 +/- 6%). Patients were randomized into two groups. One group received TMZ (20 mg tid) for 3 months (n = 19), while another group received a placebo during the same period (n = 15). On study entry and at 3 months, all patients underwent a gated Single Photon Emission Computed Tomography (SPECT) myocardial scintigraphy with a 2-day stress(Bruce)-rest protocol (500 MBq tetrofosmin). At 3 months, TMZ-treated patients had a significant improvement in systolic wall thickening (P < 0.05) and ejection fraction (P = 0.007) as compared with control patients. These effects were more marked in patients with more severe reversible perfusion defects on initial evaluation and were not associated with changes in myocardial defects (P = 0.38). Total exercise time was also improved in TMZ-treated patients (20.5%, P < 0.05 vs. controls).

CONCLUSIONS

In diabetic cardiomyopathy, short-term TMZ improved left ventricular systolic function and functional capacity despite no change in myocardial perfusion. These benefits were more evident in patients with more severe perfusion defects on initial evaluation, suggesting that chronic myocardial ischemia is a requirement for the effects of TMZ on left ventricular systolic performance.

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

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

Metabolic Derangements in the Insulin‐Resistant Heart

Myocardium is flexible when it comes to energy substrate utilization; it uses fatty acid, glucose, lactones, and ketones for its energy requirement. The myocardial energy substrate preference varies in a dynamic manner depending on myocardial perfusion, energy demand, substrate availability, and local/systemic hormonal changes. The authors discuss the metabolic perturbations seen in insulin-resistant myocardium and how they result in structural and other biochemical changes that ultimately result in left ventricular hypertrophy and diastolic and systolic dysfunction. The authors also discuss the utility of metabolic imaging to study metabolic derangement as seen in insulin-resistant rodents. The role of positron emission tomography and cine-magnetic resonance imaging coregistration in quantifying myocardial glucose uptake is demonstrated in fasted, 13-week old Sprague-Dawley rats under insulin-/glucose-stimulated conditions. This study demonstrates the utility of in vivo, noninvasive positron emission tomography and cine-magnetic resonance imaging modalities to longitudinally follow insulin resistance models during disease progression and after specific interventions.

Myocardial fatty acid metabolism and cardiac performance in heart failure

It is well established that cardiac metabolism is abnormal in heart failure (HF). Experimental studies suggest that in severe HF, cardiac metabolism reverts to a more fetal-like substrate use characterized by enhanced glucose and downregulated free fatty acid (FFA) metabolism. Correspondingly, in humans, when FFA levels are similar, myocardial glucose metabolism is increased, and FFA metabolism is decreased. However, depression of left ventricular function and insulin resistance induces a shift back to greater FFA uptake and oxidation by increasing circulating FFA availability. Myocardial insulin resistance may further impair myocardial glucose uptake and lead to an energy depletion state. Experimental and preliminary clinical studies suggest that metabolic modulators enhancing myocardial glucose oxidation may improve cardiac function in patients with chronic HF. However, it has been found that acute FFA deprivation is harmful to the cardiac performance. Optimizing myocardial energy metabolism may serve as an additional approach for managing HF, but further studies are warranted.

Effect of strain at low-frequency loading on peri-implant bone (re)modelling: a guinea-pig experimental study

OBJECTIVES

To investigate whether controlled early loading enhances peri-implant bone mass and bone-to-implant contact. Low-frequency stimulation (3 Hz) and varying force amplitudes, causing varying strains, were applied in three guinea-pig series.

MATERIAL AND METHODS

Three series of guinea-pigs received percutaneous TiO(2)-blasted implants in both tibiae. One week after implant installation, one implant was stimulated with a sinusoidally varying bending moment while the contra-lateral implant served as an unloaded control. Force amplitudes of 0.5, 1 and 2 N were applied on a 20-mm-long cantilever, resulting in strains of 133, 267 and 533 muepsilon, respectively, measured by a strain gauge bonded on the surface of the tibial bone at 1.3 mm from the implant's distal surface. Implant stability was followed by means of resonance frequency analysis. Bone-to-implant contact and bone mass [BM (%) bone occupied area fraction] were analysed histomorphometrically.

RESULTS

A significant positive effect on the difference in bone mass at the stimulated vs. at the control side was observed in the distal half peri-implant marrow cavity for early mechanical stimulation at a frequency of 3 Hz (P<0.0001). An optimum was reached for the applied load, which causes a strain of approximately 267 muepsilon 1.3 mm from the implant. Implant stability gradually increased in time; no significant effect of early stimulation could be measured.

CONCLUSIONS

The effect of early controlled mechanical stimulation on the peri-implant bone, in this cortical bone model, is strongly dependent on force amplitude/strain at low-frequency stimulation.

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

BACKGROUND

In patients with ischemic cardiomyopathy, mortality rate and quality of life are unsatisfactory. We investigated the effects of the metabolic agent trimetazidine (TMZ) on exercise tolerance and prognostic markers B-type natriuretic peptide (BNP) and cardiac troponin T (cTnT) plasma levels.

METHODS

Fifty patients with ischemic cardiomyopathy were randomized either to receive TMZ (20 mg, TID) in addition to their conventional treatment (TMZ group, n = 25) or to continue their usual drug therapy (control group, n = 25) for 6 months. Patients were evaluated at baseline, at 1 month, and at 6 months (echocardiography and 6-minute walking test). At enrollment and at the end of follow-up, blood testing was performed for determination of BNP and cTnT plasma levels.

RESULTS

After 6 months, no significant New York Heart Association class changes occurred in all patients (P = NS). In the TMZ group, a significant increase of exercise tolerance (P < .01) was detected, whereas left ventricular ejection fraction was unchanged (28% +/- 4%, 29% +/- 5%, and 32% +/- 5% at baseline, at 1 month, and at 6 months, respectively; P = NS). In the TMZ group, BNP was significantly reduced (6 months, 135 +/- 22 vs 252 +/- 44 pg/mL; P < .001), whereas it was significantly increased in controls (6 months, 288 +/- 46 vs 239 +/- 59 pg/mL; P < .02); cTnT significantly (P < .001) reduced during TMZ treatment, whereas it was unchanged in the control group.

CONCLUSIONS

Six-month TMZ treatment improves exercise tolerance and reduces plasma levels of BNP and cTnT in patients with compensated ischemic cardiomyopathy.

Potential of metabolic agents as adjunct therapies in heart failure

Heart failure continues to have a significant morbidity and mortality rate despite several recent advances in treatment such as additional neurohumoral blockades and cardiac resynchronisation therapy. There is emerging evidence that, irrespective of etiology, heart failure is associated with an energetic disorder and that this may contribute to the pathogenesis of the syndrome. Recently, a number of studies have suggested that some metabolic agents may have potential as adjunctive therapy in patients with heart failure. These agents cause a shift of myocardial-substrate utilization away from free fatty acids toward glucose. Free fatty acid utilization consumes more oxygen to generate an equivalent amount of energy compared with glucose. Some of these agents are also effective antianginals, presumably by reducing the myocardial oxygen requirement. In this review we will discuss some of the current issues and progresses relating to metabolic manipulation in heart failure.

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.

Metabolic Mechanisms in Heart Failure

Although neurohumoral antagonism has successfully reduced heart failure morbidity and mortality, the residual disability and death rate remains unacceptably high. Though abnormalities of myocardial metabolism are associated with heart failure, recent data suggest that heart failure may itself promote metabolic changes such as insulin resistance, in part through neurohumoral activation. A detrimental self-perpetuating cycle (heart failure --> altered metabolism --> heart failure) that promotes the progression of heart failure may thus be postulated. Accordingly, we review the cellular mechanisms and pathophysiology of altered metabolism and insulin resistance in heart failure. It is hypothesized that the ensuing detrimental myocardial energetic perturbations result from neurohumoral activation, increased adverse free fatty acid metabolism, decreased protective glucose metabolism, and in some cases insulin resistance. The result is depletion of myocardial ATP, phosphocreatine, and creatine kinase with decreased efficiency of mechanical work. On the basis of the mechanisms outlined, appropriate therapies to mitigate aberrant metabolism include intense neurohumoral antagonism, limitation of diuretics, correction of hypokalemia, exercise, and diet. We also discuss more novel mechanistic-based therapies to ameliorate metabolism and insulin resistance in heart failure. For example, metabolic modulators may optimize myocardial substrate utilization to improve cardiac function and exercise performance beyond standard care. The ultimate success of metabolic-based therapy will be manifest by its capacity further to lessen the residual mortality in heart failure.

Metabolic imaging using PET

INTRODUCTION

There is growing evidence that myocardial metabolism plays a key role not only in ischaemic heart disease but also in a variety of diseases which involve myocardium globally, such as heart failure and diabetes mellitus. Understanding myocardial metabolism in such diseases helps to elucidate the pathophysiology and assists in making therapeutic decisions.

MEASUREMENT

As well as providing information on regional changes, PET can deliver quantitative information about both regional and global changes in metabolism. This capability of quantitative measurement is one of the major advantages of PET along with physiological positron tracers, especially relevant in evaluating diseases which involve the whole myocardium.

DISCUSSION

This review discusses major PET tracers for metabolic imaging and their clinical applications and contributions to research regarding ischaemic heart disease and other diseases such as heart failure and diabetic heart disease. Future applications of positron metabolic tracers for the detection of vulnerable plaque are also highlighted briefly.

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.

Emerging drugs for acute and chronic heart failure: current and future developments

Heart failure continues to be a major public health issue. Although angiotensin-converting enzyme inhibitors and beta-adrenergic blockers have been broadly used as evidence-based therapies in heart failure, morbidity and mortality remains high. Furthermore, treatment for acute decompensated heart failure and diastolic heart failure (or 'heart failure with preserved ejection fraction') is far from perfect. This review provides a broad overview of some of the novel compounds under investigation for the treatment of heart failure. Novel strategies include drugs that aim to alleviate congestion and improve hemodynamics, drugs that preserve renal function, drugs that reduce arterial and myocardial stiffness, drugs that module myocardial contractility, drugs that affect metabolic and hormonal balance, and drugs that act on existing and novel physiologic targets.

Inhibition of free fatty acids metabolism as a therapeutic target in patients with heart failure

Recent studies have evidenced that alterations of cardiac metabolism can be present in several cardiac syndromes. In heart failure, wasting of subcutaneous fat and skeletal muscle is relatively common and suggests an increased utilisation of non-carbohydrate substrates for energy production. In fact, fasting blood ketone bodies as well as fat oxidation during exercise have been shown to be increased in patients with heart failure. This metabolic shift determines a reduction of myocardial oxygen consumption efficiency. A direct approach to manipulate cardiac energy metabolism consists in modifying substrate utilisation by the heart. To date, the most effective metabolic treatments include several pharmacological agents that directly inhibit fatty acid oxidation. Clinical studies have shown that these agents can substantially increase the ischaemic threshold in patients with effort angina. However, the results of current research is also supporting the concept that shifting the energy substrate preference away from fatty acid metabolism and towards glucose metabolism could be an effective adjunctive treatment in patients with heart failure, in terms of left ventricular function and glucose metabolism improvement. In fact, these agents have also been shown to improve overall glucose metabolism in diabetic patients with left ventricular dysfunction. In this paper, the recent literature on the beneficial therapeutic effects of modulation of cardiac metabolic substrates utilisation in patients with heart failure is reviewed and discussed.

Diabetes and heart failure in the post-myocardial infarction patient

Diabetes mellitus, a disease which is increasing in prevalence, is a major risk factor for coronary heart disease. In patients following acute myocardial infarction, the presence of diabetes is a powerful risk factor for the development of heart failure, and this intersection of heart failure and diabetes following myocardial infarction carries substantial risk. The poor prognosis associated with heart failure in diabetic patients following myocardial infarction is likely multifactorial. Aggressive strategies for prevention and treatment of heart failure are crucial to reducing the risk associated with diabetes and heart failure following myocardial infarction. This review summarizes epidemiologic, pathophysiologic, and therapeutic data related to diabetes and heart failure in the post-myocardial infarction setting.

Optimizing cardiac fatty acid and glucose metabolism as an approach to treating heart failure

Despite the recent introduction of new therapeutic approaches to treat heart failure, mortality from heart failure remains high, and patients still frequently experience progression of contractile dysfunction and ongoing left ventricular enlargement. Therefore, new treatments are needed for heart failure that work independently of mechanisms already targeted. Emerging evidence suggests that the failure of the myocardium in heart failure is affected by alterations in the energy substrate metabolism. In particular, there is now evidence that in the failing heart, shifting metabolism away from a preference for fatty acids toward more carbohydrate oxidation can improve contractile function and slow the progression of pump failure.

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.

CVT-4325 Inhibits Myocardial Fatty Acid Uptake and Improves Left Ventricular Systolic Function without Increasing Myocardial Oxygen Consumption in Dogs with Chronic Heart Failure

BACKGROUND

Inhibition of myocardial fatty acid oxidation has been suggested as a therapeutic approach for improving cardiac function in chronic heart failure (HF). The novel piperazine derivative CVT-4325 was shown to inhibit fatty acid oxidation in cardiac mitochondria and in isolated perfused rat hearts. In the present study, we tested the hemodynamic and metabolic effects of acute intravenous CVT-4325 in dogs with HF.

METHODS AND RESULTS

HF (LV ejection fraction <or=35%) was created in eight dogs by multiple sequential intracoronary microembolizations. Treatment with CVT-4325 administered intravenously as 0.5 mg/kg bolus followed by a continuous infusion of 0.8 mg/kg/h for 40 min reduced free fatty acid (FFA) uptake (4.51+/-0.96 to 1.65+/-0.32 micromols/min, p<0.04), coronary blood flow (56+/-3 to 46+/-4 ml/min, p<0.01), and myocardial oxygen consumption (MVO2) (240+/-23 to 172+/-7 micromols/min, p<0.03), and increased LV ejection fraction (30+/-2 to 37+/-1%, p<0.0001). In the same study, but on a different day, the same dogs were treated with an inactive analogue of CVT-4325 (CVT-2540), and no hemodynamic or metabolic effects were observed.

CONCLUSIONS

In dogs with HF, acute intravenous infusion of CVT-4325 reduces FFA uptake and improves LV systolic function without increasing MVO2. The improvement in LV systolic function in the absence of an increase in MVO2 and a lower FFA uptake is consistent with the concept that inhibition of myocardial fatty acid oxidation may be an effective treatment for HF.

Clinical benefits of a metabolic approach in the cardiac rehabilitation of patients with coronary artery disease

Patients referred for cardiac rehabilitation may benefit from combining trimetazidine with exercise training because both treatments produce synergic benefits on the cardiovascular system. There is evidence that trimetazidine improves left ventricular (LV) function in patients with ischemic and diabetic cardiomyopathy by shifting the cellular energy substrate reference from fatty acids to glucose oxidation, and that this effect is associated with a better outcome. Recently, results have demonstrated that trimetazidine improves radial artery endothelium-dependent relaxation related to its antioxidant properties. Similarly, exercise training has been demonstrated to improve diastolic filling and systolic function in patients with ischemic cardiomyopathy, in relation to enhanced perfusion and contractility of dysfunctional myocardium. Patients with viable myocardium, in theory, should have the greatest benefits because trimetazidine improves contractility of dysfunctional hibernating/stunned myocardium, whereas exercise has documented efficacy in improving endothelial vasomotor response of coronary arteries, stimulating coronary collateral circulation and small vessel growth, improving LV function, and increasing functional capacity. At present, there are no published reports about the efficacy of the combination of trimetazidine with exercise training. In this article, we discuss the rationale for using trimetazidine in cardiac rehabilitation, the identification of patients referred for cardiac rehabilitation who might benefit the most from the addition of trimetazidine to standard therapy, and the documented benefits.

Role of trimetazidine in management of ischemic cardiomyopathy

Despite treatment with conventional agents, a high proportion of patients with ischemic cardiomyopathy continue to have symptoms. Moreover, a substantial proportion shows progressive contractile dysfunction leading to left ventricular (LV) enlargement and heart failure. Therefore, a need exists for new treatments for ischemic cardiomyopathy that tackle mechanisms other than those already addressed by conventional agents. Emerging evidence suggests that in patients with ischemic cardiomyopathy, LV dysfunction develops as a result of alterations in substrate metabolism, which contribute to contractile dysfunction and the progression of LV remodeling. Trimetazidine, a novel pharmacologic agent that acts on myocardial metabolic pathways, appears to protect the heart from the deleterious effects of ischemia, and it has been shown to enhance LV contractility in patients with stunned or hibernating myocardium. This article reviews recent clinical trials that have assessed the therapeutic role of trimetazidine in patients with ischemic cardiomyopathy. Trimetazidine has been shown to improve symptoms and LV ejection fraction and to have a beneficial effect on the inflammatory profile and endothelial function in these patients. These results suggest that trimetazidine is a useful adjunct to our current armamentarium for the treatment of patients with ischemic cardiomyopathy.

Modification of myocardial substrate use as a therapy for heart failure

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

Rationale for a metabolic approach in diabetic coronary patients

The incidence of ischaemic heart disease and acute myocardial infarction are greater in people with diabetes than in nondiabetic individuals. Heart disease patients with diabetes have a higher incidence of mortality during and following an acute myocardial infarction and a high risk for progression to heart failure post-infarction. The greater occurrence of ischaemic heart disease is partially due to a poorer coronary artery disease risk factor profile in diabetic patients, and, importantly, due to diabetes-induced abnormalities in the myocardium, termed 'diabetic cardiomyopathy'. The main metabolic abnormalities in the diabetic myocardium are impaired carbohydrate metabolism, specifically reduced pyruvate oxidation in the mitochondria and a greater reliance on fatty acids and ketone bodies as fuels. The healthy heart takes up glucose and lactate and converts them to pyruvate; however, in the diabetic heart there is a reduced capacity to oxidize pyruvate, and thus less glucose and lactate uptake. The defective metabolism is due to high circulating free fatty acids and ketone body concentrations in the plasma, resulting in greater acetyl-Co-enzyme A/Co-enzyme A and reduced nicotinamide adenonine dinucleotide/nicotinamide adenonine dinucleotide+ ratios in the mitochondria, and the subsequent inhibition of pyruvate dehydrogenase. Pharmacological inhibition of fatty acid oxidation during ischaemia increases myocardial pyruvate oxidation and provides clinical benefit to patients with stable angina or ischaemic left ventricular dysfunction. Recent clinical trials with trimetazidine, an inhibitor of the fatty acid beta-oxidation enzyme long chain 3-ketoacylthiolase, showed improvement in cardiac function and exercise performance in diabetic patients with ischaemic heart disease, illustrating the effectiveness of this approach in diabetes.

Vascular endothelial dysfunction in diabetic cardiomyopathy: pathogenesis and potential treatment targets

Cardiovascular complications account for significant morbidity and mortality in the diabetic population. Diabetic cardiomyopathy, a prominent cardiovascular complication, has been recognized as a microvascular disease that may lead to heart failure. Pathogenesis of diabetic cardiomyopathy involves vascular endothelial cell dysfunction, as well as myocyte necrosis. Clinical trials have identified hyperglycemia as the key determinant in the development of chronic diabetic complications. Sustained hyperglycemia induces several biochemical changes including increased non-enzymatic glycation, sorbitol-myoinositol-mediated changes, redox potential alterations, and protein kinase C (PKC) activation, all of which have been implicated in diabetic cardiomyopathy. Other contributing metabolic abnormalities may include defective glucose transport, increased myocyte fatty acid uptake, and dysmetabolism. These biochemical changes manifest as hemodynamic alterations and structural changes that include capillary basement membrane (BM) thickening, interstitial fibrosis, and myocyte hypertrophy and necrosis. Diabetes-mediated biochemical anomalies show cross-interaction and complex interplay culminating in the activation of several intracellular signaling molecules. Studies in both animal and human diabetes have shown alteration of several factors including vasoactive molecules that may be instrumental in mediating structural and functional deficits at both the early and the late stages of the disease. In this review, we will highlight some of the important vascular changes leading to diabetic cardiomyopathy and discuss the emerging potential therapeutic interventions.

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.

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.

Myocardial substrate metabolism in the normal and failing heart

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

Myocardial metabolic manipulation: a new therapeutic approach in heart failure?

Myocardial metabolic manipulation using drugs such as trimetazidine may offer a new therapeutic approach to the treatment of heart failure.

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.

Diabetic cardiomyopathy: mechanisms, diagnosis and treatment

Independent of the severity of coronary artery disease, diabetic patients have an increased risk of developing heart failure. This clinical entity has been considered to be a distinct disease process referred to as 'diabetic cardiomyopathy'. Experimental studies suggest that extensive metabolic perturbations may underlie both functional and structural alterations of the diabetic myocardium. Translational studies are, however, limited and only partly explain why diabetic patients are at increased risk of cardiomyopathy and heart failure. Although a range of diagnostic methods may help to characterize alterations in cardiac function in general, none are specific for the alterations in diabetes. Treatment paradigms are very much limited to interpretation and translation from the results of interventions in non-diabetic patients with heart failure. This suggests that there is an urgent need to conduct pathogenetic, diagnostic and therapeutic studies specifically in diabetic patients with cardiomyopathy to better understand the factors which initiate and progress diabetic cardiomyopathy and to develop more effective treatments.