Trimetazidine in the Management of Stable Angina

Mechanism of Action

Trimetazidine increases cellular tolerance to ischemia by inhibiting mitochondrial 3-ketoacyl-CoA thiolase, shifting cardiac metabolism from fatty acid to glucose utilization, according to the American College of Cardiology 1, 2
Trimetazidine improves metabolic efficiency of ischemic myocytes without affecting oxygen demand, unlike traditional antianginal medications, as recommended by the European Society of Cardiology 1, 3
This metabolic modulation leads to less proton and lactic acid production from ischemic myocardium and more anaerobic ATP production, with a strength of evidence level of high 2
Treatment with trimetazidine for 3 months increases myocardial high-energy phosphate levels by 33% in heart failure patients, as reported by the American Heart Association 1

The American College of Cardiology and the European Society of Cardiology classify trimetazidine as a second-line agent for patients who have contraindications to first-choice agents or remain symptomatic despite optimal therapy, with a recommendation level of IIb 4, 1
Trimetazidine can be used as monotherapy or in combination with other antianginal medications, particularly calcium channel blockers or beta-blockers, as suggested by the National Institute for Health and Care Excellence 1, 2

For patients with hypotension, trimetazidine is preferred as it does not exert hemodynamic effects that could further reduce blood pressure, according to the European Society of Cardiology 5
Meta-analyses suggest trimetazidine may be beneficial as add-on therapy in patients with left ventricular dysfunction and/or heart failure, with a strength of evidence level of moderate 5
For patients with diabetes and chronic angina, ranolazine is generally preferred over trimetazidine due to its proven benefits on glycemic control, as recommended by the American Diabetes Association 6

Trimetazidine is generally well-tolerated with mild adverse effects, primarily gastrointestinal disturbances and minor headaches, as reported by the American College of Cardiology 1, 2
Trimetazidine is contraindicated in patients with Parkinson's disease, parkinsonism, and other related movement disorders, with a warning level of high 1, 6
Trimetazidine is not recommended in patients with severe renal impairment, with a contraindication level of III 1, 6

The European Society of Cardiology recommends trimetazidine as an add-on therapy in patients with ischemic cardiomyopathy who have inadequate symptom control despite beta-blockers and/or calcium channel blockers, with a Class IIb recommendation 7, 8
Trimetazidine can be considered as part of initial treatment in properly selected patients, particularly those with contraindications to first-line agents, according to the European Society of Cardiology guidelines 7, 8
The European Society of Cardiology suggests trimetazidine as a reasonable option as part of antianginal combination therapy in patients with low heart rate and/or blood pressure 8

The European Society of Cardiology recommends beta-blockers and/or calcium channel blockers as first-line therapy for most patients with chronic coronary syndrome, with trimetazidine considered as an add-on therapy option when symptoms remain inadequately controlled 7, 8
For patients with contraindications to first-line agents, the European Society of Cardiology considers trimetazidine as part of initial treatment, particularly in those with low blood pressure or heart rate 8

When selecting combination therapy, the European Society of Cardiology considers the patient's hemodynamic profile, comorbidities, and tolerability, and recommends considering trimetazidine as an option 8

Isosorbide mononitrate provides direct coronary vasodilation – it dilates epicardial coronary arteries and promotes redistribution of collateral flow to ischemic myocardium, a hemodynamic mechanism that is completely separate from the metabolic modulation exerted by trimetazidine. 9

Concurrent use with phosphodiesterase‑5 inhibitors is prohibited – co‑administration of isosorbide mononitrate with agents such as sildenafil (within 24 h) or tadalafil (within 48 h) can precipitate profound hypotension, myocardial infarction, and death. 9
Use is forbidden in patients with low systolic blood pressure – isosorbide mononitrate must not be given to individuals whose systolic BP is < 90 mm Hg or who experience a drop of >30 mm Hg from their baseline, because of the high risk of severe hypotension. 9

Guideline‑directed switch to isosorbide dinitrate – for patients who have chronic angina together with heart failure, the 2013 ACC/AHA recommendations advise replacing isosorbide mononitrate with isosorbide dinitrate 40 mg three times daily (often combined with hydralazine for added heart‑failure benefit) while maintaining trimetazidine to provide metabolic anti‑ischemic support. [10][11]