L-carnitine therapy boosts cardiac health following heart attack, study reports

L-carnitine significantly improves cardiac health in patients after a heart attack, according to a multicenter team of investigators in a study published in Mayo Clinic Proceedings.

Researchers conducted a literature review and meta-analysis of 13 controlled trials of more than 3,600 patients to determine the effects of L-carnitine versus placebo or control on morality, ventricular arrhythmias, angina, heart failure, and reinfarction. The trials were identified via searches of the Ovid MEDLINE, PubMed, and Excerpta Medica (Embase) databases between May and August 2012.

There were 250 deaths, 220 cases of new heart failure, and 38 recurrent heart attacks among 3,629 patients enrolled in the studies.

This review found that L-carnitine was associated with:

• Significant 27% reduction in all-cause mortality (number needed to treat 38)

• Highly significant 65% reduction in ventricular arrhythmias (number needed to treat 4)

• Significant 40% reduction in the development of angina (number needed to treat 3)

• Reduction in infarct size

There were numerically fewer myocardial reinfarctions and heart failure cases associated with L-carnitine, but this did not reach statistical significance.

“This is the first meta-analysis (to my knowledge) indicating survival benefit in patients who have experienced an acute myocardial infarction if given L-carnitine,” said lead author James J. DiNicolantonio, PharmD, Wegmans Pharmacy, Ithaca, N.Y.

L-carnitine is a trimethylamine, which occurs in high amounts in red meat and is found in certain other foods, and is also widely available as an over-the-counter nutritional supplement that is claimed to improve energy, weight loss, and athletic performance. Its potential role in treating heart disease was first reported in the late 1970s.

It is known that during ischemic events L-carnitine levels are depleted. The researchers wanted to determine the effects of targeting cardiac metabolic pathways using L-carnitine to improve free fatty acid levels and glucose oxidation in these patients. By performing a systematic review and meta-analysis of the available studies published over several decades, they looked at the role of L-carnitine compared with placebo or control in patients experiencing an acute myocardial infarction.

In a Mayo Clinic press release, Dr DiNicolantonio observed, “Although therapies for acute coronary syndrome, including percutaneous coronary intervention, dual antiplatelet therapy, beta-blockers, statins, angiotensin-converting enzyme inhibitors, omega-3 fatty acids, and cardiac rehabilitation, have markedly improved clinical outcomes, adverse cardiovascular events still occur too frequently after acute coronary syndrome. One promising therapy for improving cardiac health involves using L-carnitine to improve free fatty acid levels and glucose oxidation.

“L-carnitine therapy can already be considered in selected patients with high-risk or persistent angina after acute myocardial infarction who cannot tolerate treatment with ACE inhibitors or beta-blockers, considering its low cost and excellent safety profile,” he concluded.