About two in three heart failure patients in Singapore also suffer from iron deficiency, which adds to their symptoms of fatigue and breathlessness.
Most are unable to get enough iron through their food, or even with iron supplements.
Furthermore, many struggle with the side effects of taking iron pills, such as constipation and nausea.
Associate Professor Carolyn Lam of the National University Heart Centre Singapore (NUHCS) said iron is "the key ingredient for energy production in every cell of the body".
In an effort to mitigate the symptoms of heart failure, the NUHCS and Tan Tock Seng Hospital have started a pilot trial to inject iron directly into patients' bloodstreams.
There is no side effect to this method of giving iron as it does not go through the stomach, Prof Lam said.
The trial checks these patients before they are injected and six months after to see if they fare better.
Cardiologists hope that the 1g of iron injected into the blood will go straight to the bone marrow where it can be stored for use in the following months.
They have, so far, recruited 34 of the 50 patients needed for the trial, and hope to complete the study by next year.
The trial is studying only the more serious heart failure patients who are hospitalised.
Prof Lam has been heartened by a similar study in Europe.
Results released at the European Society of Cardiology (ESC) Congress, which she attended together with 16 others from the NUHCS, found significant improvement in the group which received one to two injections of iron.
That one-year study compared 150 patients given intravenous iron against a similar number given a placebo. Those given intravenous iron were able to walk 33m farther at 24 weeks, 42m more at 36 weeks and, even a year later, could manage 36m more.
There was also a 61 per cent reduction in hospitalisation in that group.
However, there was no effect on deaths, said Professor Piotr Ponikowski, president of the ESC Heart Failure Association, who presented the findings, adding that this could be due to the short follow-up period.
He added: "Hospitalisations due to heart failure are an economic burden for society, resulting in poor outcomes and impaired quality of life for patients."
Patients from nine European countries on this trial were given between 500mg and 3.5g of iron either as one or two injections.
Prof Lam said the Singapore study will see if it has the same effect on Asians.
Based on blood from more than 750 heart failure patients, cardiologists found that racially, iron deficiency was highest among Indians (82 per cent) and lowest among Chinese (58 per cent), with Malays falling in between (63 per cent).
Prof Lam would also like to find out if the difference is due to genetics or food intake. She said, for example, that black tea - which is popular among Indians - is known to reduce absorption of iron. She added that iron deficiency can also reduce a person's IQ.
This story was first published in The Straits Times on Sept 7, 2014.