Coronary heart disease is a condition in which the supply of blood and oxygen to the heart is reduced due to the narrowing of the arteries supplying the heart. A heart attack is caused when one of these arteries becomes blocked. Modern treatment for a heart attack is called primary percutaneous coronary intervention (PPCI). PPCI involves opening the blocked artery with a balloon and placing a stent (a small metal tube) in the artery to hold it open.

Research has shown that after opening the blocked artery, inflammation develops within the heart. This inflammation is generated by the immune system. Initial studies have suggested that certain immune system cells (T-cells) may be involved in causing much of the damage that occurs in the heart following a heart attack. The drug ciclosporin temporarily inhibits the immune system and it has been shown in a small number of patients that it reduces the size of the heart attack. The aim of this clinical trial is to investigate in a larger number of patients whether the size of the heart attack is reduced in patients treated with the drug ciclosporin prior to PPCI relative to patients treated with a placebo (saline).

To participate in the trial you must be having a large heart attack (STEMI - ST segment elevation myocardial infarction) and be undergoing a PPCI to unblock your artery. You must also be aged over 18 years. You will be randomised to receive either a single dose of the drug ciclosporin or placebo before your blocked artery is opened. Half the people will get the drug ciclosporin. This randomisation will enable us to compare the results to see whether treatment with ciclosporin reduces the size of the heart attack compared with placebo.

There may be no immediate benefit from taking part in the trial but the information we get from this trial will help improve the treatment of people having a heart attack in the future. As far as we know there are no disadvantages of taking part in the trial. If you are randomised to the 'drug' group, there is a very small risk of side effects from ciclosporin, such as high blood pressure and slight worsening of kidney function. We do not expect any side effects as the ciclosporin is only given once in the trial. On rare occasions allergic reactions have been observed. If any ciclosporin-related side effects were to occur, they would be expected soon after the drug was administered.

This is a single centre, randomised, double-blind, parallel group, placebo-controlled phase II/III trial comparing the efficacy of ciclosporin versus placebo in 68 patients with acute myocardial infarction undergoing PPCI. The trial is set in a tertiary care centre (Freeman Hospital, Newcastle upon Tyne, UK) and patients will be recruited over a period of 18 months. The trial is designed to show superiority regarding its primary endpoint. During initial hospitalisation following myocardial infarction, treatment is given once prior to performing the PPCI in the catheter laboratory. The duration of study for each patient is 12 months until final follow-up (12 weeks randomised controlled trial (RCT) followed by 9 months study follow-up). Should treatment with ciclosporin look promising, a larger trial will be designed to evaluate ciclosporin treatment fully. In contrast to the previous study, this trial is not restricted to anterior STEMI patients. It will also analyse changes in inflammatory response following reperfusion and will use MRI (current gold standard) in every patient to quantify infarct size, ejection fraction and microvascular obstruction.