News Release

ANP reduces infarct size and reperfusion injury and increases ejection fraction post heart-attack

Peer-Reviewed Publication

The Lancet_DELETED

Patients given human atrial natriuretic peptide (ANP) post heart-attack have lower infarct size, fewer reperfusion injuries, and better outcomes than those in a control group. These are the conclusions of authors of an Article in this week's edition of The Lancet.

Professor Masafumi Kitakaze, National Cardiovascular Centre Suita, Osaka, Japan, and colleagues, did two randomised trials (the J-WIND studies), one of which assessed the effect of ANP and the other the effect of nicroandil on infarct size and cardiovascular outcome.

In the ANP trial, 277 acute heart-attack patients were randomised to receive intravenous ANP at a dose of 0.025µg/ kg per min for three days, and 292 patients the same dose of placebo. In the nicroandil trial, 276 patients were randomised to receive intravenous nicroandil (0.067 mg/kg as a bolus, followed by 1.67 µg/kg as a 24-hour continuous infusion), and 269 patients the same dose of placebo. Median follow-up was 2.7 years in the ANP trial and 2.5 years for the nicroandil trial.

The researchers found that in the ANP trial, infarct size was reduced by around 15% and left-ventricular ejection fraction (LVEF) increased by an average of 5% in patients given ANP compared with placebo. In the nicroandil trial, nicroandil administration did not decrease infarct size, however oral administration of nicroandil during follow-up did increase the LVEF between the chronic and acute phases.

On the ANP results, the authors hypothesise: "The reduction of infarct size and the improvement of LVEF might decrease mechanical stress on the non-infarcted myocardium, which might decrease hypertrophy and dilation of the non-infarcted myocardium. Since cardiac hypertrophy and dilation cause diastolic and systolic heart failure, a reduction of infarct size and an increase of LVEF could mediate beneficial clinical outcomes. However, we need to do another large-scale clinical trial to target clinical outcomes such as cardiovascular death, because our primary aim here was to test the reduction of infarct size."

They conclude: "Our finding that treatment with ANP in the acute phase reduced the incidence or readmission to hospital for chronic heart failure, could help to reduce the physical, medical, and economic burdens on people around the world."

In an accompanying Comment, Dr Richard Bogle and Dr Martin Wilkins, Imperial College London and Hammersmith Hospital, London, UK say: "Use of ANP as a treatment for acute myocardial infarction needs further investigation in a double-blind study, to assess the dose-response association, to test the robustness of the findings, and to further evaluate the mechanism of action before exposing many patients to this treatment."

###

The paper associated with this release can be viewed at the link below:
http://multimedia.thelancet.com/pdf/press/HAP.pdf


Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.