ResMed's shock result of its clinical trial, which put a group of patients at increased risk of dying and, in turn, closed the door on a new avenue of growth, has pushed the stock down 18 per cent.

Following a 15 per cent plunge in ResMed shares overnight on the New York Stock exchange, its Australian stock fell $1.51 to $6.74 at midday AEST.

The $12 billion company dual-listed company said on Wednesday night that its SERVE-HF trial of a particular form of sleep therapy for patients who suffer from both heart failure and central sleep apnoea failed to protect those patients from death or complications associated with heart failure.

In fact, the trial found the risk of dying for those patients was 10 per cent per year, compared with 7.5 per cent for patients who did not receive the adaptive-servo ventilation treatment.

ResMed scrambled to limit the damage, saying it would change the labelling on its ASV device to warn a sub-set of heart failure patients of this increased risk, according to Bloomberg.

For more details, go to: http://www.smh.com.au/business/resmed-shares-slump-on-shock-heart-failure-trial-result-20150514-gh17ey