Patients who had a stent fitted in narrowed arteries at the same time as the one that triggered a heart attack were 64% less likely to die or suffer another
serious heart attack.
The five-year study was carried out by cardiologists at specialist heart centres across the UK, including the Golden Jubilee Hospital in Clydebank.
Repairing arteries also cut the risk of patients suffering angina and the method was found to be more cost effective for the NHS.
Heart disease is the main cause of death in Scotland.
It accounts for more than 18,500 deaths each year, around a third of all deaths. Patients who suffer a heart attack normally undergo an emergency operation called angioplasty where a stent - a thin cylindrical metal mesh tube - is inserted into the blocked artery to restore normal blood.
However, around half of patients have significant narrowings in other arteries which could cause another heart
attack in the future.
The 'PRAMI' study recruited 465 patients and found that this risk was reduced dramatically if other arteries were repaired at the same time.
Professor Keith Oldroyd, of the Golden Jubilee National Hospital, said: "The PRAMI trial shows very clearly that patients have a much better outcome if these other narrowed arteries are stented at the same time as the one that triggered the attack.
"This strategy is also much more cost effective for the Health Service."
The Golden Jubilee has established itself as one of the UK's leading 'heart-attack centres' since its creation five years ago.
The research was published recently in the New England Journal of Medicine.