Between 2004 and 2010, one-third more Britons than Swedes died within a month of having a heart attack, a study found.
More than 11,000 deaths could have been avoided if UK care standards were as good as Sweden's, the authors claim.
The team assessed quality of care and outcomes for all heart attack patients treated in hospital in the UK and Sweden from 2004 to 2010.
In total, records relating to 391,077 patients from 242 hospitals in the UK and 119,786 from 86 hospitals in Sweden were assessed and analysed.
Results said that 30 days after a heart attack, 10.5% of UK patients discharged from hospital died, compared with 7.6% in Sweden.
Taking into account a variety of influences, they estimated that 11,263 lives could have been saved by matching Swedish standards.
Co-author Dr Tomas Jernberg, from the Karolinska University Hospital in Sweden, said: "Procedures to open up constricted coronary arteries, were used more often and earlier in Sweden, where they were applied in 59% of cases compared with 22% in the UK."
Drugs such as beta blockers were also less likely to be prescribed to British patients.
Dr Mike Knapton, associate medical director at the British Heart Foundation, said:"Sweden's early adoption meant they saw the benefits quicker and this is reflected in the figures. However, the UK has caught up and last year the majority of patients received this treatment."