Failures in heart attack care are leading to tens of thousands of deaths, a new study has found.
Around 33,000 deaths could have been avoided over a 10-year period if heart attack after-care guidelines were followed, researchers said.
One patient is dying every month per each hospital because medics across England and Wales are not stringently following after-care treatment recommendations, experts have estimated.
The study, funded by the British Heart Foundation (BHF) and the National Institute for Health Research, analysed 389,057 cases of non-ST elevation myocardial infarction (NSTEMI) - the most common type of heart attack - in patients treated across 247 hospitals in England and Wales between January 2003 and January 2013.
Researchers from the University of Leeds and University College London looked at 13 treatments that are recommended for those who have suffered from an NSTEMI.
They found that almost nine in ten patients did not receive at least one of the interventions that they should have been given.
The most frequently missed interventions were; dietary advice, advice to help people to stop smoking, the prescription of a type of anti-clotting drug known as P2Y12 inhibitors and receiving a coronary angiography - a test that allows medics to view the coronary arteries using dye and x-rays.
The study, published in the European Heart Journal: Acute Cardiovascular Care, also found that missed interventions with the strongest impact on reduced survival were; coronary angiography, cardiac rehabilitation (a rehab programme which helps improve a patient's health), smoking cessation advice, and the prescription of statins.
"If all eligible patients in the study had received optimal care at the time of guideline publication, then 32,765 deaths may have been prevented," the authors concluded.
Dr Chris Gale, associate professor of cardiovascular health sciences at the Leeds Institute of Cardiovascular and Metabolic Medicine, who led the research, said: "What we've highlighted here is the unacceptable deficit in the care being given to people after they've had an NSTEMI heart attack.
"We calculate that roughly one patient per month per hospital in England and Wales is losing their life as a direct consequence of this deficit.
"The good news is that now we've identified the problem, we can certainly fix it. Simple interventions, such as prescribing statins, are being missed, and this is resulting in loss of life."
BHF medical director Professor Peter Weissberg added: "This study shows that many people in the UK are receiving suboptimal care after a heart attack and that lives are being lost as a consequence.
"Over the years the BHF has invested millions of pounds of donated money on research that demonstrates how best to identify and treat people who have had a heart attack. Hospitals need to apply the lessons learnt from this research and we're committed to working with the NHS to improve patient care.
"Applying clinical guidelines in heart disease costs little and in the long-term saves money and, most importantly, saves lives."
Professor Huon Gray, NHS England's national clinical director for heart disease, said: "Immediate and long-term survival rates after a heart attack are improving thanks to advances in treatment and aftercare, but this study shows there are opportunities to improve outcomes further.
"National and international guidelines are clear, and these findings should act as a reminder to providers and commissioners of care that best practice should always be followed."