MedWire News: The adoption of evidence-based therapy for acute myocardial infarction (AMI) is associated with improved long-term survival and has probably contributed to the continuing decline in heart disease mortality in Australia, research shows.

The claims are based on a 12-year follow-up study of the Perth MONICA (monitoring trends and determinants in cardiovascular disease) project. This is a population-based cohort of 4451 consecutive patients with a definite AMI according to the World Health Organization criteria admitted to hospitals in ffice:smarttags" />Perthduring 1984–1987, 1988–1990, and 1991–1993.

The study, by Tom Briffa (" smilieid="7" border="0" src="./images/smilies/default/tongue.gif" />laceType w:st="on">University" smilieid="7" border="0" src="./images/smilies/default/tongue.gif" />laceType> of " smilieid="7" border="0" src="./images/smilies/default/tongue.gif" />laceName w:st="on">Western Australia" smilieid="7" border="0" src="./images/smilies/default/tongue.gif" />laceName>,Crawley) and fellow investigators, assessed trends in long-term survival among patients who survived the first 28 days after AMI and the impact of evidence-based pharmacotherapy and coronary revascularization.

The 1991–1993 cohort had a 7.6% lower absolute risk for all-cause mortality during 12 years of follow-up (or a 28% relative risk reduction) compared with the 1984–1987 cohort, Briffa et al report in the British Medical Journal.

The improved survival in the most recent cohort remained statistically significant after adjusting for demographic factors, coronary risk factors, severity of disease, and event complications.

However, it was not apparent after further adjustment for in-hospital medical treatments and coronary revascularization procedures performed within 12 months of the index event.

Briffa and co-authors say that their study reveals improvements in long-term survival after AMI that are associated with changes in treatment, “exemplified by antiplatelets, thrombolysis, beta-blockers, and coronary artery revascularization.”

“The magnitude of the contribution of evidence-based treatment to the decline in mortality of coronary heart disease remains unanswered as does the contribution of chronic cardioprotective pharmacotherapy,” they add.