Almost half of the drop is attributable to lifestyle changes, especially smoking and diet, it suggests.
The research team used a combination of published data on the use and effectiveness of specific treatments for heart disease and associated risk factors, such as smoking, cholesterol, high blood pressure, obesity, diabetes, and a sedentary lifestyle.
Between 1985 and 2000, deaths from coronary artery disease in Ireland fell by 47% in those aged 25 to 84, resulting in almost 3800 fewer deaths in 2000 than in 1985.
Almost 44% of the drop-off was attributable to better, and more timely, treatment, including tackling heart failure and secondary prevention.
But just under half of the figure (48%) was attributable to sharp falls in smoking, which accounted for over 25%, and in cholesterol, which accounted for 30%. Falls in high blood pressure accounted for 6%.
Smoking rates have fallen more slowly in Ireland than they have in the UK and other developed countries, but have been given a boost by a ban on workplace smoking, which came into force in 2004.
Rises in rates of obesity, diabetes, and sedentary lifestyles offset these favourable trends by around 13% or 500 deaths. And the authors suggest that if these trends continue, they threaten to overturn the substantial health gains made.
Journal
Journal of Epidemiology and Community Health