Scientists found one sugar-sweetened beverage a day was enough to increase the risk of dying from cardiovascular disease (CVD) affecting the heart and arteries.
For people obtaining a quarter of their calories from added sugar, the risk tripled compared with those whose sugar contribution was less than 10%.
Sugar consumption in the top fifth of the range studied doubled the likelihood of death from heart disease.
The researchers specifically focused on added sugar in the diet - that is, sugar added in the processing or preparing of food, rather than natural sources.
Dietary guidelines from the World Health Organisation recommend that added sugar should make up less than 10% of total calorie intake.
Yet many processed foods and beverages are packed with sugar. A single can of fizzy drink, for instance, may contain 35 grams of sugar, providing 140 calories.
The American study found that between 2005 and 2010, added sugar accounted for at least 10% of the calories consumed by more than 70% of the US population.
The data were matched against heart disease mortality over a typical period of 14.6 years, during which a total of 831 CVD deaths were recorded.
The authors concluded: "A higher percentage of calories from added sugar is associated with significantly increased risk of CVD mortality."
Professor Naveed Satta, of the British Heart Foundation Glasgow Cardiovascular Research Centre, commented: "Helping individuals cut not only their excessive fat intake, but also refined sugar intake, could have major health benefits, including lessening obesity and heart attacks.
"The first target, now taken up by an increasing number of countries, is to tax sugar-rich drinks."