Hospitalisation in China for the most serious form of heart attack more than quadrupled over a decade, according to research published on Tuesday in The Lancet. In 2001, Chinese hospitals admitted 3.7 people per 100,000 population for a type of cardiac arrest known as ST-segment elevation myocardial infarction, or STEMI. In 2011, this rose to 15.8 people per 100,000. The study, based on admission records from 162 hospitals, was not designed to explore the reasons for the rise. The authors, though, suggest more people were exposed to heart-attack risk during this period -- rates for smoking, high blood pressure, diabetes and cholesterol increased -- while at the same time access to emergency treatment probably improved. "We know that this period was marked by an increasing prevalence of cardiovascular risk factors and that China has launched healthcare reform, which recently doubled annual expenditures for health care to improve access," said Jing Li of the Chinese Academy of Medical Sciences. Outside commentators said the study would shed light on a key aspect of health in China, where figures are often absent or sketchy. "Publication of these data is an important step towards improving healthcare in China and should be cherished as an opportunity that could translate into saving hundreds of thousands of lives," said Gregg Stone, a professor at Columbia University Medical Center in New York. It would help to pinpoint geographical gaps in hospital coverage and advise emergency doctors on the best treatment for STEMI patients, he said.