Lea en español

The overall death rate among Americans after adjusting for age rose slightly in 2015 — the first increase in a decade — with heart disease deaths basically flat and stroke deaths on the rise, preliminary federal data show.

The numbers out this week from the Centers for Disease Control and Prevention show that after two decades in decline, the death rate from heart disease — the nation’s top killer — did not go down.

The overall death rate — the number of deaths per 100,000 Americans — increased from 723.2 in 2014 to 729.5 in 2015, according to the CDC’s National Center for Health Statistics. Death rates provided in the report were adjusted based on the nation’s age distribution.

“We’re curious to see what’s driving that,” said Farida Ahmad, the lead investigator on the report. The final data will be released in December.

For heart disease, the death rate remained mostly unchanged, with 166.7 deaths per 100,000 people in 2014 compared to 167.1 deaths in 2015. The stroke death rate rose from 36.4 in 2014 to 37.4 in 2015.

Ahmad and her fellow researchers want to know whether the flat rate in heart disease is causing the higher mortality rate by no longer offsetting other causes of death that are on the rise. It is the first time since 1993 that the heart disease death rate has not declined, she said.

Although it is too soon to sound the alarm on the lack of progress in deaths from heart disease, the numbers may indicate that the significant gains made in reducing heart disease over the past 50 years have finally stagnated, said Joseph A. Hill, M.D., Ph.D., chief of cardiology at UT Southwestern Medical Center in Dallas.

Better drugs and technology — such as cholesterol-lowering statins and artery-opening stents — have allowed people at risk to live longer, Hill said. But many then live with heart failure, creating new challenges for doctors in the face of increasing rates in obesity and diabetes, he said.

“The picture of heart disease is changing,” Hill said.

Among the other causes of death included in the report, death rates from cancer and HIV fell, while rising death rates were seen for Alzheimer’s disease, drug overdoses and suicides.

For conditions that can lead to cardiovascular disease, the diabetes death rates were similar between 2014 and 2015, but high blood pressure-related deaths rose slightly.

Researchers used nationwide death certificate data to calculate the statistics.