Temporal Trends and Projected Mortality of Heart Failure and Interstitial Lung Disease among Adults Aged ≥55 Years in the United States, 1999–2040: A CDC WONDER Analysis
This CDC WONDER analysis reveals that mortality from coexisting heart failure and interstitial lung disease among U.S. adults aged 55 and older significantly increased from 1999 to 2024, with projections indicating a continued rise through 2040, disproportionately affecting older males, White individuals, and non-metropolitan populations.
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Heart failure and interstitial lung disease are two distinct medical challenges that often strike the same people, particularly as they grow older. Heart failure is a condition where the heart muscle becomes too weak or stiff to pump blood effectively throughout the body. Interstitial lung disease is a broad term for a group of disorders that cause scarring and thickening of the tissue inside the lungs, making it difficult for oxygen to pass into the blood. While doctors have long known that these conditions can occur together, creating a difficult situation where the heart struggles to push blood through scarred lungs and the lungs struggle to supply enough oxygen to a failing heart, the full picture of how often they kill people together has remained unclear. Understanding this connection is vital because when these diseases overlap, they can worsen each other's effects, leading to a much higher risk of death than either condition would cause on its own.
A new analysis of national records has now mapped out exactly how often these two conditions appear together on death certificates in the United States and how that pattern has changed over time. Researchers examined data spanning from 1999 to 2024, focusing on adults aged 55 and older. They looked for cases where both heart failure and interstitial lung disease were listed as contributing factors to a person's death, regardless of which one was the primary cause. By tracking these numbers year by year, the team was able to see not just how many people died, but how the risk shifted across different groups of people, different parts of the country, and different decades. They also used statistical models to project what might happen in the coming years, looking ahead to 2040 to see if these trends are likely to continue.
The results show a clear and worrying upward trend. Between 1999 and 2024, the rate of deaths involving both conditions rose significantly. In the year 1999, there were about 4 deaths per 100,000 people in this age group. By 2024, that number had climbed to more than 7 deaths per 100,000. The increase was not steady; it sped up noticeably between 2016 and 2021, a period that saw the sharpest rise in mortality rates. The researchers project that this climb will not stop. Their models suggest that by 2030, the rate could reach nearly 9 deaths per 100,000, and by 2040, it could rise to almost 11 deaths per 100,000. This suggests that the burden of these combined diseases is growing and will continue to grow for the foreseeable future.
When the researchers broke down the data by different groups, they found that the risk was not shared equally. Men faced a higher risk of death than women throughout the entire study period. Older adults, specifically those aged 75 and older, carried the heaviest burden, with death rates more than ten times higher than those seen in adults aged 55 to 74. White individuals had the highest overall rates, but the study also noted a particularly sharp increase in recent years among Black or African American populations. People living in rural areas, outside of major cities, also faced higher death rates compared to those in metropolitan areas. Geographically, the South and the Midwest showed the highest numbers, with the South projected to see the steepest increase in the years ahead.
The study also looked at where these deaths occurred. The vast majority happened inside medical facilities, such as hospitals, reflecting the acute and severe nature of the final stages of these combined illnesses. A significant number also occurred in people's homes or in nursing facilities, highlighting that many of these patients spend their final days in settings where specialized care for both heart and lung conditions might be harder to access. The researchers noted that the data comes from death certificates, which rely on doctors accurately listing both conditions. This means the true number of cases might be even higher if some doctors missed one of the diagnoses when filling out the paperwork, especially in rural areas where specialists are less common.
Despite the limitations of relying on death records, the study provides a crucial map of a growing public health challenge. It confirms that the combination of heart failure and interstitial lung disease is becoming more deadly and is affecting specific groups of people more than others. The findings point to a need for better care strategies that address both the heart and the lungs together, rather than treating them as separate problems. As the population continues to age, the researchers warn that without targeted interventions to improve diagnosis and treatment in the most vulnerable communities, the number of deaths from this dual burden will likely continue to rise through the middle of the century.
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