Association Between Aging of the US Population and Heart Disease Mortality From 2011 to 2017

Key Points

Question  Was the rapid increase in the number of adults aged 65 years and older from 2011 to 2017 associated with mortality related to heart disease?

Findings  In this quality improvement study of all US adults aged 65 years and older, the total size of this population increased from 41.4 million to 50.9 million between January 1, 2011, and December 31, 2017. Overall, the number of deaths increased by 8.5% for heart disease and 38.0% for heart failure, most of which were in the 65 years and older age group.

Meaning  With the population of adults aged 65 years and older projected to increase an additional 44% from 2017 to 2030, innovative and effective approaches to prevent and treat heart disease are needed.

Importance  A deceleration in the rate of decrease of heart disease (HD) mortality between 2011 and 2014 has been reported. In the context of the rapid increase in the population of adults aged 65 years and older, extending the examination of HD mortality through 2017 has potentially important implications for public health and medical care.

Objective  To examine changes in the age-adjusted mortality rate and the number of deaths within subcategories of HD from 2011 to 2017 in conjunction with the change in the size of the US population during the same period.

Design, Setting, and Participants  In this quality improvement study, the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) data set was used to identify national changes in the US population aged 65 years and older and in the age-adjusted mortality rates and number of deaths that were listed with an underlying cause of HD, coronary heart disease (CHD), heart failure, and other HDs from January 1, 2011, to December 31, 2017.

Main Outcomes and Measures  Changes from 2011 to 2017 in the US population and in age-adjusted mortality rates and number of deaths that were listed with an underlying cause of HD, CHD, heart failure (both as an underlying and a contributing cause), and other HDs overall, by sex and race/ethnicity.

Results  The total size of this population of US adults aged 65 years and older increased 22.9% from 41.4 million to 50.9 million between January 1, 2011, and December 31, 2017, while the population of adults younger than 65 years increased by only 1.7%. During this period, the age-adjusted mortality rate decreased 5.0% for HD and 14.9% for CHD while increasing 20.7% for heart failure and 8.4% for other HDs. The number of deaths increased 8.5% for HD, 38.0% for heart failure, and 23.4% for other HDs while decreasing 2.5% for CHD. A total of 80% of HD deaths occurred in the group of adults aged 65 years and older.

Conclusions and Relevance  The substantial increase in the growth rate of the group of adults aged 65 years and older who have the highest risk of HD was associated with an increase in the number of HD deaths in this group despite a slowly declining HD mortality rate in the general population. With the number of adults aged 65 years and older projected to increase an additional 44% from 2017 to 2030, innovative and effective approaches to prevent and treat HD, particularly the substantially increasing rates of heart failure, are needed.

A 2016 study reported a marked deceleration in the rate of decrease of heart disease (HD) mortality between January 1, 2011, and December 31, 2014, compared with the rate of decrease between January 1, 2000, and December 31, 2011,¹ and variability in this pattern by HD subtype.² This report examines the association between combined patterns of HD mortality subtypes and demographic changes in the population, especially the increase in the number of adults aged 65 years and older and the number of deaths associated with HD in the United States.

In this quality improvement study, the number of deaths, mortality rates, and US population data between January 1, 2000, and December 31, 2017, were obtained from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) data set,^3,4 which includes underlying and contributing causes of death from death certificates filed in the 50 states and the District of Columbia. The World Health Organization³ has defined the underlying cause of death as the disease or injury that initiated the series of events leading directly to death and a contributing cause of death as a disease or injury that can be considered a contributing factor leading to death. To categorize the underlying and contributing causes of death, we used codes from the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10)⁴ as follows: all HD (ICD-10 codes I00-I09, I11, I13, and I20-I51), coronary heart disease (CHD; ICD-10 codes I20-I25), heart failure (HF; ICD-10 code I50), and all other HDs (ICD-10 codes I00-I09, I11, I13, I26-I49, and I51). The population projection for 2030 was obtained from the US Census Bureau.⁵ The institutional review board of Kaiser Permanente Northern California determined this study to be exempt from review because it used a deidentified government-issued public-use data set and therefore did not represent human subjects research. Mortality rates were age adjusted using the direct method, with data from the 2000 US census used to define the standard population.⁶ We performed further analyses to address issues regarding coding of HF by exploring HF that was listed as the underlying cause of death among those who died suddenly and by restricting the main analysis to adults younger than 85 years.

The total US population of adults aged 65 years and older increased from 41.4 million in 2011 to 50.9 million in 2017 (22.9% total increase; 3.5% annualized increase; eTable 1 in the Supplement).³ The population of adults aged 65 years and older is projected to increase to 73.1 million by 2030 (43.8% total increase; 2.8% annualized increase from 2017-2030).⁵ Population increases by sex and race/ethnicity from 2011 to 2017 for the group of adults aged 65 years and older included increases of 25.8% in men, 20.7% in women, 18.9% in adults with white ancestry, 51.3% in adults with Asian/Pacific Island ancestry, 41.6% in adults with Hispanic ancestry, 30.8% in adults with black ancestry, and 41.9% in adults with American Indian/Alaskan native ancestry. The population younger than 65 years increased by 1.7%.

Deceleration in the rate of decrease of HD mortality continued through 2017, with the age-adjusted HD mortality rate decreasing only 5.0% (<1% annualized decrease) from 2011 to 2017 (Table 1; Figure). An estimated 80% of HD deaths occurred in adults aged 65 years and older (80% CHD, 92% HF, and 76% other HDs). The substantial increase in the growth rate of the adult population aged 65 years and older, who are at highest risk of HD, combined with the slow decrease in HD mortality, was associated with an increasing number of HD deaths since 2011 (n = 50 880; 8.5% total increase) after a substantial decrease in HD deaths between 2000 and 2011. The number of HD deaths increased in all subgroups.

The age-adjusted mortality rate associated with CHD continued to decrease, with a 14.9% decrease (2.7% annualized decrease) from 2011 to 2017 (Table 1; Figure). The number of CHD deaths decreased but at a much slower rate (2.5% total decrease from 2011-2017) and was virtually unchanged from 2015 to 2017 (0.2% decrease). The mortality rate decreased in all subgroups, and the number of deaths increased in women and white adults while decreasing in men and all other race/ethnicity groups.

The age-adjusted mortality rate for HF listed as the underlying cause increased substantially (20.7% total increase; 3.2% annualized increase) from 2011 to 2017, which, when combined with the 22.9% increase in the number of adults aged 65 years and older, resulted in a 38% increase in the number of deaths with HF as the underlying cause (Table 2; Figure). Increases in both the mortality rate and the number of deaths associated with HF increased in all subgroups. The substantial increase in the mortality rate and number of deaths with HF listed as the underlying cause was consistent with patterns that occurred for HF listed as a contributing cause (Table 2; Figure). The age-adjusted mortality rates decreased from 2000 to 2011 for HF as the underlying cause and from 2000 to 2012 for HF as a contributing cause, and the rates increased thereafter for both HF as the underlying cause and HF as a contributing cause through 2017. Similarly, the number of deaths associated with either HF as the underlying cause or HF as a contributing cause decreased from 2000 to 2009, and they increased steadily thereafter to 80 480 and 352 119, respectively, in 2017.

Increases in the age-adjusted rate of other HDs and the number of deaths from 2011 to 2017 were 8.4% and 23.4%, respectively (Figure; eTable 2 in the Supplement). The mortality rate increased in men and all race/ethnicity groups with the exception of adults with Asian/Pacific Island ancestry, while the number of deaths increased in all subgroups.

We also examined the distribution of HF and CHD listed as an underlying or contributing cause of death when both were present. From 2011 to 2017, there were 513 deaths with HF listed as the underlying cause and CHD listed as a contributing cause compared with 518 692 deaths with CHD listed as the underlying cause and HF listed as a contributing cause (eTable 3 in the Supplement). Nearly all deaths in patients with CHD and HF were coded with an underlying cause of CHD.

Two ICD-10 categories, ICD-10 code I46 (cardiac arrest) and ICD-10 code I49.0 (ventricular fibrillation or flutter), were likely to include a high proportion of adults who died suddenly. From 2011 to 2017, the annual number of deaths with HF as the underlying cause with a contributing cause of cardiac arrest or ventricular fibrillation or flutter increased by 3460 from 8634 to 12 094 deaths (eTable 4 in the Supplement), which represented 15.6% of the total increase in deaths with HF listed as the underlying cause and an estimated 2.9% of all deaths with cardiac arrest or ventricular fibrillation or flutter listed as a contributing cause.

In an analysis restricted to those younger than 85 years, the age-adjusted HF mortality rate and the number of HF deaths increased by 42.6% and 23.4%, respectively, from 2011 to 2017, both of which exceeded the increases for the entire age range (eTable 5 in the Supplement).

The deceleration in the decrease of the HD mortality rate, which was previously reported for the 2011 to 2014 period compared with the 2000 to 2011 period, continued through 2017. Combined with the rapid growth rate of the population of adults aged 65 years and older, this deceleration was associated with an 8.5% increase (n = 50 880) in the number of HD deaths. The probable reasons for the deceleration in the decrease of the HD mortality rate were discussed in an earlier publication, with the most notable factors being the substantial increases in obesity and diabetes rates that began in the mid-1980s.¹ For HF, the rapid population growth in the group of adults aged 65 years and older, combined with a substantial increase in the HF mortality rate, were associated with a 38% increase in the number of deaths with HF listed as the underlying cause. Between 2015 and 2030, the prevalence of HF nationally was projected to increase by 37% (57% in those aged ≥65 years).⁷ If separated from all HDs, HF would be the eighth leading cause of death in the United States.

Although we could not discern mortality associated with type of HF in the current data set because HF with preserved ejection fraction was not coded, a report from the American Heart Association entitled “Get With the Guidelines Heart Failure,”⁸ which was linked to Medicare data from adults aged 65 years and older, reported that among patients admitted for HF between 2005 and 2009, 46% had HF with preserved ejection fraction and 46% had HF with reduced ejection fraction, both with 5-year mortality rates of 75%.⁹ The emergence of HF with preserved ejection fraction as a highly prevalent HF phenotype is notable because, to our knowledge, no proven disease-modifying therapies currently exist. Our data regarding the 2011 to 2017 increases in mortality associated with HF and the racial/ethnic disparities in HF-related mortality, with the highest mortality rates observed among black adults, are consistent with other published findings.^2,10

The potential exists for misclassification of death certificate coding of HF because of the inability to access and use clinical information obtained before death. Our results suggest that the potential miscoding of HF in the settings of cardiac arrest or ventricular fibrillation or flutter and in adults who are 85 years and older is unlikely to change our results significantly. Additional limitations include the possibility that the increasing use of echocardiography, which identifies some patients with occult HF, and the increased recognition of HF with preserved ejection fraction may be associated with increased coding of HF on death certificates. Our analyses, especially the comparisons between mortality with HF listed as the underlying cause and HF listed as a contributing cause, highlight the heterogeneous cardiac function characteristics and multiple potential etiologies of HF and the limitations in current data surveillance at a national level. National data are lacking regarding the type of HF, the measurement of adherence to guideline-directed medical therapy, the consequences of the Medicare Hospital Readmissions Reduction Program, and finally, the adverse effects of social factors associated with health in at-risk groups, all of which may be factors associated with the increase in HF mortality.

In summary, despite a decrease in age-adjusted mortality associated with HD and CHD, the increasing rates of death associated with HF and other forms of HD, coupled with the continued rapid increase in the population of adults aged 65 years and older, seem to be associated with a steady, substantial increase in the total number of HD deaths. The projected 44% increase in the number of adults aged 65 years and older from 2017 to 2030 can be expected to create challenges for the capacity of public health and medical care efforts to prevent and manage HD. Innovative and effective approaches for surveillance, prevention, and treatment are needed to address the expanding burden of HD mortality, particularly for the substantially increasing rates of HF.

Accepted for Publication: September 11, 2019.

Corresponding Author: Stephen Sidney, MD, MPH, Kaiser Permanente Northern California, Division of Research, 2000 Broadway, Oakland, CA 94612 (steve.sidney@kp.org).

Published Online: October 30, 2019. doi:10.1001/jamacardio.2019.4187

Author Contributions: Dr Sidney had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Sidney, Rana.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Sidney, Rana.

Critical revision of the manuscript for important intellectual content: Go, Jaffe, Solomon, Ambrosy, Rana.

Administrative, technical, or material support: Sidney.

Supervision: Rana.

Conflict of Interest Disclosures: Dr Sidney reported receiving grants from the National Heart, Lung, and Blood Institute outside the submitted work. Dr Go reported receiving grants from the National Institute on Aging and the National Heart, Lung, and Blood Institute during the conduct of the study. No other disclosures were reported.

Meeting Presentation: This paper was presented at the annual meeting of the National Forum for Heart Disease and Stroke Prevention; October 30, 2019; Washington, DC.