Abstract
Background
The prevalence of heart failure (HF) is increasing in aging societies, such as Japan. The current incidence rate (IR) of HF hospitalization in Japan is unknown.
Methods and Results
We conducted a regional population-based study assessing the IR of HF hospitalization in Nobeoka City. Data were collected over a period of 3 years from all patients with HF admitted for the first time to hospitals and clinics. 406 HF hospitalizations were registered (54% female; mean age 82 years). The IR of HF hospitalization was 129/100,000 person-years. The difference in the IR between women and men was not significant (131 vs. 127/100,000 person-years, respectively; P=0.767). The age-adjusted IR in the 2015 Japanese population was 105/100,000 person-years. According to 5-year age bands, the IR of HF hospitalization gradually increased up to 60–70 years of age, then increased rapidly in those aged ≥95 years for both sexes. The IR ratio compared with age <65 years was higher in women than men in each older age group.
Conclusions
In this population-based study, the current IR of HF hospitalization in a region of Japan was higher than the IR from another study conducted in a different region in early 2000. By presenting detailed age-related data, the research findings will contribute to estimating the number of HF hospitalizations in other areas of Japan.
Key Words: Heart failure, Hospitalization, Incidence rate, Japan
Heart failure (HF) is an emerging epidemic in aging societies.1 HF is the primary cause of hospitalization in elderly people, and the prognosis of patients hospitalized with HF remains poor, with in-hospital mortality rate ranging from 4% to 7%, and 60- to 90-day mortality ranging from 7% to 11%.2 Furthermore, in the US, hospitalizations account for 79% of lifetime costs of HF.3 Therefore, hospitalization for HF is a major social problem in aging societies. To develop up-to-date healthcare strategies for the management of HF, a population-based study is needed to determine the epidemiological characteristics of hospitalization for HF, including its incidence rate.
Japan is at the forefront of aging societies and is facing an increase in hospitalization for HF. The Japanese Registry of All Cardiac and Vascular Diseases (JROAD) reported an increase in the number of patients hospitalized with HF.4 In a different study, JROAD reported that 44% of the hospitalization costs for acute cardiovascular diseases were spent on patients with HF.5
However, more population studies of patients hospitalized with HF have been conducted in the US and Europe than in Japan.6–12 A literature review identified a single Japanese population-based study12 that reported the incidence rate of hospitalization for HF in 2002–2005. Considering Japan’s increasingly aging population, the incidence rate may have changed since that study was conducted.
Nobeoka City, Japan, has a population of 120,000 and is relatively isolated from other urban centers, with medical care largely self-contained within the city. This provides a suitable environment to accurately estimate the incidence rate of diseases. In a previous study we reported the incidence rate of acute coronary syndrome in the city.13 In the present study we collected data from all public hospitals and private clinics with admission facilities and conducted a population-based study to evaluate the incidence rate of hospitalization for HF in Nobeoka City.
Methods
Study Design
Nobeoka City is located in the east of Kyusyu Island and has a population of approximately 120,000 people (123,822 in 2015; 122,372 in 2016; 120,696 in 2017).14 As of 2017, approximately 33% of the population of Nobeoka City was aged ≥65 years, which is greater than the percentage of Japan’s population overall aged ≥65 years (28%).15 Nobeoka City provides a highly suitable setting for epidemiological research because the city is relatively isolated from other urban centers and medical care is practically self-contained within the city. There is 1 public hospital (the Miyazaki Prefectural Nobeoka Hospital) and 25 private clinics with admission facilities in the city; all these hospitals were included in the present study (Table 1). Of the participating hospitals, only Miyazaki Prefectural Nobeoka Hospital and Hospital G employed board-certified cardiologists. Miyazaki Prefectural Nobeoka Hospital was registered as a certified hospital of the Japanese Circulation Society for the study period.
Table 1.
List of all Public Hospitals or Private Clinics With Admission Facilities in the Study City
| Hospital or clinic | No. beds | No. board-certified cardiologists |
No. hospitalized HF patients |
|---|---|---|---|
| A (Miyazaki Prefectural Nobeoka Hospital) |
410 | 4 | 181 |
| B | 72 | 0 | 117 |
| C | 108 | 0 | 70 |
| D | 76 | 0 | 13 |
| E | 195 | 0 | 9 |
| F | 125 | 0 | 6 |
| G | 76 | 1 | 5 |
| H | 17 | 0 | 2 |
| I | 19 | 0 | 2 |
| J | 7 | 0 | 1 |
| K | 80 | 0 | 0 |
| L | 19 | 0 | 0 |
| M | 54 | 0 | 0 |
| N | 57 | 0 | 0 |
| O | 93 | 0 | 0 |
| P | 52 | 0 | 0 |
| Q | 42 | 0 | 0 |
| R | 40 | 0 | 0 |
| S | 307 | 0 | 0 |
| T | 381 | 0 | 0 |
| U | 19 | 0 | 0 |
| V | 19 | 0 | 0 |
| W | 19 | 0 | 0 |
| X | 19 | 0 | 0 |
| Y | 19 | 0 | 0 |
| Z | 16 | 0 | 0 |
This study adhered to the principles of the Declaration of Helsinki and was approved by the institutional review boards of Miyazaki Prefectural Nobeoka Hospital (No. 20210628-4) and the National Cerebral and Cardiovascular Center (No. M30-007-6). Because patient data were anonymized, the requirement for consent was waived. However, we publicized the study by posting an easy-to-understand summary of the study on a board in Miyazaki Prefectural Nobeoka Hospital and on the hospital’s website (https://nobeoka-kenbyo.jp/info/patient/20190215/1259/), thereby allowing patients to withdraw from the study.
Patient Identification
The study included consecutive adult patients (aged ≥20 years) with their first hospital admission for HF recorded between January 2015 and December 2017. Patients were enrolled in the study if they were established residents of Nobeoka City. In Miyazaki Prefectural Nobeoka Hospital, hospitalization for HF was identified using a 2-step process.6,16 First, for case selection, the primary discharge diagnoses of the patients were reviewed using the International Classification of Diseases codes for HF (I50, I11.0, I13.0, I13.2).17 Second, the complete records (including inpatient and outpatient records) of potential cases were manually reviewed to validate the diagnosis of HF using the Framingham criteria.18 In the other hospitals and clinics, all hospitalization records were checked to identify HF hospitalization cases using the Framingham criteria.
Elderly individuals were defined as those aged ≥65 years; these individuals were categorized into 3 groups as follows: young-old (aged 65–74 years), old-old (aged 75–84 years), and very old (aged ≥85 years).5,19
Echocardiographic evaluations were performed on patients diagnosed with HF at the Miyazaki Prefectural Nobeoka Hospital. The median duration between echocardiography and admission was 0.5 days (interquartile range [IQR] 0–2 days). Left ventricular ejection fraction (LVEF) was evaluated using standard procedures.20
Statistical Analysis
Continuous variables are expressed as the mean±SD, whereas variables with a skewed distribution are presented as the median with IQR. Categorical variables are expressed as numbers and percentages.
Using the annual population data of Nobeoka City, we calculated the crude incidence rate of hospitalization for HF according to age and sex distribution by dividing the number of cases admitted with HF for the first time by age- and sex-specific person-years of observation. In addition, the age-standardized incidence rate was obtained using a direct method based on the 2015 and 1985 Japanese standard populations.21 The incidence rate ratio was estimated with Poisson regression.
Two-tailed P<0.05 was considered statistically significant. Statistical analyses were performed using SPSS version 24.0 (IBM, Armonk, NY, USA) and R statistical software version 4.0.2 (R Foundation for Statistical Computing, Vienna, Austria).
Results
In all, 406 adults were admitted with HF for the first time during the 3-year study period. The mean patient age was 82±12 years, and 54% of the study participants were female. Of the 26 participating hospitals or clinics, 10 institutions had the capacity to provide inpatient treatment of HF, and more than half of all patients were admitted to institutions without board-certified cardiologists (Table 1). Among 166 (41%) who underwent echocardiographic examinations on admission, the mean LVEF was 44±14% and the proportion of HF with preserved ejection fraction (LVEF ≥50%), HF with mildly reduced ejection fraction (LVEF 40–50%), and HF with reduced ejection fraction (LVEF <40%) was 34%, 26%, and 40%, respectively.
The crude incidence rate of hospitalization for HF was 129/100,000 person-years (age ≥45 years, 183/100,000; age ≥65 years, 313/100,000; age ≥85 years, 981/100,000). Overall, the difference in the incidence rate between women (131/100,000 person-years) and men (127/100,000 person-years) was not significant (incidence rate ratio 1.03; 95% confidence interval [CI] 0.85–1.25; P=0.767). The age-adjusted incidence rate of hospitalization for HF for the standard Japanese population model of 2015 and 1985 was 105 (95% CI 75–148) and 39 (95% CI 26–65) per 100,000 person-years, respectively.
According to 5-year age bands, the incidence rate of hospitalization for HF increased gradually from 60 to 70 years of age and then increased rapidly, reaching an incidence rate of 2,265/100,000 person-years among those aged ≥95 years (Table 2; Figure 1). Figure 2 shows the incidence rate ratios in older age groups compared with the non-elderly group (age <65 years) for both men and women. The 3 older age groups for both men and women had a significantly higher incidence rate of hospitalization for HF than the non-elderly group. The graph showing the incidence rate ratios for women is above that for men, suggesting that the effect of aging on the incidence rate of hospitalization for HF was more pronounced in women than in men (Figure 2).
Table 2.
Incidence Rate of Hospitalization for HF in the Study City According to Age and Sex
| Men | Women | Men and women | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Person- years (3 years) |
Incident case |
Incidence rate (per 100,000 person-years) |
Person- years (3 years) |
Incident case |
Incidence rate (per 100,000 person-years) |
Person- years (3 years) |
Incident case |
Incidence rate (per 100,000 person-years) |
|
| Age group (years) | |||||||||
| 20–34 | 25,970 | 0 | 0 (0–14) |
24,702 | 0 | 0 (0–15) |
50,672 | 0 | 0 (0–7) |
| 35–39 | 10,905 | 4 | 37 (10–94) |
10,848 | 1 | 9 (0–51) |
21,753 | 5 | 23 (8–54) |
| 40–44 | 12,103 | 2 | 17 (2–60) |
12,227 | 1 | 8 (0–46) |
24,330 | 3 | 12 (3–36) |
| 45–49 | 10,586 | 1 | 9 (0–60) |
11,086 | 0 | 0 (0–33) |
21,672 | 1 | 5 (0–26) |
| 50–54 | 10,867 | 3 | 28 (6–81) |
11,609 | 2 | 17 (2–62) |
22,476 | 5 | 22 (7–52) |
| 55–59 | 12,081 | 2 | 17 (2–60) |
13,210 | 1 | 8 (0–42) |
25,291 | 3 | 12 (2–35) |
| 60–64 | 14,324 | 12 | 84 (43–146) |
15,536 | 7 | 45 (18–93) |
29,860 | 19 | 64 (38–99) |
| 65–69 | 15,692 | 10 | 64 (31–117) |
17,015 | 10 | 59 (28–108) |
32,707 | 20 | 61 (37–94) |
| 70–74 | 10,238 | 14 | 137 (75–229) |
12,641 | 10 | 79 (38–146) |
22,879 | 24 | 105 (67–156) |
| 75–79 | 9,199 | 20 | 217 (133–336) |
13,086 | 16 | 122 (70–199) |
22,285 | 36 | 162 (113–224) |
| 80–84 | 7,829 | 49 | 626 (463–827) |
12,413 | 42 | 338 (244–457) |
20,242 | 91 | 450 (362–552) |
| 85–89 | 4,235 | 38 | 897 (635–1,231) |
8,782 | 55 | 626 (472–815) |
13,017 | 93 | 714 (577–875) |
| 90–94 | 1,248 | 23 | 1,843 (1,168–2,765) |
4,243 | 50 | 1,178 (875–1,554) |
5,491 | 73 | 1,329 (1,042–1,671) |
| ≥95 | 309 | 7 | 2,265 (911–4,668) |
1,467 | 26 | 1,772 (1,158–2,597) |
1,776 | 33 | 1,858 (1,279–2,610) |
|
All ages (≥20 years) |
145,586 | 185 | 127 (109–147) |
168,865 | 221 | 131 (114–149) |
314,451 | 406 | 129 (117–142) |
|
Age-standardized incidenceA |
NA | NA | 138 (84–227) |
NA | NA | 86 (55–142) |
NA | NA | 105 (75–148) |
ACalculated using the Japanese model population in 2015. HF, heart failure.
Figure 1.
Incidence rate of hospitalization for heart failure (HF) in Nobeoka City according to age and sex. Inset, the incidence rate of hospitalization for HF in men and women aged <80 years.
Figure 2.
Incidence rate ratio based on the incidence rate of hospitalization for heart failure in a men and women according to age group. *P<0.001 compared with age <65 years.
Discussion
This study found that the incidence rate of hospitalization for HF in the study population was 129/100,000 person-years between 2015 and 2017. The incidence rates are provided in 5-year age bands by sex for reference to the current number of hospitalizations for HF in other regions of Japan.
Despite the differences in diagnostic criteria and population sources, the identified incidence rate of hospitalization for HF in this study is lower than in Western countries (Table 3). There are 2 possible reasons for this. The first factor to consider is ethnic differences. A population-based study that included individuals aged 45–65 years from 4 different communities in the US found that African Americans had a higher incidence rate of hospitalization for HF than Caucasians across most age groups.7 Consistent with this, other studies have found that African Americans have a higher incidence rate of HF than Caucasians.22,23 Furthermore, a multi-ethnic population-based cohort study of atherosclerosis, which included 6,814 Americans, found that Chinese Americans had a lower incidence of chronic HF (100/100,000 person-years) than African Americans (460/100,000 person-years), Hispanics (350/100,000 person-years), and Caucasians (240/100,000 person-years).24 In the present study, the population was Japanese, and therefore racial differences between the present study and the studies conducted in Western countries need to be taken into consideration.
Table 3.
Comparison of the Study Methods and Results Between Previous Population-Based Studies and the Present Study
| Author(s) | Population source |
Diagnostic criteria |
Years | Incidence rate (per 100,000 person-years) |
||
|---|---|---|---|---|---|---|
| Total | Males | Females | ||||
| Barker et al6 | Individuals aged ≥65 years with health plan memberships for ≥2 years (9,272 people in 1970–1974; 31,399 people in 1990–1994), USA |
Diagnostic codes (primary and secondary) confirmed by Framingham criteria |
1970–1974 | 1,000 | 1,170 | 860 |
| 1990–1994 | 1,130 | 1,270 | 1,180 | |||
| Loehr et al7 | Individuals aged 45–65 years from 4 communities without prevalent HF (population of 14,994), USA |
Diagnostic codes (primary and secondary) |
1987–1989 | 570 | ||
| Schaufelberger et al8 | Residents of Sweden aged 45–84 years (population of 2,900,000) |
Diagnostic codes (primary and secondary) |
1988–2000 | 237–317 | 171–244 | |
| Jhund et al9 | Residents of Scotland (population of 5,000,000) |
Diagnostic codes (primary diagnosis) |
1986–2003 | 105–162 | 101–160 | |
| Corrao et al10 | Beneficiaries of the Italian National Health System from Lombardy (population of 10,000,000), Italy |
Diagnostic codes (primary diagnosis) |
2011 | 295 | 318 | 204 |
| Goldberg et al11 | Individuals aged ≥25 years who were residents of the Worcester, MA, metropolitan area (population of 478,000), USA |
Diagnostic codes (primary and secondary) confirmed by Framingham criteria |
2000 | 219 | 194 | 250 |
| Ogawa et al12 | Individuals aged ≥20 years who were residents of the Ninohe district (population of 67,307) Japan |
Framingham criteria | 2002–2005 | 94 | 96 | 92 |
| Present study | Individuals aged ≥20 years who were residents of Nobeoka City (population of 120,000) Japan |
Framingham criteria | 2015–2017 | 127 | 131 | 129 |
The second factor is the lower prevalence of coronary artery disease in Japan than in Western countries.25,26 Ischemic HF accounts for 33–57% of HF etiologies.27 According to the MIYAGI-AMI Registry Study, the incidence rate of acute myocardial infarction is much lower in Japan (7.4 to 27.0/100,000 person-years) than in Western countries (Finland, 824/100,000 person-years; UK, 823/100,000 person-years; Canada, 605/100,000 person-years; US, 508/100,000 person-years; France, 314/100,000 person-years; Italy, 270/100,000 person-years).25,28
To the best of our knowledge, only 1 population study of patients hospitalized with HF has been conducted in Japan (Table 3). Ogawa et al investigated the incidence rate of hospitalization for HF in the Ninohe district, Japan, in 2002–2005.12 The region had a resident population of 67,307, with 26% aged ≥65 years. The reported incidence rate of hospitalization for HF in that study (94/100,000 person-years) was lower than in the present study. However, the age-adjusted incidence rate for the standard Japanese population model of 1985 was 39/100,000 person-years, which is the same as our result of 39/100,000 person-years (95% CI 26–65). These findings suggest that the increasing incidence rate of hospitalization for HF in Japan can be attributed to aging. Moreover, the findings suggest that policies and medical developments in Japan over the past decade have not been sufficiently effective in reducing hospitalization for HF. However, differences in geology (e.g., temperature) and lifestyle between the 2 study regions may influence the incidence rate of hospitalization for HF. Therefore, it is difficult to discuss the longitudinal trends of hospitalization for HF in Japan based on these 2 studies alone. It is necessary to accumulate data from other regions.
Furthermore, our results show that HF was treated in many hospitals that did not have a board-certified cardiologist. This emphasizes the importance of a regional population-based study that includes all hospitals and clinics for the assessment of the epidemiological features of HF.
In the elderly group, although the incidence rate of hospitalization for HF was lower in females than in males (Figure 1), the incidence rate ratio compared with the non-elderly group was higher in females than in males (Figure 2), implying that the incidence rate of hospitalization for HF in non-elderly females was much lower than in non-elderly males. This could be reflected by a higher proportion of HF with a preserved ejection fraction in women29 and the difference in the etiology of HF according sex: for example, HF in females has a lower correlation with ischemic etiology.30 One of the major mechanisms underlying the low incidence rate of hospitalization for HF in non-elderly females may be cardioprotection elicited by sex hormones.31 Specifically, estrogen promotes angiogenesis and vasodilation and reduces reactive oxygen species, oxidative stress, and fibrosis.32
Study Limitations
This study has some limitations. First, our study population (120,000) was smaller than that of previous studies conducted in Western countries.8–11 However, the study was conducted in a region isolated from other areas and included approximately twice the size of the population in a previous Japanese study.12 Second, the incidence rate of hospitalization for HF observed in this study may reflect genetic and/or environmental factors. The Japanese population is quite homogeneous and has the longest life expectancy.33 However, the availability of comprehensive information from Japan with its rapidly aging population may be a crucial factor in the development of future perspectives in other countries.
Conclusions
This population-based study explored the current incidence rate of hospitalization for HF in a region of Japan, which was higher than that in a previous study conducted in another region in early 2000.12 By presenting detailed age-related data, the research findings will contribute to estimating the number of hospitalizations for HF in other areas of Japan.
Sources of Funding
This study was supported by ASAHI KASEI. The funder had no role in study design, data collection, data analysis, interpretation of data, writing of the report, and decision to submit the paper for publication. All authors had full access to all the data in the study, and the corresponding author had the final responsibility for the decision to submit the paper for publication. The authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.
Disclosures
Y.M. is a member of Circulation Reports’ Editorial Team. The remaining authors have no conflicts of interest to declare.
IRB Information
This study was approved by the Miyazaki Prefectural Nobeoka Hospital (No. 20210628-4) and the National Cerebral and Cardiovascular Center (No. M30-007-6).
Appendix
The Nobeoka Heart Study Investigators contributing to the present study are listed below:
Atsushi Yamamoto (Iryouhoujin Syouwakai Kurosebyouin); Yoshimi Kinoshita (Iryouhoujin Koujinkai Tanimurabyoin); Kazuo Kanai (Nobeoka Rehabilitation Hospital); Hiroshi Ookita (Medical Corporation Nobeokahoyoen); Shiko Naganuma (Iryouhoujin Midorinokaze Naganumaiin); Tomohiro Ohshige (Ohshige Ladies Clinic); Kanetoshi Takebayashi (Inoue Hospital); Fumiaki Matsuoka (Nobeoka Clinic); Yuhei Takao (Iryouhoujin Koushoukai Takaoganka); Hiromichi Okamura (Iryouhoujin Shadan Kajyoukai Okamura Hospital); Shunichi Sugimoto (Sugimoto Hospital); Jyunichi Miyata (Miyatanaikaiin); Koshiro Maeda (Ogawa Clinic); Ikuo Nomura (Nomura Hospital); Tatsuyuki Tahara (Tahara Hospital); Yasushi Osaki (Ohsaki Orthopedic Surgery Clinic); Hironori Shiotsuki (Kuroki Hospital); Yoshitaki Chuganji (Chuganji Obstetrics and Gynecology Clinic); Yoshihiko Ushiroda (Nobeokashi Ishikaibyouin); Hidetaka Tanaka (Medical Corporation Yuryukai Nishishina Clinic); Nobuhiro Sato (Atago Orthapedic Hospital); Kotaro Hirata (Iryouhouzin Kyuukoukai Hiratahigasikyusyubyouin); Kensei Yoshida (Yoshidabyouin); Yasuhide Souda (Souda Hospital); Koji Akasu (Nobeoka Kyoritu Hospital)
Acknowledgments
The authors thank Mustumi Tanaka and Yuki Noguchi for their excellent assistance with data management. The authors also thank Editage (www.editage.com) for English language editing a draft of this paper.
Data Availability
The deidentified participant data will not be shared.
References
- 1. Braunwald E.. Shattuck lecture -- cardiovascular medicine at the turn of the millennium: Triumphs, concerns, and opportunities. N Engl J Med 1997; 337: 1360–1369. [DOI] [PubMed] [Google Scholar]
- 2. Farmakis D, Parissis J, Lekakis J, Filippatos G.. Acute heart failure: Epidemiology, risk factors, and prevention. Rev Esp Cardiol (Engl Ed) 2015; 68: 245–248. [DOI] [PubMed] [Google Scholar]
- 3. Dunlay SM, Shah ND, Shi Q, Morlan B, VanHouten H, Long KH, et al.. Lifetime costs of medical care after heart failure diagnosis. Circ Cardiovasc Qual Outcomes 2011; 4: 68–75. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Yasuda S, Miyamoto Y, Ogawa H.. Current status of cardiovascular medicine in the aging society of Japan. Circulation 2018; 138: 965–967. [DOI] [PubMed] [Google Scholar]
- 5. Kanaoka K, Okayama S, Nakai M, Sumita Y, Nishimura K, Kawakami R, et al.. Hospitalization costs for patients with acute congestive heart failure in Japan. Circ J 2019; 83: 1025–1031. [DOI] [PubMed] [Google Scholar]
- 6. Barker WH, Mullooly JP, Getchell W.. Changing incidence and survival for heart failure in a well-defined older population, 1970–1974 and 1990–1994. Circulation 2006; 113: 799–805. [DOI] [PubMed] [Google Scholar]
- 7. Loehr LR, Rosamond WD, Chang PP, Folsom AR, Chambless LE.. Heart failure incidence and survival (from the Atherosclerosis Risk in Communities study). Am J Cardiol 2008; 101: 1016–1022. [DOI] [PubMed] [Google Scholar]
- 8. Schaufelberger M, Swedberg K, Köster M, Rosén M, Rosengren A.. Decreasing one-year mortality and hospitalization rates for heart failure in Sweden; data from the Swedish Hospital Discharge Registry 1988 to 2000. Eur Heart J 2004; 25: 300–307. [DOI] [PubMed] [Google Scholar]
- 9. Jhund PS, Macintyre K, Simpson CR, Lewsey JD, Stewart S, Redpath A, et al.. Long-term trends in first hospitalization for heart failure and subsequent survival between 1986 and 2003: A population study of 5.1 million people. Circulation 2009; 119: 515–523. [DOI] [PubMed] [Google Scholar]
- 10. Corrao G, Ghirardi A, Ibrahim B, Merlino L, Maggioni AP.. Burden of new hospitalization for heart failure: A population-based investigation from Italy. Eur J Heart Fail 2014; 16: 729–736. [DOI] [PubMed] [Google Scholar]
- 11. Goldberg RJ, Spencer FA, Farmer C, Meyer TE, Pezzella S.. Incidence and hospital death rates associated with heart failure: A community-wide perspective. Am J Med 2005; 118: 728–734. [DOI] [PubMed] [Google Scholar]
- 12. Ogawa M, Tanaka F, Onoda T, Ohsawa M, Itai K, Sakai T, et al.. A community based epidemiological and clinical study of hospitalization of patients with congestive heart failure in northern Iwate, Japan. Circ J 2007; 71: 455–459. [DOI] [PubMed] [Google Scholar]
- 13. Ogata S, Marume K, Nakai M, Kaichi R, Ishii M, Ikebe S, et al.. Incidence rate of acute coronary syndrome including acute myocardial infarction, unstable angina, and sudden cardiac death in Nobeoka City for the super-aged society of Japan. Circ J 2021; 85: 1722–1730. [DOI] [PubMed] [Google Scholar]
- 14. Nobeoka City.. Nobeoka City Statistics. https://www.city.nobeoka.miyazaki.jp/soshiki/1/1364.html (accessed December 25, 2021).
- 15. Statistics Bureau of Japan.. Statistics. https://www.stat.go.jp/english/data/index.html (accessed December 25, 2021).
- 16. Goldberg RJ, Spencer FA, Farmer C, Meyer TE, Pezzella S.. Incidence and hospital death rates associated with heart failure: A community-wide perspective. Am J Med 2005; 118: 728–734. [DOI] [PubMed] [Google Scholar]
- 17. Thygesen SK, Christiansen CF, Christensen S, Lash TL, Sørensen HT.. The predictive value of ICD-10 diagnostic coding used to assess Charlson comorbidity index conditions in the population-based Danish National Registry of Patients. BMC Med Res Methodol 2011; 11: 83. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. McKee PA, Castelli WP, McNamara PM, Kannel WB.. The natural history of congestive heart failure: The Framingham study. N Eng J Med 1971; 285: 1441–1446. [DOI] [PubMed] [Google Scholar]
- 19. Mogensen UM, Ersbøll M, Andersen M, Andersson C, Hassager C, Torp-Pedersen C, et al.. Clinical characteristics and major comorbidities in heart failure patients more than 85 years of age compared with younger age groups. Eur J Heart Fail 2011; 13: 1216–1223. [DOI] [PubMed] [Google Scholar]
- 20. Lang RM, Bierig M, Devereux RB, Flachskampf FA, Foster E, Pellikka PA, et al.. Recommendations for chamber quantification: A report from the American Society of Echocardiography’s Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005; 18: 1440–1463. [DOI] [PubMed] [Google Scholar]
- 21. Ministry of Health, Labour and Welfare.. Report on the results of the study for the revision of the reference population n.d. https://www.mhlw.go.jp/stf/000020200529_1.html (accessed December 25, 2021).
- 22. Bibbins-Domingo K, Pletcher MJ, Lin F, Vittinghoff E, Gardin JM, Arynchyn A, et al.. Racial differences in incident heart failure among young adults. N Engl J Med 2009; 360: 1179–1190. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Kalogeropoulos A, Georgiopoulou V, Kritchevsky SB, Psaty BM, Smith NL, Newman AB, et al.. Epidemiology of incident heart failure in a contemporary elderly cohort: The health, aging, and body composition study. Arch Intern Med 2009; 169: 708–715. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. Bahrami H, Kronmal R, Bluemke DA, Olson J, Shea S, Liu K, et al.. Differences in the incidence of congestive heart failure by ethnicity: The multi-ethnic study of atherosclerosis. Arch Intern Med 2008; 168: 2138–2145. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25. Takii T, Yasuda S, Takahashi J, Ito K, Shiba N, Shirato K, et al.. Trends in acute myocardial infarction incidence and mortality over 30 years in Japan: Report from the MIYAGI-AMI Registry Study. Circ J 2010; 74: 93–100. [DOI] [PubMed] [Google Scholar]
- 26. Sekikawa A, Satoh T, Hayakawa T, Ueshima H, Kuller LH.. Coronary heart disease mortality among men aged 35–44 years by prefecture in Japan in 1995–1999 compared with that among White men aged 35–44 by state in the United States in 1995–1998: Vital statistics data in recent birth cohort. Jpn Circ J 2001; 65: 887–892. [DOI] [PubMed] [Google Scholar]
- 27. Sato N, Kajimoto K, Asai K, Mizuno M, Minami Y, Nagashima M, et al.. Acute decompensated heart failure syndromes (ATTEND) registry. A prospective observational multicenter cohort study: Rationale, design, and preliminary data. Am Heart J 2010; 159: 949–955.e1. [DOI] [PubMed] [Google Scholar]
- 28. Sekikawa A, Ueshima H, Kadowaki T, El-Saed A, Okamura T, Takamiya T, et al.. Less subclinical atherosclerosis in Japanese men in Japan than in White men in the United States in the post-World War II birth cohort. Am J Epidemiol 2007; 165: 617–624. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29. Masoudi FA, Havranek EP, Smith G, Fish RH, Steiner JF, Ordin DL, et al.. Gender, age, and heart failure with preserved left ventricular systolic function. J Am Coll Cardiol 2003; 41: 217–223. [DOI] [PubMed] [Google Scholar]
- 30. Azad N, Kathiravelu A, Minoosepeher S, Hebert P, Fergusson D.. Gender differences in the etiology of heart failure: A systematic review. J Geriatr Cardiol 2011; 8: 15–23. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31. Hayward CS, Kelly RP, Collins P.. The roles of gender, the menopause and hormone replacement on cardiovascular function. Cardiovasc Res 2000; 46: 28–49. [DOI] [PubMed] [Google Scholar]
- 32. Iorga A, Cunningham CM, Moazeni S, Ruffenach G, Umar S, Eghbali M.. The protective role of estrogen and estrogen receptors in cardiovascular disease and the controversial use of estrogen therapy. Biol Sex Differ 2017; 8: 33. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33. World Health Organization (WHO).. World Health Statistics 2018: Monitoring health for the SDGs, sustainable development goals. 2018. https://apps.who.int/iris/handle/10665/272596 (accessed December 20, 2021).
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The deidentified participant data will not be shared.