Introduction
Cardiovascular diseases are leading causes of mortality and morbidity worldwide. Although there has been a decrease in age-standardised mortality rates in several regions of the world, the absolute number of deaths associated with CVDs has been increasing, mainly in middle-income and low-income countries. (1,2) Cardiovascular diseases are leading causes of death in Hungary followed by malignant cancers. (3-5) Diseases of the circulatory system accounted for 55% of mortality among females and 45%- among males in 2015 (6).
Our paper intends to analyse mortality data among people aged above 65 years due to ischaemic heart disease (IHD) within CVDs. According to World Health Organization (WHO) data, IHD is the most common cause of mortality registered globally. (6) Despite the fact that age-standardised mortality due to IHD has decreased in recent years, the associated disease burden has remained considerably high and has increased globally and in Hungary as well. (7-10) IHD is responsible for more than half of Disability-Adjusted Life Years (DALY) due to cardiovascular diseases. (6)
Mortality data due to IHD vary considerably per region. Data for different countries also vary markedly with time. (11) Nowadays, IHD has been increasingly affecting middle-aged populations of low- and middle-income countries, mainly due to changes in lifestyle, stress and other factors. (12) Although the health status of the population in Eastern Europe, including Hungary, has been improving, quality of life indicators have remained lower compared to Western European countries. (13,14) Societal, political and economic changes have negatively impacted health status in countries of the former Soviet Union. (11,15)
Our aim was to analyse and compare international and national mortality data associated with IHD above 65 years of age per region.
Data and methods
We performed a retrospective, quantitative analysis on age-specific, ischaemic heart disease mortality per 100,000 population among people aged 65 years and above. Our analysis focused on countries selected from the WHO European Region including the following Western European countries (N=17; Austria, Belgium, Denmark, Finland, France, Germany, Greece, the Netherlands, Ireland, Luxemburg, Norway, Italy, United Kingdom, Portugal, Sweden, Spain, Switzerland), Eastern European countries (N=10; Bulgaria, Bosnia-Herzegovina, Czechia, Croatia, Poland, Hungary, Romania, Serbia, Slovakia, Slovenia), and countries of the former Soviet Union (N=15; Azerbaijan, Estonia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Russia, Armenia, Tajikistan, Turkmenistan, Ukraine, Uzbekistan). Due to availability of data, we analysed the period between 1990 and 2016 with special focus on the years 1990, 2004 and 2016.
We investigated change through time in standardised mortality due to ischaemic heart disease and regional inequalities among the above groups of countries.
Data were derived from the World Health Organisation, European Mortality Database on the following indicator: „SDR, ischaemic heart disease, 65+, per 100 000” (International classification of diseases 10: I20-I25)”. Data for the given countries originate from national registries.
Besides descriptive statistics (mean confidence interval; distribution: standard deviation, SD) time-series analysis, and mathematical statistics tests (Kruskal-Wallis test) were performed at 95% confidence interval (CI) (p<0.05). Upon testing preconditions the requirements for normality testing (Shapiro-Wilk test) were not fulfilled, thus we decided to perform a Kruskal-Wallis, non-parametric test.
MS Excel 2007 SPSS 22.0 programmes were used for analyses.
Results
In 1990, age-specific mortality per 100,000 population among males above age 65 years was an average 2.2 times higher in post-Soviet countries (3133.51; SD=499.33; min=2371.15: Tajikistan; max=4125.20: Estonia) than in Western European countries (1391.00; SD=600.15; min=604.42: France; max=2379.13: Finland). Age-specific mortality due to IHD among males was minimally higher in Eastern Europe (1418.98; SD=765.89; min=599.71: Croatia; max=2834.57: Czechia) than in Western Europe in 1990. In 2004, mortality caused by IHD among males older than 65 years was an average 3.7 times higher in post-Soviet states (3201.42; SD=840.57; min=2063.90: Tajikistan; max=4947.58: Moldova) and 1.7 times higher in Eastern European countries (1491.38; SD=570.85; min=771.77: Slovenia; max=2575.41: Slovakia) compared to Western European countries (869.17; SD=289.32; min=441.83: France; max=1506.00: Finland). In 2016, age-specific mortality per 100,000 population was 4.3 times higher among males in post-Soviet countries (2204.41; SD=908.77; min.=702.68: Georgia; max.=3513.83: Kyrgyzstan), and 1.9 times higher in Eastern European countries (994.27; SD=402.38; min.=511.85: Slovenia; max.=1695.57: Hungary) than in Western European countries (513.00; SD=196.87; min.=297.20: Netherlands; max.=987.18: Finland). Significant differences were found with regard to mortality due to IHD among males between Eastern-, Western European countries and countries of the former Soviet Union (1990; 2004; 2016: p<0.05). (Figure 1)
In 1990, Age-specific mortality among females was three times higher on average in post-Soviet states (2257.45 SD=375.40; min=1623.20: Kyrgyzstan; max=2821.50: Turkmenistan), 1.27 times higher in Eastern European countries (948.61; SD=550.69; min=279.80:Croatia; max=1723.63: Czechia) compared to Western European countries (746.91; SD=320.64; min=320.38: France; max=1289.87: Finland). In 2004, age-specific mortality among females was 4.53 times higher in post-Soviet states (2202.12; SD=666.07; min=1352.07: Tajikistan; max=3819.84: Moldova), and 2.15 times higher in Eastern Europe (1045.03; SD= 436.95; min=476.90: Slovenia; max=1416.01: Hungary) than in Western Europe (486.30; SD=176.98; min=205.76: France; max=812.92: Finland). In 2016, standardised mortality rates among females were 5.91 times higher in post-Soviet states (1566.44; SD=790.25; min=455.37: Georgia; max=2766.81: Kyrgyzstan), 2.45 times higher in Eastern Europe (649.77; SD=295.80; min=233.09: Slovenia; max=1118.89: Hungary) than in Western Europe (264.93; SD=105.98; min=148.14: Netherlands; max=482.83: Austria). Significant differences were found with regard to mortality due to IHD among females above age 65 years between Eastern-, Western European countries and countries of the former Soviet Union (1990; 2004; 2016: p<0.05). (Figure 2)
Between 1990 and 2016 age-standardised mortality due to IHD among males and females decreased most markedly in Western European countries (males: -63.12%; females: -64.53%) followed by the Eastern European countries we examined (males: -29.93%, females: -31.50%), and countries of the former Soviet Union (males: -29.65%; females: -30.61). Regarding Western European countries, age-specific mortality due to IHD showed a continuous decline with minimal fluctuation from 1990 until the end of the period under examination. In the case of Eastern European countries, we found the highest rates in both sexes in 1997 and saw an increase between 1990 and 1997 (males: +36.27%; females: +40.65%), and a continuous decrease between 1997 and 2016 with minor fluctuations (males: -48.58%; females: -51.30%). In post-Soviet countries, age-specific mortality due to IHD was the highest in 1996 among females, and in 2003 among males. Among women, standardised mortality increased by 11.58% in total between 1990 and 1996 and showed an overall decrease with minor fluctuations between 1996 and 2016 (-37.81%). With regard to standardised mortality in males, the period between 1990 and 2003 witnessed a 12.5% increase, followed by a decrease between 2003 and 2016 (-37.46%) with slight fluctuations (Figure 3).
Figure 4 shows percentage change in age-specific mortality due to IHD in males. Azerbaijan, Estonia, Belarus, France, Ireland, Kazakhstan, Russia, Spain, Serbia, Slovakia, Tajikistan, Turkmenistan and Ukraine are not represented due to lack of data. During the entire period investigated age-specific mortality among males decreased on average by 39.91% in each country. 20 countries were found to have reported better than average data and in 10 countries decrease was smaller than average. Out of the latter group, six were post-Soviet and four were Eastern European countries. Mortality due to IHD among males over 65 years of age showed a decrease in all countries examined during the period between 1990 and 2016 except for Croatia (+97.89%), Kyrgyzstan (+46.46%), Bosnia-Herzegovina (+14.61%) and Moldova (+1.04%). Compared to the base year, by 2016, most favourable changes were registered in Denmark (-82.02%), Georgia (-78.19%) and the Netherlands (-77.04%) among males. The smallest change was witnessed in Hungary (-11.57%) followed by Russia (-12.69%) and Poland (-27.39%) among males above age 65 years.
With regard to females, similar to males, we intended to present percentage change in age-specific, mortality due to IHD for countries selected for examination. Some countries are missing from the graph due to lack of available data (Azerbaijan, Belarus, France, Ireland, Kazakhstan, Russia, Spain, Serbia, Slovakia, Tajikistan, Turkmenistan, Ukraine). Based on data available, mortality rates due to IHD among females aged above 65 years improved with 37.68% on average in each country. 21 countries witnessed better than average and nine countries less than average change. Out of the latter group, five were Eastern European countries and four were former Soviet countries.
Among females age above 65 years, mortality due to IHD decreased between 1990 and 2016 except for Croatia (+202.27%), Kyrgyzstan (+70.45%) and Bosnia-Herzegovina (+38.79%). Compared to the base year, the most favourable change by 2016 was found to have been reported Denmark (-83.82%) followed by Georgia (-81.15%) and the Netherlands (-76.81%) among women. Mortality due to IHD decreased the least in Moldova (-2.24%), Hungary (-10.26%), and Poland (-13.62%) among females older than 65 years. (Figure 5)
Discussion
In our study, we examined mortality due to IHD in the population aged above 65 years in Eastern-, Western European countries and post-Soviet states within the WHO European Region.
The past 25 years have seen a decrease in standardised mortality due to IHD worldwide nonetheless, marked regional inequalities have persisted. High-income countries have reported the most positive change (2,12,16). According to our analysis, age-specific mortality due to IHD in the population older than 65 years was the lowest in Western European countries in both males and females and the highest in countries of the former Soviet Union. Nevertheless, upon comparing Eastern European and post-Soviet countries only minimal change was observable between 1990 and 2016 with regard to average standardised mortality rates. During the period analysed, male mortality rates increased in two Eastern European countries (Croatia, Bosnia-Herzegovina) and two former Soviet states (Kyrgyzstan, Moldova). Regarding females, two Eastern European countries (Croatia, Bosnia-Herzegovina) and one post-Soviet country (Kyrgyzstan) were found to have had an increase in age-standardised mortality. We suspect that the sharp increase in this respect, as found in Croatia, may have been due to variations in fulfilling reporting obligations. The above is supported by the fact that mortality due to IHD reportedly dropped considerably between 1995 and 2011 in Croatia (17). Unfavourable data with regard to Bosnia-Herzegovina have also been published by other researchers. Cardiovascular risk factors, the effects of stress and the economic situation of the country are suspected to be in the background of high mortality rates. (18) The increase in Kyrgyzstan as described above is in line with other findings (11).
During the period between 1990 and 2016, mortality due to IHD among people aged above 65 years decreased less than the Eastern European average in Hungary; decrease among males was 11.57% and 10.26% among females.
Comparing data for Hungary with those of Visegrad countries, we found that in 1990 mortality due to IHD among people aged older than 65 years higher in Czechia than in Hungary. In 2016, age-specific mortality was higher in Hungary than in Czechia. Our analysis revealed that during the period between 1990 and 2016, mortality rates decreased much more markedly in both sexes in Czechia than in our country. In Poland, age-specific mortality due to ischaemic heart disease was considerably lower both in 1990 and in 2016 than in Hungary. There were no data available on Slovakia for the years 1990 and 2016. Between 1990 and 2016, in the years with available data, age-specific mortality due to ischaemic heart disease in the population above 65 years was higher in both sexes in Slovakia than in our country. Regarding risk factor prevalence, in Visegrad countries, according to WHO data, in 2015, Hungary and Poland nearly exactly the same prevalence rates of smoking in males and a slightly higher prevalence in females, in Hungary. In the Czech Republic, the prevalence of smoking was higher in both sexes than in our country. With regard to Slovakia, smoking prevalence was higher among men compared to Hungary (19). The prevalence of obesity was higher in both sexes in Hungary than in Poland or Slovakia. In Czechia it was higher among women than in our country. (20) Regarding statin adherence, we can hereby present some Hungarian research data: according to Jánosi et al. 54.4% of patients showed good statin adherence one year after suffering a myocardial infarction (21). J. Tomcsányi investigated statin adherence among patients having had an acute myocardial infarction and found an average 70% adherence rate (22). Earlier findings published by Kiss et al. revealed lower persistence with regard to statin therapy in comparison with other countries (23).
The results of our analyses may have been distorted by the fact that 12 countries, including Belarus and Ukraine, could not be included in the analysis comparing countries regarding the years 1990 and 2016 due to lack of statistical data.
Mortality indices are greatly impacted by societal-, political- and economic stress. Lower socio-economic status correlates with unfavourable health status indices. (24,25) After 1990, Eastern European countries and post-Soviet states have witnessed significant societal changes. After 2004 the majority of Eastern European countries joined the European Union. (26,27)
Increasing in life expectancy, the aging of the society, the inadequate adherence to evidence-based guidelines, issues arising during the implementation and facilitation of preventive measures and the COVID epidemic have all contributed to the very high disease burden associated with cardiovascular diseases (28-30). The morbidity and mortality associated with cardiovascular diseases depend on the prevalence of risk factors that play a role in their development. Regarding DALY, smoking has continued to be the most important risk factor, smoking cessation programmes play a crucial role (31-33). In 2015, the prevalence of smoking in Hungary among males aged older than 15 years was 32%, and 24.8% among females according to WHO data (19). Concerning the development of IHD, obesity is also one of the main risk factors (34-36). In 1990, the prevalence of obesity in Hungary was 16.9%, in 2016 it was 26.4% in the population above age 18. (20) Rising incomes result in higher food consumption levels among people with lower incomes as well resulting in higher prevalence of obesity in these groups and consequently, a higher risk of CVDs. Regarding the prevention of obesity, population-level strategies e.g. the introduction of the public health product tax and food-health regulations concerning mass catering may prove beneficial. (37,38)
Besides a bigger emphasis devoted to primary prevention, the favourable change in mortality statistics are also due to development of the healthcare system including advances in therapeutic and diagnostic modalities and the establishment of cardiac-catheter centres. (39-41) Between 1993 and 2007, the mortality rates associated with acute myocardial infarction decreased from 15,000 to 8,400. In 2007, mortality due to acute myocardial infarction accounted for 47% of all-cause mortality in 1993 per 100,000 population. Improvement in this respect is due to highly effective pharmacoceuticals in addition to advancement in medical intervention and emergency care therapies. (42) Further measures are necessary to improve mortality statistics targeting the reduction of cardiovascular risk factors and the promotion and facilitation of healthy lifestyle. (12,43-45) The 2021 Guideline of The European Society of Cardiology includes the most up-to-date protocols with regard to cardiovascular risk assessment which contain details on individual risk reduction strategies and therapeutic targets. The guideline designates the promotion and facilitation of a healthy lifestyle to be followed lifelong as the most important preventive factor. The guideline also emphasizes the assessment of psycho-social stress, the importance of anti-thrombocyte therapy, disease-specific interventions and introduces the benefits of life-long risk assessment. The prevention guideline mentions public health policy, representation, the application of societal risk reduction strategies and the introduction of measures to reduce air-pollution among methods targeting societal risk reduction. (44)
The introduction of regulations regarding the lower taxes on healthy foods has been an important element in health-policy decision making.
Our research has some limitations which may have influenced our findings including lack of available data from the WHO database (lack of mortality data on IHD which could be expressed in absolute numbers, occasional lack of standardised mortality data), differences in mortality statistics used by the different countries, variations in reporting obligations and differences in data validation protocols. The comparison of our results with findings of other research is limited due to differences in geographical categorisation of the countries. Due to considerable lack of available data we could not extend the timeline of our research to include further years.