Hypertension is the most important risk factor for stroke[85]. Despite this, national data of blood pressure levels or blood pressure control is not systematically collected in most European countries. The accuracy of existing figures is dependent on access to diagnostic testing and monitoring which varies from country to country.
According to WHO estimates (Figure 5), high blood pressure affects 20% of the population in Israel rising up to 39% in Estonia. As observed in previous studies[98], there is generally a higher prevalence in Eastern European countries.
Eurostat (Cardiovascular disease statistics, data extracted October 2016, provided by European Health Interview Survey (EHIS), 2006-10) found a similar East-West gradient.
The highest percentage of self-reported hypertension (adults aged ≥15 years) was recorded in Hungary (32%), Bulgaria (30%), Latvia (29%), Germany (29%), and Lithuania (28%), whereas the lowest shares were recorded in Norway (13%), France (14%), Sweden (16%), the United Kingdom (16%), and the Benelux countries (all below 17%). A significant age-gradient was observed for hypertension with 52% of those aged over 75 years being affected, ranging from 36% in Belgium to 73% in Bulgaria. Hypertension is significantly more common in stroke patients than in the general population (Appendix 1, Table 1). There are again significant variations between countries and studies. Prevalence rates for hypertension ranged from 54% in Spanish and Italian studies to 87% in a Croatian study.
Stroke guidelines issued by the European Stroke Organisation in 2008 include primary prevention measures, such as regular checks of blood pressure, blood glucose, and cholesterol, as well as advocating a healthy lifestyle with regards to smoking, alcohol, physical activity, and diet.
The vast majority of European countries have developed national guidelines for the primary and secondary prevention of stroke covering all or most of those risk factors.
Some countries have developed secondary prevention, but no primary prevention guidelines (e.g. Czech Republic[9]), or have national guidelines that cover only some risk factors, while local guidelines cover other aspects (e.g. Greece and Malta: no national hypertension guideline[9]). There are very few countries that have no national or local guideline covering hypertension, e.g. Latvia[9]. Despite the wide availability of guidelines, there is significant under-treatment.
Figure 6 shows the percentage of the population reporting the use of antihypertensives in 15 European countries in 2008 according to Eurostat data together with the estimated percentage of the population affected by high blood pressure[86]. Clearly, there is a considerable issue of under-treatment. In several other European studies, low treatment rates of hypertension have been observed, but with some improvements since 2000 (Table 6)
Figure 6: Population affected by hypertension (WHO data) and self-reported use of antihypertensives (Eurostat 2008 data, ranked by the relative gap between hypertension and the use of antihypertensives
Table6: Percentage of hypertensive patients taking antihypertensives (primary prevention)
|
Country |
% – year |
Further details; other studies |
|
| General population | Portugal | 39% – 2003 | national sample, control rate 11%[99] |
| Spain | 59% – 2008-10 | national sample[100] | |
| Italy | 64% – 2013-4 | national sample[101] | |
| Germany | 55% – 1998
72% – 2008/11 |
multi-centre[102]; significant regional differences[103] | |
| Pre-stroke | Estonia | 58% – 2001-3 | Tartu stroke register[14] |
| Poland | 78% – 1995/9
91% – 2010/13 |
Warsaw stroke register[104] | |
| UK | 55% – 2007-10 | South London Stroke Register[105];
Significant increase in patients prior to and in the year after stroke (UK primary care database 1999-2008)[106] |
Even more important than treatment rates are control rates. What proportion of people are getting treatment that is enough to lower blood pressure to recommended levels? Low control rates have been reported from many European countries. Two large international studies using primary care data, the EUROASPIRE primary care surveys[107] and the EURIKA study[108] consistently showed low control rates in hypertensive patients between 48% in Greece and 28% in Romania (Figure 7). Similarly, several national or local studies reported low control rates in treated patients between 33% (Greece) and 72% (Germany) (Table 7).
Figure 7: Proportion of hypertensive patients with controlled blood pressure (<140/90mmHg, EURIKA: proportion of all hypertensive patients (treatment rates >90%), EURASPIRE: proportion of treated patients)
Table 7: Proportion of hypertensive patients with controlled blood pressure (Control rate)
|
Country |
Control rate |
| Austria [109] | 41% of treated, and adherent patients |
| Spain[100] | 43% of treated patients, 25% of hypertensive patients 2008/10 (16% in 2000/1) |
| Italy[101] | 58% of treated patients in 2013/14, 33% in 2000 to 2011 |
| Italy[110] | 47% of treated patients |
| Greece[111] | 33% of treated patients (51% of hypertensive patients were treated) |
| Germany[112] | 72% of treated patients in 2008/11, 42% in 1998 |
| Portugal[113] | 37% of hypertensive patients in 2008/9 |
| Iceland[114] | 27% of hypertensive patients in Icelandic GP database |
Low control rates for hypertension are also found among people who have had a stroke (i.e. secondary prevention). Figure 8 presents data from the stroke-specific module of the EUROASPIRE study (2006-8 data[115]), showing control rates of 32% or less in those with known hypertension in four European countries. An Irish stroke population study (6 months after ischaemic stroke), modelled on the EUROASPIRE protocol, found uncontrolled blood pressure in 63% of patients[116].
Figure 8: the percentage of hypertensive stroke patients treated with antihypertensives (treatment rate) and of those achieving adequate hypertension control (control rate)
Measuring how many people get treatment does not accurately reflect how many people’s high blood pressure is being controlled. Blood pressure control is a relevant measure that needs to be encouraged in future studies.
It is clear that existing guidelines are not being implemented well in every day clinical practice; there are poor treatment rates for hypertension across Europe and even worse hypertension control rates, although several studies do report some improvement over the last decade.
Across Europe primary and secondary prevention strategies
are not working well enough to control hypertension,
the biggest risk factor for stroke.
