Heartbeat: the global burden of stroke due to untreated hypertension

Hypertension is a world-wide health burden that increases the risk of adverse cardiovascular outcomes with considerable geographical variation in awareness of the condition, appropriate treatment and blood pressure control. In this issue of Heart , O’Donnell and colleagues1 present the results of a standardised case–control study in 32 countries with over 13 000 cases of acute first stroke matched to controls by age, sex and site. The association of hypertension with stroke was highest in countries with a lower gross national income and higher in younger versus older patients (figure 1). Compared with those with treated hypertension, untreated hypertension was associated with a higher OR for stroke incidence, younger age at first stroke, risk of intracerebral haemorrhage versus ischaemic stroke. Figure 1 Figures report the association of hypertension with stroke by age (A) and GNI (B), demonstrating an increased slope in magnitude of association of hypertension with stroke by reducing age and reducing GNI, which is modified by treatment status. Within increasing intensity of antihypertensive therapy, there is a diminution in slope of curve. While a gradient remains for risk of stroke by age among treatment groups, there is an inversion of gradient by GNI. These figures illustrate that increased uptake of antihypertensive therapy are expected to have greatest impact in younger populations and in lower-income regions. Multivariable model including age, smoking, waist-to-hip ratio, diabetes, physical activity, alternate healthy eating index, alcohol intake, psychosocial factors, apolipoproteins and cardiac risk factors. GNI, gross national income; PAR, population attributable risk. In an editorial, Sarfo2 summarises the concept of population attributable risk (PAR) of hypertension for stroke in high income countries compared with low- and middle-income countries : ‘the PAR of aware and treated hypertension for stroke was 22.2% vs 17.3%, aware …