[Target values in hypertension treatment. Will they apply in older patients with hypertension, diabetics and in patients with IHD?].
The incidence of isolated systolic hypertension increases with age since 50 years. Systolic pressure appears to have higher prognostic importance than diastolic pressure in patients older than 50 years. Treatment of isolated systolic hypertension importantly decreases cerebrovascular events, coronary events as well as overall mortality. Studies providing the relevant evidence have mostly been conducted at the beginning of 1990s. The baseline systolic pressure in all these studies was 160 mmHg and higher. This is because the isolated systolic hypertension then was defined as systolic pressure of 160 mmHg or higher and diastolic hypertension as pressure of 95 mmHg or higher. No study confirming that systolic pressure lowering to the range of 140-159 mmHg in older patients would positively affect morbidity and mortality, with a further aim to achieve systolic pressure levels of less than 140 mmHg, have been conducted so far. The recommendation to aim, even in older patients, for the target values of less than 140 mmHg is based mainly on observational studies. Possible existence of the diastolic pressure J-curve in patients with ischemic heart disease represents another unresolved issue. There is a lack of randomised studies on this subject comparing reduction of the diastolic pressure to below 80, below 70 mmHg and below 60 mm Hg. The joint guidelines of the European Society of Hypertension and European Society of Cardiology recommend the target value of <140/90 mmHg for the treatment of isolated systolic hypertension, and systolic pressure of less than 130 mmHg in patients with diabetes, cardiovascular or renal diseases (following myocardial infarction, cerebrovascular event or renal dysfunction), in patients with metabolic syndrome and in patients with the overall cardiovascular SCORE-based risk of > or = 5%. There are no data available confirming that lowering blood pressure to these target values is justified. The 'lower the blood pressure is better' rule applies to cerebrovascular events only. The data from the large ONTARGET study show that lowering of the systolic blood pressure to less than 130 mmHg does not bring any benefit to hypertonics with high cardiovascular risk, except from cerebrovascular events. The J-curve exists for cardiovascular mortality, myocardial infarction and probably also for diabetics, with the turning point at about 130 mmHg. Further reduction of blood pressure increases cardiovascular mortality and myocardial infarctions. We believe that, in the current atmosphere of contradictory data on the diastolic pressure and coronary events relationship J-curve, caution is needed in older patients with isolated systolic hypertension and IHD in cases when the on-treatment diastolic pressure falls below 70 mmHg. In such a situation we would not insist on reaching the systolic pressure target value. We believe that this should apply to older patients with ischemic heart disease in particular. In summary, it is possible to conclude that hypertension treatment target blood pressure values of less than 140/90 mmHg are justified. However, target values of less than 130/80 mmHg in diabetics, in patients with a cardiovascular disease and in other patient groups (metabolic syndrome, overall cardiovascular risk of 5% or higher) are challenged by the results of a range of large studies, and verification in prospective studies is of utmost importance.
Klinika kardiologie IKEM Praha. widimsky@seznam.cz
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D001794:Blood Pressure; D048909:Diabetes Complications; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000150:complications*