Isolated systolic hypertension as a treatable risk factor.

Isolated systolic hypertension (ISH) is characterised by elevated systolic (SBP) and somewhat lowered diastolic blood pressure (DBP). ISH occurs predominantly in elderly hypertensives as a result of aortic stiffness, which increases with age. Elevated SBP and even more so widened pulse pressure (PP=SBP-DBP) are recognised as important risk factors for stroke and ischaemic heart disease. ISH therefore requires consistent drug therapy, combined with lifestyle advice. It is important to lower SBP without reducing DBP too much, in order to avoid a further widening of the PP. Large-scale intervention studies (SHEP, SYST-EUR, SYST-China, and INSIGHT) have demonstrated that thiazide diuretics and calcium antagonists are the drugs of choice to protect against stroke and MI. ACE inhibitors, AT-blockers and omapatrilate may be considered because of their haemodynamic effects and their additional benefit in patients with heart failure or diabetes. Nitrates and NO-donors reduce SBP more than DBP because of their effects on the large conduit arteries. Spironolactone is of potential interest since it may reduce aortic stiffness.