An article published in this week's edition of The Lancet reports that treatment to lower high systolic blood pressure in non-diabetic patients is associated with a reduction in left ventricular hypertrophy (LVH), a thickening of the heart muscle that can lead to heart failure and rhythm problems. As a result, a lowering of systolic blood pressure targets from the currently recommended 140 mm/Hg or less to below 130 mm Hg should be the treatment goal in low-risk patients with high blood pressure.
Although there is a need for further confirmation,hypertension guidelines advise that blood pressure be lowered to less than 140/90 mm Hg. Evidence from earlier trials does not suggest a blood pressure target of below 130/80mm Hg in high-risk patients with cardiovascular disease or diabetes. On the other hand, the level to which systolic blood pressure should be lowered in patients without high cardiovascular risk has not been assessed in clinical trials. In fact, there is presently no proof to support a lower treatment target in patients with high blood pressure without diabetes.
Paolo Verdecchia from the Hospital S. Maria della Misericordia and ANMO Research Centre in Italy and collaborators conducted a ground-breaking randomised trial. They examined the cardiovascular effects of a systolic blood pressure target below 130 mm Hg (tight control) compared with a target below 140 mm Hg (usual control) in non-diabetic patients with hypertension.
Between 2005 and 2007, a total of 1,111 non-diabetic patients aged 55 years or older were recruited from 44 centres in Italy. They all had a systolic blood pressure of 150 mm Hg or higher. At random, 553 patients were assigned to a target systolic blood pressure of less than 140 mm Hg and 558 patients to less than 130 mm Hg. Antihypertensive drugs were used to lower blood-pressure and customized to individual patients' needs. Every four months for two years, blood pressure was checked. At the final two-year visit patients were tested for LVH.
After two years, tight (below 130 mm Hg) compared to usual (below 140 mm Hg) blood-pressure control reduced systolic blood pressure and decreased the probability of LVH and clinical events. In general, systolic blood pressure was 3.8 mm Hg lower and diastolic blood pressure 1.5 mm Hg lower in the tight-control group. Also, patients in the usual-control group were more likely to have LVH (17 percent) than in the tight-control group (11.4 percent) after two years. Even if the number of events of clinical outcome was small, coronary revascularisation and new-onset atrial fibrillation were considerably less common in the tight-control group.
The authors write in conclusion: "Because of the poor amount of blood-pressure control in the general population and clinical trials, and because of the direct relation between cardiovascular protection and blood-pressure lowering, the results…lend support to a lower blood pressure goal than is recommended at present in non-diabetic patients with hypertension."
In an associated remark, Bo Carlberg from University Hospital, Umeå, Sweden, warns that before shifting guidelines in low-risk patients with hypertension: "A systolic blood pressure treatment goal below 130 mm Hg should be evaluated in adequately powered randomised trials. Only after that will it be possible to evaluate in which groups of patients such treatment is beneficial and the cost effectiveness of such treatment."
"Usual versus tight control of systolic blood pressure in non-diabetic patients with hypertension (Cardio-Sis): an open-label randomised trial"
Paolo Verdecchia, Jan A Staessen, Fabio Angeli, Giovanni de Simone, Augusto Achilli, Antonello Ganau, Gianfrancesco Mureddu, Sergio Pede, Aldo P Maggioni, Donata Lucci, Gianpaolo Reboldi, on behalf of the Cardio-Sis investigators
Lancet 2009; 374: 525-33
The Lancet
Written by Stephanie Brunner (B.A.)
Source: Medical News Today
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