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. Thus, 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, concludes an Article published in this week's edition of The Lancet.
Despite a lack of evidence, hypertension guidelines recommend that blood pressure be lowered to less than 140/90 mm Hg. Evidence from previous trials does lend support to a blood pressure target of below 130/80mm Hg in high-risk patients with cardiovascular disease or diabetes. However, the level to which systolic blood pressure should be lowered in patients without high cardiovascular risk has not been evaluated in clinical trials. Indeed, there is currently no evidence to support a lower treatment target in patients with high blood pressure without diabetes.
For the first time, Paolo Verdecchia from the Hospital S. Maria della Misericordia and ANMO Research Centre in Italy and colleagues conducted a randomised trial to examine 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.
In total, 1111 non-diabetic patients aged 55 years or older with a systolic blood pressure of 150 mm Hg or higher were recruited from 44 centres in Italy between 2005 and 2007. Patients were randomly assigned to a target systolic blood pressure of less than 140 mm Hg (553) or less than 130 mm Hg (558). Antihypertensive drugs were used to lower blood-pressure and tailored to individual patients' needs. Blood pressure was checked every 4 months for 2 years and at the final 2-year visit patients were tested for LVH.
Over 2 years, tight (< 130 mm Hg) compared to usual (< 140 mm Hg) blood-pressure control reduced systolic blood pressure and decreased the likelihood of LVH and clinical events. Overall, systolic blood pressure was 3.8 mm Hg lower and diastolic blood pressure 1.5 mm Hg lower in the tight-control group. In addition, patients in the usual-control group were more likely to have LVH (17%) than in the tight-control group (11.4%) at 2 years. Although the number of events of clinical outcome was small, coronary revascularisation and new-onset atrial fibrillation were significantly less frequent in the tight–control group.
The authors conclude: "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 accompanying Comment, Bo Carlberg from University Hospital, Umeå, Sweden, cautions that before changing 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."
Dr Paolo Verdecchia, Hospital S. Maria della Misericordia, Perugia, Italy. T) +39 (075) 5782213; 5782207; 5782476; 5782478 E) verdec@tin.it
Dr Bo Carlberg, University Hospital, Umeå, Sweden. T) +46 70 577 5883 E) bo.carlberg@medicin.umu.se
For full Article and Comment, see: http://press.thelancet.com/hypertensionbp.pdf
Journal
The Lancet