Randomized study of traditional versus aggressive systolic blood pressure control (Cardio-Sis): rationale, design and characteristics of the study population. Cardio-Sis Study Group

The hypothesis that a therapeutic strategy aimed at lowering systolic blood pressure (SBP) below 130 mm Hg is superior to a conventional strategy targeted at below 140 mm Hg in hypertensive subjects has never been tested in randomized intervention studies. The Studio Italiano Sugli Effetti Cardiovascolari del Controllo della Pressione Arteriosa Sistolica (Cardio-Sis) is a multi-centre study in non-diabetic, treated hypertensive subjects aged >55 years with uncontrolled SBP (>or=150 mm Hg) and at least one additional cardiovascular risk factor (ClinicalTrials.gov identifier: NCT00421863). Subjects are randomized to an SBP goal <140 mm Hg (conventional) or <130 mm Hg (aggressive), independently of baseline and achieved diastolic blood pressure (BP). Anti-hypertensive drugs dispensed for the study are restricted to a list of specific drugs. The primary outcome of the study is based on regression of left ventricular hypertrophy (LVH) using electrocardiography (ECG). The hypothesis is that subjects without LVH regression or with new development of LVH 2 years after randomization are 19% with conventional strategy and 12% with aggressive strategy. Secondary outcome is a composite pool of pre-specified fatal and non-fatal events. Randomization of 1111 subjects was completed by February 2007. Mean age of subjects (41% men) at entry was 67 years. BP was 158/87 mm Hg (systolic/diastolic) and prevalence of LVH by ECG was 21.0%. Cardio-Sis is the first randomized study specifically designed to compare two different SBP goals. Results will be broadly applicable to subjects with uncontrolled SBP under anti-hypertensive treatment