Prevention of cardiovascular events with an antihypertensive regimen of amlodipine adding perindopril as required versus atenolol adding bendroflumethiazide as required, in the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA): a multicentre randomised controlled trial

The apparent shortfall in prevention of coronary heart disease (CHD) noted in early hypertension trials has been attributed to disadvantages of the diuretics and β blockers used. For a given reduction in blood pressure, some suggested that newer agents would confer advantages over diuretics and β blockers. Our aim, therefore, was to compare the effect on non-fatal myocardial infarction and fatal CHD of combinations of atenolol with a thiazide versus amlodipine with perindopril. We did a multicentre, prospective, randomised controlled trial in 19 257 patients with hypertension who were aged 40–79 years and had at least three other cardiovascular risk factors. Patients were assigned either amlodipine 5–10 mg adding perindopril 4–8 mg as required (amlodipine-based regimen; n=9639) or atenolol 50–100 mg adding bendroflumethiazide 1·25–2·5 mg and potassium as required (atenolol-based regimen; n=9618). Our primary endpoint was non-fatal myocardial infarction (including silent myocardial infaction) and fatal CHD. Analysis was by intention to treat. The study was stopped prematurely after 5·5 years' median follow-up and accumulated in total 106 153 patient-years of observation. Though not significant, compared with the atenolol-based regimen, fewer individuals on the amlodipine-based regimen had a primary endpoint (429 vs 474; unadjusted HR 0·90, 95% CI 0·79–1·02, p=0·1052), fatal and non-fatal stroke (327 vs 422; 0·77, 0·66–0·89, p=0·0003), total cardiovascular events and procedures (1362 vs 1602; 0·84, 0·78–0·90, p