The Hypertension Optimal Treatment (HOT) study: Implications for hypertension management and the J-shape curve

Epidemiologic surveys in the United States indicate that only a minority of patients with hypertension have adequate blood pressure control on therapy . Concern over the J-curve may be leading physicians to undertreat hyperten sion. The existence of a J-curve, the increase in cardiovascular mortality when the blood pressure is lowered beyond the threshold for myocardial perf usion, has been actively debated. The Hypertension Optimal Treatment (HOT) study was designed to address the following concerns with respect to antihypertensive treatment: (1) How aggr essively should blood pressure be towered? (2) What is the optimum target p ressure in terms of minimum cardiovascular risk? and (3) Does aspirin thera py provide added cardiovascular benefits in patients being treated for hype rtension? In the HOT study, 18,790 patients were randomized to diastolic blood pressu re target groups of less than or equal to 90 mm Hg, less than or equal to 8 5 mm Hg, or less than or equal to 80 mm H and further randomized to 75 mg/d ay aspirin or placebo. Felodipine was given as baseline therapy with the ad dition of other agents according to a five-step regimen. A major achievement in the trial was a greater than 20-mm Hg reduction in b lood pressure in all three target blood pressure groups. The incidence of c ardiovascular morbidity and mortality was low in HOT, in comparison with pr evious trials. Event: rates, except for myocardial infarction (MI), were si milar in all three target blood pressure groups, but aggressive treatment a fforded significant cardioprotection to diabetic patients. The optimum dias tolic blood pressure in terms of minimum cardiovascular risk was between 80 and 85 mm Hg. Coadministration of low-dose aspirin provided added cardiova scular benefit without significantly increasing the risk of fatal bleeding. However, because of the close degree of blood pressure reduction among the three target blood pressure groups in this study, the issue of the J-curve could not be resolved.