Two large Brazilian trials presented on Saturday at the American Heart Association Scientific Sessions in Chicago, and published simultaneously in the New England Journal of Medicine, tested the same question in two populations and got opposite answers: how low should systolic blood pressure go?
In OPTIMAL-STROKE, 4,368 patients with a previous ischemic stroke (92 percent) or transient ischemic attack (8 percent), enrolled at 30 centres in Brazil a median of one year after their event, were randomised to a systolic target below 120 mm Hg or to standard treatment below 140 mm Hg. Over a median follow up of 3.9 years, the primary composite of cardiovascular death, nonfatal heart attack, nonfatal stroke or hospitalisation for unstable angina or heart failure occurred in 10.9 percent of the intensive group (236 of 2,172) against 13.5 percent of the standard group (297 of 2,196), a hazard ratio of 0.79 (95 percent confidence interval 0.67 to 0.94, p equals 0.007). The intensive group used an average of three drug classes against two in the control group and sustained a systolic difference of about 13 mm Hg. Serious adverse events were similar (15.1 against 15.3 percent), but the composite renal outcome was more frequent with intensive treatment (3.9 against 2.2 percent, hazard ratio 1.76), driven mainly by sustained falls in estimated glomerular filtration rate of at least 50 percent, and hyponatremia was also more common (3.3 against 2.2 percent).
In OPTIMAL-DIABETES, 9,476 adults aged 50 and older with type 2 diabetes, blood pressure between 130 and 180 mm Hg and other risk factors, enrolled at 33 sites in Brazil, were randomised to the same two targets. Over a median follow up of four years, major cardiovascular events occurred in 6.0 percent of the intensive group (286 patients) against 6.7 percent on standard treatment (315 patients), about a 10 percent lower risk that was not statistically significant. Serious adverse event rates were also similar. The investigators cautioned that the result should not be read as proof that intensive lowering is ineffective in diabetes, only that any benefit is likely smaller than in patients without diabetes and may be too modest for even a trial this size to confirm definitively.
Read together, the pair refines rather than settles the target debate. After a stroke, pushing below 120 mm Hg prevented roughly one event for every 38 patients treated over four years, at a measurable kidney cost that clinicians will have to weigh patient by patient. In diabetes, the standard below 140 mm Hg target survives this test, and the case for going lower now rests on smaller effects than guidelines debates have often assumed. Both trials were conducted in Brazil, and the stroke trial was open label, limits the investigators themselves cited.