Lowering blood pressure after stroke or with diabetes poses challenges, in research and practice

CHICAGO — High blood pressure has earned its reputation as the silent killer. If someone has diabetes or has had a stroke, the risk of serious cardiovascular events posed by hypertension climbs even higher. Three studies presented Saturday at the American Heart Association’s scientific sessions reported on recent attempts to lower blood pressure in people with these challenging medical histories, and how medical care should reach across specialties to treat them. One small but diverse trial tested a common diuretic after a stroke, another looked at intensifying treatment to reach lower-than-standard post-stroke blood pressure goals, and the third looked at going lower in people living with type 2 diabetes. Each of the scientists leading the studies and the experts commenting on them at a media briefing emphasized the role of blood pressure. Adding a widely available drug earlier held promise for controlling blood pressure, but it was a split decision between the effects of lower numbers post-stroke and with diabetes. “Blood pressure is defined in guidelines as the most important modifiable risk factor for recurrent stroke,” Jordana Cohen of the Perelman School of Medicine at the University of Pennsylvania, said. “We know that blood pressure control after stroke is suboptimal.” Her trial, called REDUCE, took advantage of the common, cheap diuretic spironolactone — sometimes called a water pill. It’s usually given to people late in treatment, after three other medications haven’t worked. But when spironolactone was given to people right after a stroke, they were more likely than those receiving usual post-stroke care to see their blood pressure drop three months later to less than 130/80 mm Hg. Small changes are important, Cohen said about the trial, whose mission was to measure blood pressure reduction, not cardiovascular outcomes.. When blood pressure goes down by as little as 7 mm, that reduction has been associated with a 38% lower risk of recurrent stroke. The trial was presented as an abstract and has not yet been published in a medical journal. In his comments, Bruce Ovbiagele of the UCSF Weill Institute for Neurosciences, said it’s well known that one-third of stroke patients don’t meet blood pressure guidelines, and said the study offers hope for a better approach. “We also know that one year after a stroke has occurred, about one out of five stroke survivors have discontinued their antihypertensive medications,” he said. “This wonderful notion to try and use spironolactone is a great one because it’s a medication that’s cheap. It’s available and recognizable to so many clinicians.” A much larger blood pressure trial in Brazil tested whether aiming for a top number of 120 mm or lower would be better than the currently recommended 140 mm. “Almost all patients enter stroke-based antihypertensive therapy. But what we don’t know is how low should we go,” Gisele Sampaio of the Federal University of Sao Paulo in Brazil said about her OPTIMAL-STROKE study, published in the New England Journal of Medicine. People who took medications to reach this lower systolic blood pressure goal were significantly less likely to die or have cardiovascular events within four years, compared to those who received standard treatment to lower levels below 140 mm Hg, the study found. The nonfatal events in the OPTIMAL-STROKE study included heart attack, stroke, and hospitalization for chest pain or heart failure. Achieving these lower numbers will require medical supervision, including monitoring kidney function. There was no increase in the risk of end-stage renal disease, in the need for dialysis, or in deaths but some markers of renal function were off, Otavio Berwanger of Imperial College London and chair of the OPTIMAL study steering committee, said about the study. But there were changes in electrolyte levels consistent with using a diuretic or how much water people drink The related OPTIMAL-DIABETES trial, also published in the New England Journal of Medicine, came to a different conclusion. Karla Santo of Einstein Hospital Israelita in Sao Paulo reminded her audience that the ideal blood pressure target in patients with type 2 diabetes is still uncertain. Her study sought to evaluate the lower target of less than 120 in these patients. Its findings were neutral: Among patients with type 2 diabetes, aiming at a systolic blood pressure of less than 120 mm Hg, rather than less than 140 mm Hg, did not reduce the occurrence of major cardiovascular events or deaths. Shawna Nesbitt of UT Southwestern Medical Center pointed out differences between men and women and between younger and older patients in these two older trials and the newer OPTIMAL-DIABETES trial. She also wondered about longer follow-up. “I think it very strongly suggests that this trial supports rather than rebukes what we already have seen in other trials treating hypertension more aggressively in patients with diabetes,” she said. “We might begin to think about blood pressure treatment in a more nuanced way. That is to say, perhaps we’ve been lumping patients together in a way that may not necessarily always be advantageous.” One common challenge that may arise is how to apply these results in the U.S. “Post-stroke care is very fragmented. Neurologists take care of patients in hospital. Then patients go into primary care,” Ovbiagele said. “So how does a nephrologist and neurologist and a primary care person manage the utilization of the medications?” Cheryl Bushnell of Wake Forest University said doctors know what to do. “It’s not the what, but it’s the how,” she said in her comments. “Managing blood pressure in stroke patients is incredibly difficult, I say as somebody who has to own that as a clinician. Is it the neurologist? Is it the nephrologist? Is it the primary care doctor?”