Dr Irv Loh weighs in on the new blood pressure guidelines, discussing the implications from the SPRINT study and how they will effect American healthcare.
Hot off the virtual presses Friday, 11 September 2015, were the news releases from the SPRINT study, an NIH sponsored collaborative study asking the analogous question for hypertension management to what lipidologists have been asking about cholesterol management: should the goals of therapy be lower than the extant acceptable guidelines? The answer seems to be an unequivocal yes, with perhaps only modest caveats.
The study cohort was a bit more than 9,300 male and female subjects aged 50 years or older, apparently at high risk of cardiovascular disease or had existing renal disease. They were randomized to one of two systolic BP target arms. One was the current acceptable target of 140 torr (mm Hg), and the other was <120 torr. The data and safety monitoring committee recommended premature termination of the study, due to be completed in 2017, due to statistically significant improved outcome in the lower BP treated group. Apparently, the more aggressively treated group had a third less strokes, myocardial infarctions and heart failure, and mortality was reduce by almost 25%.
Now these data confirm the outcomes benefit of that incremental lowering. More aggressive therapy averages three or more drugs, and that was the case in the SPRINT data. But fortunately, the vast majority of these agents are now generic. The issues of additional cost in co-pays, possible adverse effects of lower SBPs, especially in the elderly with their increased fall risk and attendant complications, need to be sorted out.
But the implications for American healthcare may be profound. The American Heart Association estimates that there are almost 79 million hypertensive American citizens, and despite therapy, about half of those still have SBPs >140 torr. Also, the last NIH hypertension guidelines intimated that in the elderly, it may be even OK for them to have a SBP of 150 torr since the evidence for benefit was lacking. Since 28% of the SPRINT cohort was over 75 years of age, careful subset analysis will need to ensure that the benefits of lower SBP apply to that population as well, and are weighed against the risks associated with lower mean cerebral perfusion pressures. For those and other detailed data, e.g., effect on renal function, incidence of dementia, we will need to await the publication of the manuscript itself and corroborating data from other studies.
For now, these results would seem to put our patients with validated, not just labile or white coat hypertension, elevated systolic BPs in our therapeutic cross hairs for increased attention to therapeutic lifestyle changes, appropriate use of combination drug management, and enhanced compliance to our therapeutic recommendations.
Dr. Irving Kent Loh MD, FACC, FAHA (Epidemiology & Prevention), FCCP, FACP is a board certified internist and sub-specialty board certified cardiac specialist with an emphasis on preventive cardiology. He founded and directs the Ventura Heart Institute, which conducts education, research and preventive cardiovascular programs. Dr. Loh is a former Assistant Professor of Medicine at UCLA School of Medicine. He is Chief Medical Officer and Co-founder of Infermedica, an artificial intelligence company for enhancing clinical decision support for patients and healthcare providers.