Letter by Koh Regarding Article, “J Curve in Patients Randomly Assigned to Different Systolic Blood Pressure Targets: An Experimental Approach to an Observational Paradigm”
Authors: Kwang Kon Koh
Journal: Circulation (2018)

Kalkman and colleagues 1 presented an interesting and timely post hoc analysis of the pooled database of the SPRINT (Systolic Blood Pressure Intervention Trial) and ACCORD (Action to Control Cardiovascular Risk in Diabetes) trials, which randomly allocated patients at high vascular risk to an intensive (systolic blood pressure [SBP] <120 mm Hg) or conventional (SBP <140 mm Hg) target.It is interesting to note that for both blood pressure (BP) targets, an identical J-curve shape was present, with a nadir for cardiovascular events and all-cause mortality just below the SBP target.Patients in the lowest SBP stratum were older, had a higher body mass index, smoked more often, and had a higher frequency of diabetes mellitus and cardiovascular events.Low on-treatment SBP levels are associated with increased cardiovascular events and all-cause mortality.A recent network meta-analyses reported that an achieved SBP <120 mm Hg was associated with the greatest reduction in the risk of cardiovascular disease. 2 The 2017 American College of Cardiology/American Heart Association guideline proposes more aggressive BP targets and goals for treatment relative to prior guidelines.The 2017 guideline strategy to tailor treatment to a combination of both BP and underlying 10-year estimated risk of a patient's estimated 10-year atherosclerotic cardiovascular disease risk is a huge step forward for hypertension management.However, the guideline extended the goal of <130/80 mm Hg to all high-risk adults regardless of diabetes mellitus status and age. 3 The new guideline recommends more aggressive pharmacological treatment in older patients.A study estimated the deaths prevented and excess serious adverse events incurred if the SPRINT intensive SBP treatment goal were implemented in all eligible US adults.The authors observed that if fully implemented in eligible US adults, intensive SBP treatment could prevent ≈107 500 deaths per year.However, a consequence of this treatment strategy could be an increase in serious adverse events. 4n older (≥65 years of age) patients with hypertension, intensive SBP control (SBP <140 mm Hg) decreased major adverse cardiovascular events but increased the risk of renal failure. 5Therefore, the Eighth Joint National Committee took a targeted approach to consideration of previous trials and concluded that SBP targets should be <140 mm Hg or <150 mm Hg in those ≥60 years of age.Physicians should keep in mind that rates of serious adverse events of hypotension, syncope, electrolyte abnormalities, and acute kidney injury or failure, but not of injurious falls, were higher in the intensive treatment group than in the standard-treatment group. 1,4,5The benefit of further BP-lowering treatment should be outweighed by an increase in the risk of adverse events related to antihypertensive therapy and renal outcomes, particularly in older patients.Optimal BP threshold may vary across organs and be higher for the kidney than for the heart and brain.Likewise, higher BP thresholds may be necessary for individuals who are at increased risk for cerebral or coronary