Recommendations for Treating Hypertension

Abstract

Hypertension is themost common cardiovascular risk factor in the United States, affecting approximately two-thirds of adults aged60yearsorolder.1Observational studieshavedemonstrateda linear relationshipbetweenbloodpressure (BP)and risk of cardiovascular events. Randomized controlled trials (RCTs) have found that loweringBPby as little as 10mmHg in patientswithhypertension can reduce aperson’s lifetime risk forcardiovascularandstrokedeathby25%to40%.2Yet forsuch a common and treatable condition, the ideal treatment goal remains uncertain—both overall and as a function of a patient’s age. Compared with younger patients, older patients withhypertension are at increased risk for cardiovascular and stroke events yet are more vulnerable to complications related to pharmacological treatment of hypertension. The last JointNationalCommittee (JNC7)Guideline, sponsoredbytheNationalHeart,Lung,andBlood Institute (NHLBI), was released more than a decade ago.3 The updated recommendations formanagement of high blood pressure from the panel members appointed to the JNC 8 Committee was launched 5 years ago. Theprocess used in themost recent update differed from the prior guideline by focusing on select clinical questions that were to be answered solely using evidence from RCTs. Despite this empirical approach, the panel’s summary recommendationswereultimatelynot sanctionedby the NHLBI.Thepanel’s report isnowpublished in JAMAasastandalone document,4 and it remains unclear as to whether, or when, or by whom another consensus national hypertension guideline will again be formulated. Where does this leave practitioners, patients, and policy makers? The major difference between the JNC 7 report and the current panel recommendations centers on whether target BP treatment goals should be more conservative (ie, set higher) inoldervsyoungerpopulations.Specifically, JNC7concluded that all adult patientswithhypertension (regardless of their age) should have their BP reduced to a systolic BP (SBP) of lower than 140 mm Hg, with even tighter control in patientswithdiabetesor renal disease (SBP<130mmHg). In contrast, the current recommendation raises target SBP goals to 150mmHgor lower in thoseaged60yearsorolder,whileeliminating the tighter control recommendations in patients with diabetes and renal disease. How the panel selected these treatment goals depended in part on how existing trial evidence (or lack thereof) was interpreted. Prior guidelines were generally based on the totality of evidence, including observational studies, RCTs, and meta-analyses, as well as expert opinion. Noting that the risks for cardiovascular events in untreated adults increased rapidly as SBP was elevated beyond 140 mm Hg, experts defined hypertension and its treatment targets at this level. Nevertheless, direct RCT evidence to support this threshold is limited. The original hypertension RCTs were selective and generally excluded elderly patients. Later trials that focused specifically on older populations found that treating isolated SBP was beneficial, yet these trials had treatment intervention targets of SBP lower than 160 mm Hg.4 More recently, 2 Japanese RCTs directly compared a more intensive treatment strategy (lowering SBP <140 mm Hg) vs a more conservative one (<150 mm Hg) among older patients (≥65 years).5,6 Neither trial found a significant difference in the primary outcome, yet both trials had relatively short follow-up and limited overall power to exclude a clinically meaningful difference in outcomes. The evidence gap for patients younger than 60 years is even more profound because no RCTs have specifically addressed ideal SBP targets in this age group. These limitations in the available RCT evidence pool created challenges for determining consensus recommendations. Does the absence of evidence lead to the conclusion of evidenceof absence? In this case, panelmembers came todifferent conclusions. In older populations, the majority of the panel interpreted the lack of definitive benefit from RCTs as grounds to raise the SBP treatment goal recommendation to 150mmHg; however, for patients younger than 60 years, the paucity of any trial evidence providedno reason for the panel to change the existing treatment goal of SBP at 140 mmHg. How the panel’s conclusions are viewedmay partially be influenced by the recommendations’ ultimate purpose. The original term for practice “guidelines” was borrowed from a mountain-climbing technique in which experienced guides marked the best and safest paths for hikers to take by placing ropes along the way.7 In medicine, clinicians initially formed guidelines to suggest a safe direction when managing difficult clinical situations. If this original purpose had remained intact, then thedebate around a specific SBP thresholdwould most likely not be so intense. Clinicians would still be free to considermoreaggressive treatmentgoals for ahealthyasymptomatic 60-year-old patient, while electing a more conservative treatment goal for a 75-year-old patient with a history of falls. Yet over time, as guidelines have become more formalized, deviations from guideline recommendations have become less tolerated. Furthermore, guideline recommendaEditorials