JNC 8将老年人收缩压控制目标放宽至150 mmHg

JNC 8专家小组现将≥60岁一般人群的血压控制目标设定为低于150/90 mmHg，而长期以来这类患者都以收缩压低于140 mmHg为控制目标，这是一个重大的变化。JNC 8是美国国立心肺血液研究所(NHLBI)于2008年组建的一支专家团队，主要负责更新美国官方高血压管理指南。

专家小组称做出这一决定是因为没有明确证据证明低于140 mmHg的控制目标能产生更多的效益。显然这一决定会引发争议，而且专家小组还将糖尿病或慢性肾病患者的血压控制目标放宽至低于140/90 mmHg (之前的JNC 7指南将此设定为130/80 mmHg)。至此，美国预防、检测、评估与治疗高血压全国联合委员会第八次报告(JNC 8)尘埃落定，该项目由于花费的时间比预期多了好几年，在最后几个月中又经历了多次波折，因而引起了不少争议；前JNC 8专家小组最终于12月18日发布了其高血压管理指南(JAMA 2013 Dec. 18 [doi:10.1001/jama.2013.284427])。


美国高血压管理指南现将60岁及以上人群的血压控制目标设定为低于150/90 mmHg；相比过去使用的低于140 mmHg，这是一次重大的变化。

作为该专家小组的主席之一，美国爱荷华大学家庭医学教授Paul A. James博士称，对于没有合并糖尿病或慢性肾病的60岁及以上高血压患者，这一新的低于150 mmHg的收缩压控制目标“肯定会引发争议”。他在接受采访时说：“A级证据显示将血压控制在150 mmHg以下能切实改善患者结局，但没有证据支持我们应该将血压降至更低水平”，即低于140 mmHg。“好消息是专家小组没有发现将患者的收缩压控制在140 mmHg以下会产生任何危害。但是既然我们没有强有力的证据证明这能带来额外效益，为何还要增加患者出现药物不良事件的风险呢？”

James博士强调道，他所在的专家小组是自己发布了其得出的结论和指南，他们只是作为“第8届全国联合委员会(JNC 8)指派的专家小组成员。”去年6月NHLBI的领导宣布将停止开展发布心血管疾病管理指南的工作，取而代之的是资助证据回顾评估并且与其他机构合作来发布指南。NHLBI将胆固醇、肥胖和生活方式指南安排给美国心脏学会(AHA)和美国心脏病学会(ACC)来发布，但并没有针对JNC 8专家小组作出类似的安排，因此在去年夏天NHLBI正式解散该小组之后它成为了前JNC 8专家小组。

美国纽约州立大学的医学教授Michael A. Weber博士评论道，前JNC 8专家小组对于临床证据的“解读非常狭隘”，证据也相当不完整。“制定指南的目的是一组专家尽可能多地基于相关证据，并且根据其判断和经验来提供符合患者最佳利益的推荐意见。”他提到了ACCOMPLISH、INVEST和VALUE试验的结果，这些试验都表明将60岁以上患者的收缩压控制在140 mmHg以下是有益的，不过他也承认在所有这几项试验中上述结果并非来自事先确定的主要分析。


Paul A. James博士
 
Weber博士是美国高血压学会(ASH)和国际高血压学会(ISH)组建的一支专家小组的负责人，1天前(12月17日)该专家小组自己也发布了一套高血压诊断与管理指南(J. Clin. Hypertension 2013 [doi:10.1111/ch.1223])。Weber博士指出，ASH/ISH指南和前JNC 8专家小组的指南大部分内容都是相似的，主要的争议点就是60~79岁一般人群的收缩压控制目标。ASH/ISH指南是将80岁及以上高血压一般人群的收缩压控制目标设定为低于150 mmHg。

前JNC 8专家小组补充道，如果年龄大于或等于60岁的一般人群正在接受稳定的、耐受良好的抗高血压治疗，并且收缩压低于140 mmHg，则不建议更改治疗或者调高收缩压控制目标。

当然，将这类患者的收缩压控制目标设为低于150 mmHg也得到了一些人的支持。美国韦恩州立大学医学院院长John M. Flack教授说：“前JNC 8专家小组基于相关证据提出了合理的老年患者血压控制推荐意见。”但是他质疑前JNC 8专家小组为何要把糖尿病或慢性肾病患者的血压控制目标从之前的低于130/80 mmHg调高至140/90 mmHg。他在接受采访时说：“过去十年内我们已经取得了如此大的进步，现在来放宽高危人群的血压控制目标将引发相当大的争议。”新发布的ASH/ISH高血压指南也将糖尿病或慢性肾病患者的血压控制目标设定为低于140/90 mmHg。

美国杜克大学医学教授Eric D. Peterson博士评论道，前JNC 8专家小组发布的指南“将引发许多讨论，讨论的焦点将是150 mmHg的控制目标是否正确。” Peterson博士及其同事在这份指南的随刊评论中指出，目前权威指南中制定的高血压控制目标有着越来越重要的意义，因为这往往与医生的“绩效评估指标”挂钩，医生对此负有严格的责任(JAMA 2013 Dec. 18 [doi:10.1001/jama.2013.284430])。

Peterson博士在接受采访时说：“我是ACC/AHA绩效评估指标工作小组的负责人，我们将面临进退两难的困境，因为目前的绩效指标是要求把血压控制在140/90 mmHg以下。”该ACC/AHA工作小组是美国国家质量论坛心血管疾病绩效评估指标的主要制定者。Peterson博士说：“工作小组需要以某种方式回应这一指南”，但我们会考虑现行的各种指南及其支持证据，对于这个问题的最终决定目前尚不清楚。

Peterson博士说：“我不太担心社区中会有多少医生使用这一指南。一方面，我们不希望看到医生受到限制，感觉自己必需把所有患者的血压都控制在一些不可思议的数字以下。”正如他在评论中所说的那样，需要权衡的问题是高血压治疗目标与临床实践中实际达到的目标之间往往存在差距。如果这种关系仍然存在，又接受了将60~79岁患者的控制目标放宽至低于150 mmHg，那么处于这一年龄段的许多美国患者可能会终止治疗，但其实他们的收缩压高于150 mmHg。

James博士和Peterson博士声明无相关利益冲突。Weber博士声明担任诺华、武田制药和Forest公司的顾问。Flack博士声明担任诺华、美敦力和Back Beat Hypertension公司的顾问，并且接受了诺华和美敦力公司提供的经费资助。

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By: MITCHEL L. ZOLER, Cardiology News Digital Network

The group of experts who had constituted the JNC 8 panel, a team assembled in 2008 by the National Heart, Lung, and Blood Institute to update official U.S. hypertension management guidelines, set the target blood pressure for the general population aged 60 years or older to less than 150/90 mm Hg, a major break from long-standing practice to treat such patients to a target systolic pressure of less than 140 mm Hg.

This decision, which the panel contends was driven by lack of clear evidence for extra benefit from the below–140 mm Hg target, will surely prove controversial, along with the panel’s relaxing of target blood pressures for patients with diabetes or chronic kidney disease to less than 140/90 mm Hg (increased from 130/80 mm Hg in the prior, JNC 7 guidelines). That controversy would be a fitting final curtain for the Eighth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 8), a project that courted controversy by running years longer than anticipated and then generating several plot twists during the final months leading up to Dec. 18, when the former JNC 8 panel published its hypertension-management guideline (JAMA 2013 Dec. 18 [doi:10.1001/jama.2013.284427]).
 
The new target of a systolic pressure of less than 150 mm Hg for hypertensive patients aged 60 or older without diabetes or chronic kidney disease "is definitely controversial," said Dr. Paul A. James, cochairman of the panel and professor of family medicine at the University of Iowa in Iowa City. "There is A-level evidence that getting blood pressure below 150 mm Hg results in improved outcomes that really matter, but we have no evidence at this time to support going lower," to less than 140 mm Hg. "The good news is that the panel is comfortable that we don’t do harm," by treating patients to less than 140 mm Hg. "But why put patients at increased risk for medication adverse events when we don’t have strong evidence of benefit?" he said in an interview.

He stressed that his group released their conclusions and guideline on their own, identifying themselves as "the panel members appointed to the Eighth Joint National Committee (JNC 8)." Leaders from the National Heart, Lung, and Blood Institute announced last June that the agency was pulling out of the business of issuing cardiovascular-disease management guidelines, and would instead fund evidence reviews and partner with other organizations to issue guidelines. The NHLBI arranged for its cholesterol, obesity, and lifestyle guidelines to be released through the American Heart Association and American College of Cardiology, but no similar arrangement worked out for the JNC 8 panel, which became the former panel when the NHLBI officially dissolved it by late summer.

The former JNC 8 panel applied "a very narrow interpretation" of the clinical evidence where the evidence is very incomplete, commented Dr. Michael A. Weber, professor of medicine at State University of New York, Brooklyn. "The purpose of guidelines is for a group of experts to be guided as far as they can by the evidence, and then use their judgment and experience to make recommendations that in the best interests of patients." He cited findings from the ACCOMPLISH, INVEST, and VALUE trials that show benefits from treating patients older than 60 years to a systolic pressure of less than 140 mm Hg, though he admitted that in each of these studies the findings did not come from primary, prespecified analyses.

Dr. Weber led a panel organized by the American Society of Hypertension and International Society of Hypertension that released its own set of hypertension diagnosis and management guidelines a day earlier, on Dec. 17 (J. Clin. Hypertension 2013 [doi:10.1111/ch.1223]). Where they overlap, the guidelines from ASH/ISH and from the former JNC 8 panel are mostly the same, with the systolic target for the general population aged 60-79 years being the main area of contention, Dr. Weber said. The ASH/ISH guideline set a systolic target of less than 150 mm Hg for the general hypertensive population aged 80 years or older.

The former-JNC 8 panel also qualified their 150 mm Hg–target by adding that if general population patients aged 60 years or older are on stable, well-tolerated antihypertensive treatment and have a systolic pressure of less than 140 mm Hg, changing treatment and aiming for a higher systolic pressure is not recommended.

The target of less than 150 mm Hg for these patients also had defenders. "They made a reasonable recommendation for the elderly based on the evidence," said Dr. John M. Flack, professor and chief of medicine at Wayne State University in Detroit. But he took the JNC 8 panel to task for relaxing the systolic and diastolic pressure targets for patients with either diabetes or chronic kidney disease from the prior target of less than 130/80 mm Hg to new targets of less than 140/90 mm Hg. "Relaxing blood pressure targets in high-risk groups when so much progress has been made over the last decade is going to be very controversial," he said in an interview. The new ASH-ISH hypertension guideline also set a blood pressure target of less than 140/90 mm Hg for patients with diabetes or chronic kidney disease.

The guideline from the former JNC 8 panel "will produce a lot of discussion, and the main target will be whether the 150 mm Hg target is right or not," commented Dr. Eric D. Peterson, professor of medicine at Duke University in Durham, N.C. In an editorial that accompanied the published guideline, Dr. Peterson and his associates also noted that the hypertension goals specified in authoritative guidelines had a magnified importance these days because they often are incorporated into "performance measures" to which physicians can be often held rigidly accountable.(JAMA 2013 Dec. 18 [doi:10.1001/jama.2013.284430]).

"I chair the ACC/AHA Task Force on Performance Measures, and we will be in a bind because the current performance measures call for a blood pressure target of less than 140/90 mm Hg," he said in an interview. The ACC/AHA task force is one of the main contributors of performance measures for cardiovascular disease to the U.S. clearing house for performance measures, the National Quality Forum. "The Task Force will need to respond to this guideline in some way," he said, but the Task Force takes into account the range of current guidelines that exist and their backup evidence, so how it will decide on this issue remains uncertain.

"My concern is not so much with the number they came up with as with how it will be used by physicians in the community," Dr. Peterson said. On one hand, you don’t want physicians to get carried away and feel they need to treat all their patients to below some magical number." As he pointed out in his editorial, the counterbalancing problem is that there is always a gap between the hypertension treatment goals and what is often achieved in practice. If that relationship remains and the accepted goal for patients aged 60-79 years becomes less than 150 mm Hg, then many U.S. patients in this group may end up treated but with systolic pressures above 150 mm Hg.

Dr. James and Dr. Peterson said that they had no disclosures. Dr. Weber said that he has been a consultant to Novartis, Takeda, and Forest. Dr. Flack said that he has been a consultant to Novartis, Medtronic, and Back Beat Hypertension and received funding from Novartis and Medtronic.