New Evidence Suggests 2014 Hypertension Guidelines Could Backfire
但数据结果证明，2014版指南中认定的这些不具降压治疗资格的患者其估算的10年心血管事件风险极高。因此，Dr. William B. Borden在美国心脏病学会科学大会上警告称，广泛应用2014专家组建议或许会对心血管健康造成重大不良后果。
乔治华盛顿大学的心血管病专家. William B. Borden
由于2014专家组指南在高血压管理方面做出了重大修订，Dr. Borden及其同事试图量化分析这一更为宽松的治疗方案对心血管健康可能造成的影响。为此，他们查询了美国国家心血管数据登记实践创新与临床最佳实践（NCDR PINNACLE）登记中心，后者是一个有关心脏病门诊患者的自发性质量改进项目。
在1 185 253例病历记录有高血压诊断或血压高于140/90 mmHg的患者中，60%达到了2003 JNC-7治疗目标（JAMA 2003;289:2560-72），这意味着剩余的40%患者应开始或加强降压治疗，以期达到治疗目标（见图表）。相比之下，在美国心脏病临床实践中，74%的高血压患者达到了2014年专家组报道推荐的、更为宽松的治疗目标（JAMA 2014;311:502-20）。
Dr. Borden及其同事将精力集中于其中15%符合JNC-7建议治疗标准但不符合2014专家组指南治疗标准的高血压患者——这173 519例患者全部为PINNACLE登记中心相关的心脏病中心患者。有趣的是，这15%的数据与明尼阿波利斯的Dr. Michael D. Miedema在一项分析中所报道的17%的比率非常接近，这项分析的数据来源于他在同一时段发表的社区动脉粥样硬化风险（ARIC）研究，其受试人群更倾向于老年患者初级护理人群。
之后，研究者们建立了一个建模操作，目的是评估将血压150 mmHg左右（2014专家组指南建议）的老年人收缩压降低至约140 mmHg（JNC-7治疗目标）的临床影响。为此，研究者们根据两项随机对照临床试验——老年收缩期高血压项目（SHEP）和老老龄人群高血压试验（HYVET）的结果进行了推演。
“这相当于对10-11例患者治疗10年能预防1次心血管事件的发生，” Dr. Borden称。
由于该研究人群包含80 000例以上超过60岁的患者，粗略计算在10年期间可避免8 000次心血管事件的发生，他补充道。
实际上，指南专家组中有5名成员持强烈反对意见并出版了少数派报道（Ann. Intern. Med. 2014;160:499-503），他们认为阻止将60岁以上患者的治疗目标从JNC-7推荐的140/90 mmHg调整至150/90具有不利作用这一观点证据不足。他们警告说，这一改动可能会使最近几十年间实现的心血管及脑血管患病率和死亡率的大幅下降情况不进反退。他们还总结认为，举证的责任应由提倡增高治疗阈值至150/90 mmHg的一方承担，以证实这对60岁以上患者有益，而这些支持者们尚未提供过相应证据。
“我对于2014专家组高血压指南非常担忧。老年人的高血压患病率最高，而他们的病情控制最不充分。根据现有数据，我很担心如果按照新指南行事，心血管事件的发生会增多，”纽约医学院（瓦尔哈拉）的Dr. Wilbert F. Aronow称，他曾主持委员会撰写了首部ACC/AHA老年人高血压控制指南（J. Am. Coll. Cardiol. 2011;57:2037-114）。
NCDR PINNACLE登记中心及该项研究由美国心脏病学会基金会赞助，Dr. Borden和Dr. Aronow声称无相关经济利益关系。
CHICAGO (FRONTLINE MEDICAL NEWS) – Nearly one in seven patients in U.S. ambulatory cardiology practices who would have been recommended for initiation or intensification of antihypertensive drug therapy under the 2003 Seventh Joint National Committee guidelines are no longer treatment candidates under the 2014 expert panel recommendations.
These patients who no longer qualify for antihypertensive therapy under the 2014 guidelines turn out to have a disturbingly high average estimated 10-year risk of cardiovascular events. As a result, widespread adoption of the 2014 expert panel recommendations could have major adverse consequences for cardiovascular health, Dr. William B. Borden cautioned at the American Heart Association scientific sessions.
“Given the size and underlying cardiovascular risk of the population affected by the changes in the 2014 panel recommendations, close monitoring will be required to assess changes in practice patterns, blood pressure control, and – importantly – any changes in cardiovascular morbidity and mortality,” said Dr. Borden, a cardiologist at George Washington University in Washington.
Because the 2014 expert panel guidelines represent a major shift in hypertension management, Dr. Borden and coinvestigators sought to quantify the potential cardiovascular health impact of this more lenient treatment approach. For this purpose they turned to the National Cardiovascular Data Registry Practice Innovation and Clinical Excellence (NCDR PINNACLE) Registry, a voluntary quality improvement project involving outpatient cardiology practices.
Of 1,185,253 patients with hypertension as identified in their chart by a recorded diagnosis or notation of blood pressure greater than 140/90 mm Hg, 60% met the 2003 JNC 7 goals (JAMA 2003;289:2560-72), meaning the other 40% were candidates for initiation or intensification of antihypertensive therapy in order to achieve those goals (see chart). In contrast, 74% of hypertensive patients in U.S. cardiology practices met the less aggressive targets recommended in the 2014 expert panel report (JAMA 2014;311:502-20).
Thus, fewer than two-thirds of hypertensive patients in outpatient cardiology practices met the 2003 JNC 7 blood pressure targets, while three-quarters met the liberalized 2014 targets.
Dr. Borden and coworkers zeroed in on the 15% of hypertensive patients – that’s fully 173,519 individuals in cardiology practices participating in the PINNACLE Registry – who would have been eligible for treatment under the JNC 7 recommendations but not the 2014 expert panel guidelines. Interestingly, that 15% figure was closely similar to the 17% rate reported by Dr. Michael D. Miedema of the Minneapolis Heart Institute in an analysis of a more primary care population of older patients in the Atherosclerosis Risk in Communities (ARIC) study he presented in the same session.
Dr. Borden and coinvestigators determined from medical records that the PINNACLE Registry group whose antihypertensive therapy treatment status changed between the two guidelines was at substantial baseline cardiovascular risk: Nearly two-thirds had been diagnosed with CAD, 54% had diabetes, 27% had a history of heart failure, 25% had a prior MI, and 23% had a prior transient ischemic attack or stroke.
This large group of patients who fell through the cracks between two conflicting sets of guidelines turned out to have a mean 10-year Framingham Risk Score of 8.5%. Upon incorporating the patients’ stroke risk using the atherosclerotic cardiovascular disease (ASCVD) risk score embedded in the 2013 ACC/AHA cholesterol management guidelines, their 10-year risk shot up to 28%.
The investigators then conducted a modeling exercise aimed at estimating the clinical impact of lowering systolic blood pressure in the elderly from about 150 mm Hg, as recommended in the 2014 expert panel guidelines, to about 140 mm Hg, as was the goal in JNC 7. To do so they extrapolated from the results of two randomized controlled clinical trials: the Systolic Hypertension in the Elderly Program (SHEP) and the Hypertension in the Very Elderly Trial (HYVET).
The result? Extrapolating from SHEP data, the 10-year ASCVD risk in these real-world elderly hypertensive patients caught between two conflicting sets of guidelines would drop from 28% to 19%. Using HYVET data, the average 10-year ASCVD risk would fall to 18.4%.
“This is equivalent to a number-needed-to-treat of 10-11 patients for 10 years in order to prevent one cardiovascular event,” according to Dr. Borden.
For the more than 80,000 patients over age 60 in the study population, that works out to roughly 8,000 cardiovascular events averted over the course of 10 years, he added.
The 2014 expert panel recommendations were based on a strict evidence-based review of published randomized controlled trials. The guidelines are new enough that it remains unclear if they will be embraced by clinicians or incorporated into performance measures and value-based health care purchasing programs.
The 2014 guidelines are considered highly controversial. The guideline committee comprising some of the nation’s top hypertension researchers was initially convened to come up with what was intended to be the long-awaited JNC 8 report; however, in the midst of the process the sponsoring National Heart, Lung, and Blood Institute declared it was getting out of the guideline-writing business altogether. As a result, the guidelines ultimately published carried the imprimatur of “the 2014 expert panel,” rather than the more prestigious official stamp of JNC 8.
Indeed, five members of the guideline panel felt strongly enough to break away and issued a minority report (Ann. Intern. Med. 2014;160:499-503) in which they argued there is insufficient evidence of harm stemming from the JNC 7 goal of 140/90 mm Hg in patients over age 60 to justify revising the target to 150/90. They warned that this step could reverse the impressive reductions in cardiovascular and cerebrovascular morbidity and mortality realized in recent decades. And they concluded that the burden of proof should be on those who advocate raising the treatment threshold to 150/90 mm Hg to demonstrate that it has benefit in patients over age 60, which they haven’t done.
“I’m very concerned about the [2014 expert panel] guidelines. Older individuals have the highest prevalence of hypertension, they’re the least adequately controlled, and based on the available data I’m concerned that if people follow the new guidelines there’s going to be an increase in cardiovascular events,” said Dr. Wilbert F. Aronow of New York Medical College, Valhalla, who chaired the writing committee for the first-ever ACC/AHA clinical guidelines for controlling high blood pressure in the elderly (J. Am. Coll. Cardiol. 2011;57:2037-114).
The NCDR PINNACLE Registry and this study were supported by the American College of Cardiology Foundation. Dr. Borden and Dr. Aronow reported having no financial conflicts.
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