In an article published in Hypertension Research, the writing committee of the Japanese Society of Hypertension (JSH) updated the Society’s 2009 Guideline for Hypertension Management using principles of evidence-based medicine based in part on the 2011 Report of the Institute of Medicine (USA) Clinical Practice Guidelines We Can Trust.1, 2 As described in the JSH 2014 Report, the primary objective of the JSH 2014 is to standardize antihypertensive treatment in order to optimize prevention of diseases of the brain/heart/kidney in the Japanese population. The Report acknowledges the importance of primary care clinicians, as well as teams that include nurses, dieticians and pharmacists, in caring for hypertensive patients in Japan, and directs its recommendations toward all of these groups. Accordingly, members of organizations representing primary care providers, clinical pharmacologists, pharmacists, clinical nutritionists and patients were included in the guideline development and review process. JSH 2014 clearly states that its recommendations are not proscriptive and that therapeutic strategies should be tailored to the specific needs and comorbidities of each patient.

The process of guideline development

Preparation of JSH 2014 began at the 15 May 2012 meeting of the JSH Board of Directors. Dr Kazuaki Shimamoto was selected as Chairperson, and a committee was constituted to update the JSH 2009 guideline according to advances in scientific knowledge, bearing in mind recent modifications of the European and British guidelines. Committee members disclosed potential conflicts of interest, including relationships with industry and participation in studies that were evaluated in the Report. The Report was divided into 13 chapters, and for each chapter, a PubMed search was carried out covering the period January 2009—June 2013 using ‘disease’, ‘target of blood pressure control’ and ‘selected antihypertensive drugs’ as key words. Evidence obtained from published studies was classified into six levels, with systematic reviews and meta-analyses of randomized controlled trials (RCTs) assigned to the highest level, followed by individual RCTs; descriptive studies (case reports, case series) and expert opinion were assigned to the lowest evidence levels. JSH 2014 acknowledges that a major limitation of attempting to use RCT data as its primary evidence base is that most pertinent RCTs of antihypertensive treatment with important health outcomes were carried out in Europe or the United States. Patient characteristics and disease outcomes of hypertension are very different in these populations. For example, rates of fatal and non-fatal stroke are 3–4 times higher than the rates of myocardial infarction (MI) in Japan, whereas MI is more prevalent than stroke in the West. Conceivably, this and other genetic and environmental differences could complicate efforts to extrapolate data from published RCTs to Japanese patients, highlighting the need for more RCTs of blood pressure (BP) treatment to be carried out in Japan.

Treatment recommendations were then graded based on the level of evidence supporting them. Draft recommendations were opened to public comment on the JSH website, and input was solicited from representatives of the Patient Corporation on issues related to home BP measurement, telephone consultations, lifestyle modifications and guidelines for patients. Representatives of The Japan Pharmaceutical Association were asked to comment on cost issues, characteristics and adverse effects of antihypertensive drugs and health insurance coverage.

Scope of the JSH 2014 Guideline

The JSH 2014 Report is encyclopedic, covering virtually every topic relevant to clinical hypertension and its complications, and is heavily referenced, including over 1100 citations. The introductory chapter deals with the epidemiology of hypertension and its major health outcomes in Japan, and includes descriptions of national level public health programs designed to reduce the BP and cardiovascular disease (CVD) risk of the population. This is followed by a chapter devoted to the measurement of BP in the clinic and home setting, which includes definitions of various forms of hypertension, including white coat, masked, morning and evening hypertension, as well as recommendations for use of home and 24-h ambulatory BP monitoring (ABPM) in hypertension management. Basic aspects of the diagnostic evaluation of the patient with suspected hypertension, including the focused history, physical examination and laboratory testing, are also outlined in this chapter. The principles of antihypertensive treatment, including both lifestyle modification and pharmacologic therapy, as well as the detailed characteristics of the various antihypertensive drug classes, are discussed. In addition to the general population of adults with hypertension, the Report includes recommendations for evaluation and treatment of many subgroups of hypertensive persons, including children, pregnant women, the elderly, and those with secondary hypertension, target organ damage and comorbid conditions that complicate BP management, such as diabetes, chronic kidney disease (CKD), dementia, obesity, asthma/COPD, gout/hyperuricemia and liver diseases. Special conditions, including hypertensive emergencies and urgencies, as well as the perioperative evaluation and management of hypertensive persons, are also discussed in depth.

The broad scope of JSH 2014 is both a strength and a weakness. The lengthy and complex document provides useful and up-to-date information on the management of many subgroups of hypertensive persons with a large variety of comorbidities, both acute and chronic. However, the length of the report and its extremely detailed and scholarly discussions of topics in the literature, some of which remain controversial, limit its usefulness for the busy primary care provider. While JSH has made a commendable effort to make this guideline evidence-based, its broad scope dictates that it must provide guidance for management decisions in many clinical areas where there is little or no RCT evidence of benefit or harm of treatment. Evidence from RCTs represents the gold standard for determining efficacy and effectiveness of treatments, and caution must be used in interpreting guidance based on expert opinion and observational data, which may be subject to unintended bias.

Comparison with other current hypertension guidelines

Table 1 compares JSH 2014 and the 2014 U.S. Hypertension Guideline (JNC 8).3 In contrast to the comprehensive JSH 2014 Guideline, the 2014 U.S. Hypertension Guideline focuses on the three critical questions in hypertension identified by committee members as most important:

  1. 1

    In adults with hypertension, does initiating antihypertensive pharmacologic therapy at specific BP thresholds improve health outcomes?

  2. 2

    In adults with hypertension, does treatment with antihypertensive pharmacologic therapy to a specified BP goal lead to improvements in health outcomes?

  3. 3

    In adults with hypertension, do various antihypertensive drugs or drug classes differ in comparative benefits and harms on specific health outcomes?

Table 1 Comparison of JSH 2014 Hypertension Guideline and 2014 U.S. Hypertension Guideline (JNC 8)

The JNC 8 committee did not attempt to redefine hypertension, but did define thresholds and goals for its pharmacologic treatment. To facilitate implementation by a broad spectrum of health-care providers, treatment goals were simplified. Similar treatment goals were defined for all hypertensive persons, except when evidence review supported different goals for a particular sub-population, that is, those over age 60 years without CKD or diabetes. Similarly, the same four medication classes, ACE-I, ARB, CCB or diuretic, were recommended for the general population of hypertensives, except when evidence review indicated a preference for a specific medication class, as in racial, CKD and diabetic subgroups.

Important issues covered in JSH 2014, but not included in the US Hypertension Guideline, relate to the use of combination therapy (including fixed-dose combinations) and the role of home BP measurement/monitoring and ABPM in achieving and maintaining BP control and preventing CVD outcomes. These important questions were identified by JNC 8 committee members but could not be addressed due to lack of resources.

Table 2 places JSH 2014 in the context of other currently used hypertension guidelines. JSH 2014 and some other guidelines recommend treatment to lower BP goals for patients with diabetes and CKD, particularly CKD with proteinuria, based on observational studies. Recent guidelines from the American Diabetes Association (ADA)4 and JNC 83 have raised systolic BP goals for patients with diabetes to those recommended for the general hypertensive population based on evidence from RCTs. Consistent with JSH 2014, the Kidney Disease Improving Global Outcome (KDIGO)5 and JNC 83 guidelines have raised systolic BP goals to <140 mm Hg for patients with CKD but without proteinuria. All guidelines recommend a systolic BP goal of <150 mm Hg for the elderly, but differ in the age cutoff for this recommendation. This is defined as 75 years in JSH 2014,1 60 years in JNC 83 and 80 years in the guidelines of the Canadian Hypertension Education Program (CHEP),6 the European Society of Hypertension/European Society of Cardiology (ESH/ESC)7 and the National Institute for Health and Clinical Excellence (NICE) of the UK.8 Of note, a minority of the JNC 8 panel disagreed with the recommendation to increase the target systolic BP from <140 to <150 mm Hg in persons aged 60 years or older without diabetes or CKD, based on expert opinion.9 The minority group expressed concern that increasing the goal might cause harm by increasing the risk for CVD, including CVD mortality, in Americans older than 60 years. The lack of consistency in recommendations is understandable given the lack of clear RCT evidence in many clinical situations. This caveat is particularly applicable to JSH 2014, as few RCTs of sufficient size and duration to yield clear CVD outcomes enrolled large numbers of East Asian participants.

Table 2 Guideline comparisons of goal BP and initial drug therapy for adults with hypertension