甲谷 友幸

Unlike other international guidelines but in accord with the earlier Japanese Society of Hypertension (JSH) guidelines, the 2019 JSH guidelines (“JSH 2019”) continue to emphasize the importance of out-of-office blood pressure (BP) measurements obtained with a home BP device. Another unique characteristic of JSH 2019 is that it sets clinical questions about the management of hypertension that are based on systematic reviews of updated evidence. JSH 2019 states that individuals with office BP &lt  140/90 mm Hg do not have normal BP. The final decisions regarding the diagnosis and treatment of hypertension should be performed based on out-of-office BP values together with office BP measurements. For hypertensive adults with comorbidities, the office BP goal is usually &lt 130/80 mm Hg and the home BP goal is &lt 125/75 mm Hg. Recommendations of JSH 2019 would be valuable for not only Japanese hypertensive patients but also Asian hypertensive patients, who share the same features including higher incidence of stroke compared with that of myocardial infarction and a steeper blood pressure-vascular event relationship.

Epidemiologic studies have consistently demonstrated an increased risk of cardiovascular disease during colder temperatures. Hemodynamic changes associated with cold temperature and an increase in thrombogenicity may both account for the increase in cardiovascular risk and mortality. Studies using both in-office and out-of-office BP measurements have consistently shown an elevation in BP during the colder seasons. The large difference in BP between cold and warm months may increase the incidence of hypertension and reduce the hypertension control rate, potentially resulting in increased cardiovascular risk, especially among those at risk of cardiovascular disease. The current trends in global warming and climate change may have a profound impact on the epidemiology of hypertension and cardiovascular disease, as changes in the climate may significantly affect both BP variability and cardiovascular disease, especially in those with high cardiovascular risk and the elderly. Furthermore, climate change could have a significant influence on hypertension in Asia, considering the unique characteristics of hypertensive patients in Asia. As an increase in ambient temperature decreases the mean daytime average and morning surge in BP, but increases the nocturnal BP, it is difficult to predict how environmental changes will affect the epidemiology and prognosis of hypertension in the Asian-Pacific region. However, these seasonal variations in BP could be minimized by adjusting the housing conditions and using anticipation medicine. In this review, we discuss the impact of seasonal variation in the ambient temperature on hypertension and cardiovascular disease and discuss how this may impact the epidemiology of hypertension and cardiovascular disease.

Hypertension professionals from Asia have been meeting together for the last decade to discuss how to improve the management of hypertension. Based on these education and research activities, the Hypertension, brain, cardiovascular and renal Outcome Prevention and Evidence in Asia (HOPE Asia) Network was officially established in June 2018 and includes experts from 12 countries/regions across Asia. Among the numerous research and review papers published by members of the HOPE Asia Network since 2017, publications in three key areas provide important guidance on the management of hypertension in Asia. This article highlights key consensus documents, which relate to the Asian characteristics of hypertension, home blood pressure monitoring (HBPM), and ambulatory blood pressure monitoring (ABPM). Hypertension and hypertension-related diseases are common in Asia, and their characteristics differ from those in other populations. It is essential that these are taken into consideration to provide the best opportunity for achieving “perfect 24-hour blood pressure control”, guided by out-of-office (home and ambulatory) blood pressure monitoring. These region-specific consensus documents should contribute to optimizing individual and population-based hypertension management strategies in Asian country. In addition, the HOPE Asia Network model provides a good example of the local interpretation, modification, and dissemination of international best practice to benefit specific populations.

The Hypertension Cardiovascular Outcome Prevention and Evidence in Asia (HOPE Asia) Network was set up to improve the management of hypertension in Asia with the ultimate goal of achieving “zero” cardiovascular events. Asia is a diverse continent, and the prevalence of hypertension has increased over the last 30 years. There are a number of Asia-specific features of hypertension and hypertension-related cardiovascular complications, which means that a region-specific approach is needed. White-coat hypertension will become more of an issue over time as Asian populations age, and masked hypertension is more prevalent in Asian than in Western countries. Identifying and treating masked hypertension is important to reduce cardiovascular risk. Abnormal patterns of blood pressure (BP) variability common in Asia include exaggerated early morning BP surge and nocturnal hypertension. These are also important cardiovascular risk factors that need to be managed. Home blood pressure monitoring (HBPM) is an important tool for detecting white-coat and masked hypertension, and monitoring BP variability, and practices in Asia are variable. Use of HBPM is important given the Asia-specific features of hypertension, and strategies are needed to improve and standardize HBPM usage. Development of HBPM devices capable of measuring nocturnal BP along with other information and communication technology-based strategies are key developments in the widespread implementation of anticipation medicine strategies to detect and prevent cardiovascular events in patients with hypertension. Region-wide differences in hypertension prevalence, control, and management practices in Asia highlight the importance of information sharing to facilitate best practices.

Ambulatory blood pressure monitoring (ABPM) can measure 24-hour blood pressure (BP), including nocturnal BP and diurnal variations. This feature of ABPM could be of value in Asian populations for preventing cardiovascular events. However, no study has yet investigated regarding the use of ABPM in actual clinical settings in Asian countries/regions. In this study, 11 experts from 11 countries/regions were asked to answer questionnaires regarding the use of ABPM. We found that its use was very limited in primary care settings and almost exclusively available in referral settings. The indications of ABPM in actual clinical settings were largely similar to those of home BP monitoring (HBPM), that is, diagnosis of white-coat or masked hypertension and more accurate BP measurement for borderline clinic BP. Other interesting indications, such as nighttime BP patterns, including non-dipper BP, morning BP surge, and BP variability, were hardly adopted in daily clinical practice. The use of ABPM as treatment guidance for detecting treated but uncontrolled hypertension in the Asian countries/regions didn't seem to be common. The barrier to the use of ABPM was primarily its availability in referral centers, patient reluctance owing to discomfort or sleep disturbance was the most frequent barrier. ABPM use was significantly more economical when it was reimbursed by public insurance. To facilitate ABPM use, more simplified indications and protocols to minimize discomfort should be sought. For the time being, HBPM could be a reasonable alternative.

Hypertension is highly prevalent in Japan, affecting up to 60% of males and 45% of females. Stroke is the main adverse cardiovascular event, occurring at a higher rate than acute myocardial infarction. Reducing blood pressure (BP) therefore has an important role to play in decreasing morbidity and mortality. The high use of home BP monitoring (HBPM) in Japan is a positive, and home BP is a better predictor of cardiovascular event occurrence than office BP. New 2019 Japanese Society of Hypertension Guidelines strongly recommend the use of HBPM to facilitate control of hypertension to new lower target BP levels (office BP &lt  130/80 mm Hg and home BP &lt  125/75 mm Hg). Lifestyle modifications, especially reducing salt intake, are also an important part of hypertension management strategies in Japan. The most commonly used antihypertensive agents are calcium channel blockers followed by angiotensin receptor blockers, and the combination of agents from these two classes is the most popular combination therapy. These agents are appropriate choices in South East Asian countries given that they have been shown to reduce stroke more effectively than other antihypertensives. Morning hypertension, nocturnal hypertension, and BP variability are important targets for antihypertensive therapy based on their association with target organ damage and cardiovascular events. Use of home and ambulatory BP monitoring techniques is needed to monitor these important hypertension phenotypes. Information and communication technology-based monitoring platforms and wearable devices are expected to facilitate better management of hypertension in Japan in the future.

背景:Brugada症候群における心室性不整脈イベントにおいて就寝中や食後などの副交感神経活性との関連性が示唆されている。しかしながら不整脈発生時の状況およびtriggerとなる生活要因に関して、いまだ不明な点も多い。われわれはBrugada症候群における不整脈イベントの発生状況を検討した。方法:当院で植込み型除細動器(ICD)植込み術を施行したBrugada症候群連続32例を対象にICD適切作動を認めた患者背景を検討した。心室性不整脈に対しての適切動作を起こした9例と作動のなかった23例を比較検討した。ICD植込み前を含め心室性不整脈のみられた11例においてイベント発生時の血清カリウム値の関連について検討した。結果:適切作動と習慣性飲酒の関連性について検討した結果、適切作動群において有意に習慣性飲酒を多く認めた(適切作動群89%vs非作動群35%、p=0.002)。適切作動イベントに関するKaplan-Meyer生存曲線では、習慣性飲酒のある群において有意に適切作動を認めていた(Log rank 8.06、p=0.0045)。またICD植込み時と比して心室性不整脈発生時には有意に血清カリウム値が低かった(血清K濃度4.4±0.2vs3.4±0.4mmol/L、p<0.0001)。結論:Brugada症候群における不整脈イベントと飲酒との関連性を認めた。低カリウム血症が不整脈イベントの一因であるかどうかは不明であるが、就寝前の高炭水化物食の摂取やアルコールの摂取が不整脈イベントに関係している可能性が示唆された。(著者抄録)

【目的】心血管リスクを持つ患者での圧受容体反射(baroreflex sensitivity:BRS)と低酸素イベント、経皮的動脈血酸素飽和度(SpO2)との関連を調べること。【方法】心血管リスク(高血圧、脂質異常症、糖尿病、喫煙)のうち1つ以上を持つ200名(男性52%、平均63±11歳)を対象とした。タスクフォースモニタ(CNSystems、日本光電)を用いて、5分間心電図と非侵襲的血圧測定を行い、BRSを測定した。また、パルスオキシメーターを用いて就寝中のSpO2を測定し、睡眠中の3%酸素飽和度低下指数(ODI)を測定した。【結果】BRSは3%ODIに逆相関していた(r=-0.20、p=0.005)。しかし、平均SpO2はBRSとは関連しなかった(r=0.10、p=0.19)。女性は男性よりBRSは低く(10.4±5.1 vs.12.9±11.0ms/mmHg、p=0.045)、糖尿病患者では非糖尿患者よりBRSは低かった(8.9±4.0 vs.12.1±8.6ms/mmHg、p=0.025)。年齢、性、糖尿病の有無を補正後も3%ODIはBRSと有意な負の相関を示した(β=-0.18、p=0.013)。【結語】夜間の低酸素イベントはBRSの低下と関連したが、平均のSpO2はBRSには関連しなかった。(著者抄録)

心不全においては心房細動、心室期外収縮、心室頻拍など、多くの不整脈が認められ、その不整脈が多いほど予後不良である。一方で、不整脈を減少させることの努力は必ずしも予後を改善するものではなく、心不全自体の管理が重要である。β遮断薬、レニン-アンジオテンシン系抑制薬、必要に応じて利尿薬投与といった標準的心不全治療を行い、不整脈管理のために必要な場合にはアミオダロンに代表されるIII群抗不整脈薬の使用、心房細動、心室頻拍などに対するカテーテルアブレーション、致死的転帰を回避するためのICD、心臓再同期を改善させるCRTなどの非薬物治療を含めた集学的な管理が求められる。(著者抄録)

症例は55歳，男性．繰り返す上室頻拍を認めたため，アブレーションを行った．プログラム刺激で，順行性伝導は2回のjump upを認めたことにより，三重伝導路と考えられた．心室刺激時の最早期心房興奮は冠静脈洞入口部からさらに遠位側で起こっており，冠静脈造影を施行したところ，最早期心房興奮部位は冠静脈内であることを確認した．イソプロテレノール負荷下の心房期外刺激では上室頻拍は誘発できなかったが，jump upの後に心室二重応答を伴った房室結節2エコーが出現した．房室結節エコー時と心室刺激時の最早期心房興奮は一致していた．通常のKoch三角下方の解剖学的遅伝導路を通電したが，jump upのみならず逆行性伝導も残存していた．CARTOシステムで心室刺激時の心房興奮をmappingしたところ，最早期心房興奮部位はやはり冠静脈内であることを確認した．CARTOでの逆行性最早期心房興奮を指標に，温度コントロール45℃，出力制限25Wで冠静脈内の天井を通電したところ，逆行性伝導は消失した．アブレーション後に冠静脈造影を施行したが，狭窄や穿孔などの合併症はなかった．