Chronic risk factors, such hypertension, diabetes mellitus, dyslipidemia, smoking, and inflammation as well as aging that develops vascular damages, contribute silent development of atherosclerotic cerebro-cardiovascular disease (AS-CCVD). Once vascular damage surpasses a critical threshold, acute risk factors such as BP surges, hemodynamic fluctuations, obstructive sleep apnea, mental or physical stress, environmental changes, and infections can precipitate AS-CCVD events. Even if the initial event is not fatal, patients rarely achieve full recovery and ultimately succumb to recurrent episodes of AS-CCVD. It is important to recognize that AS-CCVD is fundamentally a multi-vascular disease, necessitating its consideration as a multi-organ disorder with profound impacts on the brain, heart, kidneys, peripheral vasculature, and other organ systems. For instance, while the initial event may manifest as a myocardial infarction, the subsequent event could present as a stroke, vice versa. Accordingly, the prevention of AS-CCVD must extend beyond secondary prevention of the initial event to encompass the broader context of multi-vascular and multi-organ disease prevention. Notably, hypertension serves not only as a chronic risk factor but also as a direct trigger for events such as stroke, heart failure, and acute coronary syndrome/chronic coronary syndrome. Therefore, strict BP management over a 24-hour period throughout the year is essential [1].
The most frequent complication of hypertension in Japan and East Asia is stroke, unlike coronary artery disease (CAD) in the case of Western countries [2]. In Japan, the incidence of stroke is approximately three times higher than that of myocardial infarction, although the incidence of myocardial infarction has been increasing in recent years, especially in urban areas. A comprehensive meta-analysis of randomized control trials (RCTs) on antihypertensive treatment in patients with hypertension has demonstrated that a 10 mmHg reduction in systolic blood pressure (SBP) is associated with a 27% reduction in stroke risk and a 17% reduction in CAD risk [3]. This finding highlights that stroke prevention is more susceptible to BP reduction than CAD. In a meta-analysis of RCTs on antihypertensive treatment for CAD patients, lowering SBP blow 130 mmHg, compared to lowering to 136–140 mmHg, has shown to reduce heart failure by 30% and stroke by 20% without increasing all-cause or cardiovascular mortality, and reduced insignificantly myocardial infarction and angina by 10% each [4]. Furthermore, in a meta-analysis of RCTs of CAD patients having BP below 140/90 mmHg without hypertension, it has been demonstrated that antihypertensive drugs reduce stroke by 23%, myocardial infarction by 20%, heart failure by 29%, cardiovascular death by 17%, and all-cause mortality by 13% [5]. On the other hand, a systematic review/meta-analysis of RCTs on antihypertensive administration in CAD patients achieving SBP below 130 mmHg has shown that lowering DBP below 80 mmHg is associated with a 31% reduction in heart failure and suggests a trend towards reductions in all-cause death, myocardial infarction, angina pectoris, and stroke [6]. Taken together, the Japanese Society of Hypertension guidelines for the management of hypertension (JSH2019) recommend a BP target of less the 130/80 mmHg for patients with CAD [2]. Very recently, Oba et al. have reported in this volume of Hypertension Research that among Japanese CAD patients enrolled in the CLIDAS study, a BP below 130/80 mmHg at discharge is associated with a 17% reduction in major adverse cardiac and cerebral event (a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke) and a 31% reduction in stroke, compared to patients with BP greater than 130/80 mmHg [7]. This large-scale observational study has provided supportive evidence for the validity of the strict BP target of less than 130/80 mmHg for Japanese CAD patients, as proposed by JSH2019 guidelines. The safe lower limit of achieved BP remains to be clarified. Careful attention to reverse causality should be necessary as renal insufficiency, advanced vascular damage, and left ventricular systolic dysfunction have been identified as significant factors for increased cardiovascular or all-cause mortality in patients with low BP [8].
Finally, it is important to highlight that Oba et al. clearly demonstrated the significant role of strict BP control in preventing future strokes in patients with CAD [7]. This finding provides valuable insights for BP management in CAD patients, particularly among Japanese and East Asian populations, where stroke remains the most prevalent form of hypertensive organ damage.
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