Diastolic Blood Pressure Levels and Cardiovascular Risk in Elderly Women: The Need for a Personalized Approach

High blood pressure (BP) is a major risk factor for cardiovascular (CV) morbidity and mortality, therefore appropriate BP lowering treatment contributes to prevent major cardiovascular diseases (CVDs). Despite this, the lower thresholds of BP which should be attained without causing harm are still a matter of debate. The latest International guidelines recommend a goal to maintain BP levels around 130/80 mm Hg on antihypertensive therapy.1 The European Society of Hypertension/European Society of Cardiology guidelines issued in 2018 recommend BP targets not lower than 120/70 mm Hg.2 The reasons for this caution, especially for diastolic BP levels, originate from data showing that both very low and high BP levels are linked to adverse outcomes (the so-called “J-Curve”), suggesting that intensive BP reductions might even be counterproductive.3,4 This holds particularly true for elderly people in whom the safe targets for diastolic BP have not been clearly defined. Indeed, in the last 2 decades, several studies including the Hypertension Optimal Treatment (HOT)5 highlighted greater CV benefits with diastolic levels <80 mm Hg, especially in diabetic patients. Similarly, a recent participant data analysis by the The Blood Pressure Lowering Treatment Trialists’ Collaboration including individual data from 358,707 participants from 51 randomized clinical trials found that pharmacological BP reduction is effective across a wide range of ages for prevention of major CVD down to less than 120/70 mm Hg. Stratified effects on all-cause death followed a similar pattern, with no evidence to suggest that treatment increased deaths in any age group.6 On the other end, epidemiologic studies seem to suggest the clinical advantages associated with not exceeding in diastolic BP reduction for specific subgroups of elderlies. For instance, “frail” elderly subjects, such as those with previous cerebrovascular events would benefit from relatively higher BP levels to provide sufficient perfusion to the brain.7 Also for elderly patients with coronary heart disease (CHD) the pathophysiological importance of diastolic BP for coronary circulation has often generate cautious positions.3,4 A recent study pooling data from the SPRINT and ACCORD-BP trials reported that, among patients at high CV risk pharmacologically treated to achieve systolic BP of less than 130 mm Hg, individuals with a diastolic BP of less than 60 mm Hg showed an increased risk of CVD.8 Other studies did not confirm such results.9 Blurred issues are also represented by the threshold to target in patients not receiving antihypertensive therapy and by the diastolic BP thresholds in specific populations such as elderly women.10,11 The findings from the study by Haring et al.12 contribute to fill a gap in evidence for age and gender-specific diastolic BP levels effects on mortality and major CV outcomes. The authors investigated the rates of total mortality, CV mortality, and CVD in a study population consisting of 7,875 multiethnic women over 70 years old with an average follow-up time of 5.3 years. The authors found that death rates were higher at both low (≤60 mm Hg, 27.8%) and high levels (≥90 mm Hg, 25%) of diastolic BP compared with the 61 to 89 mm Hg range (17.6%). The higher mortality risk associated with low and high diastolic BP levels was also present in those aged 80 years or older. Women with a diastolic BP less than or equal to 60 mm Hg, compared with women with higher diastolic BP levels, were more likely to be white, have a prior history of stroke or CHD, have a lower systolic BP, were less frequent on antihypertensive medication and more likely to have a body mass index of less than 25 kg/m2. On the other hand, diastolic BP was not related to CV death in the analyses excluding those with diabetes or after excluding those with history of CHD or stroke. Finally, diastolic BP was not associated, either in linear or quadratic relationships, with CVD events in this population. These results seem to point out the importance of comorbidities and of the general status of the elderly patients, when considering diastolic BP targets. Indeed, in the study by Haring et al., elderly women with lower diastolic BP seem to be at higher risk of death, as proven by an increased overall mortality, but CV death is not increased in patients without diabetes or previous CHD. This suggests that elderly patients with lower levels of diastolic BP, due to many comorbidities, could be exposed to a higher risk of death. In addition, elderly patients could also tolerate poorly an intensive BP lowering strategy, being more susceptible to adverse effects of drug treatment. In this view, the “biologic” age of patients appears to be a very important aspect in the clinical evaluation of elderly patients, especially when considering the strength of the antihypertensive treatment and the diastolic BP to aim.13 This supports a more “personalized” approach for BP management in the elderly patients, particularly when they present a high CV risk profile and are more susceptible to develop CV events.14 Finally, another interesting point of the present study by Haring12 is the use of home BP measurements. Indeed, in this specific population the achievement of office BP could represent a hurdle and be challenging in the clinical practice, also due to the frequently compromised mobility of these patients. Future observational and interventional studies are needed to achieve sufficient information on home BP trends and to define home diastolic BP targets in the elderly also to minimize the risk of overtreatment. The authors declared no conflict of interest.