Does the benefit from treating to lower blood pressure targets vary with age? A systematic review and meta-analysis

Impact of pre-procedural diastolic blood pressure on major adverse cardiovascular events in non ST-segment elevation myocardial infarction patients following revascularization

Previous reports have observed a consistent J-shaped relationship between cardiac events and diastolic blood pressure (DBP). However, the EPHESUS study clearly showed that myocardial reperfusion abolished the J-shaped association, suggesting a different association pattern after revascularization. Therefore, in this study, we investigated the different patterns in which DBP affects cardiovascular risk in non ST-segment elevation myocardial infarction (NSTEMI) patients after revascularization, which may benefit the risk stratification for NSTEMI patients. We obtained the NSTEMI database from the Dryad data repository and analyzed the association between preprocedural DBP and long-term major adverse cardiovascular events (MACEs) in 1486 patients with NSTEMI following percutaneous coronary intervention (PCI). Multivariate regression models were used to assess the impact of DBP on outcomes in an adjusted fashion according to DBP tertiles. The p value for the trend was calculated using linear regression. When examined as a continuous variable, a multivariate regression analysis was repeated. Pattern stability was verified by interaction and stratified analyses. The median (interquartile range) age of the patients was 61.00 (53.00-68.00) years, and 63.32% were male. Cardiac death showed a graded increase as the DBP tertile increased (p for trend = 0.0369). When examined as a continuous variable, a 1 mmHg increase in DBP level was associated with an 18% higher risk of long-term cardiac death (95% CI: 1.01-1.36, p = 0.0311) and a 2% higher risk of long-term all-cause death (95% CI: 1.01-1.04; p = 0.0178). The association pattern remained stable when stratified by sex, age, diabetes, hypertension, and smoking status. An association between low DBP and higher cardiovascular risk was not observed in our study. We showed that higher preprocedural DBP increased the risk of long-term cardiac death and all-cause death in patients with NSTEMI following PCI.

Systolic Blood Pressure and Mortality in Community-Dwelling Older Adults: The Role of Frailty

OBJECTIVES

To investigate whether frailty modifies the association of systolic blood pressure (SBP) with cardiovascular mortality and all-cause mortality in community-dwelling older adults.

DESIGN

A prospective cohort study.

SETTING

A population-based study of nationally representative older Chinese adults in a community setting.

PARTICIPANTS

This study included participants aged 65 years or older from the Chinese Longitudinal Healthy Longevity Survey 2002-2014 and followed up to 2018.

MEASUREMENTS

Participants were divided into two groups according to a frailty index based on the accumulation of a 44-items deficits model. The association between SBP and mortality was analyzed using multivariable-adjusted Cox proportional hazards models.

RESULTS

Among 18,503 participants included, the mean age was 87.2 years and the overall median follow-up time was 42.7 months. We identified 7808 (42.2%) frail participants (mean frailty index=0.33), in which 7533 (96.5%) died during the follow-up. Effect modification by frailty was detected (P for interaction=0.032). Among frail participants, a U-shaped association was found with hazard ratios of 1.16 (95% CI, 1.02-1.32) for SBP < 100 mmHg, and 1.11 (95% CI, 1.00-1.24) for SBP ≥ 150 mmHg compared with SBP 120-130 mmHg. For non-frail older adults, a tendency toward higher risk among those with SBP ≥ 130 mmHg was observed. The analyses towards cardiovascular mortality showed similar results.

CONCLUSION

Our results suggest the presence of effect modification by frailty indicating a possible negative effect for elevated SBP in non-frail older adults and a U-shaped relationship of SBP in frail older adults with respect to mortality even after adjusting for diastolic blood pressure.

Effect of Intensive Blood Pressure Lowering on Cardiovascular Outcomes: A Systematic Review Prepared for the 2020 U.S. Department of Veterans Affairs/U.S. Department of Defense Guidelines

BACKGROUND

Recent clinical trials suggest that treating patients with hypertension to lower blood pressure (BP) targets improves cardiovascular outcomes.

PURPOSE

To summarize the effects of intensive (or targeted) systolic BP (SBP) and diastolic BP (DBP) lowering with pharmacologic treatment on cardiovascular outcomes and harms in adults with hypertension.

DATA SOURCES

Multiple databases, including MEDLINE and EMBASE, were searched for relevant systematic reviews (SRs) published in English from 15 December 2013 through 25 March 2019, with updated targeted searches through 8 January 2020.

STUDY SELECTION

8 SRs of randomized controlled trials examining either a standardized SBP target of -10 mm Hg (1 SR) or BP lowering below a target threshold (7 SRs).

DATA EXTRACTION

One investigator abstracted data, assessed study quality, and performed GRADE assessments; a second investigator checked abstractions and assessments.

DATA SYNTHESIS

The main outcome of interest was reduction in composite cardiovascular outcomes. High-strength evidence showed benefit of a 10-mm Hg reduction in SBP for cardiovascular outcomes among patients with hypertension in the general population, patients with chronic kidney disease, and patients with heart failure. Evidence on reducing SBP for cardiovascular outcomes in patients with a history of cardiovascular disease (moderate strength) or diabetes mellitus (high strength) to a lower SBP target was mixed. Low-strength evidence supported intensive lowering to a 10-mm Hg reduction in SBP for cardiovascular outcomes in patients with a history of stroke. All reported harms were considered, including general adverse events, serious adverse events, cognitive impairment, fractures, falls, syncope, hypotension, withdrawals due to adverse events, and acute kidney injury. Safety results were mixed or inconclusive.

LIMITATIONS

This was a qualitative synthesis of new evidence with existing meta-analyses. Data were sparse for outcomes related to treating DBP to a lower target or for patients older than 60 years.

CONCLUSION

Overall, current clinical literature supports intensive BP lowering in patients with hypertension for improving cardiovascular outcomes. In most subpopulations, intensive lowering was favored over less-intensive lowering, but the data were less clear for patients with diabetes mellitus or cardiovascular disease.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs, Veterans Health Administration.

Age-Specific Associations Between Systolic Blood Pressure and Cardiovascular Disease: A 10-Year Diabetes Mellitus Cohort Study

Background The relationship between systolic blood pressure (SBP) and cardiovascular disease (CVD) among patients with diabetes mellitus remains unclear. The study aimed to explore age-specific associations between SBP and CVD. Methods and Results A population-based retrospective cohort study was conducted on 180 492 Chinese adults with type 2 diabetes mellitus in 2008-2010, with follow-up to 2017. Age-specific associations (<50, 50-59, 60-69, and 70-79 years) between the average SBP in the previous 2 years and CVD risk were assessed by adjusted Cox proportional hazards regression with age-specific regression dilution ratios and patient characteristics stratified by subgroups. During a median follow-up of 9.3 years (1.5 million person-years), 32 545 patients developed a CVD, with an incidence rate of 23.4 per 1000 person-years. A positive and log-linear association between SBP and CVD risk was observed among the 4 age groups without evidence of a threshold down to 120 mm Hg, but the magnitude of SBP effect on CVD attenuated with increased age. The CVD risk in the age group <50 years was ≈22% higher than the age group 70 to 79 years (hazard ratio [HR], 1.33 [95% CI, 1.26-1.41] versus HR, 1.09 [95% CI, 1.07-1.11]). Each 10-mm Hg higher SBP was associated with 12% (HR, 1.12 [95% CI, 1.10-1.13]), 11% (HR, 1.11 [95% CI, 1.10-1.13]), and 20% (HR, 1.20 [95% CI, 1.17-1.22]) higher risk of all composite CVD events, individual CVD, and CVD mortality, respectively. Conclusions There is a significant log-linear relationship between baseline SBP and the risk of CVD among patients with diabetes mellitus in China. The risk increases from an SBP of 120 mm Hg onward. Age influences this relationship significantly, with younger patients (<50 years) having a greater risk of CVD for a similar rise in SBP as compared with those who are older. These findings suggest that differential target blood pressures stratified by age maybe useful.

Myocardial reperfusion reverses the J-curve association of cardiovascular risk and diastolic blood pressure in patients with left ventricular dysfunction and heart failure after myocardial infarction: insights from the EPHESUS trial

Aims

The described association of low diastolic blood pressure (DBP) with increased cardiovascular outcomes could be due to reduced coronary perfusion or is simply due to reverse causation. If DBP is physiologically relevant, coronary reperfusion after myocardial infarction (MI) might influence DBP–risk association.

Methods and results

The relation of achieved DBP with cardiovascular death or cardiovascular hospitalization, cardiovascular death, and all-cause death was explored in 5929 patients after acute myocardial infarction (AMI) with impaired left ventricular function, signs and symptoms of heart failure, or diabetes in the EPHESUS trial according to their reperfusion status. Cox regression models were used to assess the impact of reperfusion status on the association of DBP and systolic blood pressure (SBP) with outcomes in an adjusted fashion. In patients without reperfusion, lower DBP &lt;70 mmHg was associated with increased risk for all-cause death [adjusted hazard ratios (HRs) 1.80, 95% confidence interval (CI) 1.41–2.30; P &lt; 0.001], cardiovascular death (HR 1.70, 95% CI 1.3–3.22; P &lt; 0.001), cardiovascular death or cardiovascular hospitalization (HR 1.54, 95% CI 1.26–1.87; P &lt; 0.001). In patients with reperfusion, the risk increase at low DBP was not observed. At low SBP, risk increased independently of reperfusion. A sensitivity analysis in the subgroup of patients with optimal SBP of 120–130 mmHg showed again risk reduction of reperfusion at low DBP. Adding the treatment allocation to eplerenone or placebo into the models had no effects on the results.

Conclusion

Patients after AMIs with a low DBP had an increased risk, which was sensitive to reperfusion therapy. Low blood pressure after MI identifies in patients with particular higher risk. These data support the hypothesis that low DBP in patients with stenotic coronary lesions is associated with risk, potentially involving coronary perfusion pressure and the recommendations provided by guidelines suggesting lower DBP boundaries for these high-risk patients.

Unsolved Problem: (Isolated) Systolic Hypertension with Diastolic Blood Pressure below the Safety Margin

The problem of high systolic blood pressure (sBP) combined with low diastolic blood pressure (dBP) requires attention because sBP is directly and continuously related to the most important criterion, i.e., all-cause mortality, whereas dBP becomes inversely related to it after the age of 50-60 years. The European Society of Cardiology and European Society of -Hypertension (ESC/ESH) 2018 guidelines for hypertension (HTN) are helpful because they recommend a lower safety cut-off for in-treatment dBP. To prevent tissue hypoperfusion, these guidelines recommend that dBP should be ≥70 mm Hg during treatment. A patient with very elevated sBP (e.g., 220 mm Hg) and low dBP (e.g., 65 mm Hg) is difficult to treat if one strictly follows the guidelines. In this situation, the sBP is a clear indication for antihypertensive treatment, but the dBP is a relative contraindication (as it is <70 mm Hg, a safety margin recognized by the 2018 ESC/ESH guidelines). The dilemma about whether or not to treat isolated systolic hypertension (SH) patients with low dBP (<70 mm Hg) is evident from the fact that almost half (45%) remain untreated. This is a common occurrence and identifying this problem is the first step to solving it. We suggest that an adequate search and analysis should be performed, starting from the exploration of the prognosis of the isolated (I)SH subset of patients with a very low dBP (<70 mm Hg) at the beginning of already performed randomized clinical trials.