Which Target Blood Pressure in Year 2018? Evidence from Recent Clinical Trials

In emergency hypertension, could biomarkers change the guidelines?

BACKGROUND

Hypertension may cause target organ damage (TOD). Target blood pressure (BP) management may not be appropriate in some conditions.

AIM

We aim to assess the impact of targeted BP management in severe hypertension on renal TOD.

PATIENTS & METHODS

This is a prospective cohort study involving patients admitted due to severe hypertension (BP > 180/120) associated with any symptoms. The study involved patients referred to the ICU in our tertiary center during the period between August 2017 and February 2018. All patients underwent target BP treatment according to recent guidelines. Hs-Troponin T (hs-TNT) and serum creatinine (s.creat) were measured in all patients on admission and 24 h later. Patients were divided into Group A (with initial normal hs-TNT) and Group B (with initial high hs-TNT). The main outcome was in-hospital renal-related morbidity (including renal failure).

RESULTS

Four hundred seventy consecutive patients with hypertensive crises were involved in the study. Group B had a significantly higher incidence of in-hospital mortality (4 patients) and renal TOD (acute renal dysfunction) than Group A (P value = 0.001 and 0.000 respectively). There was a significant difference between initial s.creat on admission and follow-up s.creat values in Group B with significant elevation of their s.creat on the following 24 h (P = 0.002), while this difference is insignificant in Group A (P = 0.34). There was a significant positive correlation between hs-TNT and the follow-up s.creat (P = 0.004).

CONCLUSION

In severe HTN, hs-TNT may be elevated due to marked afterload. Patients with severe HTN and high hs-TNT have higher s.creat values, which are associated with an increased risk of renal failure and in-hospital mortality if their BP decreases acutely to the guideline-target BP. Using biomarkers during the management of emergency HTN should be considered before following clinical guidelines. However, our findings do underscore the potential utility of hs-TNT as an indicator for risk stratification in patients with severe or emergency HTN.

The apathy, gait impairment, and executive dysfunction (AGED) triad vascular variant

Apathy, gait disturbances, and executive dysfunction (AGED) often occur together. Although they can arise independently, the presence of one might portend another. This recognition suggests the possible etiology. We focus on the most common, the vascular. We explain the AGED vascular mechanism through the ambibaric brain concept. The brain contains two complementary blood pressure systems: One high in the primitive brain (brainstem, basal ganglia, and thalamus) and a low-pressure system in the Homo sapiens brain (cerebral hemispheres). Hypertension inflicts the most damage on the primitive brain. The frontal systems connect to the basal ganglia, then the thalamus and back to the cortex. Many connections converge on the primitive brain where they are damaged by vascular disease. We need methods of determining optimal, individual blood pressures. Although the AGED triad can result from other causes, it should first signal a vascular etiology, the most prevalent, treatable, and preventable one.

Cardiovascular outcomes at recommended blood pressure targets in middle-aged and elderly patients with type 2 diabetes mellitus compared to all middle-aged and elderly hypertensive study patients with high cardiovascular risk

PURPOSE

Event-based clinical outcome trials have shown limited evidence to support guidelines recommendations to lower blood pressure (BP) to <130/80 mmHg in middle-aged and elderly hypertensive patients with diabetes mellitus or with general high cardiovascular (CV) risk. We addressed this issue by post-hoc analysing the risk of CV events in patients who participated in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial and compared the hypertensive patients with type 2 diabetes mellitus with all high-risk hypertensive patients.

MATERIALS AND METHODS

Patients were divided into 4 groups according to the proportion of on-treatment visits before the occurrence of an event (<25% to ≥75%) in which BP was reduced to <140/90 or <130/80 mmHg. Patients with diabetes mellitus (n = 5250) were compared with the entire VALUE population with high CV risk (n = 15,245).

RESULTS

After adjustments for baseline differences between groups, a reduction in the proportion of visits in which BP was reduced to <140/90 mmHg, but not to <130/80 mmHg, was accompanied by a progressive increase in the risk of CV morbidity and mortality as well as stroke, myocardial infarction and heart failure in both diabetes mellitus and in all high-risk patients. Target BP <130/80 mmHg reduced stroke risk in the main population but not in the diabetes mellitus patients. Patients with diabetes mellitus had higher event rates for the primary cardiac endpoint and all-cause mortality driven by a higher rate of heart failure.

CONCLUSION

In the high-risk hypertensive patients of the VALUE trial achieving more frequently BP <140/90 mmHg, but not <130/80 mmHg, showed principally the same protective effect on overall and cause-specific cardiovascular outcomes in patients with diabetes mellitus and in the general high-risk hypertensive population.

Blood pressure targets in adults with hypertension

BACKGROUND

This is the first update of this review first published in 2009. When treating elevated blood pressure, doctors usually try to achieve a blood pressure target. That target is the blood pressure value below which the optimal clinical benefit is supposedly obtained. "The lower the better" approach that guided the treatment of elevated blood pressure for many years was challenged during the last decade due to lack of evidence from randomised trials supporting that strategy. For that reason, the standard blood pressure target in clinical practice during the last years has been less than 140/90 mm Hg for the general population of patients with elevated blood pressure. However, new trials published in recent years have reintroduced the idea of trying to achieve lower blood pressure targets. Therefore, it is important to know whether the benefits outweigh harms when attempting to achieve targets lower than the standard target.

OBJECTIVES

The primary objective was to determine if lower blood pressure targets (any target less than or equal to 135/85 mm Hg) are associated with reduction in mortality and morbidity as compared with standard blood pressure targets (less than or equal to 140/ 90 mm Hg) for the treatment of patients with chronic arterial hypertension. The secondary objectives were: to determine if there is a change in mean achieved systolic blood pressure (SBP) and diastolic blood pressure (DBP associated with "lower targets" as compared with "standard targets" in patients with chronic arterial hypertension; and to determine if there is a change in withdrawals due to adverse events with "lower targets" as compared with "standard targets", in patients with elevated blood pressure.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to May 2019: the Cochrane Hypertension Specialised Register, CENTRAL (2019, Issue 4), Ovid MEDLINE, Ovid Embase, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing patients allocated to lower or to standard blood pressure targets (see above).

DATA COLLECTION AND ANALYSIS

Two review authors (JAA, VL) independently assessed the included trials and extracted data. Primary outcomes were total mortality; total serious adverse events; myocardial infarction, stroke, congestive heart failure, end stage renal disease, and other serious adverse events. Secondary outcomes were achieved mean SBP and DBP, withdrawals due to adverse effects, and mean number of antihypertensive drugs used. We assessed the risk of bias of each trial using the Cochrane risk of bias tool and the certainty of the evidence using the GRADE approach.  MAIN RESULTS: This update includes 11 RCTs involving 38,688 participants with a mean follow-up of 3.7 years. This represents 7 new RCTs compared with the original version. At baseline the mean weighted age was 63.1 years and the mean weighted blood pressure was 155/91 mm Hg. Lower targets do not reduce total mortality (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.86 to 1.05; 11 trials, 38,688 participants; high-certainty evidence) and do not reduce total serious adverse events (RR 1.04, 95% CI 0.99 to 1.08; 6 trials, 18,165 participants; moderate-certainty evidence). This means that the benefits of lower targets do not outweigh the harms as compared to standard blood pressure targets. Lower targets may reduce myocardial infarction (RR 0.84, 95% CI 0.73 to 0.96; 6 trials, 18,938 participants, absolute risk reduction (ARR) 0.4%, number needed to treat to benefit (NNTB) 250 over 3.7 years) and congestive heart failure (RR 0.75, 95% CI 0.60 to 0.92; 5 trials, 15,859 participants, ARR 0.6%, NNTB  167 over 3.7 years) (low-certainty for both outcomes). Reduction in myocardial infarction and congestive heart failure was not reflected in total serious adverse events. This may be due to an increase in other serious adverse events (RR 1.44, 95% CI 1.32 to 1.59; 6 trials. 18,938 participants, absolute risk increase (ARI) 3%,  number needed to treat to harm (NNTH) 33 over four years) (low-certainty evidence). Participants assigned to a "lower" target received one additional antihypertensive medication and achieved a significantly lower mean SBP (122.8 mm Hg versus 135.0 mm Hg, and a lower mean DBP (82.0 mm Hg versus 85.2 mm Hg, than those assigned to "standard target".

AUTHORS' CONCLUSIONS

For the general population of persons with elevated blood pressure, the benefits of trying to achieve a lower blood pressure target rather than a standard target (≤ 140/90 mm Hg) do not outweigh the harms associated with that intervention. Further research is needed to see if some groups of patients would benefit or be harmed by lower targets. The results of this review are primarily applicable to older people with moderate to high cardiovascular risk. They may not be applicable to other populations.