Association Between Baseline Diastolic Blood Pressure and the Efficacy of Intensive vs Standard Blood Pressure-Lowering Therapy

Impact of the PATH Statement on Analysis and Reporting of Heterogeneity of Treatment Effect in Clinical Trials: A Scoping Review

Background

The Predictive Approaches to Treatment Effect Heterogeneity (PATH) Statement provides guidance for using predictive modeling to identify differences (i.e., heterogeneity) in treatment effects (benefits and harms) among participants in randomized clinical trials (RCTs). It distinguished risk modeling, which uses a multivariable model to predict risk of trial outcome(s) and then examines treatment effects within strata of predicted risk, from effect modeling, which predicts trial outcomes using models that include treatment, individual participant characteristics and interactions of treatment with selected characteristics.

Purpose

To describe studies of heterogeneous treatment effects (HTE) that use predictive modeling in RCT data and cite the PATH Statement.

Data Sources

The Cited By functions in PubMed, Google Scholar, Web of Science and SCOPUS databases (Jan 7, 2020 - June 5, 2023).

Study Selection

42 reports presenting 45 predictive models.

Data Extraction

Double review with adjudication to identify risk and effect modeling and examine consistency with Statement consensus statements. Credibility of HTE findings was assessed using criteria adapted from the Instrument to assess Credibility of Effect Modification Analyses (ICEMAN). Clinical importance of credible HTE findings was also assessed.

Data Synthesis

The numbers of reports, especially risk modeling reports, increased year-on-year. Consistency with consensus statements was high, except for two: only 15 of 32 studies with positive overall findings included a risk model; and most effect models explored many candidate covariates with little prior evidence for effect modification. Risk modeling was more likely than effect modeling to identify both credible HTE (14/19 vs 5/26) and clinically important HTE (10/19 vs 4/26).

Limitations

Risk of reviewer bias: reviewers assessing credibility and clinical importance were not blinded to adherence to PATH recommendations.

Conclusions

The PATH Statement appears to be influencing research practice. Risk modeling often uncovered clinically important HTE; effect modeling was more often exploratory.

Intensive Blood Pressure Lowering in Individuals With Low Diastolic Blood Pressure and Elevated Troponin Levels in SPRINT

BACKGROUND

Among individuals with hypertension and low diastolic blood pressure (DBP), the optimal BP target remains controversial due to concerns that BP lowering may reduce coronary perfusion. We determined the impact of intensive BP control among individuals with elevated systolic BP who have low DBP and elevated hs-cTnT (high-sensitivity cardiac troponin T) levels.

METHODS AND RESULTS

A total of 8828 participants in SPRINT (Systolic Blood Pressure Intervention Trial) were stratified by baseline DBP. Those with low DBP (<70 mm Hg) were further stratified by elevated hs-cTnT (≥14 ng/L) at baseline. The effects of intensive versus standard BP lowering on a cardiovascular disease composite end point, all-cause death, and 1-year change in hs-cTnT were determined. The combination of low DBP/high hs-cTnT was independently associated with a higher risk for cardiovascular disease and all-cause death, as well as greater 1-year increases in hs-cTnT, compared with DBP ≥70 mm Hg. However, randomization to intensive versus standard BP lowering led to similar reductions in cardiovascular disease risk among individuals with low DBP/high hs-cTnT (hazard ratio [HR], 0.82 [95% CI, 0.57-1.19]), low DBP/low hs-cTnT (HR, 0.48 [95% CI, 0.29-0.79]), and DBP ≥70 mm Hg (HR, 0.73 [95% CI, 0.60-0.89]; P for interaction=0.20). Intensive BP lowering also led to a reduction in all-cause death that was similar across groups (P for interaction=0.57).

CONCLUSIONS

In this nonprespecified subgroup analysis of SPRINT, individuals with low DBP and elevated hs-cTnT, low DBP and nonelevated hs-cTnT, and DBP ≥70 mm Hg derived similar cardiovascular disease and mortality benefits from intensive BP lowering. These findings warrant confirmation in other studies.

Association of low diastolic blood pressure with cardiovascular outcomes and all-cause mortality: A meta-analysis

BACKGROUND

Reduction of diastolic blood pressure (DBP) below 70 mmHg may decrease perfusion to the heart and worsen cardiovascular (CV) outcomes.

AIMS

Explore the association between low DBP and CV outcomes.

METHODS

We searched the online databases until August 2023 for studies reporting the risk of all-cause mortality (ACM) or CV outcomes in patients with low versus normal DBP (70-80mm Hg).

RESULTS

Inclusion of 10 studies (n = 1,998,223 patients) found that a mean achieved DBP < 60 mmHg was associated with an increased risk of all-cause mortality (HR 1.48; 95 % CI [1.26-1.74]), especially in patients with pre-existing CV disease. It was also associated to a higher risk of major adverse cardiovascular events (HR 1.84; [1.28-2.65]) and myocardial infarction (HR 1.49; [1.13-1.97]). A DBP of 60-69 mmHg was associated with an increased risk of all-cause mortality (HR 1.11; [1.03-1.20]).

CONCLUSION

Reduction of DBP, particularly below 60 mmHg, is associated with increased risk of ACM.

Cardiovascular Disease in Diabetes and Chronic Kidney Disease

Chronic kidney disease (CKD) is a common occurrence in patients with diabetes mellitus (DM), occurring in approximately 40% of cases. DM is also an important risk factor for cardiovascular disease (CVD), but CKD is an important mediator of this risk. Multiple CVD outcomes trials have revealed a greater risk for CVD events in patients with diabetes with CKD versus those without. Thus, reducing the risk of CKD in diabetes should result in improved CVD outcomes. To date, of blood pressure (BP) control, glycemic control, and inhibition of the renin-angiotensin system (RASI), glycemic control appears to have the best evidence for preventing CKD development. In established CKD, especially with albuminuria, RASI slows the progression of CKD. More recently, sodium glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide receptor agonists (GLP1RA) have revolutionized the care of patients with diabetes with and without CKD. SGLT2i and GLP1RA have proven to reduce mortality, heart failure (HF) hospitalizations, and worsening CKD in patients with diabetes with and without existing CKD. The future of limiting CVD in diabetes and CKD is promising, and more evidence is forthcoming regarding combinations of evidence-based therapies to further minimize CVD events.

Prevalence, awareness, and treatment of isolated diastolic hypertension in the United States

BACKGROUND

Isolated diastolic hypertension (IDH) is recognized as a risk factor for cardiovascular disease, yet its clinical epidemiology remains poorly understood due to insufficient recognition. This study aims to describe the trend in the prevalence, awareness, and treatment of IDH in the United States from 2001 to 2018.

METHODS

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted in nine consecutive two-year cycles from 2001-2002 to 2017-2018, comprising a sample of 48,742 adults aged over 18 years. IDH was defined as a diastolic blood pressure ≥ 80 mm Hg with a systolic BP < 130 mm Hg by the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines.

RESULTS

In the nationally representative dataset, 8.9% of participants had IDH in 2017-2018, a decreased of 3.6% (95% confidence interval [CI], -2.6% to -5.0%, P<0.0002) since 2001-2002. IDH prevalence was highest among Mexican American (10.5%), individuals aged 40-59 (12.3%), increased with body mass index (BMI) (11.2% among those BMI ≥30.0 kg/m2), and tended to be higher in men (12.3%). A multiple regression analysis showed that men, white race/ethnicity, young and middle-aged people (aged 18-59), and increasing BMI were independently associated with increased risks of IDH. Among IDH patients, there was a modest increase in awareness (P<0.0002), from 22.4% (95%CI, 18.4% to 27.1%) in 2001-2002 to 35.0% (95%CI, 28.2% to 42.5%) in 2017-2018, with the largest percentage increases among non-Hispanic white and men. IDH treatment increased by 7.6% (95%CI, 3.1% to 12.1%) between 2001-2002 and 2017-2018, with the greatest increases occurring in Mexican American and men.

CONCLUSION

IDH prevalence is decreasing from 2001-2002 to 2017-2018 in the United States. Despite the significantly increased in both awareness and treatment, they remain below 50%.

Diastolic Blood Pressure and Intensive Blood Pressure Control on Cognitive Outcomes: Insights From the SPRINT MIND Trial

BACKGROUND

The potential benefits or harms of intensive systolic blood pressure (BP) control on cognitive function and cerebral blood flow in individuals with low diastolic blood pressure (DBP) remain unclear.

METHODS

We conducted a post hoc analysis of the SPRINT MIND (Systolic Blood Pressure Intervention Trial Memory and Cognition in Decreased Hypertension) that randomly assigned hypertensive participants to an intensive (<120 mm Hg; n=4278) or standard (<140 mm Hg; n=4385) systolic blood pressure target. We evaluated the effects of BP intervention on cognitive outcomes and cerebral blood flow across baseline DBP quartiles.

RESULTS

Participants in the intensive group had a lower incidence rate of probable dementia or mild cognitive impairment than those in the standard group, regardless of DBP quartiles. The hazard ratio of intensive versus standard target for probable dementia or mild cognitive impairment was 0.91 (95% CI, 0.73-1.12) in the lowest DBP quartile and 0.70 (95% CI, 0.48-1.02) in the highest DBP quartile, respectively, with an interaction P value of 0.24. Similar results were found for probable dementia (interaction P=0.06) and mild cognitive impairment (interaction P=0.80). The effect of intensive treatment on cerebral blood flow was not modified by baseline DBP either (interaction P=0.25). Even among participants within the lowest DBP quartile, intensive versus standard BP treatment resulted in an increasing trend of annualized change in cerebral blood flow (+0.26 [95% CI, -0.72 to 1.24] mL/[100 g·min]).

CONCLUSIONS

Intensive BP control did not appear to have a detrimental effect on cognitive outcomes and cerebral perfusion in patients with low baseline DBP.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01206062.

Isolated Diastolic Hypertension and Risk of Cardiovascular Disease: Controversies in Hypertension - Pro Side of the Argument

Isolated diastolic hypertension (IDH), defined as diastolic blood pressure in the hypertensive range but systolic blood pressure not in the hypertensive range, is not uncommon (<20%) among adults with hypertension. IDH often manifests in concurrence with other cardiovascular risk factors. Individuals with IDH tend to have lower awareness of their hypertension compared with those with both systolic and diastolic hypertension. IDH appears to be a largely underrated risk factor for cardiovascular disease events, which may be explained by inconsistent association of IDH with cardiovascular disease events. The inconsistency suggests that IDH is heterogeneous. One size does not seem to fit all in the clinical management of individuals with IDH. Rather than treating IDH as a monolithic low-risk condition, detailed phenotyping in the context of individual comprehensive cardiovascular risk would seem to be most useful to assess an individual's expected net benefit from therapy. In this review, we highlight that the clinical relevance of IDH differs by individual clinical characteristics, and elucidate groups of individuals with IDH that should be wary of cardiovascular disease risks.

The diastolic blood pressure J-curve revisited: An update

Hypertension remains a leading cause of morbidity and mortality. Recent treatment guidelines stress more strict systolic blood pressure (SBP) targets without regard for abnormally low achieved diastolic blood pressures (DBP). However, as DBP falls below a critical level, adverse events increase, the so-called J-shaped curve. Proponents argue that the low DBP is causative due to reduced coronary perfusion during diastole with obstructive coronary artery disease (CAD), whereas others postulate the J-curve represents reverse causality from underlying comorbidity. Most data are observational, derived from population-based cohorts or post-hoc analyses of randomized controlled trials (RCT) conducted for other reasons. The purpose of this review is to analyze the observational studies performed over the last decade addressing the J-curve, with consideration of earlier data. Overall, a J-curve exists, but it remains uncertain whether low DBP is causative or instead reflects reverse causation from either diseased vasculature (widened pulse pressure) or severe underlying comorbidity. The most convincing data for causation come from studies restricted to patients with documented CAD, with evidence suggesting revascularization may mitigate risk. RCTs are needed to determine if a low DBP should preclude intensification of therapy, especially with documented CAD. Firm recommendations cannot be made with contemporary data.