Isolated diastolic hypertension as defined by the 2017 American College of Cardiology/American Heart Association blood pressure guideline and incident cardiovascular events in Chinese

Isolated diastolic hypertension and cardiovascular outcomes across different diagnostic guidelines: a systematic review and meta-analysis

BACKGROUND

This systematic review aims to determine the impact of isolated diastolic hypertension (IDH) on cardiovascular outcomes.

METHODS

We searched only English language articles on PubMed and SCOPUS until July 31, 2023 to investigate the association between IDH and cardiovascular outcomes.

RESULTS

This meta-analysis of 19 studies evaluated the impact of different hypertension diagnostic guidelines (ACC/AHA: American Heart Association/American College of Cardiology; JNC7: Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; NICE/ESC: National Institute for Health and Care Excellence/European Society of Cardiology) on hypertension-related outcomes. Studies had varying sample sizes (173 to 2,969,679 participants) and study designs. In cohort studies using JNC7 guidelines, IDH was linked to increased cardiovascular disease (CVD) risk (HR: 1.45, 95% CI 1.17, 1.74), CVD mortality (HR: 1.54, 95% CI 1.23, 1.84), and coronary heart disease (CHD) risk (HR: 1.65). In studies using ACC/AHA guidelines, associations with CVD risk and CVD mortality were weaker [HR: 1.16 (95% CI 1.06, 1.25) and 1.10 (95% CI 0.95, 1.25), respectively]. Subgroup analysis revealed differences in outcomes on the basis of age and sex. Cross-sectional studies did not show significant associations with JNC7 and ACC guidelines; NICE guidelines were not used in cross-sectional studies.

CONCLUSION

IDH is associated with an increased risk of CVD. Higher diastolic blood pressure cutoffs were associated with higher cardiovascular risk. This association varied by study design and effect modification by sex and race influenced the association.

Cardiovascular Risk in Patients With Treated Isolated Diastolic Hypertension and Isolated Low Diastolic Blood Pressure

BACKGROUND

The prognosis of high or markedly low diastolic blood pressure (DBP) with normalized on-treatment systolic blood pressure on major adverse cardiovascular events (MACEs) is uncertain. This study examined whether treated isolated diastolic hypertension (IDH) and treated isolated low DBP (ILDBP) were associated with MACEs in patients with hypertension.

METHODS AND RESULTS

A total of 7582 patients with on-treatment systolic blood pressure <130 mm Hg from SPRINT (Systolic Blood Pressure Intervention Trial) were categorized on the basis of average DBP: <60 mm Hg (n=1031; treated ILDBP), 60 to 79 mm Hg (n=5432), ≥80 mm Hg (n=1119; treated IDH). MACE risk was estimated using Cox proportional-hazards models. Among the SPRINT participants, median age was 67.0 years and 64.9% were men. Over a median follow-up of 3.4 years, 512 patients developed a MACE. The incidence of MACEs was 3.9 cases per 100 person-years for treated ILDBP, 1.9 cases for DBP 60 to 79 mm Hg, and 1.8 cases for treated IDH. Comparing with DBP 60 to 79 mm Hg, treated ILDBP was associated with an 1.32-fold MACE risk (hazard ratio [HR], 1.32, 95% CI, 1.05-1.66), whereas treated IDH was not (HR, 1.18 [95% CI, 0.87-1.59]). There was no effect modification by age, sex, atherosclerotic cardiovascular disease risk, or cardiovascular disease history (all P values for interaction >0.05).

CONCLUSIONS

In this secondary analysis of SPRINT, among treated patients with normalized systolic blood pressure, excessively low DBP was associated with an increased MACE risk, while treated IDH was not. Further research is required for treated ILDBP management.

Cumulative Diastolic Blood Pressure Burden in Normal Systolic Blood Pressure and Cardiovascular Disease

BACKGROUND

The clinical significance of isolated diastolic hypertension defined by the 2017 American College of Cardiology/American Heart Association blood pressure (BP) guidelines remains inconsistent. We examined whether long-term diastolic burden predicts the first major adverse cardiovascular event in participants with sustained and untreated normal systolic BP.

METHODS

The Mass General Brigham Biobank is a New England health care-based cohort recruited between 2010 and 2021. A total of 15 979 participants aged 18 to 64 years and without prior cardiovascular disease, antihypertensives, or high systolic BP were studied. The cumulative diastolic burden was determined as the area under the curve for diastolic BP (DBP) ≥80 mm Hg over 5 years before enrollment. Major adverse cardiovascular event was defined as a composite of first incident ischemic heart disease, stroke, heart failure, or all-cause death.

RESULTS

Of the 15 979 participants, mean (SD) age at enrollment was 47.6 (14.3) years, 11 950 (74.8%) were women, and the mean (SD) systolic BP and DBP were 118.0 (12.9) and 72.2 (9.3) mm Hg, respectively. Over a median (interquartile range) follow-up of 3.5 (1.8-5.4) years, 2467 (15.4%) major adverse cardiovascular events occurred. Using Cox proportional hazards regression, each SD increase in cumulative DBP was independently associated with a hazard ratio (95% CI) of 1.06 (1.02-1.10) without effect modification by sex (P=0.65), age (P=0.46), or race/ethnicity (P=0.24). In addition to traditional risk factors, cumulative DBP modestly improved the discrimination C index (95% CI) from 0.74 (0.72-0.75) to 0.75 (0.74-0.76; likelihood ratio test, P=0.037).

CONCLUSIONS

Among individuals with normal systolic BP, cumulative DBP may augment cardiovascular disease risk stratification beyond a single DBP measure and traditional risk factors.

Isolated Diastolic Hypertension and Kidney and Cardiovascular Outcomes in CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study

Rationale & Objective

The clinical significance of isolated diastolic hypertension in patients with chronic kidney disease (CKD) is unclear. We assessed the prevalence of isolated diastolic hypertension and its association with adverse kidney and cardiovascular outcomes in participants in the Chronic Renal Insufficiency Cohort (CRIC) study.

Study Design

Prospective cohort study.

Setting & Population

CRIC study participants with complete baseline data on systolic blood pressure (SBP) and diastolic BP (DBP) (N=5,621).

Exposure

Isolated diastolic hypertension defined as SBP ≤ 130 mm Hg and DBP >80 mm Hg.

Reference Group

Normotension, defined as SBP ≤ 130 mm Hg and DBP ≤ 80 mm Hg.

Outcomes

Composite kidney events (50% decline in estimated glomerular filtration rate or onset of kidney failure), composite cardiovascular events (myocardial infarction, heart failure, stroke, or peripheral arterial disease), and all-cause mortality.

Analytical Approach

Cox proportional hazards models adjusted for demographic, health behavior, and clinical covariates.

Results

Of the 5,621 participants, 347 (6.2%) had isolated diastolic hypertension. Among the 347 participants with isolated diastolic hypertension, there was no association between isolated diastolic hypertension and the composite kidney outcome (HR, 1.17; 95% CI, 0.93-1.47; P = 0.18), composite cardiovascular events (HR, 0.91; 95% CI, 0.65-1.27; P = 0.58), or all-cause mortality (HR, 0.82; 95% CI, 0.57-1.19; P = 0.30).

Limitations

Older age of cohort and low number of participants of Asian ethnicity limit generalizability of findings. A relatively small sample size is inadequate to detect modest associations with outcomes.

Conclusions

Isolated diastolic hypertension was not associated with the risk of adverse kidney and cardiovascular events in participants with CKD.

Plain Language Summary

Clinicians frequently encounter patients with kidney disease who have controlled systolic blood pressure (BP) but high diastolic BP and do not know whether they should intensify BP treatment in an attempt to control the diastolic BP. We examined whether having controlled systolic BP but uncontrolled diastolic BP leads to worse heart and kidney outcomes in patients with chronic kidney disease. We did not find any such association. However, our study was relatively small and had a number of limitations. Till larger studies confirm or refute this finding, we recommend not increasing blood pressure medications to improve the diastolic BP control if the systolic BP is already well controlled in patients with chronic kidney disease.

Hypertension in China: epidemiology and treatment initiatives

The past two to three decades have seen a steady increase in the prevalence of hypertension in China, largely owing to increased life expectancy and lifestyle changes (particularly among individuals aged 35-44 years). Data from the China hypertension survey conducted in 2012-2015 revealed a high prevalence of grade 3 hypertension (systolic blood pressure ≥180 mmHg and diastolic blood pressure ≥110 mmHg) in the general population, which increased with age to up to 5% among individuals aged ≥65 years. The risk profile of patients with hypertension in China has also been a subject of intense study in the past 30 years. Dietary sodium and potassium intake have remained largely the same in China in the past three decades, and salt substitution strategies seem to be effective in reducing blood pressure levels and the risk of cardiovascular events and death. However, the number of individuals with risk factors for hypertension and cardiovascular disease in general, such as physical inactivity and obesity, has increased dramatically in the same period. Moreover, even in patients diagnosed with hypertension, their disease is often poorly managed owing to a lack of patient education and poor treatment compliance. In this Review, we summarize the latest epidemiological data on hypertension in China, discuss the risk factors for hypertension that are specific to this population, and describe several ongoing nationwide hypertension control initiatives that target these risk factors, especially in the low-resource rural setting.

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%.

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.

Hypertension Subtypes, Mortality Risk, and Differential Effects Between Two Hypertension Guidelines

Aim:

To examine which hypertension subtypes are primarily responsible for the difference in the hypertension prevalence and treatment recommendations, and to assess their mortality risk if 2017 American College of Cardiology (ACC)/American Heart Association (AHA) hypertension guideline were adopted among Chinese adults.

Methods

We used the nationally representative data of China Health and Retirement Longitudinal Study (CHARLS) to estimate the differences in the prevalence of isolated systolic hypertension (ISH), systolic diastolic hypertension (SDH) and isolated diastolic hypertension (IDH) between the 2017 ACC/AHA and the 2018 China Hypertension League (CHL) guidelines. We further assessed their mortality risk using follow-up data from the China Health and Nutrition Survey (CHNS) by the Cox model.

Results

The increase from the 2017 ACC/AHA guideline on hypertension prevalence was mostly from SDH (8.64% by CHL to 25.59% by ACC/AHA), followed by IDH (2.42 to 6.93%). However, the difference was minuscule in the proportion of people recommended for antihypertensive treatment among people with IDH (2.42 to 3.34%) or ISH (12.00 to 12.73%). Among 22,184 participants with a median follow-up of 6.14 years from CHNS, attenuated but significant associations were observed between all-cause mortality and SDH (hazard ratio 1.56; 95% CI: 1.36,1.79) and ISH (1.29; 1.03,1.61) by ACC/AHA but null association for IDH (1.15; 0.98,1.35).

Conclusion

Adoption of the 2017 ACC/AHA may be applicable to improve the unacceptable hypertension control rate among Chinese adults but with cautions for the drug therapy among millions of subjects with IDH.

Isolated Diastolic Hypertension and Risk of Cardiovascular Events: A Systematic Review and Meta-Analysis of Cohort Studies With 489,814 Participants

Background: The association between isolated diastolic hypertension (IDH) and cardiovascular events has been inconsistently reported. This meta-analysis of cohort studies was designed to investigate the effect of the 2018 European Society of Cardiology (ESC) definition of IDH on the risk of composite cardiovascular events, cardiovascular mortality, all-cause mortality, and all strokes including ischemic stroke (IS) and hemorrhagic stroke (HS). Methods: PubMed, Embase, the Cochrane Library, and Web of Science were searched from inception to July 6, 2021. Cohort studies that investigated the association between IDH and cardiovascular events risk, compared to normotension, were included. Pooled hazard ratios (HRs) and 95% CIs were calculated using a random-effects models and heterogeneity was evaluated using Q-test and I ² statistic. The robustness of the associations was identified using sensitivity analysis. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale. Publication bias was assessed using funnel plot, trim-and-fill method, Begg's test, and Egger's test. Results: A total of 15 cohort studies (13 articles) including 489,814 participants were included in this meta-analysis. The follow-up period ranged from 4.3 to 29 years. IDH was significantly associated with an increased risk of composite cardiovascular events (HR 1.28, 95% CI: 1.07-1.52, p = 0.006), cardiovascular mortality (HR 1.45, 95% CI: 1.07-1.95, p = 0.015), all strokes (HR 1.44, 95% CI: 1.04-2.01, p = 0.03), and HS (HR 1.64, 95% CI: 1.18-2.29, p = 0.164), but not associated with all-cause mortality (HR 1.20, 95% CI: 0.97-1.47, p = 0.087) and IS (HR 1.56, 95% CI: 0.87-2.81, p = 0.137). Subgroup analysis further indicated that IDH in the younger patients (mean age ≤ 55 years) and from Asia were significantly associated with an increased risk of composite cardiovascular events, while the elderly patients (mean age ≥ 55 years), Americans, and Europeans were not significantly associated with an increased risk of composite cardiovascular events. Conclusion: This meta-analysis provides evidence that IDH defined using the 2018 ESC criterion is significantly associated with an increased risk of composite cardiovascular events, cardiovascular mortality, all strokes and HS, but not significantly associated with all-cause death and IS. These findings also emphasize the importance for patients with IDH to have their blood pressure within normal, especially in the young adults and Asians. Trial Registration: PROSPERO, Identifier: CRD42021254108.

Association of isolated diastolic hypertension based on different guideline definitions with incident cardiovascular risk in a Chinese rural cohort

The 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline lowered the threshold (systolic blood pressure [SBP] <130 mm Hg and diastolic blood pressure [DBP] ≥80 mm Hg) for isolated diastolic hypertension (IDH), whereas the 2018 Chinese guideline still recommends the old threshold (SBP <140 mm Hg and DBP ≥90 mm Hg). This study aimed to investigate the association between IDH, as defined by both guidelines, and the risk of incident cardiovascular disease (CVD) in rural areas of northeast China. This prospective study included participants whose baseline data were collected between 2004 and 2006. The exclusion criteria were baseline CVD, incomplete data, and systolic hypertension. The primary end point was incident CVD, a composite end point including nonfatal myocardial infarction (MI), nonfatal stroke, and CVD death. Multivariate Cox models were used to evaluate the association of IDH with CVD risk. The authors analyzed 19 688 participants (7140 participants with IDH) according to the ACC/AHA guideline. Compared with normotensive participants, individuals with ACC/AHA-defined IDH were at a high risk of CVD (HR = 1.177, 95% CI: 1.035-1.339). A similar difference in CVD risk was noted when normotensive participants were compared with those with IDH, determined based on the 2018 Chinese guideline (HR = 1.218, 95% CI: 1.050-1.413). Similar results were found in participants who did not take antihypertensives at baseline. Moreover, IDH defined by either guideline was significantly associated with nonfatal MI. ACC/AHA-defined IDH was associated with a risk of CVD, implying that blood pressure management should be improved in rural areas of China.

Is Isolated Diastolic Hypertension an Important Phenotype?

PURPOSE OF REVIEW

Isolated diastolic hypertension (IDH) is a frequent hypertension phenotype. We review IDH pathophysiology, risk stratification, and therapeutic decisions.

RECENT FINDINGS

Recent guidelines lowering blood pressure cutoff levels have increased IDH prevalence and likely decreased associated cardiovascular risk. Long-term cardiovascular risk and pharmacological intervention in IDH are controversial. Narrow pulse pressure and other physiological and epidemiological characteristics are shared with a systodiastolic hypertension (SDH) subgroup. We propose that IDH be incorporated into a broader category, predominantly diastolic hypertension (PDH), defined by pulse pressure ≤ 45 mmHg and includes IDH and SDH with a narrow pulse pressure. IDH-PDH is associated with cardiovascular risk in the long term, especially in young patients. Standardization of the IDH definition and population may contribute to future research to understand genetics, pathophysiology, and eventually therapy in this important subgroup of hypertensive patients.

Isolated Diastolic Hypertension in the IDACO Study: An Age-Stratified Analysis Using 24-Hour Ambulatory Blood Pressure Measurements

[Figure: see text].

Level of systolic blood pressure within the normal range and risk of cardiovascular events in the absence of risk factors in Chinese

The risk of cardiovascular disease (CVD) at currently defined normal systolic blood pressure (SBP) levels in individuals without CVD risk factors is not well examined. We evaluated whether higher systolic blood pressure within the range considered normal is associated with a higher CVD risk in Chinese without traditional CVD risk factors. The community-based study included 25,529 individuals (mean age:47.3 ± 12.3 years;range:18–95 years) with a baseline SBP of 90–129 mmHg, who were free of CVD and traditional CVD risk factors, and who were re-examined in biennial intervals. During a mean follow-up of 10.6 ± 1.49 years (maximum. 11.5 years), 847 CVD events occurred. CVD incidence per 1000 person-years increased with higher baseline SBP levels (SBP,90–99 mmHg:1.45;100–109 mmHg:2.15;110–119 mmHg:3.06; and 120–129 mmHg:3.80). After adjusting for CVD risk factors, the categorical Cox regression suggested that the CVD risk was not statistically significant for study participants with a baseline SBP level of 100–109 mmHg, 110–119 mmHg, and 120–129 mmHg compared with those with a baseline SBP level of 90–99 mmHg. If CVD risk factors including blood pressure categories which developed during follow-up were included in a time-dependent Cox regression analysis, the normal baseline SBP was still not associated with incident CVDs. A SBP between 90 and 129 mmHg was not associated with an increased CVD risk in a healthy population.

A cohort study and meta-analysis of isolated diastolic hypertension: searching for a threshold to guide treatment

AIMS

Whether isolated diastolic hypertension (IDH), as defined by the 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline, is associated with cardiovascular disease (CVD) has been disputed. We aimed to further study the associations of IDH with (i) subclinical CVD in the form of coronary artery calcium (CAC), (ii) incident systolic hypertension, and (iii) CVD events.

METHODS AND RESULTS

We used multivariable-adjusted logistic and Cox regression to test whether IDH by 2017 ACC/AHA criteria (i.e. systolic blood pressure <130 mmHg and diastolic blood pressure ≥80 mmHg) was associated with the above outcomes in the Multi-Ethnic Study of Atherosclerosis (MESA). In a random-effects meta-analysis of the association between IDH and CVD events, we combined the MESA results with those from seven other previously published cohort studies. Among the 5104 MESA participants studied, 7.5% had IDH by the 2017 ACC/AHA criteria. There was no association between IDH and CAC [e.g. adjusted prevalence odds ratio for CAC >0 of 0.88 (95% CI 0.66, 1.17)]. Similarly, while IDH was associated with incident systolic hypertension, there was no statistically significant associations with incident CVD [hazard ratio 1.19 (95% CI 0.77, 1.84)] or death [hazard ratio 0.94 (95% CI 0.65, 1.36)] over 13 years in MESA. In a stratified meta-analysis of eight cohort studies (10 037 843 participants), the 2017 IDH definition was also not consistently associated with CVD and the relative magnitude of any potential association was noted to be numerically small [e.g. depending on inclusion criteria applied in the stratification, the adjusted hazard ratios ranged from 1.04 (95% CI 0.98, 1.10) to 1.09 (95% 1.03, 1.15)].

CONCLUSION

The lack of consistent excess in CAC or CVD suggests that emphasis on healthy lifestyle rather than drug therapy is sufficient among the millions of middle-aged or older adults who now meet the 2017 ACC/AHA criteria for IDH, though they require follow-up for incident systolic hypertension. These findings may not extrapolate to adults younger than 40 years, motivating further study in this age group.