Rationale and design: the VALsartan In Diastolic Dysfunction (VALIDD) Trial: evolving the management of diastolic dysfunction in hypertension

Pharmacotherapy for hypertension-induced left ventricular hypertrophy

BACKGROUND

Hypertension is the leading preventable risk factor for cardiovascular disease and premature death worldwide. One of the clinical effects of hypertension is left ventricular hypertrophy (LVH), a process of cardiac remodelling. It is estimated that over 30% of people with hypertension also suffer from LVH, although the prevalence rates vary according to the LVH diagnostic criteria. Severity of LVH is associated with a higher prevalence of cardiovascular disease and an increased risk of death. The role of antihypertensives in the regression of left ventricular mass has been extensively studied. However, uncertainty exists regarding the role of antihypertensive therapy compared to placebo in the morbidity and mortality of individuals with hypertension-induced LVH.

OBJECTIVES

To assess the effect of antihypertensive pharmacotherapy compared to placebo or no treatment on morbidity and mortality of adults with hypertension-induced LVH.

SEARCH METHODS

Cochrane Hypertension's Information Specialist searched the following databases for studies: Cochrane Hypertension Specialised Register (to 26 September 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2020, Issue 9), Ovid MEDLINE (1946 to 22 September 2020), and Ovid Embase (1974 to 22 September 2020). We searched the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov for ongoing trials. We also searched Epistemonikos (to 19 February 2021), LILACS BIREME (to 19 February 2021), and Clarivate Web of Science (to 26 February 2021), and contacted authors and funders of the identified trials to obtain additional information and individual participant data. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with at least 12 months' follow-up comparing antihypertensive pharmacological therapy (monotherapy or in combination) with placebo or no treatment in adults (18 years of age or older) with hypertension-induced LVH were eligible for inclusion. The trials must have analysed at least one primary outcome (all-cause mortality, cardiovascular events, or total serious adverse events) to be considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results, with any disagreements resolved by consensus amongst all review authors. Two review authors carried out the data extraction and analyses. We assessed risk of bias of the included studies following Cochrane methodology. We used the GRADE approach to assess the certainty of the body of evidence.

MAIN RESULTS

We included three multicentre RCTs. We selected 930 participants from the included studies for the analyses, with a mean follow-up of 3.8 years (range 3.5 to 4.3 years). All of the included trials performed an intention-to-treat analysis. We obtained evidence for the review by identifying the population of interest from the trials' total samples. None of the trials provided information on the cause of LVH. The intervention varied amongst the included trials: hydrochlorothiazide plus triamterene with the possibility of adding alpha methyldopa, spironolactone, or olmesartan. Placebo was administered to participants in the control arm in two trials, whereas participants in the control arm of the remaining trial did not receive any add-on treatment. The evidence is very uncertain regarding the effect of additional antihypertensive pharmacological therapy compared to placebo or no treatment on mortality (14.3% intervention versus 13.6% control; risk ratio (RR) 1.02, 95% confidence interval (CI) 0.74 to 1.40; 3 studies; 930 participants; very low-certainty evidence); cardiovascular events (12.6% intervention versus 11.5% control; RR 1.09, 95% CI 0.77 to 1.55; 3 studies; 930 participants; very low-certainty evidence); and hospitalisation for heart failure (10.7% intervention versus 12.5% control; RR 0.82, 95% CI 0.57 to 1.17; 2 studies; 915 participants; very low-certainty evidence). Although both arms yielded similar results for total serious adverse events (48.9% intervention versus 48.1% control; RR 1.02, 95% CI 0.89 to 1.16; 3 studies; 930 participants; very low-certainty evidence) and total adverse events (68.3% intervention versus 67.2% control; RR 1.07, 95% CI 0.86 to 1.34; 2 studies; 915 participants), the incidence of withdrawal due to adverse events may be significantly higher with antihypertensive drug therapy (15.2% intervention versus 4.9% control; RR 3.09, 95% CI 1.69 to 5.66; 1 study; 522 participants; very low-certainty evidence). Sensitivity analyses limited to blinded trials, trials with low risk of bias in core domains, and trials with no funding from the pharmaceutical industry did not change the results of the main analyses. Limited evidence on the change in left ventricular mass index prevented us from drawing any firm conclusions.

AUTHORS' CONCLUSIONS

We are uncertain about the effects of adding additional antihypertensive drug therapy on the morbidity and mortality of participants with LVH and hypertension compared to placebo. Although the incidence of serious adverse events was similar between study arms, additional antihypertensive therapy may be associated with more withdrawals due to adverse events. Limited and low-certainty evidence requires that caution be used when interpreting the findings. High-quality clinical trials addressing the effect of antihypertensives on clinically relevant variables and carried out specifically in individuals with hypertension-induced LVH are warranted.

How myofilament strain and strain rate lead the dance of the cardiac cycle

Movement of the myocardium can modify organ-level cardiac function and its molecular (crossbridge) mechanisms. This motion, which is defined by myocardial strain and strain rate (muscle shortening, lengthening, and the speed of these movements), occurs throughout the cardiac cycle, including during isovolumic periods. This review highlights how the left ventricular myocardium moves throughout the cardiac cycle, how muscle mechanics experiments provide insight into the regulation of forces used to move blood in and out of the left ventricle, and its impact on (and regulation by) crossbridge and sarcomere kinetics. We specifically highlight how muscle mechanics experiments explain how myocardial relaxation is accelerated by lengthening (strain rate) during late systole and isovolumic relaxation, a lengthening which has been measured in human hearts. Advancing and refining both in vivo measurement and ex vivo protocols with physiologic strain and strain rates could reveal important insights into molecular (crossbridge) kinetics. These advances could provide an improvement in both diagnosis and precise treatment of cardiac dysfunction.

Relation of N-terminal pro-B-type natriuretic peptide with diastolic function in hypertensive heart disease

BACKGROUND

Elevated natriuretic peptide levels in asymptomatic individuals without heart failure are associated with increased risk of adverse cardiovascular outcomes and may reflect subclinical cardiac dysfunction.

METHODS

In a sample of 313 asymptomatic individuals (51% women, mean age 61 years) with hypertension and diastolic dysfunction, we examined the association of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) with both conventional and advanced echocardiographic measures of systolic and diastolic function, including myocardial strain, using speckle-tracking-based analyses.

RESULTS

In univariate analyses, higher NT-proBNP was associated with greater left ventricular mass index (P = 0.003), left atrial volume index (P = 0.007), lateral E' velocity (P < 0.0001), E/E' ratio (P < 0.0001), peak global longitudinal systolic strain (P = 0.015), systolic strain rate (P = 0.021), and early diastolic strain rate (P < 0.0001). In multivariable analyses, NT-proBNP remained associated with measures of diastolic dysfunction, including lateral E' velocity (P = 0.013) and the E/E' ratio (P = 0.008). However, early diastolic strain rate was the echocardiographic parameter most strongly associated with NT-proBNP (P = 0.003).

CONCLUSIONS

In the setting of asymptomatic hypertensive heart disease and preserved ejection fraction, elevation in natriuretic peptide levels is predominantly associated with subclinical diastolic dysfunction.

Effect of antihypertensive therapy on ventricular-arterial mechanics, coupling, and efficiency

AIMS

To investigate the effect of antihypertensive therapy on ventricular-arterial mechanics, coupling, and efficiency in early-stage hypertension.

METHODS AND RESULTS

We studied 527 participants from two clinical trials assessing the effect of blood pressure lowering on diastolic function. Participants were aged ≥45 years with early-stage hypertension, no heart failure, ejection fraction (EF) ≥50%, and diastolic dysfunction using Doppler echocardiography. Effective arterial afterload and its components were assessed along with measures of left ventricular (LV) structure and function prior to and after 24-38 weeks of antihypertensive therapy. Systolic blood pressure decreased from 154 ± 18 to 137 ± 15 mmHg at follow-up. Blood pressure reduction was associated with decreases in ventricular and arterial stiffness, improvements in systemic arterial compliance and resistance, enhanced LV ejection, and reduction in cardiac work (all P < 0.001). Changes in Ea/Ees ratio were inversely correlated with those in EF (r = -0.25; P < 0.001), stroke work index (r = -0.13; P = 0.007), and LV efficiency (r = -0.98; P < 0.001); and directly related to changes in mitral E/e' (r = 0.12; P = 0.01). Adjusting for age and blood pressure change, women and obese individuals had less enhancement in ventricular-arterial coupling and efficiency compared with men and non-obese individuals (P = 0.04 and 0.007, respectively).

CONCLUSION

Antihypertensive therapy reduces arterial and ventricular stiffness, enhances ventricular-arterial coupling, reduces cardiac work, and improves LV efficiency, systolic, and diastolic function. Attenuated responses in women and among obese subjects suggest that structure-function changes may be less reversible in these groups, possibly explaining their greater susceptibility to ultimately develop heart failure.

The relationship between renal impairment and left ventricular structure, function, and ventricular-arterial interaction in hypertension

OBJECTIVES

Our objective was to define the relationship between renal dysfunction--both albuminuria and reduced estimated glomerular filtration rate (eGFR)--and cardiac structure and diastolic dysfunction among patients with chronic hypertension.

METHODS

Both albuminuria and eGFR were measured in 540 asymptomatic patients with hypertension and diastolic dysfunction assessed by reduced early mitral annular relaxation velocity (E'). The majority of patients were white, mean age was 60 ± 10 years, mean SBP was 149 ± 18 mmHg, and there was a low prevalence comorbid conditions. Albuminuria was undetectable in 148 (27%), within the normal to low range [urine albumin-to-creatinine ratio (UACR) 1-25 mg/g for men, 1-17 mg/g for women] in 292 (54%), and high or very high (UACR >25 mg/g for men, >17 mg/g for women) in 100 (19%). Estimated GFR was 60 ml/min per 1.73 m² or less in 75 (14%), 61-90 ml/min per 1.73 m² in 244 (45%), and more than 90 ml/min per 1.73 m² in 221 (41%).

RESULTS

Albuminuria, even within the normal range, was associated with greater left ventricular wall thickness (P = 0.01), higher relative wall thickness (P = 0.004), worse diastolic function reflected in lower E' (P = 0.01), greater arterial and left ventricular end-systolic stiffness (P < 0.0001 and P = 0.003, respectively), and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) level (P = 0.0025), even after adjustment for differences in baseline characteristics. In contrast, no independent relationship was observed between eGFR and parameters of cardiac structure or function.

CONCLUSION

Among asymptomatic hypertensive patients with evidence of diastolic dysfunction, the presence of albuminuria, even within the normal range, is associated with greater concentric remodeling, greater left ventricular end-systolic stiffness, and worse diastolic function.

Association of left atrial enlargement with left ventricular hypertrophy and diastolic dysfunction: a tissue Doppler study in echocardiographic practice

BACKGROUND

Left atrial (LA) enlargement is a powerful risk factor for cardiovascular diseases; little information is available about its prevalence and correlates in subjects free of overt cardiac disease seen in echocardiographic practice.

AIM

We evaluated the prevalence of LA enlargement (LAE) and the relationship with left ventricular (LV) mass and diastolic function in subjects with preserved LV systolic function referred to an echocardiographic study for routine clinical indications.

METHODS

1104 subjects (mean age 58 ± 16 years, 46% men, 57% hypertensives) underwent a comprehensive echo-Doppler examination. LAE and LV hypertrophy (LVH) were defined as LA volume index (LAVI) >29 ml/m(2) and LV mass index (LVMI) >50 g/h(2.7), respectively. Abnormalities of LV relaxation and LV filling were diagnosed by age-related thresholds of lateral annular velocity (Ei) and by early mitral flow velocity to Ei ratio (E/Ei) ≥16, respectively.

RESULTS

Overall, 10% of echocardiographic examinations fulfilled the criteria for LAE, 46% for LVH, 45% for altered LV relaxation and 5% for altered LV filling index. LVH progressively increased from 25% to 75% across LAVI quartiles. More patients in the highest quartile exhibited abnormal indexes of LV relaxation and LV filling compared with lower quartiles. In multivariate analysis, LV mass index (β = 0.408), age (β = 0.188), E/Ei ratio (β = 0.140) and Ei (β = 0.140) emerged as major correlates of LAE (p at least <0.01 for all).

CONCLUSIONS

LAE is a frequent finding in patients with preserved systolic function seen in current practice; this abnormality is strongly related to LVH and to diastolic dysfunction. Early detection of LAE may identify patients at higher cardiovascular risk and promote appropriate prevention strategies.

Therapeutic approaches to diastolic dysfunction

Progressive abnormalities of passive stiffness or active relaxation of the myocardium that impair ventricular filling during diastole may be an important contributor to the development of heart failure in patients with preserved ejection fraction. In this review, we discuss the epidemiology and pathophysiology of diastolic dysfunction and heart failure with preserved ejection fraction, highlighting potential therapeutic approaches and exploring the limited available evidence base for improving clinical outcomes in patients with these challenging entities.

Effect of intensive versus standard blood pressure lowering on diastolic function in patients with uncontrolled hypertension and diastolic dysfunction

Diastolic dysfunction may precede development of heart failure in hypertensive patients. We randomized 228 patients with uncontrolled hypertension, preserved ejection fraction, and diastolic dysfunction to 2 targeted treatment strategies: intensive, with a systolic blood pressure target of <130 mm Hg, or standard, with a systolic blood pressure target of <140 mm Hg, using a combination of valsartan, either 160 or 320 mg, plus amlodipine, either 5 or 10 mg, with other antihypertensive medications as needed. Echocardiographic assessment of diastolic function was performed at baseline and after 24 weeks in a prospective, open-label, blinded end point design. Blood pressure was reduced significantly in both groups, from 161.2+/-13.9/90.1+/-12.0 to 130.8+/-12.3/74.9+/-9.1 mm Hg (P<0.0001) in the intensive arm and from 162.1+/-13.2/93.7+/-12.2 to 137.0+/-12.9/79.6+/-11.0 mm Hg (P<0.0001) in the standard arm (P<0.003 for between-group comparisons). Myocardial relaxation velocity improved from 7.6+/-1.1 to 9.2+/-1.7 cm/s (Delta 1.54+/-1.4 cm/s; P<0.0001) in the intensive arm and from 7.5+/-1.3 to 9.0+/-1.9 cm/s (Delta 1.48+/-1.6 cm/s; P<0.0001) in the standard arm, with no difference between the 2 strategies in the achieved improvement (P=0.58). The degree of improvement in annular relaxation velocity was associated with the extent of systolic blood pressure reduction, and patients with the lowest achieved systolic blood pressure had the highest final diastolic relaxation velocities.

Hypertension and cardiac failure in its various forms

Hypertension clearly increases the risk of systolic or diastolic heart failure. With aging population and advancements in treatment of cardiovascular diseases, the prevalence of heart failure is ever-increasing and is a principal cause of cardiovascular morbidity and mortality. Treating hypertension has been shown to decrease the risk of development of heart failure and hence underscores the early recognition and treatment of hypertension and hypertensive heart disease. Antihypertensive treatment with drugs from all classes except direct vasodilators is effective in reversing LVH and preventing heart failure. Also, all of the major classes of antihypertensive drugs, particularly beta-blockers and RAS antagonists, with the exception of calcium antagonists, have been shown to improve survival in patients who have LV systolic dysfunction. However, phenotyping and identifying the pathophysiology and appropriate treatments for patients who have diastolic dysfunction and heart failure with preserved ejection fraction has been a daunting task. At this time, treatment of these patients is largely empiric, focusing on BP control, and treating or avoiding intravascular volume overload.

Diastolic dysfunction and heart failure with preserved ejection fraction: rationale for RAAS antagonist/CCB combination therapy

A large number of patients who present with signs or symptoms of heart failure (HF) do not have evidence of left ventricular systolic dysfunction. As a result, HF in the presence of normal or preserved ejection fraction, or diastolic HF, is increasingly recognized as a health care challenge. Guidelines have been issued for the classification, diagnosis, and prevention of HF from diastolic dysfunction, but treatment of this condition remains problematic. Antihypertensive agents that have been proven in clinical trials to improve outcomes in HF with systolic dysfunction, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers, have not yet demonstrated comparable benefits in patients with diastolic dysfunction. Combination therapy using an antagonist of the renin-angiotensin-aldosterone system and a calcium-channel blocker has potential advantages over monotherapy and is being explored in several ongoing clinical trials.

Effects of cardiac energy efficiency in diastolic heart failure: assessment with positron emission tomography with 11C-acetate

Diastolic heart failure (DHF) has become a high social burden, and its major underlying cardiovascular disease is hypertensive heart disease. However, the pathogenesis of DHF remains to be clarified. This study aimed to assess the effects of cardiac energy efficiency in DHF patients. (11)C-Acetate positron emission tomography and echocardiography were conducted in 11 DHF Japanese patients and 10 normal volunteers. The myocardial clearance rate of radiolabeled (11)C-acetate was measured to calculate the work metabolic index (WMI), an index of cardiac efficiency. The ratio of peak mitral E wave velocity to peak early diastolic septal myocardial velocity (E/e') was calculated to assess left ventricular (LV) filling pressure. The LV mass index was greater and the mean age was higher in the DHF patients than in the normal volunteers. There was no difference in WMI between the two groups. However, WMI varied widely among the DHF patients and was inversely correlated with E/e' (r=-0.699, p=0.017). In contrast, there was no correlation in the normal volunteers. In conclusion, the inefficiency of energy utilization is not a primary cause of diastolic dysfunction or DHF, and cardiac efficiency may not affect diastolic function in normal hearts. However, the energy-wasting state may induce the elevation of LV filling pressure in DHF patients, which was considered to principally result from the progressive diastolic dysfunction.

Effect of angiotensin receptor blockade and antihypertensive drugs on diastolic function in patients with hypertension and diastolic dysfunction: a randomised trial

BACKGROUND

Diastolic dysfunction might represent an important pathophysiological intermediate between hypertension and heart failure. Our aim was to determine whether inhibitors of the renin-angiotensin-aldosterone system, which can reduce ventricular hypertrophy and myocardial fibrosis, can improve diastolic function to a greater extent than can other antihypertensive agents.

METHODS

Patients with hypertension and evidence of diastolic dysfunction were randomly assigned to receive either the angiotensin receptor blocker valsartan (titrated to 320 mg once daily) or matched placebo. Patients in both groups also received concomitant antihypertensive agents that did not inhibit the renin-angiotensin system to reach targets of under 135 mm Hg systolic blood pressure and under 80 mm Hg diastolic blood pressure. The primary endpoint was change in diastolic relaxation velocity between baseline and 38 weeks as determined by tissue doppler imaging. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00170924.

FINDINGS

186 patients were randomly assigned to receive valsartan; 198 were randomly assigned to receive placebo. 43 patients were lost to follow-up or discontinued the assigned intervention. Over 38 weeks, there was a 12.8 (SD 17.2)/7.1 (9.9) mm Hg reduction in blood pressure in the valsartan group and a 9.7 (17.0)/5.5 (10.2) mm Hg reduction in the placebo group. The difference in blood pressure reduction between the two groups was not significant. Diastolic relaxation velocity increased by 0.60 (SD 1.4) cm/s from baseline in the valsartan group (p<0.0001) and 0.44 (1.4) cm/s from baseline in the placebo group (p<0.0001) by week 38. However, there was no significant difference in the change in diastolic relaxation velocity between the groups (p=0.29).

INTERPRETATION

Lowering blood pressure improves diastolic function irrespective of the type of antihypertensive agent used.

Clinical trials update from the American College of Cardiology 2007: ALPHA, EVEREST, FUSION II, VALIDD, PARR-2, REMODEL, SPICE, COURAGE, COACH, REMADHE, pro-BNP for the evaluation of dyspnoea and THIS-diet

This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure, presented at the American College of Cardiology meeting in March 2007. Unpublished reports should be considered as preliminary data, as analyses may change in the final publication. The ALPHA study suggested that patients with heart failure (HF) due to idiopathic dilated cardiomyopathy who have a negative T-wave alternans test have a good prognosis and are unlikely to benefit from ICD therapy. EVEREST provides some evidence of short-term symptom benefit of tolvaptan in patients with acute decompensated HF but no clinically important long-term benefit. FUSION II failed to show a benefit of nesiritide in patients with chronic decompensated HF. Reducing blood pressure in hypertensive patients improved diastolic dysfunction in VALIDD. Eplerenone did not improve left ventricular remodelling in mild to moderate chronic HF. Selecting HF patients for revascularisation using FDG-PET imaging did not significantly improve outcome. Crataegus extract added to standard HF therapy did not reduce morbidity or mortality in SPICE. The COURAGE study, conducted in patients without HF or major cardiac dysfunction, showed that PCI did not reduce cardiac morbidity or mortality and can be safely deferred in patients with stable coronary disease on optimal medical therapy. The COACH study failed to show that HF nurse-intervention could reduce hospitalisations but did show trends to lower mortality, especially amongst patients with reduced ejection fraction; however, the smaller REMADHE study suggested striking benefits on morbidity and mortality. A large study of BNP provided additional information on its ability to distinguish cardiac and pulmonary breathlessness. The importance of dietary intervention in post-MI patients was highlighted by the findings of THIS-diet study.

Left ventricular diastolic function following myocardial infarction

An acute myocardial infarction causes a loss of contractile fibers which reduces systolic function. Parallel to the effect on systolic function, a myocardial infarction also impacts diastolic function, but this relationship is not as well understood. The two physiologic phases of diastole, active relaxation and passive filling, are both influenced by myocardial ischemia and infarction. Active relaxation is delayed following a myocardial infarction, whereas left ventricular stiffness changes depending on the extent of infarction and remodeling. Interstitial edema and fibrosis cause an increase in wall stiffness which is counteracted by dilation. The effect on diastolic function is correlated to an increased incidence of adverse outcomes. Moreover, patients with comorbid conditions that are associated with worse diastolic function tend to have more adverse outcomes after infarction. There are currently no treatments aimed specifically at treating diastolic dysfunction following a myocardial infarction, but several new drugs, including aldosterone antagonists, may offer promise.