Hypertension and diastolic heart failure

In patients with hypertension, pressure overload leads to left ventricular hypertrophy (LVH), myocardial fibrosis, and impaired diastolic filling without systolic dysfunction. Presently, diastolic heart failure accounts for about 50% of the heart failure population. Fatigue, dyspnea, reduced exercise tolerance, and peripheral edema are common presenting complaints. As a group, patients with diastolic heart failure are older and predominantly female. Diuretics are effective for treating congestive symptoms. β Blockers and heart rate-lowering calcium blockers show benefit in smaller studies but have not been evaluated in definitive clinical trials. Renin-angiotensin-aldosterone system blockers reduce blood pressure, LVH, and myocardial fibrosis; however, long-term studies with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers demonstrate little effect on symptoms or survival, and inconsistent effects on heart failure hospitalization. At present, evidence-based treatment includes antihypertensive therapy to reduce progression from hypertension to heart failure. In patients with established heart failure, diuretics and other empiric treatments are used to control symptoms.     

Primary diastolic heart failure

Diastolic heart failure is defined clinically when signs and symptoms of heart failure are present in the presence of preserved left ventricular systolic function (ejection fraction >45%). The incidence and prevalence of primary diastolic heart failure increases with age and it may be as high as 50% in the elderly. Age, female gender, hypertension, coronary artery disease, diabetes, and increased body mass index are risk factors for diastolic heart failure. Hemodynamic consequences such as increased pulmonary venous pressure, post-capillary pulmonary hypertension, and secondary right heart failure as well as decreased cardiac output are similar to those of systolic left ventricular failure, although the nature of primary left ventricular dysfunction is different. Diagnosis of primary diastolic heart failure depends on the presence of preserved left ventricular ejection fraction. Assessment of diastolic dysfunction is preferable but not mandatory. It is to be noted that increased levels of B-type natriuretic peptide does not distinguish between diastolic and systolic heart failure. Echocardiographic studies are recommended to exclude hypertrophic cardiomyopathy, infiltrative heart disease, primary valvular heart disease, and constrictive pericarditis. Myocardial stress imaging is frequently required to exclude ischemic heart disease. The prognosis of diastolic heart failure is variable; it is related to age, severity of heart failure, and associated comorbid diseases such as coronary artery disease. The prognosis of severe diastolic heart failure is similar to that of systolic heart failure. However, cautious use of diuretics and/or nitrates may cause hypotension and low output state. Heart rate control is essential to improving ventricular filling. Pharmacologic agents such as angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers are used in selected patients to decrease left ventricular hypertrophy. To decrease myocardial fibrosis, aldosterone antagonists have a potential therapeutic role. However, prospective controlled studies will be required to establish their efficacy in primary diastolic heart failure.     

Left ventricular diastolic dysfunction as a cause of congestive heart failure. Mechanisms and management.

OBJECTIVE: To define the mechanisms underlying left ventricular diastolic dysfunction in patients with congestive heart failure and normal systolic function and to identify the patients at risk for this syndrome. STUDY SELECTION: Studies were selected that describe the clinical observations of congestive heart failure with normal systolic function and that provide experimental and clinical insights into the mechanisms responsible for ventricular diastolic dysfunction. DATA SYNTHESIS: Recent studies indicate that a large number of patients (up to 40% in some series) presenting with congestive heart failure have preserved left ventricular systolic function. The factors contributing to altered left ventricular diastolic function include fibrosis, hypertrophy, ischemia, and increased afterload. The latter three factors, alone or in combination, predispose to impaired left ventricular relaxation, an active energy-requiring process. Thus, decreased left ventricular diastolic distensibility (increased diastolic pressure at any level of diastolic volume) may arise not only from altered passive elastic properties stemming from fibrosis or increased muscle mass but also from derangements in the dynamics of ventricular relaxation. RESULTS: In patients with essential hypertension, all four of the above mechanisms may be operative. Considering the prevalence of hypertension in the general population, hypertension appears to be an important underlying factor in many patients with heart failure on the basis of diastolic mechanisms. In the patient presenting with dyspnea and elevated filling pressures, but with a nondilated, normally contracting ventricle, treatment with standard heart failure medications (such as digitalis, diuretics, and vasodilators) is often ineffective and may be deleterious. Such patients may respond more favorably to beta-blockers and calcium-channel blockers. CONCLUSIONS: Diastolic dysfunction should be considered in the patient presenting with heart failure symptoms but with normal systolic function, particularly in hypertensive patients with left ventricular hypertrophy.     

Aspects of the Use of Angiotensin-Converting Enzyme Inhibitors and Calcium Antagonists in Treatment of Heart Failure in the Older Patient

The syndrome of congestive heart failure may result from either systolic or diastolic dysfunction of the left ventricle. Diastolic left ventricle dysfunction is particularly common in the geriatric age group, and is associated with left ventricular hypertrophy resulting from aging and hypertension. The clinical differentiation of these two patterns is important in understanding the pathophysiologic process and in selecting appropriate therapy. Angiotensin-converting enzyme (ACE) inhibitors are useful in systolic dysfunction, both in improving clinical manifestations of reduced cardiac output and in actually prolonging survival. ACE inhibitors are also beneficial in diastolic heart failure by promoting regression of left ventricular hypertrophy, thus improving diastolic physiological function. Calcium antagonists improve diastolic function by reducing blood pressure of hypertensive subjects, reducing left ventricular mass, and theoretically, by facilitating the energy-dependent transport of calcium ions from the actin-myosin complex into the sarcoplasmic reticulum. However, because of the negative inotropic properties of the calcium antagonists, they should be used cautiously, if used at all, in patients with significant systolic dysfunction, at least until the results of clinical trials using these drugs in systolic congestive heart failure are available.     

Dyspnoe bei normaler systolischer Funktion

30-50% of patients presenting with symptoms of congestive heart failure exhibit a near normal left ventricular systolic function at rest, and an impaired diastolic function of the heart may be causative. Despite a better prognosis than in systolic heart failure, frequency of hospitalizations due to diastolic heart failure is comparable with systolic heart failure. According to the criteria of Vasan and Levy diagnosis of diastolic heart failure is probable, if symptoms and signs of heart failure are accompanied in proximity (within 72 h) by objective evidence of normal left ventricular systolic function. Newer echocardiographic techniques (e. g., tissue Doppler) aid to confirm the diagnosis and to determine the severity of dysfunction and may substitute invasive demonstration of impaired left ventricular relaxation, filling, compliance or stiffness for standardized diagnosis. Incorporation of biochemical test (BNP [brain natriuretic peptide]) allows differential diagnosis and may increase the accuracy of diagnosis. Due to inconsistent diagnostic criteria, data from prospective randomized controlled trials for the treatment of diastolic heart failure are rare. Basic principles include treatment of the underlying disease, i. e., control of hypertension, diabetes, or obstructive airway disease. Angiotensin 1 antagonists (ARB) have proven effective in regression of left ventricular hypertrophy (LIFE) and may reduce morbidity, but not mortality (CHARM). Maintenance of sinus rhythm, heart rate control (beta-blockers, calcium channel blockers) and anti-ischemic therapy may be indicated in view of pathophysiological aspects. Diuretics should be administered with caution in patients with symptoms of congestion, digitalis is not useful in the treatment of isolated diastolic heart failure. The results of ongoing trials (e. g., I-Preserve) may offer new therapeutic options, and evidence-based guidelines for the so far often unsatisfactory treatment of diastolic dysfunction/heart failure are awaited.     

From Hypertension to Heart Failure

The prevalence of heart failure is increasing in modern societies. Hypertension is a major contributor to the development of heart failure, whether through the development of left ventricular hypertrophy and diastolic dysfunction or by promoting atherosclerosis and myocardial infarction, which eventually leads to systolic dysfunction and left ventricular dysfunction. Effective therapy for hypertension can prevent more than 50% of heart failure events. Most studies done in the last three decades have used β blockers with diuretics as the modality of therapy. These agents have been shown to effectively prevent the development of heart failure. More recent comparative studies have shown that use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are also effective in preventing heart failure. Calcium channel blockers, however, seem to be less effective in preventing development of heart failure in patients with hypertension. It needs to be emphasized that the most important variable in preventing heart failure is the appropriate treatment of hypertension.     

Left Ventricular Hypertrophy in Hypertension. Part III. Reversibility of Left Ventricular Hypertrophy During Treatment With Antihypertensive Drugs

Results of prospective trials of effects of various antihypertensive drugs on left ventricular hypertrophy in patients with hypertensive disease are reviewed. According to 2 meta-analyses angiotensin converting enzyme inhibitors are most effective inducers of regression of left ventricular hypertrophy. However in comparative randomized trials in patients with hypertension ability of diuretics, lipophilic beta-adrenoblockers, long-acting calcium antagonists, and angiotensin receptor blockers to cause regression of left ventricular hypertrophy was not inferior to that of angiotensin converting enzyme inhibitors.     

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 β-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.     

Risk Reduction Following Regression of Cardiac Hypertrophy

Cardiac hypertrophy in essential hypertension is documented to be an independent risk factor for congestive heart failure, coronary heart disease and cardiac sudden death. Reduction of left ventricular hypertrophy therefore emerged as a new challenge of antihypertensive treatment. Sympatholytic agents, calcium entry blockers, and angiotensin converting enzyme inhibitors have been found to reduce left ventricular hypertrophy, whereas vasodilators (and most likely also diuretics) are unable to reduce left ventricular mass despite good control of arterial hypertension. Several studies indicated that reduction of left ventricular hypertrophy is not detrimental to cardiac pump function: systolic and diastolic function were found to be maintained at rest and during exposure to increased pressure load. In hypertensive patients with left ventricular hypertrophy ventricular arrythmias have been reported to be increased and to be the pathophysiological link for the increased risk of cardiac sudden death. Reduction of cardiac hypertrophy was found to be accompanied by a reduction of prevalence and severity of ventricular arrhythmias if treated with betablockers, calcium entry blockers or converting enzyme inhibitors. Whether reduction of cardiac hypertrophy indeed decreases the cardiovascular risk attributed to left ventricular hypertrophy is unknown at present, although clinical studies support such a viewpoint.     

Arterial hypertension and systolic left ventricular dysfunction: therapeutic approach

Arterial hypertension is a cardinal precursor of congestive heart failure, and diastolic dysfunction is the most frequent mechanism for it. Systolic left ventricular dysfunction, although less frequent, has a worse prognosis. Most cases of systolic dysfunction in patients with hypertension is due to acute myocardial infarction, although other mechanisms can be involved. In some studies, non-ischemic hypertensive systolic dysfunction is the etiology of chronic heart failure in up to 10% of patients with dilated cardiomyopathy. Diastolic dysfunction and left ventricular hypertrophy are also associated with a higher risk of heart failure and systolic dysfunction. Given the poor prognosis of patients with congestive heart failure and dilated cardiomyopathy, it is fundamental to try to prevent the development of left ventricular dysfunction by means of a correct control of blood pressure, regression of left ventricular hypertrophy and prevention of coronary artery disease. When systolic dysfunction is established, angiotensin converting enzyme inhibitors are the treatment of choice; diuretics and digoxin can be added in patients with overt congestive heart failure. Recent studies suggest that other drugs, such as carvedilol and losartan, can be beneficial, but current evidence is still scarce.     

Arterial hypertension and chronic heart failure

Arterial hypertension, alone or in combination with ischemic heart disease, precedes the development of heart failure. The Framingham study demonstrated that hypertension was the major risk factor in the development of heart failure. Arterial hypertension is not a sole factor contributing to the development of heart failure. The syndrome of heart failure is a consequence of multiple systemic responses and the development of heart failure is a complex and progressive process associated with cardiovascular disease resulting from risk factors: hypertension, obesity, smoking and dyslipidaemia. Arterial hypertension is the main precursor of left ventricular hypertrophy. Initially, this process causes diastolic dysfunction in the early stages of primary hypertension. Systolic dysfunction is rarely observed in those subjects. Left ventricular hypertrophy is also an important risk factor for myocardial infarction and ventricular arrhythmias. Asymptomatic systolic and diastolic left ventricular dysfunction may both progress to overt HFThe primary prevention of heart failure patients should be based upon strategies providing tight and sustained blood pressure control. This therapy should include an agent that inhibits the renin–angiotensin–aldosterone system. Treatment of arterial hypertension in patients with HF must take into account the prevalent type of cardiac dysfunction—diastolic or systolic.     

Therapy for diastolic heart failure

There is little objective to guide the therapy of patients with diastolic heart failure. Because of the similarities of pathophysiology abnormalities in diastolic and systolic heart failure, it is a reasonable inference to suggest that the proven therapy for systolic heart failure may also be of benefit in patients with diastolic heart failure. Treatment of underlying or exacerbating conditions in diastolic heart failure, such as hypertension, left ventricular hypertrophy, ischemia, diabetes, anemia, obesity and pulmonary disease is an important means of managing diastolic heart failure. Control of systolic blood pressure is effective in improving and preventing the development of diastolic heart failure. Treatment of diastolic heart failure is most effective when it is associated with hypertension. Production of systolic arterial pressure acutely reduces pulmonary congestion, ischemia, and chronically may lead to regression of left ventricular hypertrophy. Patients with diastolic heart failure in the absence of hypertension are very difficult to treat.     

Left Ventricular Diastolic Function in the Elderly

Previous studies using pulsed Doppler echocardiography have demonstrated a pattern of abnormal left ventricular relaxation associated with increasing age. Specifically, aging is associated with decreased peak velocity of early diastolic mitral inflow, increased peak velocity of late diastolic inflow, increased isovolumic relaxation time, and early diastolic deceleration time. Abnormal relaxation can progress to significantly elevated left atrial pressure—characterized by increased early peak velocity and shortened isovolumic relaxation time and deceleration time—as part of the disease processes. Left ventricular diastolic dysfunction is highly prevalent, occurring in one half to two thirds of elderly patients with congestive heart failure, in association with normal systolic function. Left ventricular hypertrophy, which is commonly related to systemic arterial hypertension, and ischemic heart disease are the two major causes of abnormal left ventricular diastolic function in the elderly. Recently, newer echocardiographic techniques have been described that allow more accurate evaluation of left ventricular diastolic function. Treatments for left ventricular diastolic dysfunction should focus on the underlying disease etiology as well as on the derangement in left ventricular diastolic function. Although calcium channel blockers and angiotensin—converting enzyme inhibitors have been used clinically to treat diastolic dysfunction, their effects on prognosis remain unproven.     

Heart failure with preserved systolic function

Optional statement At least 30% of patients with congestive heart failure have preserved systolic function in the absence of significant valvular heart disease. These patients have diastolic dysfunction. Patients are frequently older and hypertensive. The rate of hospitalization in these patients is similar to that in patients with systolic dysfunction. Mortality is intermediate between that of patients with systolic dysfunction heart failure and normal subjects. Diagnosis requires a clear demonstration of the presence of the heart failure syndrome, normal systolic function, and the absence of valvular disease that could increase left atrial pressures. The diagnosis is supported by evidence of diastolic dysfunction that, from a practical point of view, will be provided most frequently by tissue Doppler imaging. Few randomized data are available on efficacy of therapeutic approaches. Acute treatment centers on reducing central blood volume with diuretics and nitrates and controlling heart rate, particularly in the setting of atrial fibrillation. Further treatment centers on reversing underlying pathophysiologic changes, particularly left ventricular hypertrophy. Control of hypertension and antagonism of the renin-angiotensin-aldosterone system appear to be promising therapeutic approaches.     

Heart failure in elderly patients

Several structural and functional changes contribute to heart failure in elderly patients: an age dependent increase in sympathetic nervous activity, left ventricular wall diameter, myocardial fibrosis and apoptosis, micro- and macrovascular coronary sclerosis, aortic stiffness. As a consequence, diastolic, but also systolic heart failure is a frequent finding in elderly patients. The relation of systolic to diastolic heart failure is clearly shifted towards diastolic heart failure in elderly patients, especially in women. Mortality is increased with systolic dysfunction in elderly patients compared to younger heart failure patients. Mortality is less with diastolic dysfunction, but still higher compared to elderly without heart failure. In addition, morbidity is increased both with diastolic and systolic heart failure in elderly patients. Cognitive dysfunction is a frequent finding. After exclusion of specific cardiac and extracardiac reasons for dyspnoea, drug therapy of systolic heart failure in elderly is similar to younger patients. However, the physiological decrease of renal function and the more frequent renal impairment in elderly patients with heart failure needs to be considered. Guideline recommendations for drug therapy are based in most cases on studies conducted in younger systolic heart failure patients. A recent meta-analysis of randomized beta-blocker trials suggests improved survival with beta-blockers even in the elderly subgroup. Guidelines for the treatment of diastolic heart failure are available only recently. The term heart failure with normal left ventricular ejection fraction (LVEF) has been proposed instead of diastolic heart failure. Given the increased morbidity and mortality in elderly patients with heart failure and normal LVEF, therapy should include general measures, such as physical activity, weight reduction, volume restriction. Specific therapy includes optimal control of systolic and diastolic blood pressure, diuretics, nitrates, and frequency-control. However, randomized trials evaluating the efficacy of specific therapies in heart failure with normal LVEF are still missing.     

Left ventricular diastolic dysfunction: risks, identification, and treatment

Risk factors of cardiovascular disease, such as hypertension, diabetes, and myocardial infarction, if left untreated, will increase the risk of the development of chronic heart failure. Much is known about the pathophysiology and effective treatments of chronic heart failure from left ventricular systolic dysfunction; however, little clinical trial evidence exists concerning benefits of treating patients with chronic heart failure and preserved systolic function, also known as left ventricular diastolic dysfunction. Rather, an understanding of the pathophysiology and patient signs and symptoms has usually dictated choice of treatments. With the results of ongoing trials, as well as the Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity (CHARM)-Preserved and the Digitalis Investigation Group (DIG) trials, clinical evidence is accumulating to support effective treatments in patients with left ventricular diastolic dysfunction. The focus of this review is to discuss the risks of, identification of, and rationale for therapeutic choices being employed for treating left ventricular diastolic dysfunction and implications from studies that may support these choices.     

Diastolic Dysfunction as a Cause of Exercise Intolerance

Tachycardia accompanying exercise shortens the duration of diastole, reducing the time available for the left ventricular (LV) filling. Thus, the LV must fill more rapidly for the stroke volume to increase (or even be maintained) during exercise. Normally, this is accomplished without requiring an excessive increase in left atrial (LA) pressure by an acceleration of LV relaxation and a fall in LV early diastolic pressure during exercise. This response is lost following the development of heart failure due to systolic dysfunction, both in experimental animals and in patients. In fact, in such situations, LV relaxation slows and LV early diastolic pressure increases due to exercise. Thus, any diastolic dysfunction present at rest in CHF during systolic dysfunction is exacerbated during exercise. Similarly, patients with primary diastolic dysfunction heart failure with preserved systolic function may not be able to augment LV filling rates without an abnormal increase in LA pressure. Thus, diastolic dysfunction may contribute to exercise intolerance, both in systolic dysfunction and primary diastolic dysfunction. Acute studies suggest that treatment with angiotensin II receptor blockers or verapamil may improve exercise tolerance in some patients with primary diastolic dysfunction.     

Eplerenone: A Selective Aldosterone Blocker

Recent studies suggest that aldosterone may play a larger role than once appreciated in normal physiologic function and cardiovascular disease. Some of the adverse cardiovascular effects that have been described include cardiac and vascular fibrosis, vascular necrosis and inflammation, impaired endothelial function, reduced fibrinolysis, hypertension, left ventricular hypertrophy (LVH), congestive heart failure, and cardiac arrhythmias. In light of these findings, the ability to block the actions of aldosterone has gained increased therapeutic importance. Eplerenone is a selective aldosterone receptor blocker that displays little interaction with androgen and progesterone receptors. Eplerenone has already been approved for the treatment of systemic hypertension and has been evaluated in numerous hypertension subgroups, including patients with low plasma renin activity; diabetes; LVH; uncontrolled blood pressure while receiving monotherapy with angiotensin‐converting enzyme inhibitors, angiotensin‐receptor blockers, calcium channel blockers, or beta‐blockers; and in black patients. Results of these trials indicate that eplerenone lowers blood pressure and reduces end‐organ damage. Further proof of the therapeutic importance of mineralocorticoid receptor blockade comes from the eplerenone post acute myocardial infarction survival and efficacy study (EPHESUS). In this large‐scale clinical outcome trial, eplerenone was shown to reduce total mortality by 15% as well as the combined endpoint of cardiovascular mortality/cardiovascular hospitalization by 13% when administered at a mean of 7.3 days post myocardial infarction to patients with evidence of systolic left ventricular dysfunction and symptoms of heart failure. Eplerenone is well tolerated, with an adverse effect profile comparable to placebo. The advent of selective aldosterone blockers, such as eplerenone, should prove to be of great therapeutic value in hypertension control and prevention of cardiovascular disease and associated end‐organ damage.     

Diastolic heart failure

Opinion statement  

Role of angiotensin II in the evolution of diastolic heart failure

More than half of all persons with heart failure (HF) have diastolic HF. The prevalence of diastolic HF increases from 46% in persons younger than 45 years to 59% in those 85 years and older. The annual mortality rate associated with diastolic HF is >10%. Diagnosis is based on signs and symptoms of HF, elevated plasma B-type natriuretic peptide, preserved left ventricular systolic function, and evidence of diastolic dysfunction by Doppler examination on two-dimensional echocardiography. Approximately 80% of patients with diastolic HF have increased left ventricular mass and a history of hypertension. Neurohormonal activation is a key aspect of this condition. Studies suggest that activation of the renin-angiotensin-aldosterone system, specifically direct cardiac effects of angiotensin II and aldosterone, contributes to the pathogenesis and progression of diastolic dysfunction. Hence, there is a rationale for use of agents that antagonize the renin-angiotensin-aldosterone system, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and aldosterone antagonists, in patients with heart failure.