Diastolic heart failure in the community

Diastolic dysfunction in hypertension

Hypertension and coronary heart disease, often coexisting, are the most common risk factors for heart failure. The progression of hypertensive heart disease involves myocardial fibrosis and alterations in the left ventricular geometry that precede the functional change, initially asymptomatic. The left ventricular diastolic dysfunction is part of this continuum being defined by the presence of left ventricular diastolic dysfunction without signs or symptoms of heart failure or poor left ventricular systolic function. It is highly prevalent in hypertensive patients and is associated with increased cardiovascular morbidity and mortality. Despite its growing importance in clinical practice it remains poorly understood. This review aims to present the epidemiological fundamentals and the latest developments in the pathophysiology, diagnosis and treatment of left ventricular diastolic dysfunction.

Sex-specific predictors of left ventricular diastolic dysfunction in untreated hypertension

BACKGROUND

Little is known about the sex-specific differences in left ventricular (LV) diastolic dysfunction (DD) predictors. We hypothesized that arterial stiffness (AS) may play a different role in the etiology of LV DD in hypertensive men and postmenopausal women, acting independently from other established predictors of this condition, such as age, obesity, diabetes mellitus, LV remodeling, and systolic function.

OBJECTIVES

The aim of the study was to analyze the sex-specific differences in AS and other predictors of LV DD in men and postmenopausal women with untreated hypertension (HTN).

PATIENTS AND METHODS

The study included 144 patients (63 postmenopausal women and 81 men, mean age 62.7±6.7 years) with previously untreated HTN and no history of cardiovascular diseases. All patients were subjected to detailed echocardiography, vascular ultrasound, and high-resolution echotracking (eTracking) of carotid arteries.

RESULTS

In the multivariate analysis, concomitant diabetes mellitus turned out to be an independent predictor of LV DD in women (P=0.02). In turn, two independent predictors of LV DD have been identified in men: S'-tissue Doppler-derived peak LV longitudinal systolic shortening velocity (P=0.001) and β, beta stiffness index (P=0.004).

CONCLUSION

There are sex differences in the predictors of LV DD in untreated HTN. In postmenopausal women, LV DD is mostly determined by diabetes, while in men, it is determined by S', reflecting LV systolic longitudinal function, and β, a parameter of AS.

Assessment and impact of diastolic function by echocardiography in elderly patients

Doppler echocardiography is the gold standard for assessment of diastolic dysfunction, which is increasingly recognised as a cause of heart failure, especially in the elderly. Using a combination of Doppler echocardiography techniques, it is possible to identify grades of diastolic dysfunction, estimate left ventricular filling pressures and establish the chronicity of diastolic dysfunction. These physiologically-derived measures have been widely validated against invasive measurements of left heart pressures and have been shown to be prognostically valuable in a wide range of clinical settings. This review explores the mechanisms, and approaches to the assessment of diastolic dysfunction in the elderly. The challenge for clinicians is to identify pathophysiological changes from those associated with normal ageing. When used in combination, and taking age into account, Doppler echocardiographic parameters are helpful in the assessment of dyspnoea in older patients and provide prognostic insights.

General anaesthesia in elderly patients with cardiovascular disorders: choice of anaesthetic agent

Our population is aging; currently 15% of the Western population are aged >65 years, and represent 25% of those undergoing surgery. The proportion of the population aged >or=65 years is rapidly growing, and an increasing number are affected with cardiovascular disease. The older person is a high-risk patient. This is because of their altered physiology and associated co-morbidities, as well as the pharmacokinetic and pharmacodynamic changes that may alter drug responses. There is considerable variability seen in the physical and physiological states of individual patients within the older population. This has an important impact on choosing a safe anaesthetic technique for each individual, which in turn can influence the morbidity and mortality in this population. The physiological changes in the aging cardiovascular system affect the arterial and venous vasculature, myocardium and autonomic nervous system, making the older person more prone to cardiovascular instability. In addition to the physiological changes, the cardiovascular status of the older person tends to be compromised by associated pathological conditions that are more common with increasing age. Pharmacokinetic and pharmacodynamic changes must be taken into account when deciding about drug dosing in this age group. Aspects of dose reduction, titration of drugs, dosing intervals and the pharmacodynamic effects of each class of drug are explained in detail in the text. The major challenge in anaesthesia for the older person with cardiovascular disease is maintenance of haemodynamic stability, particularly in the face of reduced physiological reserve and capability to respond to periods of instability. An appropriate anaesthetic technique must be selected to minimize haemodynamic changes and maintain near normal physiological status. The other key objective is to minimize the incidence of adverse outcomes, such as perioperative myocardial ischaemia/infarction, arrhythmias, heart failure, postoperative cognitive dysfunction and stroke. No single anaesthetic regimen or agent can be advocated. Knowledge of the pharmacokinetic and pharmacodynamic principles of anaesthetic agents and their altered response in elderly patients is essential when selecting an anaesthetic agent. This article provides a practical guide to the selection and use of general anaesthetic agents in older patients with cardiovascular disorders, highlighting the differences among various agents.

Anesthesia for the elderly: selected topics

PURPOSE OF REVIEW

With the graying of the Western population, there is a continuous increase in the proportion of elderly patients undergoing surgical procedures. Geriatric anesthesia is emerging from a 'subspecialty' to the mainstream of today's anesthesia and perioperative care. Much has been written on anesthesia for the elderly, but this review will concentrate on selected topics related to elderly care that represent current unresolved and pertinent issues for the care of the elderly surgical patient.

RECENT FINDINGS

Postoperative cognitive dysfunction, cardiac diastolic dysfunction and prophylactic perioperative beta-blockade in the process of major noncardiac surgery are three main topics that have recently attracted great interest in clinical practice and research, and have therefore been chosen as the selected topics for this current review.

SUMMARY

Although age is a clear risk factor for postoperative cognitive dysfunction, the association of general anesthesia with cognitive dysfunction is less clear, as is the effect of anesthesia per se or surgery on long-term cognitive dysfunction. Cardiac diastolic dysfunction is a relatively new and evolving concept in anesthesia and perioperative medicine, yet clearly diastolic dysfunction even with a normal ejection fraction may have a significant effect on the perioperative outcome and management of elderly patients. Small, but powerful studies have shown significant outcome benefit with prophylactic perioperative beta-blockade in high-risk patients undergoing major noncardiac surgery. Data from other studies, however, are still conflicting and the final verdict awaits larger scale outcome studies.

Heart failure and left ventricular remodeling after reperfused acute myocardial infarction in patients with hypertension

In the thrombolytic era, hypertension has been shown to adversely affect the development of heart failure after acute myocardial infarction (AMI). We sought to examine the relation between antecedent hypertension and heart failure after mechanical reperfusion and to test the impact of postinfarction left ventricular remodeling on heart failure in hypertensive patients. A series of 953 patients (324 hypertensives) with AMI treated with successful primary percutaneous coronary intervention underwent a 5-year follow-up. A subgroup of 325 subjects underwent 2D echocardiography at admission, 1 month, and 6 months. From day 1 to 6 months, despite similar improvement in regional and global left ventricular function and similar 6-month infarct artery patency rate, left ventricular end-diastolic volume increased in the normotensives (122+/-36 mL to 131+/-47 mL; P<0.001) but not in the hypertensives (127+/-41 mL to 128+/-31 mL; P=0.768). At 6 months, the incidence of left ventricular remodeling in hypertensive and normotensive patients was not different (22% versus 28%; P=0.210). However, at 5 years, the incidences of hospitalization for heart failure (7% versus 3%; P=0.014) and of New York Heart Association functional class > or =2 (53% versus 40%; P<0.001) were higher in hypertensive as compared with normotensive patients. Hypertension was found to be a predictor of heart failure (hazard ratio, 2.23; P=0.015). In conclusion, patients with antecedent hypertension are at higher risk to develop heart failure after AMI, even when successfully reperfused by primary percutaneous coronary intervention. However, the increased incidence of heart failure in hypertensive patients is not associated with a greater propensity to postinfarction left ventricular remodeling.

BNP as a marker of diastolic dysfunction in the general population: Importance of left ventricular hypertrophy

BNP is a marker of systolic left ventricular dysfunction (LVSD) and heart failure. To assess BNP for the detection of diastolic dysfunction in the general population, we examined 1678 subjects within an age- and sex-stratified survey (MONICA Augsburg). BNP was measured using a commercially available RIA (Shionogi). BNP increased in subjects with diastolic dysfunction (mean 20.3+/-4.7 pg/ml vs. control 9.6+/-0.5 pg/ml, p<0.001), but to a lesser extent than in subjects with LV hypertrophy (LVH, mean 37.3+/-49.1 pg/ml, p<0.001 vs. control) or LVSD (mean 76.2+/-23.2 pg/ml, p<0.001 vs. control). Individuals with sole diastolic abnormality displayed BNP concentrations at the control level (mean 9.7+/-1.7 pg/ml). In univariate analysis, age, BMI, systolic blood pressure, left atrial size, LV mass index, diastolic dysfunction and EF displayed a significant correlation with BNP (p<0.001). However, LV mass index displaced diastolic dysfunction as a significant predictor of BNP in multivariate analysis. Upon ROC analysis, sensitivity and specificity for the detection of diastolic dysfunction by BNP were only 61% and 55%, respectively. Nevertheless, a normal BNP test virtually excluded the presence of diastolic dysfunction and concomitant LVH (NPV 99.9%). Increased BNP concentrations in subjects with diastolic dysfunction are strongly related to LVH. Population-wide screening for diastolic dysfunction with BNP cannot be recommended although a normal BNP test usually excludes diastolic dysfunction and LV hypertrophy.

Bedside tests of B-type natriuretic peptide in the diagnosis of left ventricular diastolic dysfunction in hypertensive patients

AIMS

To investigate the value of B-type natriuretic peptide (BNP) in diagnosing left ventricular diastolic dysfunction in patients with hypertension.

METHODS

The left ventricular diastolic function and plasma BNP levels were assessed prospectively in 135 hypertensive patients.

RESULTS

The plasma BNP in patients with (n=61) and without (n=74) diastolic dysfunction was 122+/-105 and 18+/-16 pg/ml, respectively (p<0.001). Increased BNP levels were associated with systolic blood pressure (p<0.05), left ventricular mass index (p<0.001), the E/A ratio of transmitral flow (p<0.01) and the isovolumic relaxation time (p<0.01). A receiver-operator characteristic curve showing the sensitivity and specificity of BNP against the echocardiography diagnosis of diastolic dysfunction revealed an area under the curve (accuracy) of 0.904 (p<0.01). Using a cut-off value of >40 pg/ml, the sensitivity and specificity of plasma BNP in diagnosing left ventricular diastolic dysfunction were 79% and 92%, respectively.

CONCLUSIONS

The plasma BNP levels in patients with hypertension are closely related to left ventricular hypertrophy and filling impairment. Plasma BNP may be used to facilitate the diagnosis of left ventricular diastolic dysfunction.

Impact of Body Mass Index on Markers of Left Ventricular Thickness and Mass Calculation: Results of a Pilot Analysis

Specific correlations between body mass index (BMI) and left ventricular (LV) thickness have been conflicting. Accordingly, we investigated if a particular correlation exists between BMI and echocardiographic markers of ventricular function.

METHODS

A total of 122 patients, referred for routine transthoracic echocardiography, were included in this prospective pilot study using a 3:1 randomization approach. Patient demographics were obtained using a questionnaire.

RESULTS

Group I consisted of 80 obese (BMI was >30 kg/m2), Group II of 16 overweight (BMI between 26 and 29 kg/m2), and Group III of 26 normal BMI (BMI < 25 kg/m2) individuals. No difference was found in left ventricular wall thickness, LV end-systolic cavity dimension, fractional shortening (FS), or pulmonary artery systolic pressure (PASP) among the groups. However, mean LV end-diastolic cavity dimension was greater in Group I (5.0 +/- 0.9 cm) than Group II (4.6 +/- 0.8 cm) or Group III (4.4 +/- 0.9 cm; P < 0.006). LV mass indexed to height(2.7) was also significantly larger in Group I (61 +/- 21) when compared to Group III (48 +/- 19; P < 0.001). Finally, left atrial diameter (4.3 +/- 0.7 cm) was also larger (3.8 +/- 0.6 and 3.6 +/- 0.7, respectively; P < 0.00001).

DISCUSSION

We found no correlation between BMI and LV wall thickness, FS, or PASP despite the high prevalence of diabetes and hypertension in obese individuals. However, obese individuals had an increased LV end-diastolic cavity dimension, LV mass/height(2.7), and left atrial diameter. These findings could represent early markers in the sequence of cardiac events occurring with obesity. A larger prospective study is needed to further define the sequence of cardiac abnormalities occurring with increasing BMI.

Ventricular structure and function in aged dogs with renal hypertension: a model of experimental diastolic heart failure

BACKGROUND

Heart failure (HF) with normal ejection fraction (diastolic HF [DHF]) usually occurs in elderly patients with hypertension. The presence and significance of altered systolic and diastolic ventricular function in DHF is increasingly controversial. Our objective was to develop a clinically relevant large-animal model to better understand the pathophysiology of DHF.

METHODS AND RESULTS

Ventricular structure and function were characterized in young control (YC group; n=6), old control (OC group; n=7), and old dogs made hypertensive by renal wrapping (experimental DHF [ExDHF] group; n=8). The ExDHF group was associated with normal left ventricular (LV) volume, increased LV mass, and myocardial fibrosis. LV relaxation was impaired in ExDHF (tau=53+/-6 ms) compared with OC (tau=35+/-3 ms; P<0.05) and YC (tau=33+/-6 ms; P<0.05) dogs. The percent diastole at which relaxation is complete was increased in ExDHF (116+/-30%) compared with OC (69+/-8%; P<0.05) and YC (35+/-5%; P<0.05) dogs. The coefficient of LV diastolic stiffness was similar in OC, YC, and ExDHF dogs. Diastolic pressures increased dramatically in response to increases in blood pressure. End-systolic LV stiffness was enhanced in ExDHF dogs and after load enhancement of myocardial performance was maintained. Arterial stiffness was increased in ExDHF dogs.

CONCLUSIONS

Aged dogs with chronic hypertension exhibit LV hypertrophy and fibrosis with impaired LV relaxation but no increase in the coefficient of LV diastolic stiffness. LV systolic and arterial stiffness are increased, which may exacerbate load-dependent impairment of relaxation and contribute to increased filling pressures with hypertensive episodes. This model mimics many of the structural and functional characteristics described in the limited studies of human DHF and provides insight into the pathogenesis of DHF.

What mechanisms underlie diastolic dysfunction in heart failure?

Abnormalities of diastolic function are common to virtually all forms of cardiac failure. However, their underlying mechanisms, precise role in the generation and phenotypic expression of heart failure, and value as specific therapeutic targets remain poorly understood. A growing proportion of heart failure patients, particularly among the elderly, have apparently preserved systolic function, and this is fueling interest for better understanding and treating diastolic abnormalities. Much of the attention in clinical and experimental studies has focused on relaxation and filling abnormalities of the heart, whereas chamber stiffness has been less well studied, particularly in humans. Nonetheless, new insights from basic and clinical research are helping define the regulators of diastolic dysfunction and illuminate novel targets for treatment. This review puts these developments into perspective with the major aim of highlighting current knowledge gaps and controversies.

Antihypertensive medications and differences in muscle mass in older persons: the Health, Aging and Body Composition Study

OBJECTIVES

To evaluate whether older persons using angiotensin-converting enzyme (ACE) inhibitors have a larger lower extremity muscle mass (LEMM) than users of other antihypertensive drugs.

DESIGN

Cross-sectional analysis of data from the Health, Aging and Body Composition (Health ABC) Study.

SETTING

University of Tennessee, Memphis, and University of Pittsburgh clinics.

PARTICIPANTS

A community-based sample of 2,431 well functioning participants of the Health ABC, aged 70 to 79, who were free of heart failure, were selected according to use of antihypertensive medications: ACE inhibitors (n=197), beta-blockers (n=169), thiazides (n=216), calcium-channel blockers (n=340), or none (n=1,509).

MEASUREMENTS

LEMM, assessed using dual-energy x-ray absorptiometry, compared by index drug in analysis of variance models unadjusted and adjusted for demographics, study site, height, body fat, physical activity, blood pressure, coronary artery disease, diabetes mellitus, and chronic pulmonary disease.

RESULTS

LEMM significantly differed across the study groups, being larger in users of ACE inhibitors than in users of other drugs (unadjusted and adjusted models). LEMM was comparable in users of ACE inhibitors and no drug users. A trend toward larger LEMM was also observed in sex- and ethnicity-stratified analyses and in the subgroup of noncoronary hypertensive participants.

CONCLUSION

In older persons, use of ACE inhibitors is associated cross-sectionally with larger LEMM. This finding suggests a possible explanation of the benefits of ACE inhibitors in wasting syndromes. If confirmed in longitudinal studies, this pharmacological action might have important implications for the prevention of physical disability in older patients with hypertension.

Plasma Brain Natriuretic Peptide to Detect Preclinical Ventricular Systolic or Diastolic Dysfunction

BACKGROUND

Preclinical systolic or diastolic dysfunction is associated with increased morbidity and mortality. We postulated that plasma brain natriuretic peptide (BNP) might serve as a biomarker for preclinical ventricular dysfunction (PCVD) but that the discriminatory values for BNP may vary with age and sex.

METHODS AND RESULTS

We measured BNP, systolic and diastolic ventricular function, and clinical parameters in 2042 randomly selected residents of Olmsted County, Minn, aged 45 years or older. For preclinical systolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with more severe (0.82 to 0.92) than any (0.51 to 0.74) systolic dysfunction and were similar in men and women and in younger and older persons. For preclinical diastolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with moderate-to-severe (0.74 to 0.79) than any (0.52 to 0.68) diastolic dysfunction and were similar regardless of age or sex. Optimal discriminatory values of BNP varied with age and sex. Considering the prevalence of preclinical systolic or diastolic dysfunction and the predictive characteristics observed, using BNP to screen for PCVD would necessitate echo in 10% to 40% of those screened, with most confirmatory echocardiograms being negative, and would miss 10% to 60% of those affected.

CONCLUSIONS

BNP is a suboptimal screening test for PCVD in the population.

Beta-blockers: new standard therapy for heart failure

Despite recent advances in the diagnosis and treatment of cardiovascular disease, the prevalence of heart failure, a highly morbid and lethal condition, is increasing. Because of recent advances in basic and clinical research, beta-blockade is now established as a highly effective therapy that reduces morbidity and mortality dramatically in patients with heart failure associated with reduced systolic function. The new guidelines from the American College of Cardiology-American Heart Association recommend use of beta-blockers in all patients with symptomatic left ventricular systolic dysfunction. Now clinicians need to incorporate use of beta-blockers into their standard approach to the treatment of heart failure. We briefly summarize the basic and clinical evidence establishing the benefit of beta-blockers for heart failure and provide practical information to assist clinicians in deciding when and how to use beta-blockers in patients with heart failure.