Hypocalcaemia as a Reversible Cause of Acute Heart Failure in a Long-Term Survivor of Childhood Cancer

Hypocalcaemia is known for its neuromuscular symptoms, which are rapidly alleviated by intravenous supplementation. Calcium is also essential for both cardiac cell excitability and contraction. We present a case of acute heart failure due to hypocalcaemia in a young male with a complex medical history.

Diagnostic value of patterns of symptoms and signs of heart failure: application of latent class analysis with concomitant variables in a cross-sectional study

OBJECTIVE

The diagnosis of heart failure (HF) requires a compatible clinical syndrome and demonstration of cardiac dysfunction by imaging or functional tests. Since individual symptoms and signs are generally unreliable and have limited value for diagnosing HF, the authors aimed to identify patterns of symptoms and signs, based on findings routinely collected in current clinical practice, and to evaluate their diagnostic value, taking into account the a priori likelihood of HF.

DESIGN

Cross-sectional evaluation.

PARTICIPANTS

1115 community participants aged ≥45 years from Porto, Portugal, in 2006-2008.

MAIN OUTCOMES MEASURES

Patterns were identified by latent class analysis, using concomitant variables to predict class membership. Patterns used 11 symptoms/signs, covering dimensions of congestion and hypoperfusion. Sex, age, education, obesity, diabetes and history of myocardial infarction or HF were included as concomitants.

RESULTS

Bayesian information criteria supported a solution with three patterns: 10.1% of participants followed a pattern with symptoms of troubled breathing and signs of congestion (pattern 1), 27.8% a pattern characterised mainly by signs of congestion (pattern 2) and 62.1% were essentially asymptomatic (pattern 3); model fit was best when including concomitant variables. The likelihood ratio of patterns 1, 2 and 3 for left ventricular systolic dysfunction was 3.4, 1.1 and 0.6, and for left ventricular diastolic dysfunction 3.5, 1.4 and 0.5, respectively.

CONCLUSIONS

The use of concomitant variables can improve the diagnostic value of the symptoms and signs patterns and, consequently, improve the usefulness of the symptoms and signs for diagnosis and as an outcome measure. The potential for application in other settings of complex diagnoses is very high. These models were shown to be useful to standardise and quantify the probabilistic reasoning in clinical diagnosis, upon which decisions of further investigation and even treatment need to be made.

Indirect calibration between clinical observers - application to the New York Heart Association functional classification system

Background

Previous studies showed an inter-observer agreement for the NYHA classification of approximately 55%. The aim of this study was to calibrate the New York Heart Association (NYHA) classification system between observers, increasing its reliability.

Results

Among 1136 community-dwellers in Porto, Portugal, aged ≥ 45 years, 265 reporting breathlessness answered a 4-item questionnaire to characterize symptom severity. The questionnaire was administered by 7 physicians who also classified the subject's functional capacity according to NYHA. Each subject was assessed by one physician. We calibrated NYHA classifications by the concurrent method, using 1-parameter logistic graded response model. Discrepancies between observers were assessed by differences in ability thresholds between NYHA classes I-II and II-III. The ability estimated by the model was used to predict the NYHA classification for each observer.

Estimates of the first and second thresholds for each observer ranged from -1.92 to 0.46 and from 1.42 to 2.30, respectively. The agreement between estimated ability and the observers' NYHA classification was 88% (kappa = 0.61).

Conclusions

The study objectively indicates the main reason why several studies have reported low inter-observer is the existence of discrepant thresholds between observers in the definition of NYHA classes. The concurrent method can be used to minimize the reliability problem of NYHA classification.

Neutrophil gelatinase-associated lipocalin in the diagnosis of type 1 cardio-renal syndrome in the general ward

BACKGROUND AND OBJECTIVES

The early identification of acute heart failure (HF) patients with type 1 cardio-renal syndrome should be the first step for developing prevention and treatment strategies for these patients. This study aimed to assess the performance of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C in the early detection of type 1 cardio-renal syndrome in patients with acute HF.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

One-hundred nineteen patients admitted with acute HF were studied. NGAL and creatinine were measured in the first hospitalization morning; creatinine was also measured at least after 48 to 72 hours. Physicians were blinded to NGAL and cystatin C levels. Type 1 cardio-renal syndrome was defined as an increase in the creatinine level of at least 0.3 mg/dl or 50% of basal creatinine.

RESULTS

Type 1 cardio-renal syndrome developed within 48 to 72 hours in 14 patients (11.8%). Admission NGAL levels were higher in these patients: 212 versus 83 ng/dl. At a cutoff value of 170 ng/L, NGAL determined type 1 cardio-renal syndrome with a sensitivity of 100% and a specificity of 86.7%. The area under the receiver-operating characteristic curve of NGAL was 0.93 and that of cystatin C was 0.68.

CONCLUSIONS

Above a cutoff value of 170 ng/L, NGAL predicts 48- to 72-hour development of type 1 cardio-renal syndrome with a negative predictive value of 100% and a positive predictive value of 50%. NGAL independently associates with type 1 cardio-renal syndrome and might be a useful biomarker in the early recognition of these patients.

Clinical significance of impaired relaxation pattern in middle-aged and elderly adults in the general population

INTRODUCTION

The prevalence of diastolic dysfunction in the general population is largely unknown. The purpose of this study was to assess the prevalence of impaired relaxation pattern with normal ejection fraction (IRPNEF) in a population health survey and to analyze associated characteristics.

METHODS

This was a cross-sectional evaluation of 739 community participants aged 45 years or older, randomly selected from the general population. Subjects with left ventricular systolic dysfunction (ejection fraction < 45%), moderate or severe valvular disease or restrictive pattern were excluded, resulting in 653 individuals (age 61.4 +/- 10.3 years, 60.8% women). Diastolic dysfunction was classified according to transmitral inflow pulsed Doppler data.

RESULTS

Overall, 215 (32.9%) had impaired relaxation. IRPNEF was associated with older age (p < 0.001), arterial hypertension (p < 0.001), diabetes (p = 0.03), coronary artery disease (p = 0.006) and metabolic syndrome (p = 0.014). The echocardiographic characteristics associated with IRPNRF were LV hypertrophy (p < 0.001) and left atrial diameter index (p = 0.008). No relation was found between IRPNEF and the clinical syndrome of heart failure or increased BNP level. Nevertheless, exertion dyspnea was more prevalent among subjects with IRPNEF (p = 0.004). In stratified analysis, arterial hypertension, metabolic syndrome and echocardiographic LV hypertrophy were associated with IRPNEF in subjects younger than 65 years, but not in the elderly. Among younger subjects, in multivariate logistic regression analysis, hypertension was a significant predictor of IRPNEF even when adjusting for LV hypertrophy (OR 2.23 [95% CI 1.33-3.73]).

CONCLUSIONS

We found a high prevalence of IRPNEF in the general population, in most cases unaccompanied by overt heart failure. IRPNEF was associated with hypertension in younger subjects but not in the elderly, in agreement with the concept that in older subjects it represents a physiologic phenomenon. IRPNEF was not associated with neurohumoral activation.

Depressive symptoms and heart failure stages

The authors measured depressive symptoms cross-sectionally, across evolving stages of heart failure as defined by the American College of Cardiology, from low risk, through high risk for heart failure (Stage A), asymptomatic cardiac dysfunction (Stage B), up to symptomatic heart failure (Stage C), in a community sample of 338 noninstitutionalized adults age >or=45 years. Depressive symptoms were measured with the Beck Depression Inventory (BDI). Women scored significantly higher on the BDI. Adjusted BDI scores increased linearly with heart failure stages in women, whereas, in men, only Stage C was associated with a significantly higher score.

Effect of Saline Load and Metoclopramide on the Renal Dopaminergic System in Patients with Heart Failure and Healthy Controls

Dopamine of renal origin has natriuretic/diuretic actions by activating D1-like receptors of the nephron. Saline load increases renal dopamine production and natriuresis in healthy subjects, and, under these conditions, the activation of D2-like receptors also produces natriuresis/diuresis. Metoclopramide is a D2-like receptor antagonist. Patients with heart failure (HF) have an increased renal dopamine-synthesizing efficiency. However, the effect of salt loading was not explored in HF. We hypothesized that HF patients respond to salt loading with increased production of renal dopamine and that metoclopramide antagonizes this response. This was a randomized, controlled, crossover study exploring the effect of NaCl and metoclopramide on renal dopaminergic, sympathetic, renin-angiotensin-aldosterone, and arginine-vasopressin (AVP) systems activity on sodium handling in 9 HF patients and 9 controls. NaCl markedly increased renal dopamine production and natriuresis in both groups. Metoclopramide blunted these responses in HF patients but not in controls. NaCl decreased renin and aldosterone plasma levels in controls but not in HF patients. In these patients B-type natriuretic peptide (BNP) levels increased, but AVP was not affected. HF patients respond to salt loading with increased natriuresis. However, the mechanisms for this response are different from those found in healthy subjects. Metoclopramide has antinatriuretic effects only in HF patients.

The effect of dietary sodium restriction on neurohumoral activity and renal dopaminergic response in patients with heart failure

BACKGROUND

This work evaluates the effect of a low-sodium diet on clinical and neurohumoral parameters and on renal dopaminergic system activity in heart failure (HF) patients.

METHODS

We included 24 patients with mild-to-moderate stable HF with left ventricle ejection fraction <40%. Twelve patients were studied before and after a 15-day low-sodium diet; 12 maintained their usual diet. Serum sodium and creatinine, plasma l-DOPA, dopamine, its metabolites, BNP and aldosterone, and 24-h urinary sodium, creatinine, l-DOPA, dopamine and metabolites were measured.

RESULTS

The two groups were matched respecting to demographic and clinical parameters. Low-sodium diet caused significant reductions in weight, 24-h urinary volume and sodium and sodium fractional excretion. Renal delivery of l-DOPA and urinary excretion of l-DOPA significantly decreased while dopamine and metabolites were not affected. Urinary dopamine/l-DOPA and urinary dopamine/renal delivery of l-DOPA ratios increased, plasma l-DOPA decreased and plasma dopamine increased. Plasma aldosterone slightly rose, BNP decreased and noradrenaline and adrenaline increased. NYHA functional class was not affected by sodium restriction. Controls showed no differences.

CONCLUSIONS

These results suggest that sodium restriction leads to activation of antinatriuretic antidiuretic systems in HF patients. However, renal ability to synthesize dopamine is increased in this condition, probably as a counter-regulatory mechanism.

Impact of cardiovascular risk factors in an urban sample of Portuguese adults according to the Framingham risk prediction models

OBJECTIVES

To estimate the 10-year risk of coronary heart disease (CHD) according to the Framingham risk prediction models and to assess the impact of major risk factors in an urban sample of Portuguese adults.

METHODS

We surveyed 938 non-institutionalized adults aged 40 to 74 years, recruited by random digit dialing. A fasting venous blood sample was collected to measure glucose, total cholesterol and high-density-lipoprotein (HDL) cholesterol. Blood pressure was measured and a resting 12-lead ECG registered. Sixty-eight individuals (7.2%) were excluded due to prevalent CHD, according to self-reported information and/or ECG. Data on the remaining 532 women and 338 men at risk were used for analysis. For each participant we calculated the 10-year risk using the Framingham risk tables.

RESULTS

In this community-based sample, the expected 10-year cumulative incidence was estimated to be on average 19.3% for men and 9.5% for women. The factor with greatest impact was hypertension. Had this factor been altered such that individuals whose blood pressure was > or = 140/90 mmHg instead had high-normal blood pressure (130-139/85-89 mmHg), the risk of CHD would have been reduced to 15.7% in men and 7.3% in women. Thus, 18.6% and 23.2% of cases would have been avoided, respectively. The number of individuals in whom hypertension should be prevented to avoid one case of CHD was 15 among men and 25 among women. The impact of other risk factors expressed as a proportion of attributable cases was, in men and women respectively, 5.7% and 7.4% if none had diabetes; 12.4% and 3.2% if none smoked; 23.8% and 14.7% if total cholesterol were between 160 and 199 mg/dl instead of over 200 mg/dl; and 10.9% and 5.3% if HDL were above 45 mg/dl. If all participants did not smoke, did not have diabetes, had total cholesterol between 160 and 199 instead of over 200 mg/dl, HDL over 45 mg/dl and high-normal blood pressure instead of hypertension, the expected cumulative incidence would be 8.1% for men and 5.1% for women. This means that respectively 58.0% and 46.3% of cases would have been avoided.

CONCLUSION

Blood pressure control in this population is the intervention with greatest impact on CHD prevention. Given the tendency for risk factors to cluster and to interact, we can expect to achieve even greater success with multifactorial interventions.