Predictors of prognosis in severe chronic heart failure

Prognostic Significance of Chronic Kidney Disease (CKD-EPI Equation) and Anemia in Patients with Chronic Heart Failure Secondary to Chagas Cardiomyopathy

Background

Few studies regarding chronic kidney disease (CKD) and anemia have been conducted in patients with Chagas cardiomyopathy (CC). We evaluated the risk prediction performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and anemia in CC patients.

Methods

From 2000 to 2010, a total of 232 patients were studied in a single-center retrospective study. CKD was defined as creatinine clearance <60 mL/min/1.73 m² according to CKD-EPI equation. Anemia was defined as hemoglobin <12 g/dL (women) and <13 g/dL (men). Cox proportional hazards models were used to establish predictors for death.

Results

At baseline, 98 individuals (42.2%) had criteria for CKD and 41 (17.7%) for anemia. During follow-up, 136 patients (58.6%) died. Independently, CKD and anemia were not associated with all-cause mortality. However, when they coexisted, an additional risk was attributed for these patients. Cox proportional hazard models analysis identified systolic blood pressure (hazard ratio, 0.99; 95% confidence interval (CI), 0.98 to 1.00; P=0.015), implantable cardioverter-defibrillator (hazard ratio, 0.48; 95% CI, 0.27 to 0.85; P=0.012), left anterior fascicular block (hazard ratio, 1.52; 95% CI, 1.08 to 2.13; P=0.017), left ventricular end-diastolic diameter (hazard ratio, 1.04; 95% CI, 1.02 to 1.06; P < 0.001), and serum sodium (hazard ratio, 0.95; 95% CI, 0.92 to 0.99; P=0.020) as independent predictors for death.

Conclusions

CKD and anemia are not independent predictors for long-term mortality in CC patients. However, the prognosis is poorer in individuals with both comorbidities.

Cardiac Index by Transthoracic Echocardiography (CITE) study

AIMS

Left ventricular ejection fraction (LVEF) is the most frequently used parameter in the assessment of heart failure (HF). Cardiac index (CI) is considered a potential alternative to LVEF despite limited evidence. We aimed to assess and compare the predictive accuracy of LVEF and echocardiographically-assessed CI in HF patients.

METHODS AND RESULTS

A single-centre, retrospective cohort study was conducted in patients hospitalized for acute HF from 2010-2016. Cox proportional hazard models including either LVEF or CI were created to predict all cause death, cardiovascular (CV) death, or first HF-readmission. Of 334 patients included in the analysis, 58.7% exhibited HF with reduced LVEF (HFrEF). Left ventricular ejection fraction did not show correlation with any endpoint, while CI was predictive of HF-readmission in the entire cohort. Both the LVEF-based and CI-based models demonstrated moderate discriminative accuracy when predicting all-cause death, CV death, or HF-readmission. Left ventricular ejection fraction proved to be an independent predictor of CV mortality in HFrEF-patients, while CI was predictive of HF-readmission in the non-HFrEF group.

CONCLUSIONS

Left ventricular ejection fraction seemed to be associated more closely with disease severity in HFrEF, and CI in the non-HFrEF group, in this real-life cohort of elderly HF patients. The LVEF-based and CI-based predictive models have clinically similar predictive accuracy for mortality and HF-readmission, thus CI may be a potential alternative to LVEF in the assessment of left ventricular function. Cardiac index may be an important new tool in the assessment of HF patients with midrange or preserved LVEF.

BNP and ANP as diagnostic and predictive markers in heart failure with left ventricular systolic dysfunction

Background

The prevalence of chronic heart failure (CHF) with systolic dysfunction is increasing. Plasma natriuretic peptides have been envisaged as diagnostic and predictive markers.

Aims

To investigate the relationship between the levels of B-type natriuretic peptide (BNP) and A-type natriuretic peptide (ANP) and the clinical and functional parameters of CHF in outpatients with CHF at baseline, compared with normal healthy controls; to find out the differences in a randomised controlled trial between patients treated with an angiotensin-converting enzyme (ACE) inhibitor, captopril, or an angiotensin receptor blocker (ARB), irbesartan. These differences were assessed throughout the six-month treatment period and at the sixth month.

Methods Plasma BNP (pmol/L) and ANP (pmol/L) were

determined in 68 hypertensive patients with dilated cardiomyopathy, NYHA class III-IV and ejection fraction (EF) <40%, and in 26 normal controls. Statistical analysis for BNP and ANP was done by Student's t-test. The patient group was randomly subdivided into two subgroups of 34 patients, each treated with either an ARB, irbesartan, or an ACE inhibitor (ACE-I), captopril. BNP and ANP were measured in both subsamples and correlated with clinical, functional and neurohormonal parameters throughout a follow-up period of six months and at the sixth month.

Results

The mean EF in the patient sample was 33.43±6.52% and in the controls was 61.96 ±3.53% (p=0.000). The mean BNP (pmol/L) in patients was 44.78±54.36 and in the controls was 7.12±8.28 (p=0.000) and the mean ANP (pmol/L) was 30.32±25.97 in patients and 11.18±7.92 in controls (p=0.000). A statistically significant difference was found between patients and healthy controls. Significant correlations were found between natriuretic peptides and EF. Between the baseline phase and the sixth month, BNP and ANP decreased significantly in the ARB group. At the sixth month, both BNP and ANP were lower in the ARB group. Evidence of clinical benefit was found with both ARB or ACE-I treatment throughout the six months, with patients moving from classes III and IV to class II NYHA. Improvement of EF was also found, with transition of patients with lower EF (even <30%) to higher values. EF was higher in the ARB group at the sixth month.

Conclusions

BNP and ANP can be useful diagnostic tools in hypertensive CHF patients with moderate-to-severe LV dysfunction. The decrease in BNP and ANP in the ARB group throughout six months, as well as the lower value at the sixth month, suggest a prognostic value of these parameters.

The influence of aortoseptal angulation on provocable left ventricular outflow tract obstruction in hypertrophic cardiomyopathy

Objectives

Aortoseptal angulation (AoSA) can predict provocable left ventricular outflow tract obstruction (LVOTO) in patients with symptomatic hypertrophic cardiomyopathy (HCM). Lack of a standardised measurement technique in HCM without the need for complex three-dimensional (3D) imaging limits its usefulness in routine clinical practice. This study aimed to validate a simple measurement of AoSA using 2D echocardiography and cardiac MR (CMR) imaging as a predictor of LVOTO.

Methods

We retrospectively assessed 160 patients with non-obstructive HCM, referred for exercise stress echocardiography. AoSA was measured using resting 2D echocardiography in all patients, and CMR in 29. Twenty-five controls with normal echocardiograms were used for comparison.

Results

Patients with HCM had a reduced AoSA compared with controls (113°±12 vs 126°±6), p<0.0001. Sixty (38%) patients had provocable LVOTO, with smaller angles than non-obstructive patients (108°±12 vs 116°±12, p<0.0001). AoSA, degree of mitral valvular regurgitation and incomplete systolic anterior motion (SAM) were associated with peak left ventricular outflow tract gradient (r=0.508, p<0.0001). An angle ≤100° had 27% sensitivity, 91% specificity and 59% positive predictive value for predicting provocable LVOTO. When combined with SAM, specificity was 99% and positive predictive value 88%. Intraclass correlation coefficient of AoSA measured by two observers was 0.901 (p<0.0001). Bland-Altman analysis of echocardiographic AoSA showed good agreement with the CMR-derived angle.

Conclusions

Measurement of AoSA using echocardiography in HCM is easy, reproducible and comparable to CMR. Patients with provocable LVOTO have reduced angles compared with non-obstructive patients. AoSA is highly specific for provocable LVOTO and should prompt further evaluation in symptomatic patients without resting obstruction.

Kussmaul Physiology in Patients With Heart Failure

Background—

A paradoxical inspiratory rise in right atrial pressure (in contrast to the normal fall during inspiration), Kussmaul sign, has been described in congestive heart failure (CHF). However, the clinical and hemodynamic characteristics and clinical outcomes of patients with CHF and Kussmaul physiology have not been studied.

Methods and Results—

This is a single-center study of consecutive ambulant patients with CHF (New York Heart Association class III/IV) referred for assessment for heart transplantation between November 2011 and April 2013. Kussmaul physiology was defined as inspiratory rise in right atrial pressure during right heart catheterization. Clinical, biochemical, echocardiographic, and hemodynamic correlates were studied and outcomes assessed in patients with or without Kussmaul physiology after a mean follow-up of 379±227 days. Ninety ambulant patients (age, 53±12 years; 86% men) with CHF were studied. Kussmaul physiology was demonstrated in 39 (43%) patients, and it was associated with higher pulmonary pressures and lower cardiac index and pulmonary capacitance (all P <0.05). Patients with Kussmaul physiology were more likely to be treated with higher doses of diuretics, while higher filling pressures, N-terminal pro–B natriuretic peptide levels, and hyponatremia reflected greater neurohormonal activation. Echocardiography revealed greater left and right ventricular dimensions/volumes, restrictive transmitral filling pattern, and lower left ventricular ejection fraction and lower tricuspid annular plane systolic excursion. Peak oxygen uptake was low and comparable in both groups, but ventilation slope was higher in patients with Kussmaul physiology who also had a higher incidence of post-transplant right ventricular failure and overall mortality ( P <0.05).

Conclusions—

Kussmaul physiology is common in patients with CHF referred for heart transplantation and is associated with adverse cardiopulmonary hemodynamics. As a result of the latter, Kussmaul physiology is associated with poorer clinical outcomes. Kussmaul physiology may be useful during assessment of right heart function and pulmonary pressures before transplantation.

The association between the neutrophil/lymphocyte ratio and functional capacity in patients with idiopathic dilated cardiomyopathy

Objective:

The neutrophil/lymphocyte ratio (NLR) is an inexpensive, readily available and reliable inflammatory marker, which has a predictor value in different cardiovascular disorders. Functional capacity is one of the most important prognostic factors in patients with heart failure, which is usually stated as metabolic equivalents (MET). The goal of the study was to investigate the relationship between the NLR and functional capacity (FC) in patients with idiopathic dilated cardiomyopathy (IDC).

Methods:

Treadmill test according to modified-Bruce protocol was performed in 37 patients with IDC (mean age 46.7±11.7 years, 81.1% male) to assess their functional capacity. Baseline clinical and echocardiographic variables were obtained. Hematological and biochemical parameters were measured using standard techniques.

Results:

The patients were divided into low (<5 MET, n=18) and high (>5 MET, n=19) FC groups according to their functional status in the exercise test. The 2 groups were similar regarding age, gender and the presence of hypertension and diabetes mellitus. There was no significant difference between groups regarding echocardiographic parameters such as left ventricular ejection fraction and diameters. However, the NLR was significantly higher in low FC group compared to high FC group (3.62±2.24 vs. 2.24±0.67, p=0.002; respectively). There were significant negative correlations between the NLR, MET and left ventricular ejection fraction (r=-0.405, p=0.013 and r=-0.028, p=0.028; respectively). Diastolic dysfunction was present in all the patients with low functional capacity. A cut-off point of 2.26 for the NLR had 83% sensitivity and 69% specificity in predicting poor FC. After multivariate analysis, only the NLR remained significant predictor of poor functional status.

Conclusion:

We detected a significant association between the NLR and low FC, both of which has predictive and prognostic value in patients with heart failure. Functional capacity may depend on diastolic function rather than left ventricular ejection fraction in patients with IDC.

Prognostic Implication of QRS Variability during Hospitalization in Patients with Acute Decompensated Heart Failure

Background and Objectives

Heart failure (HF) patients display more varied QRS duration. We investigated whether QRS variability during hospitalization for acute decompensated HF is associated with poor clinical outcomes after discharge.

Subjects and Methods

One hundred seventy three patients (64% males; age 60±13 years) admitted for acute decompensated HF with severe left ventricular (LV) dysfunction (LV ejection fraction ≤35%) were consecutively enrolled. QRS variability was calculated by the difference between maximum and minimum QRS duration acquired during hospitalization. The prognostic implications on composite endpoints of death or urgent heart transplantation were analyzed.

Results

Forty-two patients (24.3%) died and three patients (1.7%) underwent urgent heart transplantation during the follow-up of 51±18 months. Patients who reached composite endpoints (n=45) showed greater QRS variability than those who did not (n=128) (20±23 ms vs. 14±14 ms, p=0.046). Patients who had high QRS variability (more than 22 ms; n=36) tended to have a higher event rate than those with QRS variability <22 ms {39% vs. 23%, hazard ratio (HR), 1.88; 95% confidence interval (CI) 1.001-3.539, p=0.05}. Adjusting with other variables, high QRS variability was an independent predictor for composite outcome (HR 1.94; 95% CI 1.023-3.683, p=0.042).

Conclusion

QRS variability measured during hospitalization for acute decompensated HF has a prognostic impact in HF patients with severe LV dysfunction.

Do optimal prognostic thresholds in continuous physiological variables really exist? Analysis of origin of apparent thresholds, with systematic review for peak oxygen consumption, ejection fraction and BNP

Background

Clinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies.

Objectives

We studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO₂), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF).

Data Sources and Eligibility Criteria

Studies testing pVO₂, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed.

Methods

First, we examined studies testing pVO₂, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk.

Results

33 studies (8946 patients) tested a pVO₂ threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10–18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO₂ (r = 0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p = 0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r = 0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r = 0.86 (p<0.0001).

Second, survival simulations always discovered a “most significant” threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r = 0.99, p<0.001).

Limitations

This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds.

Key Findings

First, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO₂, EF or BNP. Second, apparently-optimal thresholds always appear, even with no step in prognosis.

Conclusions

Emphatic therapeutic guidance based on thresholds from observational studies may be ill-founded. We should not assume that optimal thresholds, or any thresholds, exist.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

Renal function has an effect on cardiovascular mortality in patients with dilated cardiomyopathy

BACKGROUND

Chronic heart failure (CHF) is a major and growing public health problem resulting from the cardiac damage caused by a variety of disease processes. CHF has many comorbid conditions such as hypertension, coronary artery disease, peripheral artery disease and chronic kidney disease (CKD). Some of the chronic conditions may have an effect on cardiac mortality in CHF patients. We have investigated the effect of renal dysfunction on cardiovascular mortality in patients with ischemic dilated cardiomyopathy (DCM) and nonischemic DCM.

METHODS

Six hundred and thirty-seven patients with DCM were evaluated between January 2003 and January 2011. All individuals in the study population were admitted to the cardiology clinic because of decompensated heart failure. In this prospective observational study, a total of 637 patients [409 men, 228 women, 18-94 years old, mean age 63 ± 13 years; New York Heart Association (NYHA) functional class II-IV] with diagnoses of ischemic (402) and nonischemic (235) DCM were enrolled in the study. Baseline glomerular filtration rate was calculated using the Cockcroft-Gault equation.

RESULTS

By the end of the study, 228 patients had died due to cardiovascular reasons. Both DCM types had similar cardiovascular mortality [151 patients with ischemic DCM (37%) vs. 77 patients with nonischemic DCM (32%); P = NS]. Renal dysfunction had an effect on cardiovascular mortality in patients with ischemic and nonischemic DCM (respectively, glomerular filtration rate 54 ± 24, 56 ± 24; P < 0.001).

CONCLUSION

We have demonstrated that renal function is a prognostic risk marker in patients with ischemic and nonischemic DCM.

Assessing left ventricular systolic dysfunction after myocardial infarction: are ejection fraction and dP/dt(max) complementary or redundant?

Among the various cardiac contractility parameters, left ventricular (LV) ejection fraction (EF) and maximum dP/dt (dP/dt(max)) are the simplest and most used. However, these parameters are often reported together, and it is not clear if they are complementary or redundant. We sought to compare the discriminative value of EF and dP/dt(max) in assessing systolic dysfunction after myocardial infarction (MI) in swine. A total of 220 measurements were obtained. All measurements included LV volumes and EF analysis by left ventriculography, invasive ventricular pressure tracings, and echocardiography. Baseline measurements were performed in 132 pigs, and 88 measurements were obtained at different time points after MI creation. Receiver operator characteristic (ROC) curves to distinguish the presence or absence of an MI revealed a good predictive value for EF [area under the curve (AUC): 0.998] but not by dP/dt(max) (AUC: 0.69, P < 0.001 vs. EF). Dividing dP/dt(max) by LV end-diastolic pressure and heart rate (HR) significantly increased the AUC to 0.87 (P < 0.001 vs. dP/dt(max) and P < 0.001 vs. EF). In naïve pigs, the coefficient of variation of dP/dt(max) was twice than that of EF (22.5% vs. 9.5%, respectively). Furthermore, in n = 19 pigs, dP/dt(max) increased after MI. However, echocardiographic strain analysis of 23 pigs with EF ranging only from 36% to 40% after MI revealed significant correlations between dP/dt(max) and strain parameters in the noninfarcted area (circumferential strain: r = 0.42, P = 0.05; radial strain: r = 0.71, P < 0.001). In conclusion, EF is a more accurate measure of systolic dysfunction than dP/dt(max) in a swine model of MI. Despite the variability of dP/dt(max) both in naïve pigs and after MI, it may sensitively reflect the small changes of myocardial contractility.

Resting measures and physiological responses to exercise for the determination of prognosis in patients with chronic heart failure: useful tools for clinical decision-making

Despite recent advances in the management of chronic heart failure (CHF), the prognosis of many of these patients remains dire. The need for an accurate prognosis in these patients has led to the identification of several indicators purported to represent the impact of the disease. Such indicators often are obtained at rest and are not always accurate at determining the clinical status of CHF patients. As a result, the relationship between prognostic indicators and clinical outcomes is frequently weak. On the other hand, physiological responses to acute exercise may unmask patients with the worst clinical status and identify those at increased risk of poor outcomes. Therefore, the present review appraises the value of several prognostic indicators for patients with CHF collected at rest and in response to exercise. In particular, it contrasts the value and accuracy of predictors of mortality widely used in clinical settings, such as oxygen uptake, ventilatory efficiency, and left ventricular ejection fraction, with new and more direct indicators of ventricular systolic and diastolic function.

Change in Surgical Management as a Consequence of Real-Time 3D TEE: Assessment of Left Ventricular Function

Real-time 3-dimensional transesophageal echocardiography (RT 3D TEE) is a novel imaging technology that is becoming more frequently encountered in the operating room environment. The authors present a case in which the availability of 3D TEE altered the surgical management of a patient presenting for mitral valve repair. Additionally, the advantages of 3D, as opposed to 2D assessment of left ventricular function, are discussed.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

Background

Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method.

Methods

Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE.

Results

There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP.

Conclusion

Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Cystatin C in acute heart failure without advanced renal impairment

BACKGROUND

The prognostic value of cystatin C relative to glomerular filtration rate (GFR) estimated by the Modification of Diet in Renal Disease Study (MDRD) equation modified for Japan has not been investigated in acute heart failure patients with normal to moderately impaired renal function. More accurate detection of mild renal impairment might improve the risk stratification of heart failure patients, especially patients with normal to moderately impaired renal function.

METHODS

Cystatin C and creatinine levels were measured on admission in 328 consecutive patients hospitalized for worsening chronic heart failure with a GFR estimated by MDRD equation modified for Japan >or=30 mL/min/1.73 m(2).

RESULTS

During a median follow-up period of 915 days, there were 52 (16%) cardiac deaths. In stepwise Cox regression analyses including cystatin C and GFR estimated by MDRD equation modified for Japan (either as continuous variables or as variables categorized into quartiles), cystatin C (P <.0001), but not GFR estimated by MDRD equation modified for Japan, was independently associated with cardiac mortality. Adjusted relative risk according to the quartiles of these markers and Kaplan-Meier analyses revealed that the cystatin C was a better marker to separate low-risk from high-risk patients. Furthermore, receiver-operating characteristic curve analyses of these markers revealed that cystatin C showed a higher precision in predicting cardiac mortality.

CONCLUSION

Measurements of cystatin C might improve early risk stratification compared with GFR estimated by MDRD equation modified for Japan in acute heart failure patients with normal to moderately impaired renal function.

Independent prognostic value of echocardiography and N-terminal pro-B-type natriuretic peptide in patients with heart failure

BACKGROUND

Echocardiographic indices of cardiac structure and function and natriuretic peptide levels are strong predictors of mortality in patients with heart failure. Whether cardiac ultrasound and natriuretic peptides provide independent prognostic information is uncertain.

METHODS

Echocardiograms and measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) were prospectively performed in 211 patients with left ventricular systolic dysfunction who were followed for a median of 4 years. Echocardiographic variables and NT-proBNP were examined as predictors of all-cause mortality in univariable and multivariable proportional hazards models.

RESULTS

Participants averaged 57 years old (SD 12 years) and had a mean left ventricular ejection fraction of 32% (SD 11%). A total of 71 patients (34%) died during the follow-up period. N-terminal pro-brain natriuretic peptide was a strong predictor of mortality (P < .001) as were multiple echocardiographic measures. In models that included age and NT-proBNP, with other clinical variables eligible for entry by stepwise selection, significant predictors of death included left ventricular ejection fraction (P = .013) and end-diastolic volume (P < .001), left atrial volume index (P = .005), right atrial volume index (P = .003), and tricuspid regurgitation area (P = .015). In models that also included left ventricular ejection fraction, end-diastolic volume of the left ventricle (P = .019), left atrial volume (P = .026), and right atrial volume (P = .020) remained significant predictors of mortality.

CONCLUSIONS

Left ventricular size and function and left atrial and right atrial sizes are significant predictors of all-cause mortality in patients with heart failure, independent of NT-proBNP levels and other clinical variables.

Assessment of left ventricular function with 16- and 64-slice multi-detector computed tomography

BACKGROUND

Important to the risk stratification and management of cardiac patients is the assessment of left ventricular function (LVEF), thus imaging modalities which can provide both anatomical and functional data is desirable. Electrocardiographic (ECG) gated multi-detector computed tomographic (MDCT) images may provide accurate assessment of LV ejection fraction, volume and dimensions but have shown systemic errors in the past due to slow gantry rotation speed.

METHODS

Between May 2004 and January 2005, 306 patients underwent ECG-gated cardiac CT studies at the Massachusetts General Hospital. Patients with available CT data sets and a recent (within 3 months) ECHO and/or SPECT perfusion imaging were included in the study. ECG-gated data sets were acquired either with a 16-slice or with a 64-slice MDCT. Functional MDCT data sets were reconstructed in 10 cardiac phases (5-95%) with 1.5mm slices. Images were processed and interpreted by two observers blinded to ECHO and SPECT results.

RESULTS

A total of 69 patients had MDCT and ECHO or SPECT within 3 months (33 had 16-slice and 36 had 64-slice MDCT). There was fair correlation between LVEF measured by 16-slice MDCT and 'ECHO or SPECT' (62+/-10% vs. 62+/-10%; r=0.56). There was poor correlation between LVEF measured by 16-slice MDCT and ECHO (64+/-10% vs. 59+/-11%; r=0.26) and there was good correlation between LVEF measured by 16-slice MDCT and SPECT (62+/-11% and 64+/-9%, respectively; r=0.76). There was very good correlation between LVEF measured by 64-slice MDCT and 'ECHO or SPECT' (57+/-15% vs. 58+/-13%; r=0.86). There was very good correlation between LVEF measured by MDCT and ECHO (56+/-14% vs. 54+/-15%; r=0.89) and between LVEF measured by 64-slice MDCT and SPECT (60+/-13% and 60+/-14%, respectively; r=0.90).

CONCLUSION

The assessment of LVEF and LV dimensions with 64-slice MDCT provide values which are similar to those obtained by echocardiography and Tc-99m gated SPECT. The accuracy of the 64-slice MDCT with a gantry rotation speed of 330 ms (when compared to ECHO and SPECT) may be superior to that of the 16-slice MDCT at 420 ms gantry rotation.

Heart failure and a controlled trial investigating outcomes of exercise training (HF-ACTION): design and rationale

BACKGROUND

Although there are limited clinical data to support the use of exercise training as a means to reduce mortality and morbidity in patients with heart failure, current guidelines state that exercise is beneficial.

TRIAL DESIGN

The objective of this trial is to determine whether exercise training reduces all-cause mortality or all-cause hospitalization for patients with left ventricular systolic dysfunction and heart failure symptoms. After undergoing baseline assessments to determine whether they can safely exercise, patients are randomized to either usual care or exercise training. Patients in the exercise training arm attend 36 supervised facility-based exercise training sessions. Exercise modalities are cycling or walking. After completing 18 sessions, patients initiate home-based exercise and then transition to solely home-based exercise after completing all 36 sessions. Patients return for facility-based training every 3 months to reinforce their exercise training program. Patients are followed for up to 4 years. Physiologic, quality-of-life, and economic end points that characterize the effect of exercise training in this patient population will be measured at baseline and at intervals throughout the trial. Blood samples will be collected to examine biomarkers such as brain natriuretic peptide, tumor necrosis factor, and C-reactive protein.

CONCLUSIONS

Because of its relatively low cost, high availability, and ease of use, exercise training is an intervention that could be accessible to most patients with heart failure. The HF-ACTION trial is designed to definitively assess the effect of exercise training on the clinically relevant end points of mortality, hospitalization, and quality of life in patients with heart failure.

Valor pronóstico de las medidas seriadas de la functión ventricular izquierda y del rendimiento en el ejercicio en la insuficiencia cardiaca crónica

INTRODUCTION AND OBJECTIVES

The prognostic value of a single measurement of ejection fraction and peak oxygen uptake in chronic heart failure has been extensively investigated. The aim of our study was to evaluate the prognostic significance of serial changes in ejection fraction and exercise performance in moderate to severe chronic heart failure.

METHODS

182 patients (156 men, 53 [47-58] years) underwent echocardiography and cardiopulmonary exercise testing at baseline and after 10 [8-12] months. Most patients had idiopathic dilated cardiomyopathy (69%) and all patients presented left ventricular ejection fraction <45%. Median follow-up was 21 [14-34] months; cardiac death and heart transplantation were the end-points. Hazard ratio (HR, per unit) is presented with its 95% confidence interval (CI).

RESULTS

During follow-up 18 patients (9.9%) died and 14 (7.7%) underwent heart transplantation. Baseline ejection fraction (HR, 0.94, 95% CI, 0.89-0.98 P=.006) and mitral regurgitation (HR, 4.22, 95% CI, 1.63-10.92, P=.003), and delta (second examination-baseline) ejection fraction (HR, 0.93, 95% CI, 0.88-0.98, P=.01) were the only significant variables at univariate analysis. Both ejection fraction and delta ejection fraction remained independently associated with events at multivariate analysis. The prognostic power significantly increased between a model including ejection fraction alone and another one including ejection fraction plus delta ejection fraction.

CONCLUSIONS

In clinically stable patients with chronic heart failure, ejection fraction and its changes were independently associated with outcome; on the contrary, serial cardiopulmonary exercise testing did not provide significant prognostic value. Baseline plus changes in ejection fraction showed better prognostic performance than baseline ejection fraction alone.

Glucose and haemoglobin in the assessment of prognosis after first hospitalisation for heart failure

OBJECTIVE

To examine the relationship with outcome of plasma haemoglobin and glucose concentrations, measured soon after first hospital admission with chronic heart failure (CHF), in standard clinical practice.

METHODS AND RESULTS

Hospital records of 528 patients (43% women, mean age 70 years) with first hospital admission for CHF were reviewed. During follow up (mean 1257 days, range 520-1800), 240 (45%) patients died. On admission, 140 of 528 (27%) and at discharge 179 of 472 survivors (38%) were receiving treatment for diabetes. World Health Organization criteria for anaemia were met by 39% of men and 43% of women. Lower haemoglobin (hazard ratio 0.879, 95% confidence interval (CI) 0.828 to 0.933, p < 0.0001) and higher plasma glucose (hazard ratio 1.034, 95% CI 1.008 to 1.061, p = 0.009) had univariate association with all-cause mortality. On multivariate analysis, compared with patients with a normal haemoglobin for their sex, hazard ratio was 1.415 (95% CI 1.087 to 1.841, p = 0.010) for those with low haemoglobin. All-cause mortality fell linearly for haemoglobin up to 159 g/l, above which mortality increased. Glucose above the highest quartile (> 10 mmol/l) was an independent predictor of mortality (hazard ratio 1.966, 95% CI 1.376 to 2.810, p = 0.0002). In survivors of the index admission the association between glucose and mortality was linear, the relationship being stronger for patients without diabetes.

CONCLUSIONS

Lower haemoglobin and higher plasma glucose are associated with all-cause mortality in CHF. Higher glucose is associated with mortality irrespective of diabetic status.

The long-term survival benefit conferred by intermittent dobutamine infusions and oral amiodarone is greater in patients with idiopathic dilated cardiomyopathy than with ischemic heart disease

BACKGROUND

Intermittent dobutamine infusions (IDI) combined with oral amiodarone improve the survival of patients with end-stage congestive heart failure (CHF). The purpose of the present study was to evaluate whether the response to long-term treatment with IDI+amiodarone is different in patients with ischemic heart disease (IHD) versus idiopathic dilated cardiomyopathy (IDC).

METHODS

The prospective study population consisted of 21 patients with IHD (the IHD Group) and 16 patients with IDC (the IDC Group) who presented with decompensated CHF despite optimal medical therapy, and were successfully weaned from an initial 72-h infusion of dobutamine. They were placed on a regimen of oral amiodarone, 400 mg/day and weekly IDI, 10 microg/kg/min, for 8 h.

RESULTS

There were no differences in baseline clinical and hemodynamic characteristics between the 2 groups. The probability of 2-year survival was 44% in the IDC Group versus 5% in the IHD Group (long-rank, P=0.004). Patients with IDC had a 77% relative risk reduction in death from all causes compared to patients with IHD (odd ratio 0.27, 95% confidence interval 0.13 to 0.70, P=0.007). In contrast, no underlying disease-related difference in outcomes was observed in a retrospectively analyzed historical Comparison Group of 29 patients with end stage CHF treated by standard methods.

CONCLUSIONS

Patients with end stage CHF due to IDC derived a greater survival benefit from IDI and oral amiodarone than patients with IHD.

Echocardiographic ejection fraction in patients with acute heart failure: correlations with hemodynamic, clinical, and neurohormonal measures and short-term outcome

BACKGROUND

Although echocardiographic ejection fraction (EF) is frequently used for the estimation of left ventricular contractility in patients with acute heart failure, its exact role and correlations with clinical, hemodynamic, and neurohormonal variables of cardiac contractility is not known.

METHODS

Patients (343) with acute heart failure, enrolled into two prospective placebo-controlled hemodynamic studies of tezosentan, and in whom EF was available at baseline, were included. Outcome was evaluated in a subset of 94 patients who were enrolled in the placebo arms of the studies.

RESULTS

Higher echocardiographic EF was correlated with older age, increased incidence of hypertension and atrial fibrillation, and female gender. We observed weak correlation between EF and cardiac output or cardiac power and no correlation with wedge pressure, and the change in hemodynamic variables over time. Higher EF was correlated with more baseline leukocytosis and higher plasma levels of endothelin-1 and blood urea nitrogen, while lower EF was related to higher baseline B-type natriuretic peptide (BNP). We observed no overall correlations between EF and outcome.

CONCLUSIONS

In patients with acute heart failure, echocardiographic EF is weakly correlated with hemodynamic measures of left ventricular contractility and outcome; hence, it should be interpreted cautiously when evaluating patients admitted due to acute heart failure.

Clinical validation of the gated blood pool SPECT QBS processing software in congestive heart failure patients: correlation with MUGA, first-pass RNV and 2D-echocardiography

INTRODUCTION

Left (LVEF) and right ventricular ejection fraction (RVEF) as well as LV regional wall motion at rest are valuable tools to monitor and tailor treatment of congestive heart failure (CHF) patients. Gated blood pool SPECT (GBPS) is under evaluation as an "all-in-one" technique, providing information on LVEF, RVEF, and wall motion derived from a single examination. Aim of the study was to evaluate a commercially available automated GBPS processing software for EF measurements and wall motion analysis in heart failure patients.

METHODS

Thirty-two patients (12 female; mean age+/-SD: 53+/-13 years), suffering from dilated (63%), ischemic (25%) or hypertrophic (13%) cardiomyopathy, were studied. First-pass radionuclide ventriculography (FP-RNV), planar multigated radionuclide angiography (MUGA), and GBPS were performed at rest after in vivo labeling of red blood cells, and LVEF and RVEF was calculated with each method. Later on the same day LVEF was calculated by echocardiography. LV wall motion (summed motion score and wall motion index) was derived from GBPS and echocardiography using the standard 16-segment model.

RESULTS

Mean LVEF measured by GBPS, echocardiography, MUGA and FP-RNV was 33+/-13%, 37+/-15%, 41+/-14% and 45+/-13%, respectively. LVEF values calculated from GBPS showed moderate to good correlation with FP-RNV (r=0.61), MUGA (r=0.65) and ECHO (r=0.74; all p<0.01). Mean RVEF calculated by GBPS, FP-RNV and MUGA was 45+/-14%, 46+/-9% and 38+/-9%, respectively. RVEF values calculated from GBPS showed weak correlation with FP-RNV (r=0.33) and MUGA (r=0.26; all p=n.s.). Assessment of GBPS wall motion was qualitatively possible in all patients. The agreement between GBPS and ECHO was 82% (kappa=0.73). The wall motion index showed good correlation between both methods (r=0.88; p<0.001).

CONCLUSION

An automated algorithm for LVEF calculation and wall motion analysis using GBPS is feasible for clinical routine diagnostic in CHF patients. The RVEF calculation method needs to be improved before routine clinical application can be recommended.

Prognostic value of systolic mitral annular velocity measured with Doppler tissue imaging in patients with chronic heart failure caused by left ventricular systolic dysfunction

OBJECTIVE

To assess the prognostic value of various conventional and novel echocardiographic indices in patients with chronic heart failure (CHF) caused by left ventricular (LV) systolic dysfunction.

METHODS

185 patients with a mean (SD) age of 67 (11) years with CHF and LV ejection fraction < 45% despite optimal pharmacological treatment were prospectively enrolled. The patients underwent two dimensional echocardiography with tissue harmonic imaging to assess global LV systolic function and obtain volumetric data. Transmitral flow was assessed with conventional pulse wave Doppler. Systolic (Sm), early, and late diastolic mitral annular velocities were measured with the use of colour coded Doppler tissue imaging.

RESULTS

During a median follow up of 32 months (range 24-38 months in survivors), 34 patients died and one underwent heart transplantation. Sm velocity (hazard ratio (HR) 0.648, 95% confidence interval (CI) 0.463 to 0.907, p = 0.011), diastolic arterial pressure (HR 0.965, 95% CI 0.938 to 0.993, p = 0.015), serum creatinine (HR 1.006, 95% CI 1.001 to 1.011, p = 0.023), LV ejection fraction (HR 0.945, 95% CI 0.899 to 0.992, p = 0.024), age (HR 1.035, 95% CI 1.000 to 1.071, p = 0.052), LV end systolic volume index (HR 1.009, 95% CI 0.999 to 1.019, p = 0.067), and restrictive pattern of transmitral flow (HR 0.543, 95% CI 0.278 to 1.061, p = 0.074) predicted the outcome of death or transplantation on univariate analysis. On multivariate analysis, only Sm velocity (HR 0.648, 95% CI 0.460 to 0.912, p = 0.013) and diastolic arterial pressure (HR 0.966, 95% CI 0.938 to 0.994, p = 0.016) emerged as independent predictors of outcome.

CONCLUSIONS

In patients with CHF and LV systolic dysfunction despite optimal pharmacological treatment, the strongest independent echocardiographic predictor of prognosis was Sm velocity measured with quantitative colour coded Doppler tissue imaging.

Origin of symptoms in chronic heart failure

Skeletal muscle abnormalities are highly prevalent in chronic heart failure and are associated with an increase in the ergoreflex, a muscle reflex stimulated by work done. Stimulation of the ergoreflex results in increased ventilation and contributes to the increased sympathetic activation of the heart failure syndrome. The origin of the skeletal myopathy is related to a chronic imbalance between catabolic and anabolic processes, presumably as a consequence of chronic haemodynamic stress. Symptoms arise from the skeletal myopathy, causing the sensation of fatigue and contributing to the sensation of breathlessness as the myopathy affects respiratory muscle. Ergoreflex activation causes a greater ventilatory response to exercise than normal, contributing to the sensation of breathlessness.

Hypothermia is a bedside predictor of imminent death in patients with congestive heart failure

BACKGROUND

Most studies on predictors of mortality for patients with congestive heart failure (CHF) have described predictors that are either difficult to measure in routine practice or are only modestly sensitive and specific. Having observed 3 patients whose body temperature decreased shortly before death, we hypothesized that hypothermia may predict inhospital mortality.

METHODS

The medical records of 291 patients with a primary discharge diagnosis of CHF were selected from 423 admissions to Memorial Hermann Hospital, Houston, Tex, 1998, after excluding patients with comorbidities that confound body temperature, deaths for causes other than progressive pump failure, and readmissions except the last. Three groups were defined on the basis of admission body temperature (T adm): hypothermia groups T adm (95.5 degrees F-96.5 degrees F) and T adm < 95.5 degrees F, and reference group T adm > or = 96.6 degrees F. Several other known CHF risk factors were studied for confounding, and adjusted hazard ratios were calculated using Cox regression.

RESULTS

Of the 291 patients (mean age 73 years, 47% men), 17 (6%) had hypothermia on admission. Mean hospital stay was 5 days. Of the 17 (6%) patients who died of pump failure, 5 had been hypothermic on admission. Hypothermia was significantly associated with survival, and after adjusting for New York Heart Association functional class, hazard ratio for T adm < 95.5 degrees F was 4.46 (95% confidence interval 1.38-14.3) (P trend = .0283).

CONCLUSIONS

Hypothermia predicted inhospital death in these patients with CHF. If confirmed by future studies, this finding could prove useful, because temperature can be measured continuously, rapidly, and inexpensively, in or out of the hospital.

Impact of mitral valve annuloplasty on mortality risk in patients with mitral regurgitation and left ventricular systolic dysfunction

OBJECTIVES

This study was designed to assess effects of mitral valve annuloplasty (MVA) on mortality in patients with mitral regurgitation (MR) and left ventricular (LV) systolic dysfunction.

BACKGROUND

Mitral valve annuloplasty improves hemodynamics and symptoms in these patients, but effects on long-term mortality are not well established.

METHODS

We retrospectively analyzed consecutive patients with significant MR and LV systolic dysfunction on echocardiography between 1995 and 2002. Cox regression analysis, including MVA as a time-dependent covariate and propensity scoring to adjust for differing probabilities of undergoing MVA, was used to identify predictors of death, LV assist device implantation, or United Network for Organ Sharing-1 heart transplantation.

RESULTS

Of 682 patients identified, 419 were deemed surgical candidates; 126 underwent MVA. Propensity score derivation identified age, ejection fraction, and LV dimension to be associated with undergoing MVA. End points were reached in 120 (41%) non-MVA and 62 (49%) MVA patients. Increased risk of end point was associated with coronary artery disease (hazard ratio [HR] 1.80, 95% confidence interval [CI] 1.30 to 2.49), blood urea nitrogen (HR 1.01, 95% CI 1.005 to 1.02), cancer (HR 2.77, 95% CI 1.45 to 5.30), and digoxin (HR 1.66, 95% CI 1.15 to 2.39). Reduced risk was associated with angiotensin-converting enzyme inhibitors (HR 0.65, 95% CI 0.44 to 0.95), beta-blockers (HR 0.59, 95% CI 0.42 to 0.83), mean arterial pressure (HR 0.98, 95% CI 0.97 to 0.99), and serum sodium (HR 0.93, 95% CI 0.90 to 0.96). Mitral valve annuloplasty did not predict clinical outcome.

CONCLUSIONS

In this analysis, there is no clearly demonstrable mortality benefit conferred by MVA for significant MR with severe LV dysfunction. A prospective randomized control trial is warranted for further study of mortality with MVA in this population.

Stress-echocardiography in idiopathic dilated cardiomyopathy: instructions for use

A number of studies have suggested that stress-echocardiography may be used for prognostic stratification in patients with idiopathic dilated cardiomyopathy. There is no consensus on which protocol or which measurements of left ventricular contractile reserve to use. The most frequently used protocol is low-dose dobutamine stress-echocardiography, and most commonly used measures of left ventricular systolic performance are ejection fraction, wall motion score index and cardiac power output.Stress-echocardiography has been shown to predict improvement in cardiac function in patients with recently diagnosed dilated cardiomyopathy, as well as to predict which patients will benefit from the treatment with beta-blockers. Most importantly, stress-echocardiography can identify patients with worse prognosis in terms of cardiac death and need for transplantation. Additionally, contractile reserve is closely correlated with maximal oxygen consumption and can even be used for further stratification in patients with maximal oxygen consumption between 10 and 14 ml/kg/min. Future studies are needed for head-to-head comparison of various protocols in an attempt to make standardization in the assessment of patients with dilated cardiomyopathy.

Dilated cardiomyopathy: an update

Despite many advances in he diagnosis and treatment of DCM, it continues to be an important cause of cardiovascular morbidity and mortality in large-breed dogs. In the coming years, it is hoped and anticipated tht further discoveries will be made in the areas of etiology, therapy, and assessment of prognosis, ultimately with a view to having a greater impact on the clinical management of these cases.

Relationship between right ventricular ejection fraction and maximum exercise oxygen consumption: a methodological study in chronic heart failure patients

BACKGROUND

Peak oxygen consumption at maximum exercise (peak VO(2)) predicts survival in chronic heart failure (CHF) patients. Right ventricular ejection fraction (RVEF) at rest has been reported to correlate with peak VO(2). We evaluated the strength and consistency of the association between peak VO(2) and RVEF measured by different radionuclide ventriculography (RNV) techniques in a prospective cohort study.

METHODS AND RESULTS

In 58 consecutive CHF patients (mean age, 53 years; 39 patients with dilated cardiomyopathy; 48 men), upright symptom-limited bicycle ergometry was performed. During exercise, ventilatory and gas exchange data were recorded and peak VO(2) was calculated. RVEF was calculated by use of first-pass (FP) RNV with single and dual region of interest (ROI) acquisition and planar multigated acquisition (MUGA). Irrespective of the method used, RVEF showed no relevant correlation with the corresponding peak VO(2) value (r = 0.11 for FP single ROI, r = 0.06 for FP dual ROI, r = 0.16 for MUGA). Peak VO(2) or changes in peak VO(2) after 6 and 12 months of follow-up were not determined by RVEF measurements.

CONCLUSION

In CHF patients no association was found between peak VO(2) at maximum exercise and RVEF at rest with different RNV techniques. Changes in exercise capacity are not reliably reflected by changes in RVEF measurements at rest.

Prognostic implications of echocardiography in advanced heart failure

PURPOSE OF REVIEW

The growing epidemic of systolic congestive heart failure mandates strategies to identify accurately people with high morbidity and mortality. Echocardiography remains the most widely available noninvasive tool for the assessment of cardiac structure, function, and hemodynamics. Clinical data paired with echocardiographic analysis in patients with systolic heart failure obtained from a variety of investigations have allowed for the evaluation of this modality as a prognostic tool.

RECENT FINDINGS

Detailed appraisal of the literature has revealed five distinct, easy-to-evaluate echocardiographic parameters that may assist clinicians to segregate high-risk patients. The presence of or the inability to modify a left ventricular ejection fraction less than 25%, impaired right ventricular function (assessed by any of four methods), left ventricular end-diastolic dimension greater than 6.5 to 7 cm, a restrictive mitral inflow, or pulmonary hypertension (peak tricuspid regurgitant velocity >2.5 m/s) should alert clinicians of patients with high morbidity (recurrent congestive heart failure admission, arrhythmia, impaired functional capacity) and mortality. Particularly important among these variables is the presence of a restrictive mitral inflow pattern.

SUMMARY

Detailed analysis of two-dimensional and Doppler data routinely obtained from echocardiograms has established prognostic implications among patients with systolic heart failure. Although prospective clinical trials are lacking, the use of echocardiography to segregate risk should be incorporated into current strategies to treat congestive heart failure and influence clinical listing for cardiac transplantation.

Peak exercise oxygen pulse and prognosis in chronic heart failure

Cardiopulmonary variables, particularly peak oxygen consumption (peak VO(2)) corrected for total and lean body weight, have been confirmed to predict prognosis in patients with chronic systolic heart failure (HF). Only limited data are available on the prognostic ability of maximal oxygen (O(2)) pulse, an indicator of stroke volume and arteriovenous O(2) difference, especially when corrected for lean body mass. Cardiopulmonary exercise tests were performed in 209 consecutive patients with mild-to-moderate HF (mean ejection fraction 23%), followed for 19 +/- 12 months to determine the impact of maximal O(2) pulse in relation to other cardiopulmonary variables on major clinical events (13 cardiovascular deaths and 15 urgent transplantations). Compared with patients with clinical events, those without major events had a higher peak O(2) pulse (11.4 +/- 4.1 vs 9.2 +/- 2.3 ml/beat, p <0.0001) and body fat-adjusted peak O(2) pulse (15.6 +/- 5.6 vs 11.9 +/- 3.4 ml/beat, p <0.0001). In multivariate analysis, a low peak O(2) pulse was the strongest independent predictor of clinical events (chi-square 10.5, p <0.01). Although peak O(2) pulse was a stronger predictor for clinical events than any other exercise cardiopulmonary variable, including peak VO(2), peak VO(2) lean (defined as the VO(2) corrected for lean body mass), and percentage of predicted peak VO(2), this relation was further strengthened by correcting peak O(2) pulse for percent body fat (chi-square 12.4, p <0.001). In most subgroups (including women, obese subjects, those receiving beta blockers, and those with class III HF), peak O(2) pulse lean was similar to or superior to peak VO(2) lean for predicting major clinical events. Especially in patients who were class III HF and who were receiving beta blockers, peak VO(2) (cutoff 14 ml/kg/min) poorly predicted prognosis; risk stratification was best with peak O(2) pulse lean (cutoff 14 ml/beat). These data indicate the potential usefulness of peak O(2) pulse and lean body mass-adjusted O(2) pulse for predicting prognosis in patients with systolic HF.

A new method using pulmonary gas-exchange kinetics to evaluate efficacy of beta-blocking agents in patients with dilated cardiomyopathy

BACKGROUND AND OBJECTIVES

The effects of beta-blocking agents on exercise tolerance in cardiopulmonary exercise testing (CPX) have not been fully identified. Because the negative chronotropic effects of these agents produce a sluggish increase in heart rate (HR) during CPX, exercise capacity is actually underestimated by methods that depend on HR-related variables such as peak oxygen uptake (O(2)) and anaerobic threshold (AT). The aim of this study was to clarify the efficacy of beta-blocking agents by means of O(2) kinetics, a parameter independent of HR, in patients with dilated cardiomyopathy (DCM).

DESIGN AND PATIENTS

The exercise capacity of 12 patients (9 men and 3 women; mean +/- SD age, 54 +/- 12 years; New York Heart Association class I [n = 1], NYHA class 2 [n = 4], and NYHA class III [n = 6]) with DCM, who were treated with beta-blocking agents, was evaluated by CPX. O(2) was calculated from respiratory gas analysis on a breath-by-breath basis. Nine patients were treated with metoprolol (30 mg or 60 mg), two with carteolol (10 mg or 20 mg), and one patient with atenolol (25 mg).

RESULTS

All patients showed a significantly favorable results (ie, improvement in symptoms of congestive heart failure). Peak O(2) (20.4 +/- 5.1 to 18.8 +/- 5.8 mL/min/kg), AT (12.7 +/- 3.5 to 12.1 +/- 2.1 mL/min/kg), and exercise time (4.8 +/- 2.2 to 4.5 +/- 2.1 s) were unchanged. The time constant of O(2) kinetics (tau) on response to constant low-dose work loading (warm up) decreased significantly (64 +/- 30 to 44 +/- 24 s; p < 0.01) and ejection fraction increased (30 +/- 14 to 44 +/- 15%, p < 0.01) significantly following treatment with beta-blocking agents. In spite of excluding two NYHA I patients, these changes were also statistically correlated.

CONCLUSION

In the low level of exercise, tau was prolonged in patients with DCM. Although indexes of total exercise time and AT were not useful markers for clinical improvement in cardiac performance as assessed by echocardiography, measuring can validly assess the beneficial effects in heart failure treated with beta-blocking agents.