Development and prospective validation of a clinical index to predict survival in ambulatory patients referred for cardiac transplant evaluation

Prediction of sudden death in heart failure patients: a novel perspective from the assessment of the peak ectopy rate

AIMS

In patients with heart failure (HF), the association between sudden death and arrhythmic pattern at 24-h Holter monitoring [number of ventricular premature contractions per hour (VPCs/h) and presence of non-sustained ventricular tachycardia (NSVT)] has previously been investigated with conflicting results. Since both VPCs/h and NSVT disregard the time course of arrhythmic events, we developed a new index based on the short-term peak rate of ectopies and investigated its prognostic power in HF patients.

METHODS AND RESULTS

We studied 200 HF patients in sinus rhythm [age: [median (interquartile range)] 54 years [47-58], left ventricular ejection fraction (LVEF): 23% [19-28], New York Heart Association (NYHA) class II-III: 88%]. For each patient, the Holter recording was automatically scanned shifting a 30 beat window one beat at a time, and the maximum number of ectopic beats found in a window was named peak ectopy rate (PEAK_ER). The association between PEAK_ER and sudden death was assessed by Cox proportional hazards regression analysis. Survival analysis was also carried out adjusting for NYHA class, aetiology, LVEF, left ventricular end diastolic diameter, blood urea nitrogen, amiodarone, Digoxin, beta-blockers, NSVT, VPCs/h, and the standard deviation of all normal-to-normal beats. During a 5-year follow-up [31 (12-60) months], 23 patients died of sudden death. Out of the arrhythmic markers, PEAK_ER but not VPCs/h and NSVT was significantly associated with sudden death in univariable analysis (RR: 1.08, 95% CI: 1.02-1.14, P = 0.005) and after adjustment for covariates (RR: 1.09, 95% CI: 1.03-1.15, P = 0.004).

CONCLUSIONS

The investigation of the time course of arrhythmic events provides independent information in the identification of patients at increased risk of sudden death and may therefore be considered in the development of treatment strategies in HF patients.

Inverse Relationship of Blood Pressure Levels to Sudden Cardiac Mortality and Benefit of the Implantable Cardioverter-Defibrillator in Patients With Ischemic Left Ventricular Dysfunction

OBJECTIVES

This study was designed to evaluate the relationship among blood pressure (BP) levels, risk of sudden cardiac death (SCD), and benefit of the implantable cardioverter-defibrillator (ICD) in patients with ischemic left ventricular (LV) dysfunction.

BACKGROUND

Low BP has been shown to be associated with increased mortality in patients with LV dysfunction and heart failure. We hypothesized that increasing BP levels are associated with a reduction in the risk of SCD in this population, thereby limiting ICD efficacy in a lower-risk subset.

METHODS

The independent contribution of systolic blood pressure (SBP) and diastolic blood pressure (DBP) to outcome was analyzed in 1,231 patients enrolled in the prospective MADIT-II (Multicenter Automatic Defibrillator Implantation Trial II).

RESULTS

Multivariate analysis showed that in the conventional therapy arm of the trial, 10-mm Hg increments in systolic BP were independently associated with a respective 14% (p = 0.01) and 16% (p = 0.04) reduction in the risk of cardiac mortality and SCD; similar trends were shown for DBP. Defibrillator therapy provided the least survival benefit to patients in the lower-risk, upper SBP (>130 mm Hg) and DBP (>/=80 mm Hg) quartiles (hazard ratio 1.04 [p = 0.89] and 1.05 [p = 0.88], respectively), whereas a respective 39% and 38% (p = 0.002) reduction in the risk of death with ICD therapy was observed among patients with lower BP values.

CONCLUSIONS

In patients with ischemic LV dysfunction, SBP and DBP levels show an inverse correlation with sudden cardiac mortality. These noninvasive hemodynamic parameters may be useful for identifying lower-risk patients, in whom the benefit of primary defibrillator implantation is more limited.

QRS and QTc interval prolongation in the prediction of long-term mortality of patients with acute destabilised heart failure

OBJECTIVES

To quantify the prognostic utility of QRS and QTc interval prolongation in patients presenting with acute destabilised heart failure (ADHF) to the emergency department (ED).

DESIGN

Prospective cohort study among patients enrolled in the B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation (BASEL) study. QRS and QT intervals were measured in 173 consecutive patients with ADHF. QT interval was corrected using the Bazett formula. The primary end point was all-cause mortality during the 720-day follow-up.

RESULTS

QRS interval was prolonged (> or =120 ms) in 27% of patients, and QTc interval was prolonged (> or =440 ms) in 72% of patients. Baseline demographic and clinical characteristics were comparable in patients with normal and prolonged QRS or QTc intervals. A total of 78 patients died during follow-up. Interestingly, the 720-day mortality was similar in patients with prolonged and normal QTc (44% vs 42%, p = 0.546), but was significantly higher in patients with prolonged QRS interval than in those with normal QRS (59% vs 37%, p = 0.004). In Cox proportional hazards analysis, prolonged QRS interval was associated with a nearly twofold increase in mortality (HR 1.94, 95% CI 1.22 to 3.07; p = 0.005). This association persisted after adjustment for variables routinely available in the ED.

CONCLUSIONS

Prolonged QRS interval, but not prolonged QTc interval, is associated with increased long-term mortality in patients with ADHF.

Hemodynamic changes during cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a new method for the correction of inter- and/or intraventricular conduction delays of patients with heart failure. The long-term impact of CRT on central hemodynamics is not fully characterized. We performed complete right heart catheterization studies in 31 patients receiving a CRT device pre and 6 months after implantation. Most of the patients improved in their NYHA stage, their LVEF, and in parallel showed reduced right atrial (RA) pulmonary artery (PA) and pulmonary capillary wedge (PCW) pressures and pulmonary vascular resistance both at rest and at 25 watts. In addition, we found a reduction in heart rate accompanied by an increased mean arterial pressure both at rest and at 25 watts. Accordingly, brain natriuretic peptide levels (BNP) were lowered. It was concluded that, besides other well-known effects on ventricular coordination, central hemodynamics after 6 months were improved during CRT.

What can post market registries tell us about the use of cardiac resynchronization therapy?

Cardiac resynchronization therapy (CRT) has become an established therapeutic option for patients with dilated cardiomyopathies and New York Heart Association class III congestive heart failure symptoms who also have a widened QRS complex on their electrocardiograms (generally > 120 ms). Results from a number of clinical trials have shown that CRT improves patients' exercise tolerance, quality of life, and survival. There is further evidence that CRT has structural effects on the heart with improved cardiac function. Despite these salutary results, clinical trials in CRT study prespecified populations that fit the inclusion criteria for these trials. Many patients have been excluded from these clinical trials and yet may potentially benefit from CRT. Evaluation of the effects of CRT on these populations might reveal the potential to expand the use of this therapy in larger numbers of patients to CRT who may not have been included in the clinical trial. This review article will assess the limitations of some of the clinical trials in CRT and will discuss the potential for CRT registries that are presently underway to extend the patient population that may benefit from this therapeutic option.

Are women worldwide under-treated with regard to cardiac resynchronization and sudden death prevention?

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival in patients with serious structural heart disease. Likewise, cardiac resynchronization therapy (CRT) has assumed an important role in the treatment of patients with symptomatic heart failure because of its demonstrated value in improving functional class, quality of life, exercise capacity, and survival. However, these clinical trials have all primarily enrolled Caucasian males, raising the question as to whether other important subgroups benefit in a comparable way. Women have lower rates of sudden cardiac death (SCD) compared to men, and event rates lag 10-20 years behind those in men. Among patients with known coronary artery disease, women have one-fourth the risk of SCD found in men. Women with heart failure tend to present at an older age than men, and women more often have heart failure with preserved systolic function, a group in whom prophylactic ICD therapy for the prevention of SCD has not been studied. Despite these differences, analysis of clinical trial results shows that women have similar outcomes with ICD and CRT therapy compared to men. There is a lower percentage of women among device therapy patients both in clinical trials and in practice for reasons that are not clear, but at least some of the difference is likely due to differences in age at presentation and co-morbidities. In fact, device therapy overall appears to be under-utilized in both men and women, when implantation rates are compared to the prevalence of heart failure in the population as a whole.

Mode of Death From Congestive Heart Failure: Implications for Clinical Management

The care of the end-stage patient has not been extensively studied, and little is known about best care practices. Therefore, using new definitions for mode of death due to heart failure, we performed a retrospective chart review of records from a university-based heart failure disease management program to characterize the population of patients dying from heart failure and to define clinical predictors that identify patients who will likely die of metabolic and/or progressive causes. Of 74 deaths recorded over a 60-month period, 17.6% and 21.3% were deemed to be metabolic or progressive, respectively. Utilization of resources was considerable, and only a small number of patients died while in hospice. Patients who required continuous inotropic support and those with preexisting renal failure were at highest risk for non-sudden cardiac death. We conclude that prospective identification of patients at risk for metabolic and progressive heart failure death is possible. The numbers of these patients is likely to increase in an era of implantable cardioverter-defibrillators. Intervention studies designed to evaluate and improve strategies that emphasize symptom control should target this group.

Comparison of peak exercise oxygen consumption and the Heart Failure Survival Score for predicting prognosis in women versus men

The Heart Failure Survival Score (HFSS) and peak exercise oxygen consumption (VO2) predict survival in ambulatory patients with heart failure and are used for selection for cardiac transplantation. However, the populations tested have predominately been men. To investigate if peak VO2 and the HFSS predict prognosis in women, we derived HFSS and measured peak VO2 in 274 women referred for cardiac transplantation and in 278 men matched by referral year. Seven HFSS parameters were obtained, including presence of coronary artery disease, left ventricular ejection fraction, heart rate, mean arterial blood pressure, peak VO2, presence of intraventricular conduction defects, and serum sodium. Subjects were divided into high-, medium-, and low-risk strata for HFSS and VO2 based on previous cutpoints. Survival curves were derived using Kaplan-Meier analysis and compared by log-rank analysis. Follow-up averaged 929 days. For women, 1-year event-free survival in the low- (>14), medium- (10.1 to 14), and high-risk (<10 ml/kg/min) VO2 strata was 93%, 84%, and 80%, respectively. For the HFSS, 1-year event-free survival in the low- (>or=8.10), medium- (7.20 to 8.09), and high-risk (<or=7.19) strata was 90%, 87%, and 67%, respectively. Survival curves for VO2 (p <0.01) and HFSS (p <0.001) demonstrated significant differences. In both genders, the low-risk groups for HFSS and VO2 can safely have transplantation deferred. Women had better survival than men for a given peak VO2. The HFSS was consistent between genders. In conclusion, peak VO2 and the HFSS are excellent parameters to predict survival in women with congestive heart failure. THE HFSS is more consistent than the peak VO2 between the genders.

Nonlinear indices of heart rate variability in chronic heart failure patients: redundancy and comparative clinical value

AIMS

We aimed to assess the mutual interrelationships and to compare the prognostic value of a comprehensive set of nonlinear indices of heart rate variability (HRV) in a population of chronic heart failure (CHF) patients.

METHODS AND RESULTS

Twenty nonlinear HRV indices, representative of symbolic dynamics, entropy, fractality-multifractality, predictability, empirical mode decomposition, and Poincaré plot families, were computed from 24-hour Holter recordings in 200 stable CHF patients in sinus rhythm (median age [interquartile range]: 54 [47-58] years, LVEF: 23 [19-28]%, NYHA class II-III: 88%). End point for survival analysis (Cox model) was cardiac death or urgent transplantation. Homogeneous variables were grouped by cluster analysis, and in each cluster redundant variables were discarded. A prognostic model including only known clinical and functional risk factors was built and the ability of each selected HRV variable to add prognostic information to this model assessed. Bootstrap resampling was used to test the models stability. Four nonlinear variables showed a correlation >0.90 with classical linear ones and were discarded. Correlations >0.80 were found between several nonlinear variables. Twelve clusters were obtained and from each cluster a candidate predictor was selected. Only two variables (from empirical mode decomposition and symbolic dynamics families) added prognostic information to the clinical model.

CONCLUSION

This exploratory study provides evidence that, despite some redundancies in the informative content of nonlinear indices and strong differences in their prognostic power, quantification of nonlinear properties of HRV provides independent information in risk stratification of CHF patients.

[Resynchronization therapy of heart failure]

Heart failure has a high prevalence and it has a poor prognosis despite the advances in pharmacological treatment. Cardiac resynchronization therapy with biventricular pacemaker has a clinically proven efficacy in the treatment of heart failure with intraventricular dyssynchrony. Conventionally the therapy is indicated in severe drug refractory heart failure (NYHA III-IV) with optimal drug treatment, increased QRS duration (> or = 120 ms), echocardiographic parameters (left ventricular ejection fraction at most 35%). Implementation of new methods (tissue doppler echocardiography, CT, MRI, electroanatomical mapping) can help to select potentially responding patients. Individual optimization of therapy can be performed with non-invasive and invasive methods, the efficacy can be improved even in responding patients. Due to the outstanding efficiency widening the indications is a must. Currently, the efficacy is being investigated in mild heart failure and patients with narrow QRS. Several other questions (transvenous or surgical implantation, need of an implantable defibrillator) will be answered in future trials.

Influence of Blood Pressure on the Effectiveness of a Fixed-Dose Combination of Isosorbide Dinitrate and Hydralazine in the African-American Heart Failure Trial

OBJECTIVES

This study sought to assess the effect of baseline systolic blood pressure (SBP) and changes in SBP on the effectiveness of treatment with fixed-dose combination of isosorbide dinitrate and hydralazine (FDC I/H) in patients with heart failure (HF).

BACKGROUND

Low SBP is a risk factor for adverse outcomes in patients with HF. However, FDC I/H lowered SBP in the A-HeFT (African-American Heart Failure Trial) and yet prolonged survival. Whether blood pressure (BP) lowering is critical to the efficacy of FDC I/H and whether a low BP limits its effectiveness is unclear.

METHODS

The effects of FDC I/H on SBP and on mortality and hospitalization were compared in patients with a low or high baseline SBP using multivariable Cox regression models. The interaction between the effect of treatment and baseline SBP was examined.

RESULTS

Mean +/- SD baseline SBP in all of the patients was 126 +/- 18 mm Hg. Patients with baseline SBP equal to or below the median (126 mm Hg) had features of more severe HF. Baseline SBP equal to or below the median was an independent risk factor for death (hazard ratio [HR] 2.09; 95% confidence interval [CI] 1.02 to 4.29) or first hospitalization for HF (HR 1.66; 95% CI 1.18 to 2.34). The FDC I/H treatment reduced BP in patients with SBP above the median but not in patients with SBP below 126 mm Hg. The FDC I/H treatment was associated with a similar decrease in mortality or hospitalization for HF in patients with SBP below the median and above the median. The effects of FDC I/H on mortality alone were also similar.

CONCLUSIONS

In A-HeFT, patients with lower SBP had a greater risk but a similar relative benefit from the use of FDC I/H as those with higher SBP. The FDC I/H treatment did not reduce SBP in patients with low SBP. An asymptomatic low SBP should not be considered a contraindication to use of FDC I/H in patients with HF.

A Novel Two-Dimensional Echocardiographic Image Analysis System Using Artificial Intelligence-Learned Pattern Recognition for Rapid Automated Ejection Fraction

OBJECTIVES

We sought to test the hypothesis that a novel 2-dimensional echocardiographic image analysis system using artificial intelligence-learned pattern recognition can rapidly and reproducibly calculate ejection fraction (EF).

BACKGROUND

Echocardiographic EF by manual tracing is time consuming, and visual assessment is inherently subjective.

METHODS

We studied 218 patients (72 female), including 165 with abnormal left ventricular (LV) function. Auto EF incorporated a database trained on >10,000 human EF tracings to automatically locate and track the LV endocardium from routine grayscale digital cineloops and calculate EF in 15 s. Auto EF results were independently compared with manually traced biplane Simpson's rule, visual EF, and magnetic resonance imaging (MRI) in a subset.

RESULTS

Auto EF was possible in 200 (92%) of consecutive patients, of which 77% were completely automated and 23% required manual editing. Auto EF correlated well with manual EF (r = 0.98; 6% limits of agreement) and required less time per patient (48 +/- 26 s vs. 102 +/- 21 s; p < 0.01). Auto EF correlated well with visual EF by expert readers (r = 0.96; p < 0.001), but interobserver variability was greater (3.4 +/- 2.9% vs. 9.8 +/- 5.7%, respectively; p < 0.001). Visual EF was less accurate by novice readers (r = 0.82; 19% limits of agreement) and improved with trainee-operated Auto EF (r = 0.96; 7% limits of agreement). Auto EF also correlated with MRI EF (n = 21) (r = 0.95; 12% limits of agreement), but underestimated absolute volumes (r = 0.95; bias of -36 +/- 27 ml overall).

CONCLUSIONS

Auto EF can automatically calculate EF similarly to results by manual biplane Simpson's rule and MRI, with less variability than visual EF, and has clinical potential.

Usefulness of clinical, electrocardiographic, and echocardiographic parameters to detect cardiac asynchrony in patients with left ventricular dysfunction secondary to ischemic or nonischemic heart disease

OBJECTIVES

Specific evaluation using echocardiographic Doppler is superior to the measurement of the QRS complex to detect cardiac asynchrony. Nevertheless, no clinical, electrocardiographic, or echocardiographic parameters have been evaluated to obtain an accurate and easy-to-use marker of cardiac asynchrony in patients with depressed left ventricular (LV) ejection fraction. Our aim was to determine whether there is any marker of cardiac asynchrony in patients with LV systolic dysfunction that allows us to obviate the performance of a specific echocardiographic study before cardiac resynchronization therapy.

METHODS

In all, 316 consecutive patients with LV ejection fraction less than 40% were enrolled. Interventricular asynchrony was defined as an interventricular mechanical delay longer than 40 milliseconds. Intraventricular asynchrony was defined as the difference between time from Q wave to LV ejection end and the time from Q wave to the end of the systolic wave of the most delayed basal segment by Doppler tissue imaging greater than 50 milliseconds.

RESULTS

In all, 177 (56%) had ischemic and 139 (44%) had nonischemic heart disease. The logistic regression analysis showed that only the presence of left bundle branch block was an independent predictor of interventricular asynchrony despite the cause of the underlying disease (odds ratio and 95% confidence interval 7.2 [3.9-13.4], P < .001; 5.99 [2.7-13.2], P < .001; and 8.75 [3.2-23.8], P < .001 for the total population, ischemic and nonischemic groups, respectively). Nevertheless, none of the studied parameters was found as a predictor of intraventricular asynchrony.

CONCLUSIONS

The presence of left bundle branch block is a marker of interventricular asynchrony in patients with ventricular dysfunction despite the cause of the underlying cardiac disease. Nevertheless, intraventricular cardiac asynchrony cannot be detected using conventional parameters. A specific echocardiographic evaluation before cardiac resynchronization therapy must be performed in all these patients. Our aim was to determine whether there is any marker of cardiac asynchrony in patients with left ventricular systolic dysfunction that allows us to obviate the performance of a specific echocardiographic study before cardiac resynchronization therapy. Our results showed that only the presence of left bundle branch block was an independent predictor of interventricular asynchrony despite the cause of the underlying disease but none of the studied parameters was found as a predictor of intraventricular asynchrony.

Ventricular dyssynchrony in dilated cardiomyopathy: the role of biventricular pacing in the treatment of congestive heart failure

Despite advances in pharmacologic therapy, the prognosis of patients with advanced congestive heart failure (CHF) remains poor. Many of these patients have cardiac conduction abnormalities, such as left bundle-branch block or interventricular conduction delays, that can lead to ventricular dyssynchrony (abnormal ventricular activation that results in decreased ventricular filling and abnormal ventricular wall motion). Biventricular pacing is an alternative, nonpharmacologic therapy under active investigation for the treatment of CHF. Resynchronization devices with transvenous leads in the right atrium, right ventricle, and left ventricle (via the coronary sinus) have been implanted in patients to provide atrial triggered biventricular pacing. The use of such devices has been associated with improvement in ejection fraction, dP/dt, stroke work, and functional class. The proposed mechanisms involved in improving ventricular function with biventricular pacing include improved septal contribution to ventricular ejection, increased diastolic filling times, and reduced mitral regurgitation. This article reviews the pathophysiology of ventricular dyssynchrony and examine insights from clinical trials that are evaluating cardiac resynchronization therapy for CHF.

Imaging of myocardial dyssynchrony in congestive heart failure

Heart failure constitutes a major health problem in USA and Europe. Angiotensin converting enzyme inhibitors and _ blockers were shown to reduce morbidity and mortality in patients with CHF. Yet, their effectiveness is limited. A significant number of patients with heart failure manifest myocardial conduction abnormalities. Conduction abnormalities, especially in the form of left bundle branch block (LBBB) may be associated with abnormal mechanical function. Several studies demonstrated that these patients may gain benefit from biventricular (BiV) pacing in terms of improvement in exercise tolerance, heart failure morbidity and even decreased mortality. BiV pacing was also associated with improvement in ejection fraction, reduction in the extent of mitral regurgitation and a decrease in cardiac size (reverse remodeling). However, a significant number of patients do not gain benefit from biventricular pacing despite having conduction abnormalities. The underlying reason is that the electrical activity may not closely reflect mechanical activity. Several imaging modalities and techniques have been proposed to improve the selection of patients who may benefit from biventricular pacemakers. Of those, echo-Doppler, and especially, Tissue Doppler Imaging has been demonstrated as important tools for evaluating patients for cardiac resynchronization therapy (CRT) and following their response. The advantages of echo include accessibility, portability, its cost and a high temporal resolution. Yet, it is limited by its acoustic windows and scanning angles. MRI is a useful tool for evaluating patients for CRT by providing 3-D image of myocardial function. However, it is limited for follow-up after implantation due to its cost and a potential damage to the patients or pacemakers. Dyssnchrony imaging is a rapidly evolving field. New imaging techniques such as speckle tracking are promising and close update is needed to keep track of the developments and the changes in this exciting field.

Long-term hemodynamic benefit of biventricular pacing depending on coronary sinus lead position

BACKGROUND

Acute studies in cardiac resynchronization therapy (CRT) showed that hemodynamic effects may depend on the coronary sinus (CS) lead position. However, there are no data on the longterm effect of CS lead position.

METHODS

In 45 heart failure patients with left bundle branch block and QRS >150 ms (age 59+/-10 years, 17 dilative cardiomyopathy, 23 ischemic, 5 valvular), biventricular pacemakers were implanted. CS leads were positioned in posterior (P, n=15), lateral (L, n=19) or, if no other option available, anterior (A, n=11) side branches. Before and 6 months after implantation, clinical state, echocardiography, brain natriuretic peptide (BNP) and right heart catheterization were evaluated.

RESULTS

Baseline parameters were similar between groups. After 6 months, there were 32/34 responders in groups P and L compared to 7/11 responders in group A (94 vs groups P and L: Arterial pressure +8 and +9% vs +2%; PCWP -23 and -15% vs -4%, pulmonary pressure -18 and -12% vs -3% (p<0.01 for A vs P+L); cardiac index +21 and +12% vs +11% (p=0.03 for A vs P). BNP was reduced by 55, 35, and 27% (p=0.05 for A vs P). Ejection fraction increased in P and L by 40 and 41%, respectively, but only by +19% in A (p<0.03 for A vs P+L).

CONCLUSION

Chronic CRT improves ejection fraction, BNP and hemodynamic measurements predominantly in patients with lateral and posterior CS lead positions. Anterior lead positions should be avoided.

Exercise testing with concurrent beta-blocker usage: is it useful? What do we learn?

Cardiopulmonary exercise testing (CPET) has been used for the assessment of severity of heart failure (HF), secondary to left ventricular systolic dysfunction. Initial studies determined that oxygen consumption (VO2) during exercise, as a measure of functional capacity, correlated well with the hemodynamic responses related to chronic HF. These studies led to the use of peak VO2 as a prognostic indicator in chronic HF. In addition, the use of several ventilatory parameters, eg, minute ventilation/carbon dioxide production during submaximal and peak exercise, were shown to have additive and (in some studies) superior prognostic value in patients with chronic HF. However, most of these studies were performed before beta-adrenergic blockade became the main focus of therapy in chronic HF. Unlike other drugs used in the treatment of HF, these drugs do not consistently improve exercise capacity as measured by peak VO2. Several retrospective studies and one prospective study have examined the effect of long-term beta-blocker therapy on the prognostic value of CPET in patients with chronic HF. These studies indicate that patients on beta-blockers have improved overall cardiovascular outcomes compared with patients not on these drugs. In addition, peak exercise VO2 still has prognostic value in beta-blocked patients; however, the thresholds for increased risk and need for transplantation have to be lower than in patients not on these drugs. There appears to be a real demand for a comprehensive survival score tool that includes the use of beta-blockade, along with CPET performance.

A novel prognostic index to determine the impact of cardiac conditions and co-morbidities on one-year outcome in patients with heart failure

Prognostic stratification is relevant in clinical decision making in heart failure (HF). Predictors identified during hospitalization or in clinical trials may be unrepresentative of HF in the community. The aim of this study was to derive and validate, in different clinical settings, a risk stratification model for the prediction of stable HF outcomes. The study included 807 patients, 350 enrolled at discharge from the hospital (44%), 309 in the outpatient clinic (38%), and 148 in the home-care setting (18%). There were 292 patients in the derivation cohort and 515 in the validation cohort. A multivariate logistic analysis was performed to obtain the CardioVascular Medicine Heart Failure (CVM-HF) index. One-year mortality was 20.8% in the derivation cohort and 20.7% in the validation cohort. The CVM-HF index included cardiac conditions and co-morbidities and stratified the 1-year mortality risk as low (death rate 4%), average (32%), high (63%), and very high (96%). The area under the curve of the receiver-operating characteristic curve was 0.844 (95% confidence interval [CI] 0.779 to 0.89) for the derivation cohort and 0.812 (95% CI 0.76 to 0.86) for the validation cohort. Model performance was equally good in the 3 different HF settings. In a subgroup of 409 patients, the CVM-HF index (area under the curve 0.821, 95% CI 0.79 to 0.89) outperformed the most-used prognostic models (the Charlson index and the Heart Failure Risk Scoring System). In conclusion, the CVM-HF index, a novel prognostic model that is easy to derive and applicable to unselected patients, may represent a valuable tool for the prognostication of stable HF outcomes.

Validation of prognostic models among patients with advanced heart failure

BACKGROUND

The ability to accurately predict heart failure outcomes is essential to guiding treatment decisions but several competing risk stratification models exist.

METHODS AND RESULTS

We prospectively collected data on 280 patients with advanced heart failure recruited from 16 sites across the United States. Deaths and cardiac transplantations within the following 4 years were identified. Medline was searched to systematically identify widely cited heart failure severity classification models predicting long-term survival among patients with heart failure, and 4 were selected for validation. We used Kaplan-Meier survival curves, receiver-operating characteristic curves, and Cox proportional hazards modeling to identify the prognostic significance of each model's risk score and the individual contribution of the clinical components within each model. Average follow-up was 31.2 months; 148 deaths or transplantations occurred. Each model that we evaluated identified patients with significantly different prognoses. However, each was limited in overall predictive power, and many component patient characteristics did not have independent prognostic significance. Prognostic factors found to be most powerful within their models included: increasing age, ischemic cardiomyopathy, history of cardiomyopathy, ankle edema, decreased peak oxygen consumption, and absence of beta-blocker use.

CONCLUSION

Although each of the models succeeded in risk-stratifying patients to some extent, all 4 models had shortcomings. There is a need for a contemporary model, derived from a patient population managed in accordance with current heart failure guidelines, applicable to all heart failure etiologies, relying on readily available clinical data.

Changes in exercise capacity, ventilation, and body weight following heart transplantation

AIMS

Peak oxygen uptake adjusted to body weight (peak VO(2)) and ventilatory efficiency (VE/VCO(2)-slope) are important prognostic parameters in chronic heart failure. Our study prospectively examined changes in these parameters over 24 months following heart transplantation (HTx) and evaluated the potentially confounding effects of weight gain.

METHODS AND RESULTS

One hundred patients with chronic heart failure (16 female, mean age at HTx 53.9+/-9.6 years) underwent cardiopulmonary exercise testing before and 3, 6, 12 and/or 24 months after HTx. Twenty-five healthy individuals served as matched normals. VE/VCO(2)-slope during exercise improved significantly at 6 (-23.7%), 12 (-21.3%), and 24 months (-32.3%; all p<0.002 vs. baseline). At 6 months, VE/VCO(2)-slopes were similar to the matched normals (31.8+/-4.3), 46 of 78 patients achieved values within the 95% confidence interval of normal. Peak VO(2) increased significantly after HTx at 6 (+31.8%), 12 (+36.2%), and 24 months (+42.2%; all p<0.005). None of the patients reached values within the 95% CI of normal. Although VE/VCO(2)-slope and peak VO(2) were correlated inversely at every time point (p<0.03), reduction in VE/VCO(2)-slope did not correlate with increase in peak VO(2). Symptoms that limited exercise changed from dyspnoea before HTx to leg fatigue after HTx.

CONCLUSION

Following HTX, VE/VCO(2)-slope returns to normal values in the majority of patients; however, despite improvement, peak VO(2) remains abnormal in all patients. Symptoms causing patients to stop exercising change from dyspnoea to leg fatigue.

Psychosoziale Aspekte und Gesundheitsverhalten bei Herzinsuffizienz

Zusammenfassung. Für die steigende Zahl von Patienten mit Herzinsuffizienz stehen verschiedene medizinische Behandlungsansätze zur Verfügung, darunter als letzte Option die Herztransplantation (HTX). Ergänzende psychosoziale und behaviorale Interventionen erscheinen aus verschiedenen Gründen auch für Patienten auf der HTX-Warteliste sinnvoll. Unser Literaturüberblick zeigt, dass bekannte psychosoziale koronare Risikofaktoren wie Depressivität und soziale Isolation auch bei Herzinsuffizienz Morbidität und Mortalität erhöhen. Körperliche Aktivität wirkt sich dagegen günstig auf subjektive und objektive Parameter aus. Diese Faktoren stellen erste Ansatzpunkte für verhaltensorientierte Interventionen dar. Welche Rolle andere koronare Risikofaktoren (z.B. Feindseligkeit, Ärger, Ernährung und Gewichtsreduktion) spielen, ist bislang ungeklärt. Ausblickend werden einige viel versprechende Forschungsansätze skizziert.

A Simple Clinically Based Predictive Rule for Heart Failure In-Hospital Mortality

BACKGROUND

Scarce data are available to predict in-hospital mortality for decompensated heart failure (HF) in South American populations.

METHODS AND RESULTS

We evaluated 779 consecutive HF admissions defined by the Boston criteria in a tertiary care hospital. Stepwise logistic regression was used to determine independent correlates of in-hospital mortality, derived from 83 potential predictors collected on hospital admission. A clinical score rule (HF Revised Score) was created using the regression coefficient estimates derived from multivariate modeling. During hospital stay, 77 (10%) deaths occurred and 6 clinical characteristics were independently associated with in-hospital mortality: presence of cancer (P < .001), systolic blood pressure < or =124 mm Hg (P < .001), serum creatinine >1.4 mg/dL (P = .02), blood urea nitrogen >37 mg/dL (P = .03), serum sodium <136 mEq/L (P = .03), and age >70 years old (P = .03). Both the Acute Decompensated Heart Failure National Registry stratification algorithm and the proposed HF Revised Score performed adequately to predict in-hospital mortality ("c" statistics = 0.71 and 0.76, respectively). The newly proposed score, however, discriminated a very low-risk group (101 [13%]) in whom all patients were discharged home, representing patients admitted with none of the 6 predictors of risk.

CONCLUSION

HF risk stratification can be accurately accomplished during the first day of admission with simple and easily obtained clinical variables.

A futuristic perspective on clinical studies of cardiac resynchronization therapy for heart failure patients

PURPOSE OF REVIEW

Heart failure is a major public health problem. Many heart failure patients have electrical and mechanical ventricular dyssynchrony, which are risk factors for death in heart failure patients.

RECENT FINDINGS

Cardiac resynchronization therapy, by stimulating both ventricles, is a strategy to improve ventricular dyssynchrony.

SUMMARY

This paper describes the historic development of this therapy; reviews the results of completed clinical cardiac resynchronization therapy studies, and discusses ongoing and future studies.

Right heart catheterization and risk stratification in advanced heart failure

Right heart catheterization (RHC) has remained the gold standard in diagnosing elevated cardiac filling pressures. Despite advances in medical therapy, patients with persistent volume overload and heart failure (HF) have a poor prognosis. The diagnosis of volume overload can be difficult in advanced HF with clinical symptoms and signs often lacking sensitivity and specificity. Hemodynamic measurements at rest, especially pulmonary capillary wedge pressure and change in pulmonary capillary wedge pressure, have been closely linked to prognosis. However, RHC is invasive with attendant risks of complications. Noninvasive models without using catheterization-derived values have been shown to be equally predictive of survival. In selected clinical situations, especially the cardiorenal syndrome, RHC continues to play an important role. Newer invasive and noninvasive techniques to assess volume status are available, but large prospective trials are lacking. The advantage with continuous hemodynamic monitoring could be the development of an early warning system prior to the onset of symptomatic decompensation.

Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus

BACKGROUND

Oxidative stress and increased inflammation have been reported to be increased in subjects with diabetes and to be involved in the pathogenesis of cardiovascular complications after myocardial infarction (MI). It is well recognized that red wine has antioxidant and anti-inflammatory activities. We examined the effects of moderate red wine intake on echocardiographic parameters of functional cardiac outcome in addition to inflammatory cytokines and nitrotyrosine (oxidative stress marker), in subjects with diabetes after a first uncomplicated MI.

METHODS

One hundred and fifteen subjects with diabetes who had sustained a first non-fatal MI were randomized to receive a moderate daily amount of red wine (intervention group) or not (control group). Echocardiographic parameters of ventricular dys-synchrony, circulating levels of nitrotyrosine, tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-18 (IL-18) and C-reactive protein (CRP) were investigated at baseline and 12 months after randomization.

RESULTS

After 1 year of diet intervention, concentrations of nitrotyrosine (P < 0.01), CRP (P < 0.01), TNF-alpha (P < 0.01), IL-6 (P < 0.01) and IL-18 (P < 0.01) were increased in the control group compared with the intervention group. In addition, myocardial performance index (P < 0.02) was higher, and transmitral Doppler flow (P < 0.05), pulmonary venous flow analysis (P < 0.02) and ejection fraction (P < 0.05) were lower in the control group, indicating ventricular dys-synchrony. The concentrations of nitrotyrosine, CRP, TNF-alpha and IL-6 were related to echocardiographic parameters of ventricular dys-synchrony.

CONCLUSIONS

In subjects with diabetes, red wine consumption, taken with meals, significantly reduces oxidative stress and pro-inflammatory cytokines as well as improving cardiac function after MI. Moderate red wine intake with meals may have a beneficial effect in the prevention of cardiovascular complications after MI in subjects with diabetes.

Association of Heart Rate Recovery and Maximum Oxygen Consumption in Patients With Chronic Congestive Heart Failure

BACKGROUND

Peak oxygen consumption (peak VO2) is one of the strongest predictors of mortality in patients with congestive heart failure (CHF). In contrast to measurements of peak VO2, which requires analysis of expired gases, heart rate recovery, defined as maximum heart rate minus heart rate at 1 minute after exercise, is easily obtained. The current study was undertaken to determine the association between peak VO2 and heart rate recovery in patients with CHF.

METHODS

Retrospective data on VO2 and heart rate recovery were analyzed in 296 patients with CHF secondary to left ventricular systolic dysfunction (left ventricular ejection fraction [LVEF] <50%) who had undergone cardiopulmonary exercise testing (CPET). Patients exercised on a treadmill using a graded work rate protocol with the work increasing to a symptom-limited maximum. Peak oxygen consumption was defined as the highest value of oxygen uptake attained in the final 20 seconds of exercise when the respiratory exchange ratio was >1.0.

RESULTS

Heart rate recovery and peak VO2 correlated moderately (r = 0.47, p < 0.001). The degree of correlation was similar in patients receiving beta-blockers (r = 0.47, p < 0.001) and those not receiving beta-blockers (r = 0.49, p < 0.001).

CONCLUSIONS

Although heart rate recovery and peak VO2 correlated moderately, from a clinical standpoint, this finding is probably not strong enough to use heart rate recovery in lieu of peak VO2. This modest correlation of two independent predictors of outcome may suggest their usefulness when combined in a multivariate score.

Role of resynchronisation therapy and implantable cardioverter defibrillators in heart failure

The worldwide prevalence of heart failure is increasing in part because of an aging population. In the developed world, heart failure affects 1%-2% of the general population, accounting for 5% of adult hospital admissions. There is now convincing evidence supporting the beneficial effects of cardiac resynchronisation therapy for the treatment of heart failure. Numerous observational studies, as well as a series of randomised controlled trials, have shown the safety, efficacy, and long term benefits for patients with chronic systolic heart failure who have broad QRS complexes and refractory symptoms despite optimal medical therapy. These studies have consistently found statistically significant improvements in quality of life, New York Heart Association functional class, exercise tolerance, and left ventricular reverse remodelling. Recent evidence suggests that the benefit may at least in part be because of a reduction in mechanical dysynchrony.

Improved durability of the HeartMate XVE left ventricular assist device provides safe mechanical support up to 1 year but is associated with high risk of device failure in the second year

BACKGROUND

Life-threatening device failure of the HeartMate VE due to biologic inflow valve incompetence or motor failure is a major drawback of long-term mechanical support when using this left ventricular assist device (LVAD). The new XVE model is the result of recent technical improvements. The aim of this study was to compare the clinical performance and durability of the new and earlier HeartMate versions.

METHODS

We analyzed the incidence of device failure and of other device-specific complications (infections, bleeding) in 9 VE and 17 XVE patients. Explanted pumps were examined and biologic valve damage classified according to a score ranging from 0 (no visible damage) to 3 (severe destruction).

RESULTS

Mean support time was 145 +/- 92 and 267 +/- 195 days in the VE and XVE groups, respectively (difference not significant [NS]). Survival was 89% (VE) vs 75% (XVE). The incidence of device failure requiring urgent heart transplantation or device replacement was 44% (VE) vs 31% (XVE) (NS). Device failure occurred significantly later in the XVE group (200 +/- 34 vs 487 +/- 53 days, p < 0.01). Causes of device failure were inflow valve incompetence (n = 6) and motor failure (n = 3). Acute device failure caused 1 death in the XVE group. One XVE patient has been on mechanical support for > 483 days. Macroscopic inflow valve damage score after explantation of the devices was 2.2 +/- 1.1 in the VE group and 2.0 +/- 0.8 in the XVE group (NS).

CONCLUSIONS

The novel HeartMate XVE offers greater durability and provides reliable mechanical support in the first year. However, there is a high risk of life-threatening device failure in the second year. Further technical refinements are necessary to meet the challenges of safe long-term circulatory assistance.

Psychiatric evaluations of heart transplant candidates: predicting post-transplant hospitalizations, rejection episodes, and survival

The authors assessed the validity of psychiatric evaluations for orthotopic heart transplant candidates with respect to predicting adverse post-transplant outcomes. A group of 108 transplant recipients were followed for an average of 970 days, and pre-transplant evaluations were retrospectively coded for psychiatric risk factors. Previous suicide attempts, poor adherence to medical recommendations, previous drug or alcohol rehabilitation, and depression significantly predicted attenuated survival times. Also, past suicide attempt was associated with a greater risk for post-transplant infection. Assessment and early treatment for these risk factors may reduce post-transplant morbidity and mortality.

Progression of heart failure in right univentricular pacing compared to biventricular pacing

BACKGROUND

Cardiac resynchronization therapy (CRT) improves hemodynamics and symptoms of heart failure by reducing ventricular dyssynchronity. Conversely, recent studies have demonstrated that right univentricular pacing in patients with an ejection fraction below 40% aggravates heart failure. In this retrospective study, we compared progression of disease in patients with mild to moderate heart failure that were treated with a right univentricular pacing device and patients with congestive heart failure that were treated with a biventricular system.

METHODS

107 patients were included. 59 received a right ventricular pacing device and 48 a biventricular system. Patients were assessed after 1 and 6 months by NYHA class, echocardiographic parameters (EF, LVEDD) and hospitalization for heart failure.

RESULTS

Hospitalization for heart failure after implantation of the devices was more frequent in patients that received a conventional pacemaker with a single lead in the right ventricle than in patients that were treated with a CRT system (12% vs. 6%, p<0.05), although heart failure was more advanced in the CRT group at baseline. Ejection fraction in the right ventricular pacing group further decreased from 43%+/-4 at baseline to 38%+/-4 after 6 months (p<0.05). Left ventricular enddiastolic diameter (LVEDD) was 51+/-7 mm and 58+/-6 mm (p<0.05) at 6 months. In the CRT group, EF was 23%+/-4 at baseline and 31%+/-7 after 6 months (p<0.05.). LVEDD improved from 56+/-4 mm before implantation to 52+/-7 mm and 6 months (p<0.05).

CONCLUSION

Progression of heart failure symptoms in the right univentricular pacing group was more pronounced compared to the CRT group, despite the fact that patients assigned to the CRT group had more severe symptoms of heart failure at baseline. Biventricular pacing relieved symptoms of heart failure, whereas right univentricular pacing with subsequent conduction delay of the left ventricle further deteriorated pre-existing heart failure. Therefore, patients with an indication for pacemaker therapy because of bradycardia and co-existing mild to moderate heart failure might benefit from early implantation of a CRT system.

Biventricular vs. left univentricular pacing in heart failure: rationale, design, and endpoints of the B-LEFT HF study

AIMS

Cardiac resynchronization therapy (CRT) confers sustained therapeutic benefits to patients suffering from congestive heart failure (CHF) due to systolic dysfunction associated with ventricular dyssynchrony. Biventricular (BiV) pacing has, thus far, been the preferred method, as it corrects both electrical and mechanical dyssynchrony. Left ventricular (LV) only pacing, which has conferred similar benefits in pilot studies, may be an alternative treatment method. 'Biventricular vs. left univentricular pacing with ICD back-up in heart failure patients' (B-LEFT HF) is an international, prospective, randomized, parallel-design, double-blind, clinical trial to examine whether LV only pacing is as safe and effective as BiV pacing in patients suffering from CHF.

METHODS AND RESULTS

The trial will randomly assign 172 patients to either LV only or BiV pacing. The study has prospectively defined efficacy endpoints to be evaluated at 6 months, which are (i) changes in functional capacity and degree of reverse remodelling (primary) and (ii) changes in the heart failure clinical composite response (secondary).

CONCLUSION

Because LV only pacing in CRT is likely to be technically less challenging and costly than BiV, a specifically designed study is needed to compare the safety and effectiveness of the two configurations. B-LEFT HF has been designed to settle this critical issue.

Validation of a Risk Score for Dying Within 1 Year of an Admission for Heart Failure

BACKGROUND

Development of heart failure greatly reduces life expectancy. Accurate estimates of the risk of dying are needed in clinical practice and for risk adjustment in observational studies. A relatively simple risk score has been developed to determine the risk of dying within 1-year of an admission for heart failure. We wanted to evaluate the risk score's predictive validity.

METHODS AND RESULTS

Data were abstracted from the electronic medical records of 769 patients admitted to the Minneapolis Veterans Administration medical center with a primary diagnosis of heart failure. Mortality within 1 year of admission was 25%. The c-index for the risk score was 0.71 (95% confidence interval 0.67-0.76). Similar to the original derivation cohort, mortality in risk score groups was 7% for a score lower than 60 (n = 44), 14% for 61 to 90 (n = 246), 26% for 91 to 120 (n = 222), 51% for 121 to 150 (n = 106), and 50% for scores greater than 150 (n = 8).

CONCLUSION

A previously developed risk score for 1-year mortality after an admission for heart failure provided a moderate degree of discrimination in a validation cohort from a different setting. Mortality in risk score groups was consistent with the original patient cohort. These results support the validity of the risk score and its application to a different patient population.

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.

Implantable Cardioverter- Defibrillator Therapy in Clinical Practice

Pharmacologic treatment of heart failure has led to dramatic improvements in survival and quality of life. Nonetheless, heart failure often progresses despite treatment with diuretics, angiotensin-converting enzyme inhibitors, beta-adrenergic blockers, aldosterone antagonists, and digoxin. Further, despite a steady decline in the risk of death from pump failure, many patients remain at high risk for sudden cardiac death. The annual incidence of sudden cardiac death in the U.S. alone has been estimated at 184,000 to over 400,000 cases. During the past decade, substantial advances have been made in the use of device-based therapy for this population. The role of the implantable cardioverter-defibrillator (ICD) continues to evolve in routine heart failure management. The current status of ICD therapy in the treatment of heart failure patients based on randomized clinical trial results and published practice guidelines is summarized in this review.

The Valsalva maneuver: a bedside "biomarker" for heart failure

Accurate assessment of volume status remains an important clinical goal in the management of patients with heart failure. Although physical examination can provide clues to volume status, its sensitivity and reproducibility are limited. Other noninvasive methods, such as measurement of natriuretic peptides or the use of impedance cardiography, are not well validated. The cardiovascular response to the Valsalva maneuver had been proposed as a simple, inexpensive bedside test for estimating filling pressures in patients with heart failure. Our objective was to summarize and critically evaluate the evidence for the use of the Valsalva maneuver in evaluating volume status in patients with heart failure. Studies have demonstrated a significant correlation between the cardiovascular response to the Valsalva maneuver and invasively measured ventricular filling pressures in patients with clinical heart failure. Although often overlooked in clinical training and practice, the cardiovascular response to the Valsalva maneuver is a potentially useful, noninvasive means of evaluating filling pressures in patients with heart failure.

Prospective comparison of echocardiographic atrioventricular delay optimization methods for cardiac resynchronization therapy

BACKGROUND

Atrioventricular (AV) delay optimization can be an important determinant of the response to cardiac resynchronization therapy (CRT) in patients with medically refractory heart failure and a ventricular conduction delay.

OBJECTIVES

The purpose of this study was to compare two Doppler echocardiographic methods of AV delay optimization after CRT.

METHODS

Forty consecutive patients (age 59 +/- 12 years) with severe heart failure, New York Heart Association class 3.1 +/- 0.4, QRS duration 177 +/- 23 ms, and left ventricular ejection fraction 26% +/- 6% referred for CRT were studied using two-dimensional Doppler echocardiography. In each patient, the acute improvement in stroke volume with CRT in response to two methods of AV delay optimization was compared. In the first method, the AV delay that produced the largest increase in the aortic velocity time integral (VTI) derived from continuous-wave Doppler (aortic VTI method) was measured. In the second method, the AV delay that optimized the timing of mitral valve closure to occur simultaneously with the onset of left ventricular systole was calculated from pulsed Doppler mitral waveforms at a short and long AV delay interval (mitral inflow method).

RESULTS

The optimized AV delay determined by the aortic VTI method resulted in an increase in aortic VTI of 19% +/- 13% compared with an increase of 12% +/- 12% by the mitral inflow method (P <.001). The optimized AV delay by the aortic VTI method was significantly longer than the optimized AV delay calculated from the mitral inflow method (119 +/- 34 ms vs 95 +/- 24 ms, P <.001). There was no correlation in the AV delay determined by the two methods (r = 0.03).

CONCLUSION

AV delay optimization by Doppler echocardiography for patients with severe heart failure treated with a CRT device yields a greater systolic improvement when guided by the aortic VTI method compared with the mitral inflow method.

Cardiac Resynchronization Therapy

Left ventricular (LV) dysynchrony, generally defined as the effect of intraventricular conduction defects or bundle branch block to produce nonsynchronous ventricular activation, places the failing heart at a further mechanical disadvantage. The deleterious effects of ventricular dysynchrony include suboptimal ventricular filling, paradoxical septal wall motion, reduced LV contractility, increased mitral regurgitation, and poor clinical outcomes (eg, increased hospitalization and mortality). The clinical and mechanical manifestations of ventricular dysynchrony can be treated by simultaneously pacing both the right and left ventricles usually in association with right atrial sensing, resulting in atrial-synchronized biventricular pacing or cardiac resynchronization therapy (CRT). The weight of evidence supporting the routine use of CRT in patients with heart failure with ventricular dysynchrony is now quite substantial. More than 4000 patients have been evaluated in randomized controlled trials of CRT, and several thousand additional patients have been assessed in observational studies and in registries. Data from these studies have consistently demonstrated the safety and efficacy of CRT in patients with New York Heart Association class III and IV heart failure. Cardiac resynchronization therapy has been shown to significantly improve LV structure and function, New York Heart Association functional class, exercise tolerance, quality of life, and morbidity and mortality.

Waiting for a thoracic transplant in Eurotransplant*

The prospects of patients on the thoracic waiting list are governed by the chance of receiving an organ in time and by the outcome of the transplantation. The former probability is determined by a triad of disease severity, resource size and allocation rules. The aim of this study was to provide an objective description of the distributional effects of the thoracic allocation system in Eurotransplant. It appears that the interpretation of waiting-list outflow indicators is not straightforward and that it is difficult to assess the fairness of an organ allocation system in the framework of changing donor-organ availability. The timing of listing for heart transplantation can substantially be improved; whether this is also true for lung transplantation cannot be determined from the available data. Allocation schemes cannot solve the problem of organ shortage; a shift of attention toward collaboration with procurement professionals is needed.