Factors influencing the one-year mortality of dilated cardiomyopathy

Are hemodynamic parameters predictors of mortality?

This article addresses a question that the authors consider to be somewhat rhetorical: are hemodynamic parameters predictors of mortality? It reviews the specific hemodynamic abnormalities and pathophysiologic consequences distinctive to the patient who has decompensation and addresses the data that implicate abnormal hemodynamics as a treatment target associated with increased mortality. The focus is on patients who have decompensated heart failure, defined as left ventricular systolic dysfunction and an acute, subacute, or gradual worsening of symptoms while receiving optimal medical therapy.

Atrial fibrillation and the risk of death in patients with heart failure: a literature-based meta-analysis

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) are common, associated with significant morbidity and mortality, and frequently coexist. It is uncertain from published data if the presence of AF in patients with HF is associated with an incremental adverse outcome. The aim of this study was to combine the results of all studies investigating prognosis for patients with HF and AF compared with those in sinus rhythm (SR) to asses the mortality risk associated with this arrhythmia.

METHODS

Electronic databases were searched (Biological Abstracts, Current Contents, EMBASE, Medline, Medline In-progress, PubMed and Scopus), to 31 December 2006, using the key words congestive heart failure, heart failure, ventricular dysfunction, atrial fibrillation, atrial flutter, sinus rhythm, prognosis, outcome, death and hospitalization. Bibliographies of retrieved publications were hand searched. Studies were eligible if they included a HF population and if outcomes were reported by cardiac rhythm (AF or SR). Studies were reviewed by predetermined protocol (including quality assessment). Data were pooled using a random effects model.

RESULTS

Twenty studies were included (from 3380 initially identified) representing 32946 patients (10819 deaths). Nine randomized controlled trials (RCT) were included. The prevalence of AF was 15%, crude mortality rates were 46% (AF) and 33% (SR). The odds ratio for death was 1.33 (95% confidence interval (CI) 1.12-1.59) for AF compared with SR. Eleven observational studies were included. The prevalence of AF was 23%, crude mortality rates were 38% (AF) and 25% (SR). The odds ratio for death was 1.57 (95% CI 1.20-2.05) for AF compared with SR.

CONCLUSION

This meta-analysis demonstrates that AF is associated with worse outcomes for patients with HF compared with those with SR. Further research is required to determine whether the adverse outcome associated with AF is related to the arrhythmia itself, or to variables, such as HF severity, patient age and comorbidity.

Hemodynamic correlates of the third heart sound and systolic time intervals

Bedside diagnostic tools remain important in the care of patients with heart failure. Over the past two centuries, cardiac auscultation and phonocardiography have been essential in understanding cardiac pathophysiology and caring for patients with heart disease. Diastolic heart sounds (S3 and S4) and systolic time intervals have been particularly useful in this regard. Unfortunately, auscultation skills have declined considerably, and systolic time intervals have traditionally required carotid pulse tracings. Newer technology allows the automated detection of heart sounds and measurement of systolic time intervals in a simple, inexpensive, noninvasive system. Using the newer system, the authors present data on the hemodynamic correlates of the S3 and abnormal systolic time intervals. These data serve as the foundation for using the system to better understand the test characteristics and pathophysiology of the S3 and systolic time intervals, and help to define their use in improving the bedside diagnosis and management of patients with heart failure.

Impact of left ventricular volume/mass ratio on diastolic function

AIMS

To assess the impact of left ventricular (LV) volume/mass ratio on diastolic function parameters in subjects with dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) and healthy controls.

METHODS AND RESULTS

We performed echocardiography in 44 healthy controls, 35 HCM subjects, 29 DCM subjects with narrow QRS complex (DCM-n), and 27 DCM subjects with wide QRS complex (DCM-w). Mitral annulus velocity (E(a)) and transmitral E-wave velocity were used to estimate time constant of isovolumic pressure decay (tau). LV flow propagation velocity (V(p)) and early intraventricular pressure gradient (IVPG) were derived from colour M-mode of LV inflow. We calculated LV twist and peak untwisting rate (UntwR) by speckle tracking. Mean LV volume/mass ratio was 0.34 +/- 0.09 mL/g in healthy controls, 0.15 +/- 0.06 mL/g in HCM, 0.6 +/- 0.2 mL/g in DCM-n, and 0.8 +/- 0.3 mL/g in DCM-w patients (P < 0.001 for all groups). Resting LV ejection fractions were 63 +/- 7, 64 +/- 8, 31 +/- 8, and 26 +/- 8%, respectively (P < 0.01 vs. controls for DCM groups). In a multivariate analysis, LV volume/mass ratio remained a strong independent predictor of V(p) (P < 0.001), IVPG (P = 0.009), and UntwR (P < 0.001) but not for E(a) (P = 0.25).

CONCLUSION

LV volume/mass ratio had influences on diastolic function parameters independent of intrinsic diastolic function and filling pressures. It should be considered when assessing patients suspected of LV diastolic dysfunction.

A propensity-matched study of elevated jugular venous pressure and outcomes in chronic heart failure

The independence of association between elevated jugular venous pressure (JVP) and outcomes in heart failure (HF) has not been well studied. The objective of propensity-matched study was to determine if an elevated JVP had intrinsic associations with outcomes in chronic systolic and diastolic HF. Of the 7,788 participants in the Digitalis Investigation Group trial, 1,020 (13%) had elevated JVP at baseline. Propensity scores for elevated JVP were estimated for all patients based on 32 baseline characteristics and were used to match 827 pairs of patients with normal and elevated JVP. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated to compare outcomes associated with elevated versus normal JVP during 34 months of median follow-up. Before matching, all-cause mortality occurred in 31% and 47% (unadjusted HR 1.70, 95% CI 1.54 to 1.88, p <0.0001), and all-cause hospitalization occurred in 60% and 71% (unadjusted HR 1.35, 95% CI 1.25 to 1.47, p <0.0001) of patients with normal and elevated JVP, respectively. After matching, all-cause mortality occurred in 48% and 45% (matched HR 0.95, 95% CI 0.80 to 1.12, p = 0.521), and all-cause hospitalization occurred in 70% and 70% (matched HR 0.97, 95% CI 0.87 to 1.09, p = 0.613) of patients with normal and elevated JVP, respectively. Elevated JVP had no intrinsic associations with cardiovascular mortality (matched HR 0.93, 95% CI 0.77 to 1.12, p = 0.440) or hospitalization for HF (matched HR 0.94, 95% CI 0.78 to 1.14, p = 0.532). In conclusion, an elevated JVP is a marker of higher burden of sickness and poor outcomes. However, elevated JVP had no intrinsic association with mortality or hospitalization in chronic HF.

Sudden death in dilated cardiomyopathy

The purpose of this review is to examine the potential contribution of arrhythmia to the occurrence of sudden death in dilated cardiomyopathy (DCM) and to discuss current treatment options. We performed a search of the MEDLINE database from 1985 to the present and the reference citations of selected articles pertaining to the prognostic significance, management, and pathophysiology of arrhythmias in DCM. A large proportion of patients with DCM die suddenly, most secondary to ventricular arrhythmia and a smaller proportion due to bradyarrhythmia. The presence and severity of ventricular ectopy may predict risk for sudden death, but the role of electrophysiologic study and signal-averaged electrocardiography in further risk stratifying patients remains uncertain. Abnormalities of the autonomic nervous system and renin-angiotensin-aldosterone axis appear to promote the occurrence of ventricular arrhythmias. Angiotensin-converting enzyme inhibitors improve overall mortality in congestive heart failure, and the use of direct angiotensin-receptor antagonists is currently being studied. In addition, beta-receptor antagonists appear to improve morbidity and may prove to improve mortality in heart failure as well. Other interventions still under investigation include amiodarone and the implantable cardioverter-defibrillator. The underlying pathophysiology of sudden death in DCM involves primarily ventricular tachyarrhythmia. Angiotensin-converting enzyme inhibitors remain a mainstay of improving overall mortality, while further study on the roles for newer drugs and devices is ongoing.

Current Perioperative Management of the Patient With a Cardiac Rhythm Management Device

The safe and effective perioperative management of the patient with a cardiac rhythm management device (ie, pacemaker and/or implantable cardioverter defibrillator) is based entirely on the avoidance of adverse outcomes, including damage to the device, the leads, or the site of lead implantation that might prevent the device from functioning as intended. An important management principle is the potential reprogramming of such a device in the perioperative period to avoid transient interruption of device function or the delivery of inappropriate electrophysiological therapy (eg, unnecessary defibrillation or pacing). Given the large numbers of patients worldwide currently implanted with these devices, the anesthesia practitioner should become electively familiar with the current technology. This article describes the current status of cardiac rhythm management devices and discusses recommended perioperative management.

Tricuspid regurgitation contributes to renal dysfunction in patients with heart failure

BACKGROUND

In heart failure (HF), renal dysfunction is associated with an adverse prognosis. Impaired renal perfusion from left ventricular dysfunction is thought to be a principal underlying mechanism. Less is known about the influence of venous congestion, including the potential contribution of tricuspid regurgitation (TR).

METHODS AND RESULTS

Echocardiograms and a simultaneous (+/-1 day) blood sample from 196 HF patients were analyzed. Patients with at least moderate TR (n = 78) had larger right-sided cardiac cavities, higher right ventricular systolic pressure, lower estimated glomerular filtration rate (eGFR), higher serum urea nitrogen (SUN), and SUN/creatinine ratio than patients with less than moderate TR (n = 118). In multivariate linear regression analysis, TR severity (P = .003), older age (P < .001), and loop diuretic use (P = .008) were independently associated with lower eGFR, and use of inhibitors of the renin-angiotensin-aldosterone system was associated with higher eGFR (P = .001). TR severity (P < .001) and older age (P < .001) were independently associated with higher SUN. TR severity (P = .004) and smaller left ventricular end-diastolic diameter (P = .048) were independent predictors of a higher SUN/creatinine ratio (P = .004).

CONCLUSIONS

Although a causal relationship cannot be proven, we suggest that significant TR contributes to renal dysfunction in HF patients, probably by elevation of central and renal venous pressure.

Physiology of the Third Heart Sound: Novel Insights from Tissue Doppler Imaging

BACKGROUND

The third heart sound (S(3)) is thought to be caused by the abrupt deceleration of left ventricular (LV) inflow during early diastole, increased LV filling pressures, and decreased LV compliance. We sought to determine whether the ratio of early mitral inflow velocity to diastolic velocity of the mitral annulus (E/E') could confirm the proposed mechanism of the S(3).

METHODS

A total of 90 subjects underwent phonocardiography, echocardiography, tissue Doppler imaging, and left-sided heart catheterization.

RESULTS

Phonocardiography detected an S(3) in 21 patients (23%). Subjects with an S(3) had lower ejection fraction (P = .0006) and increased E deceleration rate (P < .0001), E/E' (P < .0001) and filling pressures (P < .0001). The phonocardiographic S(3) confidence score correlated with E/E' (r = 0.46; P < .0001) and E deceleration rate (r = 0.43, P = .0001). Of the echocardiographic variables, only E/E' was independently associated with the S(3) confidence score (P = .009), independently of invasively determined LV filling pressures (P = .001).

CONCLUSIONS

The most important determinants of the pathologic S(3) are an increased deceleration rate of early mitral inflow, elevated LV filling pressures, and abnormal compliance of the myocardium as measured by tissue Doppler imaging.

Prognostic markers in heart failure--congestion, neurohormones, and the cardiorenal syndrome

There are several markers of poor prognosis in heart failure (HF). The most established markers of poor prognosis in HF include neurohormonal (NH) imbalance, low ejection fraction (EF), ventricular arrhythmias, intraventricular conduction delays, low functional capacity, low SBP, and renal failure. The relative importance of these factors is unknown, as they have never been studied together. We present a 74-year-old female with nonischemic cardiomyopathy and an EF<20% who over 24 years since diagnosis, never developed clinical or hemodynamic congestion, was never hospitalized for HF, and never required a loop diuretic. She had all of the clinical indicators of poor prognosis in HF except for severe NH imbalance and renal failure, illustrating their importance in HF prognosis. While NH activation in HF is initially an adaptive mechanism, an imbalance of NH effectors causes congestion leading to a vicious cycle of congestion, renal dysfunction, and worsening of HF. The combination of NH activation and renal failure in HF is a vasomotor nephropathy known as the cardiorenal syndrome (CRS) and portends a poor prognosis. Pharmacological disruption of NH pathways early in HF may prevent CRS and, therefore, improve outcomes.

Recovery of normal ventricular function in patients with dilated cardiomyopathy: predictors of an increasingly prevalent clinical event

BACKGROUND

This investigation was designed to identify clinical variables associated with recovery of normal ventricular function in patients with dilated cardiomyopathy treated with medical therapy. Recovery of normal ventricular function with medical treatment of patients with dilated cardiomyopathy is observed with increasing frequency. However, the clinical variables associated with such dramatic improvement of ventricular performance are poorly defined.

METHODS

Fifty-three patients with dilated cardiomyopathy and reduced ejection fractions who achieved an increase in ejection fraction to > or = 40% with medical therapy were identified during follow-up in a dedicated heart failure clinic. A cohort of patients frequency-matched on baseline ejection fraction who did not recover ventricular systolic function to this magnitude constituted the control group. Clinical variables characterizing the 2 groups were compared by univariable analysis. Variables that significantly differed between the 2 groups were entered in a stepwise logistic regression analysis to identify factors independently associated with recovery of ejection fraction to > or = 40%.

RESULTS

In the final logistic regression model, QRS duration, sex, etiology of cardiomyopathy, diabetes, and systolic blood pressure were significantly associated with improvement of ejection fraction to > or = 40%.

CONCLUSIONS

Five clinical variables that are independently associated with improvement of left ventricular ejection fraction to normal or near-normal values with medical therapy alone were identified by this modeling process. These variables may be used to discriminate between patients in whom ventricular function will normalize with medical therapy alone and those who will require more aggressive pharmacologic or device therapy.

Cardiac sympathetic activity pre and post resynchronization therapy evaluated by 123I-MIBG myocardial scintigraphy

BACKGROUND

Imaging with (123)I-metaiodobenzylguanidine (MIBG) is used for the assessment of cardiac sympathetic activity (CSA). We analyzed CSA before and after cardiac resynchronization therapy (CRT), and correlated these data with CRT response.

METHODS AND RESULTS

Thirty patients with chronic heart failure and classic indications for CRT were prospectively studied before and at least 3 months after CRT. The variables analyzed were: QRS width, left-ventricular ejection fraction (LVEF), left-ventricular end-diastolic diameter (LVEDD), heart/mediastinum MIBG uptake ratio (H/M), and washout rate (WR). After CRT, patients were divided into two groups: group 1 (21 patients), responders improving to functional class (FC) I or II; and group 2 (9 patients), nonresponders remaining in FC III or IV. After CRT, only group 1 showed favorable changes in QRS width (P =.003), LVEF (P =.01), LVEDD (P =.04), and H/M ratio (P =.003). The H/M ratio and WR were associated with CRT response (P =.005 and P =.04, respectively). The H/M ratio was the only independent predictor of CRT response (P =.01). Receiver operating characteristic curves showed that the optimal H/M ratio cutoff point was 1.36 (sensitivity, 75%; specificity, 71%).

CONCLUSIONS

Improvement in CSA correlated with a positive CRT response. Lower MIBG uptake before therapy was associated with CRT nonresponse. The H/M ratio could be helpful in selecting patients for CRT.

Predicting survival in heart failure

Despite advances in the therapy of cardiovascular disorders, heart failure remains a challenging disease with a dismal prognosis. A plethora of variables have been shown to be related to survival in patients with heart failure. These include heart failure etiology, clinical presentation, ventricular performance, exercise capacity, neurohormones and, more recently, inflammatory and necrosis markers. In this review we briefly list established predictive markers and discuss whether survival can accurately be predicted in this condition.

Cardiac dilatation and pump dysfunction without intrinsic myocardial systolic failure following chronic β-adrenoreceptor activation

There is no direct evidence to indicate that pump dysfunction in a dilated chamber reflects the impact of chamber dilatation rather than the degree of intrinsic systolic failure resulting from myocardial damage. In the present study, we explored the relative roles of intrinsic myocardial systolic dysfunction and chamber dilatation as mediators of left ventricular (LV) pump dysfunction. Administration of isoproterenol, a β-adrenoreceptor agonist, for 3 mo to rats (0.1 mg·kg−1·day−1) resulted in LV pump dysfunction as evidenced by a reduced LV endocardial fractional shortening (echocardiography) and a decrease in the slope of the LV systolic pressure-volume relation (isolated heart preparations). Although chronic β-adrenoreceptor activation induced cardiomyocyte damage (deoxynucleotidyl transferase-mediated dUTP nick-end labeling) as well as β1- and β2-adrenoreceptor inotropic downregulation (attenuated contractile responses to dobutamine and salbutamol), these changes failed to translate into alterations in intrinsic myocardial contractility. Indeed, LV midwall fractional shortening (echocardiography) and the slope of the LV systolic stress-strain relation (isolated heart preparations) were unchanged. A normal intrinsic myocardial systolic function, despite the presence of cardiomyocyte damage and β-adrenoreceptor inotropic downregulation, was ascribed to marked increases in myocardial norepinephrine release, to upregulation of α-adrenoreceptor-mediated contractile effects as determined by phenylephrine responsiveness, and to compensatory LV hypertrophy. LV pump failure was attributed to LV dilatation, as evidenced by increased LV internal dimensions (echocardiography), and a right shift and increased volume intercept of the LV diastolic pressure-volume relation. In conclusion, chronic sympathetic stimulation, despite reducing β-adrenoreceptor-mediated inotropic responses and promoting myocyte apoptosis, may nevertheless induce pump dysfunction primarily through LV dilatation, rather than intrinsic myocardial systolic failure.

Canine nonischemic left ventricular dysfunction: a model of chronic human cardiomyopathy

BACKGROUND

The mechanisms of cardiac remodeling during chronic heart failure remain poorly defined. We sought to advance a chronic canine model of nonischemic cardiomyopathy.

METHODS AND RESULTS

Male dogs (n = 6) received decremental right ventricular apical tachypacing (12 months) to achieve and maintain stable left ventricular (LV) dysfunction. After 10 months of tachypacing, 120 beats/min was sufficient to maintain stable LV dysfunction. Electrocardiography, echocardiography, and tissue Doppler imaging were done to evaluate electrophysiology, LV dimensions and function, and dyssynchrony during normal sinus rhythm. The 6-minute walk test was used to evaluate functional capacity. We observed increases in both QRS duration (P < .0001) and QRS amplitude (P < .0001). LV fractional shortening was reduced from a baseline of 38.0 +/- 1.4% to 11.2 +/- 1.4% (P < .0001). LV end-diastolic dimension increased from 3.8 +/- 0.1 cm at baseline to 5.3 +/- 0.3 cm (P < .0001); LV end-systolic dimension increased from 2.3 +/- 0.1 cm to 4.7 +/- 0.2 cm (P < .0001). LV mass increased from 85.9 +/- 3.5 g at baseline to 179 +/- 13.7 g (P < .0001). There was evidence of LV dyssynchrony (P < .04) during both normal sinus rhythm and right ventricular tachypacing, compared with control dogs. The distance a dog walked in 6 minutes was significantly less at 12 months compared with normal controls (540 +/- 32 m versus 277 +/- 64 m, P < .008).

CONCLUSION

This nonischemic model of canine cardiomyopathy reproduces many aspects of chronic human heart failure including reduced fractional shortening, dilated ventricular dimensions, increased LV mass, decreased functional capacity, and dyssynchrony.

Significance of QRS complex duration in patients with heart failure

Prolongation of QRS (> or =120 ms) occurs in 14% to 47% of heart failure (HF) patients. Left bundle branch block is far more common than right bundle branch block. Left-sided intraventricular conduction delay is associated with more advanced myocardial disease, worse left ventricular (LV) function, poorer prognosis, and a higher all-cause mortality rate compared with narrow QRS complex. It also predisposes heart failure patients to an increased risk of ventricular tachyarrhythmias, but the incidence of cardiac or sudden death remains unclear because of limited observations. A progressive increase in QRS duration worsens the prognosis. No electrocardiographic measure is specific enough to provide subgroup risk categorization for excluding or selecting HF patients for prophylactic implantable cardioverter-defibrillator (ICD) therapy. In ICD patients with HF, a wide underlying QRS complex more than doubles the cardiac mortality compared with a narrow QRS complex. There is a high incidence of an elevated defibrillation threshold at the time of ICD implantation in patients with QRS > or =200 ms. Mechanical LV dyssynchrony potentially treatable by ventricular resynchronization occurs in about 70% of HF patients with left-sided intraventricular conduction delay, a fact that would explain the lack of therapeutic response in about 30% of patients subjected to ventricular resynchronization according to standard criteria relying on QRS duration. The duration of the basal QRS complex does not reliably predict the clinical response to ventricular resynchronization, and QRS narrowing after cardiac resynchronization therapy does not correlate with hemodynamic and clinical improvement. Mechanical LV dyssynchrony is best shown by evolving echocardiographic techniques (predominantly tissue Doppler imaging) currently in the process of standardization.

Prophylactic implantable cardioverter defibrillator therapy in dilated cardiomyopathy: Impact of left ventricular function

BACKGROUND

The value of an implantable cardioverter defibrillator (ICD) for primary prevention in dilated cardiomyopathy (DCM) is unclear, as randomized trials could not show a survival benefit compared to drug therapy. It has not been investigated if patients with a very poor left ventricular function (LVEF) could profit from an ICD.

METHODS

Consecutive patients with DCM who received an ICD between December 1996 and November 2003 were included in this analysis. Patients were divided in group A (secondary prevention) and group B (primary prevention). Both groups were stratified in subgroups with left ventricular ejection fraction (LVEF) below and above 20%.

RESULTS

Fifty eight patients were included (male 50, age 56.4+/-12.7 years). Follow-up was 34+/-19 months. There was no difference regarding death (18% vs. 11%), but significant differences (p value <0.05) regarding any adverse events (55% vs. 22%), any ICD intervention (48% vs. 17%) and ICD interventions for life-threatening arrhythmias (27% vs. 0%) between group A and B. LVEF was not predictive for events in group A, whereas in group B only patients with a LVEF <20% had events (p value 0.02). Over time there was an increase of the LVEF of more than 15% determined by echocardiography in 36% of patients, significantly more often in group B.

CONCLUSIONS

Indication for primary prevention with an ICD in DCM should be made with caution. Larger studies are needed to determine if patients with LVEF of <20% might benefit from an ICD.

A dilated inferior vena cava is a marker of poor survival

BACKGROUND

The inferior vena cava (IVC) morphology is often used to estimate right atrial pressure; however, the association of IVC morphology and outcome is poorly described.

METHODS

We evaluated 4383 consecutive outpatients (98% men) undergoing echocardiography at 1 of 3 Veterans Affairs laboratories.

RESULTS

Of the 3729 with adequate images, 3295 (88%) had a normal IVC (< 2 cm), 358 (10%) had a dilated IVC that collapsed at least 50% with inspiration, and 76 (2%) had dilated IVC that did not collapse. Compared with patients with a normal IVC, those with a dilated IVC were older (66 +/- 13 vs 69 +/- 12 years if dilated with collapse and 70 +/- 12 years if dilated without collapse, P = .0005) and were more likely to have a history of heart failure (11% vs 18% if dilated with collapse and 38% if dilated without collapse, P < .0001). The 90-day and 1-year survival rates were 99% and 95% for those with a normal IVC, 98% and 91% for those with a dilated IVC with collapse, and 89% and 67% for those with a dilated IVC without collapse (P < .0001). After adjustment for clinical and echocardiographic characteristics including left and right ventricular function and pulmonary artery pressure, a dilated IVC without collapse remained associated with increased mortality: hazard ratio 1.43 (1.29-1.57 compared with a normal IVC, P < .0001).

CONCLUSION

A dilated IVC without collapse with inspiration is associated with worse survival in men independent of a history of heart failure, other comorbidities, ventricular function, and pulmonary artery pressure.

Prognostic value of the QRS duration in patients with heart failure: a subgroup analysis from 24 centers of Val-HeFT

BACKGROUND

This study investigated whether QRS duration (QRS D) is a prognostic indicator in patients with heart failure (New York Heart Association [NYHA] classes II-IV).

METHODS AND RESULTS

This subgroup analysis included 248 patients with heart failure recruited in the German centers of the Valsartan Heart Failure Trial (Val-HeFT). Mean age was 60 years, mean NYHA class was 2.3, and mean left ventricular ejection fraction (EF) was 27.9%. Electrocardiograms were recorded and analyzed at the beginning of the study, at 2 weeks, 4 months, 1 year, and 2 years. The mean observation period for mortality was 25 months. Patients > or = 65 years and patients with an EF <20% had a significantly longer QRS D (P = .02; P = .0005). NYHA class, etiology of heart failure, therapy with angiotensin-converting enzyme inhibitors, amiodarone or beta-blockers, implanted defibrillator, and atrial fibrillation had no significant influence on QRS D. Total mortality was 9%: 14 patients died suddenly, 7 from heart failure, 2 from noncardiac causes. Kaplan-Meier plots show significantly different survival rates for patients with QRS D <120 ms, QRS D 120-159 ms, or QRS D > or = 160 ms (P = .0085). Multivariate analysis showed that QRS D was the only independent risk factor for all-cause mortality (P = .008). NYHA class, EF, atrial fibrillation, age, and gender failed to qualify as independent prognostic factors.

CONCLUSION

QRS duration in the surface electrocardiogram is an easily obtainable parameter with a significant prognostic impact in patients with congestive heart failure and a reduced EF. In this German subgroup of Val-HeFT patients, it was an independent predictor of all-cause mortality.

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.

Cost effectiveness of biventricular pacemakers in heart failure patients

BACKGROUND

Biventricular pacemakers have been shown to reduce mortality and hospitalizations in heart failure (HF) patients and are indicated for those with a New York Heart Association functional class of III or IV and a QRS interval of >130 ms. However, these devices currently cost in the region of dollar US 33,500 and require replacement upon battery depletion. Therefore, determination of the cost effectiveness of resynchronization therapy is important, although little data have been published to date on this topic.

METHODS AND RESULTS

A cost-utility analysis from the healthcare perspective was performed using HF patients who received a biventricular pacing device in the Cleveland Clinic Foundation. The comparator was a similarly profiled group of patients who did not receive the device but were treated medically. A Markov model was used to investigate the cost effectiveness at 1 and 5 years. Second-order Monte-Carlo simulation was used to determine the variability in results, using probabilistic sensitivity analysis. Medical treatment was dominated by biventricular pacemaker treatment at both 1 and 5 years of follow-up.

CONCLUSION

Biventricular device insertion is an economically attractive treatment option for clinically indicated HF patients.

Cardiac Transplantation

Heart transplantation is a treatment option available to patients with end-stage heart failure who meet standardized selection criteria for transplant. Through a rigorous evaluation process, professionals set out to establish the patient's severity of heart failure, screen for comorbidities that may negatively affect survival, and assess psychosocial variables necessary for successful outcomes following transplantation. Because of a limited donor organ supply, each of these factors must be examined carefully to assure that this scarce resource is used to its greatest potential benefit.

The impact of arrhythmias in acute heart failure

BACKGROUND

Arrhythmias are common in chronic heart failure and affect outcomes. The incidence and significance of new arrhythmias in acute heart failure, however, are largely unknown.

METHODS AND RESULTS

The Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations study randomized 949 patients with decompensated heart failure to receive intravenous milrinone or placebo. In the study, patients were divided into 2 groups based on the occurrence of a new arrhythmic event during their index hospitalization and analyzed for outcome. There were 59 new arrhythmic events occurring in 6% of the population. Of these, 49% were atrial fibrillation/flutter. The primary endpoint of days hospitalized for cardiovascular causes within 60 days after randomization was 30.9+/-22.7 for those in the arrhythmia group and 11.3+/-12.7 days for those with no arrhythmias (P=.0001). Mortality during index hospitalization was 26% in the arrhythmia group and 1.8% in the no arrhythmia group (P=.001). Death or hospitalization at 60 days was also worse in the arrhythmia group (35 versus 8.2%, P=.0001; 57 versus 34%, P=.001, respectively). Cox proportional hazard analysis identified new arrhythmias as an independent risk factor for the primary endpoint and death at 60 days.

CONCLUSION

New arrhythmia during an exacerbation of heart failure identifies a high-risk group with higher intrahospital and 60-day morbidity and mortality.

Idiopathic dilated cardiomyopathy in children: a single medical center's experience

BACKGROUND

The prognosis of patients with idiopathic dilated cardiomyopathy (DCM) is poor. Most patients die while waiting for cardiac transplantation because of the small number of donors in Taiwan. The purpose of this study was to review our experience with pediatric patients diagnosed with idiopathic DCM and attempt to discover prognostic factors.

METHODS

Eighteen patients with idiopathic DCM presenting between 1990 and 2004 were identified. They were classified into 2 groups according to outcome: group 1 comprised 13 patients who died; group 2 comprised 5 who survived. Clinical findings and laboratory investigations were compared between the 2 groups.

RESULTS

The age at initial diagnosis for the 18 patients (11 males, 7 females) ranged from fetus to 13 years (median, 3 months). The follow-up period ranged from 12 days to 44 months (median, 7 months) in group 1, and from 1 to 48 months (median, 39 months) in group 2. Of the 18 patients, 13 (72%) died: 11 died from severe heart failure while waiting for cardiac transplantation. The cumulative survival rate was 50% at 1 year and 28% at 4 years. The presence of arrhythmia and low left ventricular ejection fraction were predictive of a poor outcome.

CONCLUSION

The diagnosis of idiopathic DCM in children is associated with a generally poor prognosis. The lack of available donors results in significant mortality for pediatric patients awaiting transplantation. Advocating organ donation to increase the size of the organ donor pool is needed to significantly reduce the mortality rate in such patients.

[Risk stratification in congestive heart failure]

Congestive heart failure remains a severe condition. Risk stratification is necessary to assess the prognosis and discuss the potential timing of heart transplant. Numerous criteria have been used, which may be combined to define prognostic scores which, however, are rarely used in routine. A few items, however, may be used to stratify the risk of mortality and sudden death.

Hereditary hemochromatosis gene (HFE) mutations C282Y, H63D and S65C in patients with idiopathic dilated cardiomyopathy

BACKGROUND

Hereditary hemochromatosis (HH), a common autosomal recessive disease, leads to excessive iron accumulation in some organs, including the heart. It is therefore not surprising that cardiomyopathy is one of the most severe complications of HH. The HFE gene defects have been thought to contribute to idiopathic dilated cardiomyopathy (IDCM) in some patients, even though the results of genotype analyses have so far been contradictory. Hence we set out here to evaluate the prevalence and potential role of HFE mutations in patients with IDCM.

METHODS

A total of 91 IDCM patients and 102 controls were subjected to HFE mutation analyses, in which C282Y, H63D and S65C mutations were determined for each patient. We also analyzed the impact of the C282Y and H63D mutations on the left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional classes.

RESULTS

The prevalences of heterozygosity for the C282Y, H63D and S65C mutations in the IDCM patients were 13.2%, 22.0% and 2.2%, respectively. LVEDD was significantly higher (P=0.037) in those with the C282Y mutation at the end of the follow-up period than in those with no mutation.

CONCLUSIONS

Our data showed no significant deviations in C282Y, H63D and S65C mutation frequencies between the IDCM patients and controls, suggesting that these mutations do not increase the risk of IDCM. Heterozygosity for the C282Y mutation may nevertheless be a modifying factor contributing to LV dilatation and remodeling.

Relation of myocardial histomorphometric features and left ventricular contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy

BACKGROUND

This study was designed to determine the relationship between histomorphometric features and contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy.

METHODS

Twenty-four consecutive patients (21 men, aged 43.4+/-8.7 years) with idiopathic dilated cardiomyopathy underwent dobutamine stress echocardiography. Wall motion score index, ejection fraction, cardiac power output and end-systolic pressure/volume ratio were used as indices of left ventricular contractility. Left ventricular endomyocardial biopsy specimens (3-5 per patient) were routinely processed and stained with Masson trichrome, interstitial fibrosis and myocyte diameter were calculated quantitatively.

RESULTS

Myocyte diameter and interstitial fibrosis showed strongest correlation with change in wall motion score index (r=-0.667, p<0.001, and r=-0.567, p=0.004, respectively), followed by change in ejection fraction (r=-0.603, p=0.002, and r=-0.467, p=0.021, respectively). Interstitial fibrosis showed no correlation with change of cardiac power output and end-systolic pressure/volume ratio, whereas myocyte diameter was associated with change of both indices (r=-0.565, p=0.004, and r=-0.455, p=0.025).

CONCLUSIONS

Contractile reserve elicited by high-dose dobutamine is strongly related to the degree of histological disruption in patients with idiopathic dilated cardiomyopathy.

Echocardiographic predictors of morbidity and mortality in patients with advanced heart failure: the Beta-blocker Evaluation of Survival Trial (BEST)

OBJECTIVES

The aim of this study was to determine echocardiographic predictors of outcome in patients with advanced heart failure (HF) due to severe left ventricular (LV) systolic dysfunction in the Beta-blocker Evaluation of Survival Trial (BEST).

BACKGROUND

Previous studies indicate that echocardiographic measurements of LV size and function, mitral deceleration time, and mitral regurgitation (MR) predict adverse outcomes in HF. However, complete quantitative echocardiograms evaluating all of these parameters have not been reported in a prospective randomized clinical trial in the era of modern HF therapy.

METHODS

Complete echocardiograms were performed in 336 patients at 26 sites and analyzed by a core laboratory. A Cox proportional-hazards regression model was used to determine which echocardiographic variables predicted the primary end point of death or the secondary end point of death, HF hospitalization, or transplant. Significant variables were then entered into a multivariable model adjusted for clinical and demographic covariates.

RESULTS

On multivariable analysis adjusted for clinical covariates, only LV end-diastolic volume index predicted death (events = 75), with a cut point of 120 ml/m(2). Three echocardiographic variables predicted the combined end point of death (events = 75), HF hospitalization (events = 97), and transplant (events = 9): LV end-diastolic volume index, mitral deceleration time, and the vena contracta width of MR. Optimal cut points for these variables were 120 ml/m(2), 150 ms, and 0.4 cm, respectively.

CONCLUSIONS

Echocardiographic predictors of outcome in advanced HF include LV end-diastolic volume index, mitral deceleration time, and vena contracta width. These variables indicate that LV remodeling, increased LV stiffness, and MR are independent predictors of outcome in patients with advanced HF.

Cardiac resynchronization therapy for the management of chronic heart failure

While numerous pathophysiologic mechanisms may lead to the onset and progression of chronic systolic heart failure, a variety of electrophysiologic abnormalities seen in the setting of chronic left ventricular dysfunction may also contribute to the natural history of the disease. Atrial, atrial-ventricular, and inter- and intraventricular conduction disturbances may place the failing ventricle at a further mechanical disadvantage, thus contributing to the functional impairment and poor outcomes associated with chronic heart failure. In the early 1990s, attempts at treating patients with end-stage systolic heart failure using conventional pacing strategies met with equivocal results. However, this work did provide further insight into the electromechanical consequences of advanced heart failure and suggested that atrial-synchronized biventricular pacing, or cardiac resynchronization therapy, might provide better and more consistent symptomatic and hemodynamic improvement. Several landmark clinical trials have evaluated the safety and efficacy of cardiac resynchronization therapy in New York Heart Association (NYHA) class III and IV heart failure. These studies have consistently shown statistically significant improvements in quality of life, NYHA functional class ranking, exercise tolerance, and left ventricular reverse remodeling. Some studies have suggested reductions in morbidity and mortality. This latter observation has been confirmed by a recent large-scale outcomes study. Thus, cardiac resynchronization therapy should be routinely considered in eligible NYHA class III and IV heart failure patients with ventricular dyssynchrony.

Global and regional myocardial oxygen consumption and blood flow in severe cardiomyopathy with left bundle branch block

OBJECTIVE

In patients with dilated cardiomyopathy (DCM), left bundle branch block (LBBB) is a common finding. The characteristic feature is an asynchronous septal wall motion and most frequently a delay of the lateral and/or posterior wall segments. With the onset of cardiac resynchronization therapy, there is a focus on the specific pathophysiology of a LBBB. However, quantitative data on regional myocardial oxygen consumption (MVO(2)) and blood flow (MBF) are missing.

METHODS

We studied 31 patients with severe DCM and LBBB (ejection fraction 22.1+/-7.1%) and 14 patients with mild to moderate DCM without LBBB (ejection fraction 46.7+/-7.9%). Global and regional MVO(2) as well as MBF were determined from a dynamic (11)C-acetate positron emission tomography (PET) study.

RESULTS

Global MVO(2) and MBF were lower in the DCM group with LBBB than in the control group (P<0.05). Regionally, the LBBB group revealed a higher (P<0.05) MVO(2) and MBF in the lateral wall than in the other walls. The control group did not show significant differences between the myocardial walls and demonstrated a smaller variability of the parameters.

CONCLUSION

DCM patients with LBBB exhibit a more heterogeneous distribution of MVO(2) and MBF among the myocardial walls than DCM patients without LBBB. Due to the LBBB associated electromechanical alterations, the highest regional values of MVO(2) and MBF are found in the lateral wall.

Prognostic value of ambulatory electrocardiography monitoring in patients with dilated cardiomyopathy

BACKGROUND

Performance of ambulatory electrocardiography (AECG) may provide data useful for counseling patients regarding prognosis and for selecting potential patients for defibrillator implantation, but this practice remains controversial.

METHODS

We reviewed clinical and AECG data on 355 patients diagnosed with dilated cardiomyopathy (DCM). Predictors of survival were identified in a multivariable analysis using a Cox proportional hazard model. Ability of the derived model to predict outcomes was tested using a second cohort of 144 patients.

RESULTS

Nonsustained ventricular tachycardia (NSVT) was present on AECG in 31% of the subjects. Ambulatory electrocardiography provided 3 independent predictors of mortality: NSVT (relative risk [RR], 1.63; 95% confidence interval [CI], 1.06-2.51; P = .02), mean heart rate (RR, 1.03; 95% CI, 1.02-1.04; P = .0001), and heart rate range (RR, 0.990; 95% CI, 0.982-0.997; P = .008). Performance of the multivariable model was validated (area under the curve = 0.83) on a second cohort of patients.

CONCLUSION

Ambulatory electrocardiography provides useful prognostic information in patients with DCM, identifying 3 independent predictors of mortality.

Third heart sound: genesis and clinical importance

Auscultation of third heart sound has been performed for more than a century, an interest that not only persists today, but also has experienced renewed emphasis. Sophisticated study of the third heart sound by current investigative techniques has underscored the value of clinical detection with the time-honored stethoscope. This review re-examines the mechanisms of genesis of third heart sound in regard to the hemodynamic and echocardiographic aspects, and its clinical importance.

Electrocardiographic arrhythmia risk testing

Among the most compelling challenges facing cardiologists today is identification of which patients are at highest risk for sudden death. Automatic implantable cardioverter-defibrillators are now indicated in many of these patients, yet the role of noninvasive risk stratification in classifying patients at high risk is not well defined. The purpose of this review is to evaluate the various electrocardiographic (ECG) techniques that appear to have potential in assessment of risk for arrhythmia. The resting ECG (premature ventricular contractions, QRS duration, damage scores, QT dispersion, and ST segment and T wave abnormalities), T wave alternans, late potentials identified on signal-averaged ECGs, and heart rate variability are explored. Unequivocal evidence to support the widespread use of any single noninvasive technique is lacking; further research in this area is needed. It is likely that a combination of risk evaluation techniques will have the greatest predictive power in enabling identification of patients most likely to benefit from device therapy.

Mortality and rate of stroke or embolism in atrial fibrillation during long-term follow-up in the embolism in left atrial thrombi (ELAT) study

BACKGROUND

Patients with atrial fibrillation (AF) have a higher mortality and risk of stroke/embolism than patients with sinus rhythm.

HYPOTHESIS

The aim of the study was to assess the association of clinical and echocardiographic characteristics with mortality and stroke/embolism and the use of antithrombotic medication in the year 2000 in patients who participated 1990-1995 in the Embolism in Left Atrial Thrombi (ELAT) study.

METHODS

The study included 409 outpatients with nonrheumatic AF (62 +/- 12 years, 36% women, 39% intermittent AF). Patients with thrombi received anticoagulation, patients without thrombi aspirin until follow-up in 1995; thereafter, anticoagulation according to clinical risk factors was recommended. Primary events were death and secondary events were stroke/embolism. All patients were contacted during the year 2000.

RESULTS

Mean follow-up was 102 months. Mortality was 4%/year; the cause of death was cardiac (n = 84), fatal stroke (n = 26), malignancy (n = 23), sepsis (n = 5), and unknown (n = 24). Multivariate analysis identified age (p < 0.0001), heart failure (p = 0.0013), and reduced left ventricular systolic function (p = 0.0353) as predictors of mortality. Stroke/embolism occurred in 83 patients, with a rate of 3%/year. Multivariate analysis identified age (p = 0.0006) and previous stroke (p = 0.0454) as predictors of stroke/embolism. In the year 2000, 51 (21%) of the 247 surviving patients received no antithrombotic medication, 88 received (36%) oral anticoagulants, 102 (41%) acetylsalicylic acid, and 6 (2%) low-molecular heparin.

CONCLUSIONS

Therapy for heart failure and oral anticoagulation in AF should be seriously considered, especially in elderly patients and in those with previous stroke.

Risk stratification of in-hospital mortality in patients hospitalized for chronic congestive heart failure secondary to non-ischemic cardiomyopathy

The study population consisted of 234 consecutive patients hospitalized for acute exacerbation of congestive heart failure secondary to non-ischemic cardiomyopathy. Of the 234 patients, there were 55 in-hospital deaths. Their medical records were deliberatively reviewed and the association of 38 clinical, hemodynamic and biochemical variables with in-hospital mortality was evaluated by multiple stepwise logistic regression analysis. The following variables were statistically associated with in-hospital mortality: profound cardiogenic shock, severe hyponatremia, the presence of ventricular arrhythmias, history of stroke, the presence of acute renal failure, and requirement of dobutamine therapy. In stratified analyses, the rates of in-hospital mortality rose rapidly as the number of risk factors increased: 0 risk factors, 2.5%; 1 risk factor, 5.1%; 2 risk factors, 36.4%; 3 risk factors, 75%, and no less than 4 risk factors, 100%. In conclusion, our study identified 6 variables that correlated with in-hospital death in patients with heart failure secondary to non-ischemic cardiomyopathy. The identification of these variables may allow more accurate risk stratification of individuals at risk of in-hospital mortality in this clinical setting.