Prediction of outcome in dilated cardiomyopathy

The Role of AI in Characterizing the DCM Phenotype

Dilated Cardiomyopathy is conventionally defined by left ventricular dilatation and dysfunction in the absence of coronary disease. Emerging evidence suggests many patients remain vulnerable to major adverse outcomes despite clear therapeutic success of modern evidence-based heart failure therapy. In this era of personalized medical care, the conventional assessment of left ventricular ejection fraction falls short in fully predicting evolution and risk of outcomes in this heterogenous group of heart muscle disease, as such, a more refined means of phenotyping this disease appears essential. Cardiac MRI (CMR) is well-placed in this respect, not only for its diagnostic utility, but the wealth of information captured in global and regional function assessment with the addition of unique tissue characterization across different disease states and patient cohorts. Advanced tools are needed to leverage these sensitive metrics and integrate with clinical, genetic and biochemical information for personalized, and more clinically useful characterization of the dilated cardiomyopathy phenotype. Recent advances in artificial intelligence offers the unique opportunity to impact clinical decision making through enhanced precision image-analysis tasks, multi-source extraction of relevant features and seamless integration to enhance understanding, improve diagnosis, and subsequently clinical outcomes. Focusing particularly on deep learning, a subfield of artificial intelligence, that has garnered significant interest in the imaging community, this paper reviews the main developments that could offer more robust disease characterization and risk stratification in the Dilated Cardiomyopathy phenotype. Given its promising utility in the non-invasive assessment of cardiac diseases, we firstly highlight the key applications in CMR, set to enable comprehensive quantitative measures of function beyond the standard of care assessment. Concurrently, we revisit the added value of tissue characterization techniques for risk stratification, showcasing the deep learning platforms that overcome limitations in current clinical workflows and discuss how they could be utilized to better differentiate at-risk subgroups of this phenotype. The final section of this paper is dedicated to the allied clinical applications to imaging, that incorporate artificial intelligence and have harnessed the comprehensive abundance of data from genetics and relevant clinical variables to facilitate better classification and enable enhanced risk prediction for relevant outcomes.

Right bundle branch block and risk of cardiovascular mortality: the Ibaraki Prefectural Health Study

Historically, a right bundle branch block has been considered a benign finding in asymptomatic individuals. However, this conclusion is based on a few old studies with small sample sizes. We examined the association between a complete right bundle branch block (CRBBB) and subsequent cardiovascular mortality in the general population in Japan. In this large community-based cohort study, data of 90,022 individuals (mean age, 58.5 ± 10.2 years; 66.2% women) who participated in annual community-based health check-ups were assessed. Subjects were followed up from 1993 to the end of 2016. Cox proportional hazards' models and log-rank tests were used for the data analysis. CRBBB was documented in 1,344 participants (1.5%). Among all included participants, CRBBB was associated with an increased risk of cardiovascular mortality after adjustment for all potential confounders (hazard ratio [HR] 1.21; 95% confidence interval [CI] 1.06-1.38). The increased risk of cardiovascular mortality was particularly evident in women aged < 65 years (HR 2.00; 95% CI 1.34-2.98) and men aged ≥ 65 years (HR 1.28; 95% CI 1.06-1.55). CRBBB is associated with an increased risk of cardiovascular mortality in women aged < 65 years and men aged ≥ 65 years. Clinicians should be aware of the presence of CRBBB in young women and elderly men, even if they exhibit no symptoms.

Stem cell therapy for dilated cardiomyopathy

BACKGROUND

Stem cell therapy (SCT) has been proposed as an alternative treatment for dilated cardiomyopathy (DCM), nonetheless its effectiveness remains debatable.

OBJECTIVES

To assess the effectiveness and safety of SCT in adults with non-ischaemic DCM.

SEARCH METHODS

We searched CENTRAL in the Cochrane Library, MEDLINE, and Embase for relevant trials in November 2020. We also searched two clinical trials registers in May 2020.

SELECTION CRITERIA

Eligible studies were randomized controlled trials (RCT) comparing stem/progenitor cells with no cells in adults with non-ischaemic DCM. We included co-interventions such as the administration of stem cell mobilizing agents. Studies were classified and analysed into three categories according to the comparison intervention, which consisted of no intervention/placebo, cell mobilization with cytokines, or a different mode of SCT. The first two comparisons (no cells in the control group) served to assess the efficacy of SCT while the third (different mode of SCT) served to complement the review with information about safety and other information of potential utility for a better understanding of the effects of SCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all references for eligibility, assessed trial quality, and extracted data. We undertook a quantitative evaluation of data using random-effects meta-analyses. We evaluated heterogeneity using the I² statistic. We could not explore potential effect modifiers through subgroup analyses as they were deemed uninformative due to the scarce number of trials available. We assessed the certainty of the evidence using the GRADE approach. We created summary of findings tables using GRADEpro GDT. We focused our summary of findings on all-cause mortality, safety, health-related quality of life (HRQoL), performance status, and major adverse cardiovascular events.

MAIN RESULTS

We included 13 RCTs involving 762 participants (452 cell therapy and 310 controls). Only one study was at low risk of bias in all domains. There were many shortcomings in the publications that did not allow a precise assessment of the risk of bias in many domains. Due to the nature of the intervention, the main source of potential bias was lack of blinding of participants (performance bias). Frequently, the format of the continuous data available was not ideal for use in the meta-analysis and forced us to seek strategies for transforming data in a usable format. We are uncertain whether SCT reduces all-cause mortality in people with DCM compared to no intervention/placebo (mean follow-up 12 months) (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.54 to 1.31; I² = 0%; studies = 7, participants = 361; very low-certainty evidence). We are uncertain whether SCT increases the risk of procedural complications associated with cells injection in people with DCM (data could not be pooled; studies = 7; participants = 361; very low-certainty evidence). We are uncertain whether SCT improves HRQoL (standardized mean difference (SMD) 0.62, 95% CI 0.01 to 1.23; I² = 72%; studies = 5, participants = 272; very low-certainty evidence) and functional capacity (6-minute walk test) (mean difference (MD) 70.12 m, 95% CI -5.28 to 145.51; I² = 87%; studies = 5, participants = 230; very low-certainty evidence). SCT may result in a slight functional class (New York Heart Association) improvement (data could not be pooled; studies = 6, participants = 398; low-certainty evidence). None of the included studies reported major adverse cardiovascular events as defined in our protocol. SCT may not increase the risk of ventricular arrhythmia (data could not be pooled; studies = 8, participants = 504; low-certainty evidence). When comparing SCT to cell mobilization with granulocyte-colony stimulating factor (G-CSF), we are uncertain whether SCT reduces all-cause mortality (RR 0.46, 95% CI 0.16 to 1.31; I² = 39%; studies = 3, participants = 195; very low-certainty evidence). We are uncertain whether SCT increases the risk of procedural complications associated with cells injection (studies = 1, participants = 60; very low-certainty evidence). SCT may not improve HRQoL (MD 4.61 points, 95% CI -5.62 to 14.83; studies = 1, participants = 22; low-certainty evidence). SCT may improve functional capacity (6-minute walk test) (MD 140.14 m, 95% CI 119.51 to 160.77; I² = 0%; studies = 2, participants = 155; low-certainty evidence). None of the included studies reported MACE as defined in our protocol or ventricular arrhythmia. The most commonly reported outcomes across studies were based on physiological measures of cardiac function where there were some beneficial effects suggesting potential benefits of SCT in people with non-ischaemic DCM. However, it is unclear if this intermediate effects translates into clinical benefits for these patients. With regard to specific aspects related to the modality of cell therapy and its delivery, uncertainties remain as subgroup analyses could not be performed as planned, making it necessary to wait for the publication of several studies that are currently in progress before any firm conclusion can be reached.

AUTHORS' CONCLUSIONS

We are uncertain whether SCT in people with DCM reduces the risk of all-cause mortality and procedural complications, improves HRQoL, and performance status (exercise capacity). SCT may improve functional class (NYHA), compared to usual care (no cells). Similarly, when compared to G-CSF, we are also uncertain whether SCT in people with DCM reduces the risk of all-cause mortality although some studies within this comparison observed a favourable effect that should be interpreted with caution. SCT may not improve HRQoL but may improve to some extent performance status (exercise capacity). Very low-quality evidence reflects uncertainty regarding procedural complications. These suggested beneficial effects of SCT, although uncertain due to the very low certainty of the evidence, are accompanied by favourable effects on some physiological measures of cardiac function. Presently, the most effective mode of administration of SCT and the population that could benefit the most is unclear. Therefore, it seems reasonable that use of SCT in people with DCM is limited to clinical research settings. Results of ongoing studies are likely to modify these conclusions.

Algebraic formulas characterizing an alternative to Guyton's graphical analysis relevant for heart failure

Although Guyton's graphical analysis of cardiac output-venous return has become a ubiquitous tool for explaining how circulatory equilibrium emerges from heart-vascular interactions, this classical model relies on a formula for venous return that contains unphysiological assumptions. Furthermore, Guyton's graphical analysis does not predict pulmonary venous pressure, which is a critical variable for evaluating heart failure patients' risk of pulmonary edema. Therefore, the purpose of the present work was to use a minimal closed-loop mathematical model to develop an alternative to Guyton's analysis. Limitations inherent in Guyton's model were addressed by 1) partitioning the cardiovascular system differently to isolate left ventricular function and lump all blood volumes together, 2) linearizing end-diastolic pressure-volume relationships to obtain algebraic solutions, and 3) treating arterial pressures as constants. This approach yielded three advances. First, variables related to morbidities associated with left ventricular failure were predicted. Second, an algebraic formula predicting left ventricular function was derived in terms of ventricular properties. Third, an algebraic formula predicting flow through the portion of the system isolated from the left ventricle was derived in terms of mechanical properties without neglecting redistribution of blood between systemic and pulmonary circulations. Although complexities were neglected, approximations necessary to obtain algebraic formulas resulted in minimal error, and predicted variables were consistent with reported values.

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

Impaired Baroreflex Function in an Ovine Model of Chronic Heart Failure Induced by Multiple Coronary Microembolizations

Testing new therapies in heart failure (HF) requires a chronic stable model of HF in large animals. Microembolization of the coronary arteries has been used to model HF previously; however, neural control has not been previously explored in this model. Thus the aim of this study was to further characterize neural control in this model of HF. HF was induced by infusion of microspheres (45 micron; 1.3 ml) into the proximal left coronary artery or left descending coronary arteries, with three sequential embolizations over 3 weeks. Twelve to 14 weeks after the final embolization, and when ejection fraction had decreased below 45%, animals were instrumented to record blood pressure and heart rate. Baroreflex control of heart rate was investigated in conscious animals. Additionally, pressure-volume loops were constructed under anesthesia. Embolization-induced HF was associated with a decrease in mean arterial pressure (67 ± 2 vs. 85 ± 4 mmHg, p < 0.05), an increase in heart rate (108 ± 4 vs. 94 ± 4 bpm, p < 0.05), and a significant increase in left ventricular end-diastolic pressure (11.4 ± 2 vs. 6.2 ± 1 mmHg, p < 0.01). Under conscious conditions, there was a significant decrease in the gain (-8.2 ± 2 vs. -4.1 ± 1 beats/min/mmHg, p < 0.05) as well as the lower plateau of the baroreflex in HF compared to control animals. HF was also associated with significantly increased respiratory rate (107 ± 4 vs. 87 ± 4 breaths/min, p < 0.01) and incidence of apneas (520 ± 24 vs. 191 ± 8 apnea periods >4 s, p < 0.05), compared to control sheep. The microembolization model of heart failure is associated with an increase in left ventricular end-diastolic pressure, impaired cardiac function, and altered baroreflex control of the heart. These findings suggest this chronic model of HF is appropriate to use for investigating interventions aimed at improving neural control in HF.

Impaired myocardial perfusion is associated with increasing end-systolic- and end-diastolic volumes in patients with non-ischemic systolic heart failure: a cross-sectional study using Rubidium-82 PET/CT

BACKGROUND

Myocardial flow reserve (MFR, stress/rest myocardial blood flow) is a strong marker of myocardial vasomotor function. MFR is a predictor of adverse cardiac events in patients with non-ischemic systolic heart failure and previous studies using different methods have found association between myocardial blood flow and left ventricular dilatation. The aim of this study was to investigate whether there is an association between increasing end-systolic- and end-diastolic volumes (ESV and EDV) and MFR in these patients measured with Rubidium-82 positron emission tomography computed tomography (⁸²Rb-PET/CT) as a quantitative myocardial perfusion gold-standard.

METHODS

We scanned 151 patients with non-ischemic heart failure with initial left ventricular ejection fraction ≤35% with ⁸²Rb-PET/CT at rest and adenosine-induced stress to obtain MFR and volumes. To account for differences in body surface area (BSA), we used indexed ESV (ESVI): ESV/BSA (ml/m²) and EDV (EDVI). We identified factors associated with MFR using multiple regression analyses.

RESULTS

Median age was 62 years (55-69 years) and 31% were women. Mean MFR was 2.38 (2.24-2.52). MFR decreased significantly with both increasing ESVI (estimate - 3.7%/10 ml/m²; 95% confidence interval [CI] -5.6 to - 1.8; P < 0.001) and increasing EDVI (estimate - 3.5%/10 ml/m²; 95% CI -5.3 to - 1.6; P < 0.001). Results remained significant after multivariable adjustment. Additionally, coronary vascular resistance during stress increased significantly with increasing ESVI (estimate: 3.1 mmHg/(ml/g/min) per (10 ml/m²); 95% CI 2.0 to 4.3; r = 0.41; P < 0.0001) and increasing EDVI (estimate: 2.7 mmHg/(ml/g/min) per (10 ml/m²); 95% CI 1.6 to 3.8; r = 0.37; P < 0.0001).

CONCLUSIONS

Impaired MFR assessed by ⁸²Rb-PET/CT was significantly associated with linear increases in ESVI and EDVI in patients with non-ischemic systolic heart failure. Our findings support that impaired microvascular function may play a role in heart failure development. Clinical trials investigating MFR with regard to treatment responses may elucidate the clinical use of MFR in patients with non-ischemic systolic heart failure.

TRIAL REGISTRATION

Sub study of the randomized clinical trial: A DANish randomized, controlled, multicenter study to assess the efficacy of Implantable cardioverter defibrillator in patients with non-ischemic Systolic Heart failure on mortality (DANISH), ClinicalTrials.gov Identifier: NCT00541268 .

Myocardial perfusion during atrial fibrillation in patients with non-ischaemic systolic heart failure: a cross-sectional study using Rubidium-82 positron emission tomography/computed tomography

Aims

Patients with non-ischaemic systolic heart failure often have reduced myocardial blood flow without significant coronary atherosclerosis. Likewise, patients with atrial fibrillation (AF) have reduced myocardial perfusion during AF compared with sinus rhythm. The aim of this study was to explore whether there is an additive negative effect of AF during scan on the myocardial perfusion in patients with non-ischaemic systolic heart failure.

Methods and results

We included 27 young healthy controls and 114 patients with non-ischaemic systolic heart failure to a Rubidium-82 positron emission tomography/computed tomography perfusion scan (23 with AF during scan). To obtain the myocardial flow reserve (MFR = stress flow/rest flow), patients were scanned at rest and during adenosine-induced stress. Among patients, those with AF were older [years: 73; interquartile range (IQR) 65-78 vs. 67; IQR 60-74; P = 0.03] and more were men (87% vs. 62%; P = 0.02). Distribution of sex in controls did not differ from either patient group. Patients with AF had significantly lower MFR than patients without [MFR: 1.87; 95% confidence interval (CI) 1.58-2.22 vs. 2.50; 95% CI 2.06-2.86; percent difference: -21.5%; P = 0.01]. MFR remained significantly lower in the group with AF (estimate -24.2%; 95% CI -39.6% to -4.8%; P = 0.02) in an adjusted multivariable regression analysis. Further, patients had lower MFR compared with controls: 3.46; 95% CI 3.03-3.94; P < 0.0001. Additionally, coronary vascular resistance was highest in patients with AF and lowest in controls.

Conclusion

Patients with systolic heart failure had lower flow reserve than healthy controls and even lower MFR if they had AF during scan.

The Memory of the Heart

The embryological development of the heart is one of the most fascinating phenomena in nature and so is its final structure and function. The various ontogenetic passages form the evolutive basis of the final configuration of the heart. Each key step can be recognized in the final features, as the heart maintains a kind of “memory” of these passages. We can identify the major lines of development of the heart and trace these lines up to the mature organ. The aim of this review is to identify these key parameters of cardiac structure and function as essential elements of the heart’s proper functioning and bases for its treatment. We aim to track key steps of heart development to identify what it “remembers” and maintains in its final form as positively selected. A new vision based on the whole acquired knowledge must guide an in-depth scientific approach in future papers and guidelines on the topic and a complete, farsighted therapeutic conduct able to ensure the physiological correction of cardiac pathologies. The application of this modern, functional vision of the heart could improve the clinical treatment of heart disease, filling the gaps still present.

Effect of hydration status on atrial and ventricular volumes and function in healthy adult volunteers

BACKGROUND

Assessment of cardiac chamber volumes is a fundamental part of cardiac magnetic resonance (CMR) imaging. While the effects of inter- and intraobserver variability have been studied and have a recognized effect on the comparability of serial cardiac MR imaging studies, the effect of differences in hydration status has not been evaluated.

OBJECTIVE

To evaluate the effects of volume administration on cardiac chamber volumes.

MATERIALS AND METHODS

Thirteen healthy adults underwent a baseline cardiac MR to evaluate cardiac chamber volumes after an overnight fast. They were then given two saline boluses of 10 ml/kg of body weight and the cardiac MR was repeated immediately after each bolus.

RESULTS

From the baseline scan to the final scan there was a significant increase in all four cardiac chamber end-diastolic volumes. Right atrial volumes increased 8.0%, from 61.1 to 66.0 ml/m2 (P<0.001), and left atrial volumes increased 10.0%, from 50.0 to 55.0 ml/m2 (P<0.001). Right ventricular volumes increased 6.0%, from 91.1 to 96.5 ml/m2 (P<0.001), and left ventricular volumes increased 3.2%, from 87.0 to 89.8 ml/m2 (P<0.001).

CONCLUSION

Hydration status has a significant effect on the end-diastolic volumes of all cardiac chambers assessed by cardiac MR. Thus, hydration represents a "variable" that should be taken into account when assessing cardiac chamber volumes, especially when performing serial imaging studies in a patient.

Contemporary Outcome in Patients With Idiopathic Dilated Cardiomyopathy

Outcome is better in patients with idiopathic dilated cardiomyopathy (IDC) than in ischemic heart failure (HF), but morbidity and mortality are nevertheless presumed to be substantial. Most data on the prognosis in IDC stem from research performed before the widespread use of current evidence-based treatment, including implantable devices. We report outcome data from a cohort of patients with IDC treated according to current HF guidelines and compare our results with previous figures: 102 consecutive patients referred to our tertiary care hospital with idiopathic IDC and a left ventricular ejection fraction <40% were included in a prospective cohort study. After extensive baseline work-up, follow-up was performed after 6 and 13 months. Vital status and heart transplantation were recorded. Over the first year of follow-up, the patients were on optimal pharmacological treatment, and 24 patients received implantable devices. Left ventricular ejection fraction increased from 26 ± 10% to 41 ± 11%, peak oxygen consumption increased from 19.5 ± 7.1 to 23.4 ± 7.8 ml/kg/min, and functional class improved substantially (all p values <0.001). After a median follow-up of 3.6 years, 4 patients were dead, and heart transplantation had been performed in 9 patients. According to our literature search, survival in patients with IDC has improved substantially over the last decades. In conclusion, patients with IDC have a better outcome than previously reported when treated according to current guidelines.

Thromboembolism and antithrombotic therapy for heart failure in sinus rhythm: an executive summary of a joint consensus document from the ESC Heart Failure Association and the ESC Working Group on Thrombosis

Chronic heart failure (HF) with either reduced or preserved left ventricular (LV) ejection fraction is common and remains an extremely serious disorder with a high mortality and morbidity. Many complications related to heart failure can be related to thrombosis. Epidemiological and pathophysiological data also link HF to an increased risk of thrombosis, leading to the clinical consequences of sudden death, stroke, systemic thromboembolism and/or venous thromboembolism. This executive summary of a joint consensus document of the Heart Failure Association (EHFA) of the European Society of Cardiology (ESC) and the ESC Working Group on Thrombosis reviews the published evidence, summarises 'best practice', and puts forward consensus statements that may help to define evidence gaps and assist management decisions in everyday clinical practice. In HF patients with atrial fibrillation, oral anticoagulation is clearly recommended, and the CHA2DS2-VASc and HAS-BLED scores should be used to determine the likely risk-benefit ratio (thromboembolism prevention versus risk of bleeding) of oral anticoagulation. In HF patients with reduced LV ejection fraction who are in sinus rhythm there is no evidence of an overall benefit of vitamin K antagonists (e.g. warfarin) on mortality, with risk of major bleeding. Whilst there is the potential for a reduction in ischaemic stroke, there is currently no compelling reason to routinely use warfarin for these patients. Risk factors associated with increased risk of thromboembolic events should be identified and decisions regarding use of anticoagulation individualised. Patient values and preferences are important determinants when balancing the risk of thromboembolism against bleeding risk. Novel oral anticoagulants that offer a different risk-benefit profile compared with warfarin may appear as an attractive therapeutic option, but this would need to be confirmed in clinical trials.

Thrombo-embolism and antithrombotic therapy for heart failure in sinus rhythm. A joint consensus document from the ESC Heart Failure Association and the ESC Working Group on Thrombosis

Chronic heart failure (HF) with either reduced or preserved ejection fraction is common and remains an extremely serious disorder with a high mortality and morbidity. Many complications related to HF can be related to thrombosis. Epidemiological and pathophysiological data also link HF to an increased risk of thrombosis, leading to the clinical consequences of sudden death, stroke, systemic thrombo-embolism, and/or venous thrombo-embolism. This consensus document of the Heart Failure Association (EHFA) of the European Society of Cardiology (ESC) and the ESC Working Group on Thrombosis reviews the published evidence and summarizes 'best practice', and puts forward consensus statements that may help to define evidence gaps and assist management decisions in everyday clinical practice. In HF patients with atrial fibrillation, oral anticoagulation is recommended, and the CHA(2)DS(2)-VASc and HAS-BLED scores should be used to determine the likely risk-benefit ratio (thrombo-embolism prevention vs. risk of bleeding) of oral anticoagulation. In HF patients with reduced left ventricular ejection fraction who are in sinus rhythm there is no evidence of an overall benefit of vitamin K antagonists (e.g. warfarin) on mortality, with risk of major bleeding. Despite the potential for a reduction in ischaemic stroke, there is currently no compelling reason to use warfarin routinely for these patients. Risk factors associated with increased risk of thrombo-embolic events should be identified and decisions regarding use of anticoagulation individualized. Patient values and preferences are important determinants when balancing the risk of thrombo-embolism against bleeding risk. New oral anticoagulants that offer a different risk-benefit profile compared with warfarin may appear as an attractive therapeutic option, but this would need to be confirmed in clinical trials.

Deterioration of renal function by chronic heart failure is associated with congestion and oxidative stress in the tubulointerstitium

OBJECTIVE

We examined the hypothesis that renal congestion is responsible for the decline in renal function in patients with heart failure (HF) via tubulointerstitial inflammation.

METHODS

First, in a longitudinal study, we retrospectively examined the relationship between cardiac functions and the decline of renal function during a period of 6.4±3.2 years in 20 patients who had a left ventricular ejection fraction of <40% and an estimated glomerular filtration ratio (eGFR) of <60 mL/min/1.73 m(2). Second, we compared the renal histology in autopsy cases of HF-induced renal dysfunction (HF-RD), cases of nephrosclerosis (NSC) and cases of neither RD nor HF (controls) in a cross-sectional study. Third, we retrospectively examined renal function in HF patients with predominantly right, but not left, ventricular dysfunction. Results eGFR decreased at 9.4±4.6%/year in the cohort of the longitudinal study. The rate of eGFR decline was correlated with blood pressure and with diameter of the inferior vena cava (IVCd) (r=0.5) measured at the initial work-up. Multivariate analysis indicated that the IVCd is an independent determinant of decline of eGFR in HF. In the cross-sectional study, fibrosis, Rac1 expression, protein nitrosylation, and number of CD68-positive cells were increased in the tubulointerstitium in both cases of HF-RD and NSC. Peritubular capillaries in HF-RD were dilated by 35% without any change in density compared with those in the controls. In right sided HF, the reduction of IVCd after treatment was associated with improvement of eGFR.

CONCLUSION

Venous congestion may contribute to HF-induced deterioration of renal function by augmenting oxidative stress-mediated inflammation in the tubulointerstitium.

The M235T polymorphism of the angiotensinogen gene in South Indian patients of hypertrophic cardiomyopathy

INTRODUCTION

Hypertrophic cardiomyopathy (HCM) is a complex disorder and genetically transmitted cardiac disease with a diverse clinical course. The objective of the present study was to examine the association of the T704C polymorphism of exon 2 of the angiotensinogen (AGT) gene with HCM in a South Indian population from Andhra Pradesh. Subjects and methods. One-hundred and fifty HCM (90 sporadic hypertrophic cardiomyopathy [SHCM] and 60 familial hypertrophic cardiomyopathy [FHCM]) patients and 165 age- and sex-matched normal healthy controls without known hypertension and left ventricular hypertrophy were included in the study. DNA was isolated from peripheral leukocytes and the region of interest in the AGT gene bearing a missense mutation methionine to threonine substitution at codon 235 (M235T) of exon 2, was amplified by polymerase chain reaction (PCR). The PCR products were subjected to restriction digestion with the enzyme SfaNI.

RESULTS

Significant differences were detected in genotypic distribution (p = 0.04) as well as the allelic frequency (p = 0.003) between the SHCM patients and controls. The polymorphism did not show any association with FHCM.

CONCLUSION

Our results suggest that the T allele of the AGT gene is significantly associated with SHCM in a South Indian population from Andhra Pradesh. However, we did not find significant association of this polymorphism with FHCM.

Impact of atrial fibrillation on outcome of patients with idiopathic dilated cardiomyopathy: data from the Heart Muscle Disease Registry of Trieste

OBJECTIVE

There is a paucity and inconsistency of data regarding the natural history of patients affected by idiopathic dilated cardiomyopathy (IDCM) and atrial fibrillation (AF). We examined the prognostic implications of AF in a subset of patients with IDCM.

METHODS

We analyzed the data of 539 patients with IDCM enrolled in the Heart Muscle Disease Registry of Trieste.

RESULTS

At baseline, 52 (9.6%) of 539 patients had AF. There was no difference in survival of patients with either AF or sinus rhythm at enrollment (P = .28). During long-term follow-up (90 ± 58 months), AF was detected on ECG/ECG-Holter monitoring in 28 (5.7%) of 487 patients in sinus rhythm at baseline. Predictors of new onset of AF at multivariate analysis were a more dilated left atrium (OR 1.35, 95% CI 1.06-1.72; P = .01) and a lower left ventricle ejection fraction (for 10% decrease, OR 2.41, 95% CI 1.24-4.69, P = .016). Patients developing AF had higher mortality/heart transplantation rate compared to patients who maintained sinus rhythm during follow-up (P < .001). At multivariate analysis, new onset AF (HR 3.67, 95% CI 2.07-6.5; P < .001) in the first three years after diagnosis, but not baseline AF, was found to be independently associated with a worse outcome.

CONCLUSIONS

Atrial fibrillation is relatively frequent in patients with IDCM. The early development of AF during follow-up, but not its presence at baseline, is associated with poor survival.

Clinical and genetic modifiers of long-term survival in heart failure

OBJECTIVES

This study sought to identify genetic modifiers of beta-blocker response and long-term survival in heart failure (HF).

BACKGROUND

Differences in beta-blocker treatment effect between Caucasians and African Americans with HF have been reported.

METHODS

This was a prospective cohort study of 2,460 patients (711 African American, 1,749 Caucasian) enrolled between 1999 and 2007; 2,039 patients (81.7%) were treated with a beta-blocker. Each was genotyped for beta1-adrenergic receptor (ADRB1) Arg389>Gly and G-protein receptor kinase 5 (GRK5) Gln41>Leu polymorphisms, which are more prevalent among African Americans than Caucasians. The primary end point was survival time from HF onset.

RESULTS

There were 765 deaths during follow-up (median 46 months). beta-blocker treatment increased survival in Caucasians (log-rank p = 0.00038) but not African Americans (log-rank p = 0.327). Among patients not taking beta-blockers, ADRB1 Gly389 was associated with decreased survival in Caucasians (hazard ratio [HR]: 1.98, 95% confidence interval [CI]: 1.1 to 3.7, p = 0.03) whereas GRK5 Leu41 was associated with improved survival in African Americans (HR: 0.325, CI: 0.133 to 0.796, p = 0.01). African Americans with ADRB1 Gly389Gly GRK5 Gln41Gln derived a similar survival benefit from beta-blocker therapy (HR: 0.385, 95% CI: 0.182 to 0.813, p = 0.012) as Caucasians with the same genotype (HR: 0.529, 95% CI: 0.326 to 0.858, p = 0.0098).

CONCLUSIONS

These data show that differences caused by beta-adrenergic receptor signaling pathway gene polymorphisms, rather than race, are the major factors contributing to apparent differences in the beta-blocker treatment effect between Caucasians and African Americans; proper evaluation of treatment response should account for genetic variance.

Influence of intrinsic myocardial conduction on paced QRS morphology during cardiac resynchronization therapy follow up

We report two cases of patients of cardiac resynchronization therapy (CRT) whose ECGs, during follow up, showed different paced QRS morphology as compared to those of immediate post-device implantation. Parameters of leads, including sensitivity and capture thresholds, were unchanged. There was no lead dislodgement confirmed on fluoroscopy. The ECGs obtained in device off mode showed different intrinsic QRS morphology as compared to those of pre-implant morphology. These changes were attributable to electrolyte imbalance in one patient and progressive intraventricular conduction defect in the other. These cases demonstrate that intrinsic myocardial conduction pattern influences paced QRS morphology. Irreversible change in paced QRS morphology may indicate poor prognosis.

Improvement in prognosis of dilated cardiomyopathy in the elderly over the past 20 years

BACKGROUND AND PURPOSE

Although dilated cardiomyopathy (DCM) had a poor prognosis in the past, recent studies have shown better survival. However, little is known about the improvement of prognosis in the elderly. This study sought to clarify the changes in prognosis in elderly patients with DCM over the past 20 years.

METHODS AND SUBJECTS

We studied 54 consecutive patients with DCM (38 men and 16 women, aged 65-83 years) who were diagnosed at over 65 years of age. The patients were divided into two groups (group A: 12 patients diagnosed before 1990; group B: 42 patients diagnosed after 1990) because after 1990, based on growing evidence from large-scale, randomized clinical studies, we intentionally increased the use of angiotensin-converting enzyme inhibitors (ACEI) and then beta-blockers at our hospital.

RESULTS

There were no significant differences in age, gender, NYHA functional class, and the prevalence of atrial fibrillation and ventricular tachycardia between the two groups. Left ventricular (LV) size assessed by echocardiography was larger (LV end-diastolic diameter, 67+/-5.9 versus 62+/-6.6 mm; p=0.039) and LV ejection fraction measured by left ventriculography was lower (ejection fraction, 24+/-9 versus 35+/-10%; p=0.004) in group A. ACEI/angiotensin II type 1 receptor blockers (ARB) (0% versus 88%) or beta-blockers (0% versus 52%) were more frequently used in group B. Antiarrhythmics (class Ia or Ib) (75% versus 14%) were less often used in group B. The 5- and 10-year event-free survival rates for cardiac death were 75.4% and 22.0% in group A versus 81.2% and 71.3% in group B (log-rank test, p=0.014).

CONCLUSIONS

The prognosis of DCM patients in the elderly has significantly improved over the past 20 years. The advances in the pharmacologic treatment and earlier diagnosis may have contributed to the better survival.

Transcriptomic biomarkers for individual risk assessment in new-onset heart failure

BACKGROUND

Prediction of prognosis remains a major unmet need in new-onset heart failure (HF). Although several clinical tests are in use, none accurately distinguish between patients with poor versus excellent survival. We hypothesized that a transcriptomic signature, generated from a single endomyocardial biopsy, could serve as a novel prognostic biomarker in HF.

METHODS AND RESULTS

Endomyocardial biopsy samples and clinical data were collected from all patients presenting with new-onset HF from 1997 to 2006. Among a total of 350 endomyocardial biopsy samples, 180 were identified as idiopathic dilated cardiomyopathy. Patients with phenotypic extremes in survival were selected: good prognosis (event-free survival for at least 5 years; n=25) and poor prognosis (events [death, requirement for left ventricular assist device, or cardiac transplant] within the first 2 years of presentation with HF symptoms; n=18). We used human U133 Plus 2.0 microarrays (Affymetrix) and analyzed the data with significance analysis of microarrays and prediction analysis of microarrays. We identified 46 overexpressed genes in patients with good versus poor prognosis, of which 45 genes were selected by prediction analysis of microarrays for prediction of prognosis in a train set (n=29) with subsequent validation in test sets (n=14 each). The biomarker performed with 74% sensitivity (95% CI 69% to 79%) and 90% specificity (95% CI 87% to 93%) after 50 random partitions.

CONCLUSIONS

These findings suggest the potential of transcriptomic biomarkers to predict prognosis in patients with new-onset HF from a single endomyocardial biopsy sample. In addition, our findings offer potential novel therapeutic targets for HF and cardiomyopathy.

Thromboembolic risk in the patient with heart failure

Although heart failure is a procoagulant state, the incidence of arterial thromboembolism (peripheral arterial emboli and strokes) is relatively low in the outpatient setting and seems to be higher in those with concomitant atrial fibrillation or recent large anterior myocardial infarction, especially in the presence of a dyskinetic apex. Hospitalized heart failure patients, on the other hand, have an extremely high rate of deep venous thrombosis and pulmonary emboli. Outpatients with heart failure should receive anticoagulation only in the presence of atrial fibrillation or if they have experienced a prior embolic event. Patients with recent large anterior infarction or recent infarction with documented thrombus should be treated with anticoagulation for the initial 3 months after the infarct, whereas those with evidence of a mural thrombus should receive anticoagulation at least until the thrombus has resolved. Heart failure patients with ischemic cardiomyopathy should receive antiplatelet agents for the prevention of myocardial infarction, stroke, or death. Antiplatelet agents should not be prescribed for heart failure patients with nonischemic cardiomyopathy or without other evidence of atherosclerotic vascular disease. All hospitalized heart failure patients who are not taking oral anticoagulants should receive prophylaxis with low molecular weight heparins or factor Xa inhibitors.

Antithrombotic therapy for congestive heart failure

Patients with congestive heart failure (CHF) are at increased risk of thromboembolic events. However, there is much debate and uncertainty over the use of antithrombotic therapy in these patients. The evidence for oral anticoagulation is limited, although large randomised trial data are forthcoming. Aspirin may be detrimental for heart failure due to a possible interaction with angiotensin-converting enzyme inhibitors, leading to increased hospitalisations from decompensated heart failure. The objective of this review article is to summarise the available evidence regarding the risk of stroke and thromboembolic events in CHF patients, as well as the effectiveness and risks of antithrombotic therapy in these patients.

Epidemiology of idiopathic cardiomyopathy in Qatar during 1996-2003

OBJECTIVES

To report the rates of cardiomyopathies in the population below 50 years of age in Qatar.

SUBJECTS AND METHODS

We conducted a retrospective review of clinical data on patients with cardiomyopathy who were hospitalized in Hamad General Hospital, Doha. Data were collected from medical records during the 1996-2002 period and prospectively from the patients who were hospitalized during the year 2003. All cardiomyopathy patients below 50 years of age who were citizens or permanent residents in Qatar were included in this study.

RESULTS

During the study period, a total of 132 cases were recorded with idiopathic cardiomyopathies. Among these, 67.4% were males and 32.6% females; Qatari 31.8%, non-Qatari 68.2%. The consanguinity rate was high among Qatari patients. In the first 7-year study period, 1996-2002, the incidence rate of all types of cardiomyopathies was 2.5/100,000 population per year (95% CI: 1.4-3.5). It increased to 5.2/100,000 population during the year 2003 (95% CI: 3.6-6.7). Dilated cardiomyopathy was most prevalent (75.8%) in all age groups, and the incidence increased remarkably with age. Lower prevalence of hypertrophic cardiomyopathy (13.6%) and left ventricle noncompaction cardiomyopathy (6.1%) was found. In children below 15 years of age, the incidence rate for all types of cardiomyopathies was 2.7/100,000 population. The overall mortality rate was 5.3%.

CONCLUSION

Most cases of cardiomyopathy were identified at an early age: below 15 years and above 35 years of age. Introducing preventive and early diagnosis programs may have an impact on reducing the mortality and morbidity from idiopathic cardiomyopathy.

Long-Term Prognosis of Dilated Cardiomyopathy Revisited An Improvement in Survival Over the Past 20 Years

BACKGROUND

Because of their favorable prognostic effects, angiotensin converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB) and beta blockers have become background therapy in dilated cardiomyopathy (DCM). However, there are few reports concerning the long-term prognosis of Japanese patients with DCM in relation to these treatments.

METHODS AND RESULTS

One hundred and fifty patients with DCM were divided into 2 groups: group A (n=46) (diagnosis: 1982-1989) and group B (n=104) (diagnosis: 1990-2002). During follow-up period of 6.9+/-4.8 years, 62 patients died and 1 patient had a heart transplant. The survival rate at 5 and 10 years was 60.9% and 34.8%, respectively, in group A patients, and 80.9% and 65.3%, respectively, in group B patients (p=0.0079). In group A patients, ACEI/ARB or beta blockers were less frequently used (p<0.0001), whereas antiarrhythmics (class Ia or Ib) were more often used (p<0.0001). The patients treated with ACEI/ARB and beta blockers showed a better survival rate than those without (p<0.0001). The patients with antiarrhythmics showed a worse survival rate than those without (p<0.0001).

CONCLUSION

The prognosis of Japanese patients with DCM has significantly improved over the past 20 years. This improvement may be explained partly through the increased use of ACEI/ARB and beta blockers and a declining use of antiarrhythmics.

Congestive heart failure and atrial fibrillation: rhythm versus rate control

BACKGROUND

The incidence both of heart failure and atrial fibrillation is steadily increasing in the United States' population, and these conditions frequently coexist in the same patient. It is likely that the onset of one of these disorders leads to the onset and propagation of the other through multiple mechanisms. Several studies have investigated the prognosis of patients with both conditions, but a definitive conclusion regarding outcomes such as mortality and quality of life has yet to be determined.

METHODS AND RESULTS

Evidence demonstrating the improvement of left ventricular function and other hemodynamic parameters with the restoration and maintenance of sinus rhythm does exist. beta-blockade, angiotensin-converting enzyme inhibition, and aldosterone antagonism have been shown to improve survival in patients with heart failure. However, the efficacy of these therapies in patients with coexisting atrial fibrillation has not been adequately assessed. Furthermore, these therapies do not directly address the issue of rhythm management. The use of several antiarrhythmic medications and device therapy is becoming more frequent in the management of this subset of patients. Recent investigations of antiarrhythmic treatment have assessed outcomes such as survival, quality of life, exercise tolerance, and maintenance of sinus rhythm. Data from these studies suggest that antiarrhythmic therapy may be efficacious in such patients. Device therapy is another alternative which has been demonstrated to be at least as beneficial as medical therapy.

CONCLUSION

Both retrospective and prospective studies of antiarrhythmic therapy and device therapy have demonstrated promising results. Several studies are ongoing and will provide more insight into the management of such patients.

Left ventricular end-systolic stress/diameter relation as a contractility index and as a predictor of survival. Independence of preload after normalization for end-diastolic diameter

The independence of the slope of the left ventricular (LV) end-systolic stress/end systolic diameter (ESS/ESD) relation of preload (PL) after normalization for end-diastolic diameter (EDD), and the reliability of both the original and the normalized slope as contractility and prognostic indices, were assessed. We studied echocardiographically, hemodynamically, and with carotid pulse tracing, 25 normal subjects, 18 patients with coronary artery disease having a normal ejection fraction (EF), and 30 patients with idiopathic dilated cardiomyopathy (DCM). The arterial pressure was changed with intravenous infusion of phenylephrine. To investigate the effect of PL on the ESS/ESD slope, in 12 normals the PL was decreased with intravenous infusion of 40 mg of furosemide and increased with 1 l isotonic NaCl. The studied population was followed up for 18-61 months. The mean values of the slope after furosemide and after NaCl differed significantly but when the above values were divided by the EDD the differences were nullified. The mean values of the slope differed highly significantly between the three groups. The normalized slope increased the sensitivity in the discrimination. During the follow-up period 10 patients with DCM died. The original and the normalized slopes separated the deceased and survivors significantly (P < 0.002 for both indices) as compared to EF (P < 0.05). The ESS/ESD slope is a very sensitive contractility index and is also superior to EF as a prognostic parameter. The normalization of the slope eliminates its dependence on PL and improves the sensitivity in assessing decreased contractility, although it slightly decreases its prognostic value.

An overview of stress echocardiography in the study of patients with dilated or hypertrophic cardiomyopathy

Stress echocardiography is a useful noninvasive modality for measuring dynamic outflow gradient and contractility changes in patients with hypertrophic cardiomyopathy (HCM) or dilated cardiomyopathy (DCM). In patients with HCM, stress echocardiography may determine the degree of outflow tract obstruction at rest and with activity, can detect occult systolic dysfunction in symptomatic patients with a normal resting left ventricular ejection fraction, and can also be utilized to monitor the efficacy of treatment. In individuals suffering from DCM, stress echocardiography is an important aid in the evaluation of the etiology, diagnosis, and prognosis of the disease as well as the functional status of the patient during either exercise or simulated stress conditions. Dobutamine stress echocardiography, by providing a measurement of the myocardial reserve, is a useful tool to predict the systolic recovery and clinical outcome of patients with heart failure. The stress-induced change in the wall motion score index can also be used as an accurate alternative to predict the peak oxygen consumption rate and exercise capacity of the same patient population. Finally, stress echocardiography has also been used in the identification of the predilated phase of cardiomyopathy in individuals with high clinical suspicion of the disease.

Update on implantable cardioverter defibrillator trials

Many randomized trials of implantable cardioverter defibrillator (ICD) therapy versus medical treatment for the prevention of death in survivors of cardiac arrest or in patients at high risk of sudden cardiac death (SCD) have been reported. ICD therapy has been consistently efficacious in preventing SCD. ICD therapy has generally favorably impacted total mortality, but this has depended upon the control group's risk for arrhythmic and nonarrhythmic mortality. In these trials, predictors of sudden or total mortality better than ventricular dysfunction have not emerged. This review summarizes the randomized ICDs trials and the impact ICDs have on SCD prevention.

Prevalence, prognostic significance, and treatment of atrial fibrillation in congestive heart failure with particular reference to the DIAMOND-CHF study

Atrial fibrillation is a growing health problem and the most common cardiac arrhythmia, affecting 5% of persons above the age of 65 years. The number of hospital discharges for atrial fibrillation has more than doubled in the past decade. It occurs very often in patients with congestive heart failure and the prevalence increases with the severity of the disease. These two conditions seem to be linked together, and congestive heart failure may either be the cause or the consequence of atrial fibrillation. The prognosis of atrial fibrillation is controversial, but studies indicate that atrial fibrillation is a risk factor in congestive heart failure patients. In the last 10-15 years, significant advances in the treatment of heart failure have improved survival, whereas effective management of atrial fibrillation in heart failure patients still awaits similar progress. Empirically, two strategies have evolved for treatment of atrial fibrillation: 1) rhythm control, which means conversion to sinus rhythm and maintenance of sinus rhythm; and 2) rate control, which means reduction of heart rate to an acceptable frequency. It is unknown whether one of these strategies is better than the other. In this review the authors discuss the prevalence, impact, and treatment of atrial fibrillation in heart failure patients.

Clinical relationship of myocardial sympathetic nervous activity to cardiovascular functions in chronic heart failure: assessment by myocardial scintigraphy with 123I-metaiodobenzylguanidine

The aim of this study was to clarify the relationship between cardiac sympathetic nervous activity (SNA) assessed by radioiodinated metaiodobenzylguanidine (123I-MIBG), an analogue of norepinephrine and cardiovascular functions in patients with chronic heart failure (CHF). Subjects were 17 patients with CHF. A dose of 111 MBq of 123I-MIBG was administered intravenously, and 5-minute anterior planar images were obtained 15 minutes (early image) and 3 hours (delayed image) after the injection. The heart/mediastinum (H/M) count ratio was defined to quantify cardiac 123I-MIBG uptake. The washout ratio (WR) of 123I-MIBG from the heart was calculated as follows: (early counts-delayed counts)/early counts x 100 (%). Echocardiography was performed on all patients within 1 week of 123I-MIBG scintigraphy to measure stroke volume index (SVI). Blood pressure and heart rate (HR) in the resting state were also recorded to calculate cardiovascular functions including cardiac output, pulse pressure (PP), and mean blood pressure. Significant linear correlations were found between the early H/M ratio of 123I-MIBG and SVI, and between the delayed H/M ratio of 123I-MIBG and SVI, respectively. WR of 123I-MIBG was correlated with HR, and was inversely correlated with SVI and with PP, respectively. It is likely that a decrease in SVI is associated with enhanced cardiac SNA in severe CHF. 123I-MIBG scintigraphy is effective in assessing the cardiac functional status and SNA in patients with CHF in vivo. Moreover, changes in PP and HR indicate well alteration in SNA.

Progression of familial and non-familial dilated cardiomyopathy: long term follow up

BACKGROUND

It is unknown whether progression of familial idiopathic dilated cardiomyopathy differs from progression in the non-familial form. It has been suggested that familial disease indicates a worse prognosis, and that this should be considered when planning the timing of heart transplantation.

OBJECTIVE

To compare five year survival or time to heart transplantation in an unselected series of patients with dilated cardiomyopathy who had been evaluated for familial v non-familial disease through the echocardiographic investigation of first degree relatives.

DESIGN

Medical records were reviewed and questionnaires were mailed to all patients who had previously participated in a family based study of dilated cardiomyopathy. Information was gathered about survival, heart transplantation, and left ventricular ejection fraction (LVEF) measurements. Survival data were censored at the time of cardiac transplantation.

RESULTS

Follow up data were obtained for 99 of 101 patients (69 with non-familial and 30 with familial disease). Five year survival was 55% for non-familial and 51% for familial patients (NS). The main predictor of mortality was an LVEF of < 30%. Familial status did not predict mortality. There was no significant difference in follow up LVEF values between the groups.

CONCLUSIONS

Five year survival is not significantly different in the familial and non-familial forms of dilated cardiomyopathy.

Influence of gender and reported alcohol intake on mortality in nonischemic dilated cardiomyopathy

Between 1994-1998, we retrospectively studied a cohort of 396 consecutive patients with dilated cardiomyopathy, mean age 53 +/- 15 years, 74% men. The history of alcohol intake was abstracted from the medical records. During a follow-up period of 42 +/- 26 months, 83 (76% men) patients died and 15 (80% men) underwent cardiac transplantation. Men were younger and more likely to have a history of excessive alcohol intake compared with women. Gender significantly modified the risk of alcohol consumption on mortality. Although alcohol intake increased the mortality risk in women, it was protective toward death in men (hazards ratios for death were 7.3 vs. 0.44). The effect of alcohol intake on outcome was reassessed after classifying the patients into 4 groups: group 1: life-long nondrinkers; group 2: former drinkers; group 3: moderate drinkers; and group 4: heavy drinkers. Similar findings were seen. This study demonstrated that the risk of reported alcohol intake on mortality is related to gender in patients with nonischemic heart failure. Our findings deserve further study, including a larger number of females, as a possible way to improve outcome in such patients.

Clinical and epidemiological aspects of cardiomyopathies: a critical review of current knowledge

Five years after the second report of the WHO/ISFC Task Force on the definition and classification of cardiomyopathies (CM), a critical review of the matter appears well-timed. The need for a correct definition of myocardial diseases is emphasized by considering them the result of a 'direct' injury due to different known and unknown causes and not a consequence of ischemic disease or of pressure and/or volume overload. This is in order to eliminate terms like ischemic CM, valvular CM, and hypertensive CM, which are a source of confusion. The concept of myocardial injury is also reviewed. This should not only include the structural/organic macroscopic injury, but also the subcellular, ultrastructural, and molecular damage (mostly of genetic origin) of the contracting element proteins, of citosol, sarcolemma and cell membrane ion channels. As the myocardium is a complex structure, made of common fibers and of specific conduction tissue, injury may be clinically identified either by ventricular function impairment or by bioelectric function defects, i.e. tachyarrhythmias and/or bradyarrhythmias, which sometimes are the unique manifestation of the disease (arrhythmogenic CM, in the strict sense). On the basis of the morpho-functional alterations, CMs may be classified as dilated CM (which could be better identified as hypokinetic CM, referring to the functional aspect, because the morphologic aspect is not always present), hypertrophic CM, restrictive CM, and arrhythmogenic CM (including not only arrhythmogenic right ventricular CM, but also other forms, like the so-called arrhythmias of the 'apparently' healthy heart, due to 'occult' myocardial injury). Moreover, these forms may present in association, like mixed CM (dilated-arrhythmogenic, dilated-hypertrophic, etc.). From an etiologic point of view, it is advisable to maintain the distinction between specific CM, due to a known cause, and primary or idiopathic CM, including, together with sporadic forms of an unknown origin, familial forms of a genetic origin, depending on alterations of contractile or regulating functional proteins, when myocardial injury is the sole manifestation (idiopathic) of clinical picture. The most modern etiopathogenetic, pathophysiological, and clinical features of each form of CM are briefly described in order to suggest a complete definition of the disease and to state a clinical-epidemiological setting that encompasses the current knowledge.

Long-term prognosis of patients with mildly dilated cardiomyopathy

The long-term prognosis of patients with mildly dilated cardiomyopathy (MDCM) was investigated in 21 patients. MDCM was defined as left ventricular ejection fraction < or = 40% and left ventricular end-diastolic volume < or = 120 ml/m2 by left ventriculography. During a follow-up period of 6.8+/-3.7 years, there were 9 cardiac events (5 heart failure deaths, 2 sudden deaths, and 2 re-hospitalizations for heart failure). Only in the patients without cardiac events was there a significant decrease in left ventricular size (end-diastolic dimension decreased from 58+/-6 mm to 50+/-8 mm, p<0.001) and an improvement in systolic function (fractional shortening increased from 17+/-5% to 26+/-11%, p=0.007). However, left atrial dilation was observed in the patients with an event (from 39+/-5 mm to 43+/-5 mm, p=0.02). Based on proportional hazard analysis, left ventricular end-diastolic pressure and mean pulmonary artery pressure at diagnosis and left atrial dimension at the time of follow-up were significant predictors of poor outcome. A subset of patients with MDCM has impaired hemodynamics at diagnosis, left atrial dilation at follow-up and a poor prognosis, and must be followed carefully even if the left ventricular dilatation is mild.

Predictors of appropriate implantable cardioverter-defibrillator therapy in patients with idiopathic dilated cardiomyopathy

Evaluating predictors of appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with idiopathic dilated cardiomyopathy (IDC) may be helpful in developing risk stratification strategies for these patients. Fifty-four patients with IDC underwent ICD implantation and were followed up. Twenty-three patients (42%) had a class I indication for ICD implantation; the remaining patients underwent implantation for multiple risk factors for sudden death including left ventricular dysfunction, nonsustained ventricular tachycardia, syncope, or positive electrophysiologic study results. Clinical, electrocardiographic, and electrophysiologic data were collected. Appropriate ICD therapy was defined as an antitachycardia pacing therapy or shock for tachyarrhythmia determined to be either ventricular tachycardia or ventricular fibrillation. Appropriate ICD therapy was observed in 23 patients (42%). There was a significant difference in use of beta-blocker therapy between patients who did and did not have appropriate ICD therapy (p <0.0003). Cox regression analysis identified the following univariate predictors (p <0.1): class I indication (p <0.005) and lack of use of beta-blocker therapy (p <0.0007). In multivariate analysis, only lack of beta-blocker use (relative risk 0.15, 95% confidence intervals 0.05 to 0.45; p <0.0007) was identified as a predictor of appropriate ICD therapy. Of the patients who received ICD therapy, only 4 (17%) were taking beta blockers, whereas 21 of the 31 patients (68%) who did not receive ICD therapy were treated with beta blockers (p <0.0003). In patients with IDC selected for ICD implantation, the most consistent predictor of appropriate ICD therapy was lack of beta-blocker use. Attempts should be made to administer beta blockers to these patients, if tolerated.

Prognostic value of low-dose dobutamine echocardiography in patients with idiopathic dilated cardiomyopathy

STUDY OBJECTIVES

Dobutamine echocardiography is widely used for the evaluation of myocardial contractile reserve. The purpose of the study was to determine the prognostic value of low-dose dobutamine echocardiography in patients with idiopathic dilated cardiomyopathy (IDCM).

PATIENTS

The study group consisted of 77 consecutive patients with recently diagnosed IDCM (mean [+/- SD] age, 49 +/- 9 years; men, 82%) and left ventricular (LV) ejection fractions of < 40%.

INTERVENTIONS

Two-dimensional and Doppler echocardiographic variables were measured before and after the infusion of dobutamine at the rate of 10 microg/kg/min for 5 min.

MEASUREMENTS AND RESULTS

During a mean follow-up period of 63 +/- 7 months (range, 49 to 75 months) 30 patients (39%) died and five patients (6%) underwent successful heart transplantations. Using multivariate regression analysis, the only significant factors related to fatal outcome or the need for cardiac transplantation were the following: (1) LV end-systolic volume of > 150 mL after low-dose dobutamine infusion (odds ratio [OR], 2.2; confidence interval [CI], 1.2 to 4.1; p = 0.011); (2) no decrease of LV end-diastolic volume after dobutamine infusion (OR, 1.9; CI, 1.1 to 3.4; p = 0.031); (3) atrial fibrillation (OR, 2.7; CI, 1.4 to 5.3; p = 0.003); and (4) male gender (OR, 2.6; CI, 1.2 to 5.5; p = 0.017). A scoring system was proposed with one point assigned for each of the above-mentioned factors. The mortality rates for total scores of 0, 1, 2, 3, and 4 were 0%, 19%, 48%, 83%, and 100%, respectively.

CONCLUSION

The response of the LV to low-dose dobutamine infusion adds clinically valuable prognostic information to the evaluation of the patient with IDCM.

Primary prevention of sudden cardiac death in idiopathic dilated cardiomyopathy: the Cardiomyopathy Trial (CAT)

BACKGROUND

Patients with idiopathic dilated cardiomyopathy (DCM) and impaired left ventricular ejection fraction have an increased risk of dying suddenly.

METHODS AND RESULTS

Patients with recent onset of DCM (< or =9 months) and an ejection fraction < or =30% were randomly assigned to the implantation of an implantable cardioverter-defibrillator (ICD) or control. The primary end point of the trial was all-cause mortality at 1 year of follow-up. The trial was terminated after the inclusion of 104 patients because the all-cause mortality rate at 1 year did not reach the expected 30% in the control group. In August 2000, the vital status of all patients was updated by contacting patients, relatives, or local registration offices. One hundred four patients were enrolled in the trial: Fifty were assigned to ICD therapy and 54 to the control group. Mean follow-up was 22.8+/-4.3 months, on the basis of investigators' follow-up. After 1 year, 6 patients were dead (4 in the ICD group and 2 in the control group). No sudden death occurred during the first and second years of follow-up. In August 2000, after a mean follow-up of 5.5+/-2.2 years, 30 deaths had occurred (13 in the ICD group and 17 in the control group). Cumulative survival was not significantly different between the two groups (93% and 80% in the control group versus 92% and 86% in the ICD group after 2 and 4 years, respectively).

CONCLUSIONS

This trial did not provide evidence in favor of prophylactic ICD implantation in patients with DCM of recent onset and impaired left ventricular ejection fraction.

Role of implantable cardioverter defibrillators in dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (DCM) accounts for about 10,000 deaths per year in western countries. Of these deaths, 8% to 51% occur suddenly, with more than half of the events due to a ventricular arrhythmia. Improvement in diagnostic techniques and therapeutic strategies, together with changes in secular trends, have likely contributed to the reported trend toward improved survival in recent years. Identification of DCM patients at higher risk of sudden death is difficult. Poor left ventricular function is the strongest predictor of all-cause death, whereas a history of sustained unstable ventricular arrhythmia or cardiac arrest identifies patients at high risk of sudden death. Recent data suggest that a history of syncope, regardless of inducibility at programmed electrical stimulation, may be a risk factor of sudden death. Despite the absence of controlled studies, use of implantable cardioverter defibrillator therapy for primary prevention can be considered in patients with unexplained syncope as well as subgroups of DCM patients awaiting transplantation. In patients who survive a cardiac arrest or an unstable ventricular tachycardia, use of implantable cardioverter defibrillator therapy is associated with improved survival during follow-up and should be considered as a first-line therapy.

Examination of left ventricular contractile reserve by Doppler myocardial imaging in patients with dilated cardiomyopathy

Detection of left ventricular contractile reserve by means of dobutamine stress echocardiography is a well known technique. The aim of the present study was to detect velocity changes during the administration of dobutamine, to establish if Doppler myocardial imaging is a suitable method for determining left ventricular contractile reserve, and to determine if the technique provides more information than traditional stress echocardiography. Twenty-five patients (all males; mean age, 53.4 years) were examined for a clinical diagnosis of idiopathic dilated cardiomyopathy with a poor left ventricular systolic function (ejection fraction less than 30%). Doses of 5-10 and 20 mg/kg/min dobutamine were administered and elevated at 4-minute intervals. Ejection fraction was calculated using the Simpson rule. The peak systolic and the early and late diastolic velocities were measured in the basal segment of the septum and the inferior wall at baseline and at full dose of dobutamine. Results indicated that peak systolic velocity increased significantly, both in the septum (0.11±0.03 vs. 0.20±0.05 m/sec; p=0.001) and in the inferior wall (0.10±0.05 vs. 0.17±0.06 m/sec; p=0.03). Late diastolic velocities also increased significantly, both in the septum (0.17±0.05 vs. 0.22±0.07 m/sec; p=0.01) and in the inferior wall (0.18±0.08 vs.0.21±0.02 m/sec; p=0.01). There was a significant linear correlation between the relative increases in basal ejection fraction value and in peak systolic velocity upon dobutamine stimulation. Patients were divided into responders and nonresponders based on responses in either ejection fraction (25% relative increase) or peak systolic velocity (5 cm/s increase). This study concludes that 1) Doppler myocardial imaging is an adequate and simple technique to examine left ventricular contractile reserve; and 2) measurement of peak systolic velocity during dobutamine stimulation seems to be a simple and good indicator of left ventricular contractile reserve. (c)2001 CHF, Inc.

Dobutamine echocardiographic study in patients with nonischemic dilated cardiomyopathy and prognostically borderline values of peak exercise oxygen consumption: 18-month follow-up study

OBJECTIVES

We sought to study the prognostic value of dobutamine echocardiography in patients with nonischemic dilated cardiomyopathy (DCM) and prognostically borderline values of peak oxygen consumption (VO2max) during exercise.

BACKGROUND

Changes in echocardiographic variables assessed by dobutamine echocardiography can be used to evaluate the functional status of patients with chronic heart failure (CHF) and DCM.

METHODS

In 27 consecutive patients (mean age 55 +/- 15 years) with VO2max values between 10 and 14 ml/kg body weight per min, a low infusion rate (10 microg/kg per min) dobutamine echocardiographic test was performed. The induced changes in echocardiographic variables were measured, and an 18-month follow-up study was done.

RESULTS

At the end of the protocol, 9 patients (group I) had died from cardiac reasons, whereas the remaining 18 patients (group II) survived. After dobutamine infusion, the left ventricular end-systolic diameter (LVESD) was smaller in group II (6.22 +/- 0.94 cm) than in group I (6.99 +/- 0.76 cm; p < 0.05), whereas end-systolic wall stress (ESWS) was higher in group I (1030.66 +/- 193.98 g/cm2) than in group II (691.57 +/- 297.06 g/cm2; p < 0.05). The changes in LVESD and ESWS were greater in group I (0.75 +/- 0.36 cm and 463.11 +/- 159.87 g/cm2, respectively) than in group II (-0.04 +/- 0.36 cm and 83.16 +/- 291.74 g/cm2, respectively; p < 0.01 for both).

CONCLUSIONS

In the "gray" zone of VO2max, dobutamine echocardiography seems to be a valuable prognostic indicator in patients with CHF and DCM.

Intermediate-term results after partial left ventriculectomy for end-stage dilated cardiomyopathy: is there a survival benefit?

BACKGROUND

The mortality of congestive heart failure remains high despite advances in medical therapy. Partial left ventriculectomy (PLV) has been advocated as a surgical alternative for select patients with dilated cardiomyopathy.

METHODS

A prospective clinical trial of PLV for patients with end-stage idiopathic dilated cardiomyopathy was performed. Inclusion criteria were left ventricular end-diastolic diameter (LVEDD) greater than 7 cm, refractory New York Heart Association (NYHA) Class IV symptoms, and severely depressed exercise oxygen consumption.

RESULTS

Twenty patients underwent PLV with mean follow-up of 21.1 months. Sixteen were male; mean age was 50.1 years +/- 12.0 years (range 25-67 years). Left ventricle (LV) ejection fraction improved after surgery from 14.1% +/- 4.7% to 24.1% +/- 3.1% (p < 0.05, t-test) and this improvement persisted up to 3 years after operation. LVEDD and NYHA Class also were notably improved. There were two early deaths for an operative mortality of 10% (2 of 20 patients). Nine patients after initial improvement in clinical status and LV function developed worsening congestive heart failure (CHF). Six of the 9 ultimately died of complications secondary to CHF. One-, 2-, and 3-year survival rates were 84%, 64%, and 40%, respectively, by Kaplan-Meier analysis. The other three patients required listing for transplantation because of recurrent NYHA Class IV symptoms. Freedom from death or the need for listing for transplantation at 1, 2, and 3 years was 65%, 53%, and 33%, respectively. The remaining nine patients all had improvement in their NYHA classification.

CONCLUSIONS

PLV can be performed with acceptable early and intermediate term mortality; survival compares favorably to reports of similar groups of patients treated with medical therapy alone.

Radiographic measurements of cardiac size as predictors of outcome in patients with dilated cardiomyopathy

BACKGROUND

Cardiac dilatation is a predictor of poor outcome in patients with dilated cardiomyopathy. Whereas cardiac chamber dimensions or volumes can be assessed by various noninvasive and invasive techniques, simple chest radiography also may provide a valuable assessment of cardiac size.

METHODS AND RESULTS

To determine the relative power of radiographic heart measurements for predicting outcome in dilated cardiomyopathy, we retrospectively studied 88 adult patients with chest radiographs obtained within 35 days of echocardiography. Standard radiographic variables were measured for each patient, and the cardiothoracic (CT) ratio, frontal cardiac area, and volume were calculated. During a mean 4.1-year follow-up, 62 of the 88 (71%) patients died. CT ratio was the best predictor of mortality among the radiographic cardiac measurements. By multivariate analysis, a model including echocardiographic ejection fraction, New York Heart Association (NYHA) functional class, and history of heart failure was highly predictive of survival. When added to this model, CT ratio also was independently associated with mortality, but not radiographic cardiac area or volume. When radiographic variables were each added to CT ratio, they did not add incremental predictive value to the model that included CT ratio alone. Echocardiographic measurement of left ventricular (LV) size, especially when indexed for body size, was independently predictive of outcome, but it did not supersede the predictive power of CT ratio.

CONCLUSION

The simply derived radiographic CT ratio is a useful predictor of outcome in patients with dilated cardiomyopathy and compares favorably with other clinical and selected echocardiographic variables.