[Asymptomatic ventricular pre-excitation: what management?] / Pre-eccitazione ventricolare in assenza di sintomi: che strada percorrere?

The management of asymptomatic patients with ventricular pre-excitation diagnosed occasionally is controversial. In fact, the lack of clinical arrhythmias does not necessarily define a benign condition: it could be possibly due to poor conduction over the accessory pathway or, conversely, to peculiar and individual conditions, which, even if the accessory pathway is capable of fast conduction, can prevent the onset of arrhythmias. These can occur unexpectedly during follow-up and may include malignant ventricular arrhythmias, although sudden death is very rare in this clinical scenario. An aggressive strategy aiming at extensive ablation in all cases with asymptomatic ventricular pre-excitation is not justified, as well as the "wait-and-see" approach. Clinically, it is important to accurately define the individual risk of any arrhythmia related to the accessory pathway, which may require treatment. For decades, the management of asymptomatic ventricular pre-excitation has been quite inhomogeneous among centers and in some cases it is still very different. Recently, a consensus document proposed the combined use of non-invasive and invasive diagnostic tools for accurate screening of these patients. If non-invasive methodologies are unable to demonstrate poor conduction over the accessory pathway, then an invasive approach is justified for arrhythmia risk definition and, if necessary, adequate therapy.

Optimization of catheter/tissue contact during pulmonary vein isolation: the impact of atrial rhythm.

Aims: During pulmonary vein isolation (PVI), even if operators are aware of the contact force (CF), its values may greatly vary and the impact of cardiac rhythm has not been thoroughly investigated yet. This study aims at assessing the actual values of CF, the applications with suboptimal CF, and the impact of cardiac rhythm on CF during PVI. Methods and results: Twenty patients undergoing point-by-point PVI with a CF-sensing catheter were considered. CF target was between 6 and 40 g. The mean CF per application (mCF) was evaluated and considered suboptimal if ≤5 g. The real-time graphic of CF was also evaluated and classified as pulsatile if regular variations synchronous with the atrial rate were seen; otherwise it was irregular. To achieve PVI, 1458 applications were delivered; 287 (19.68%) had suboptimal mCF. A great variability of mCF was seen according to anatomy, operators and patients. Compared to applications in atrial fibrillation (AF), those in sinus rhythm (SR) showed a higher median value of mCF (11 vs. 9 g; P = 0.0099) and a lower percentage of suboptimal mCF (17.95% vs. 25.15%; P = 0.0051). Compared to the irregular, the pulsatile pattern, almost exclusively observed in SR, was associated with higher mCF (14.69 ± 8.77 vs. 10.79 ± 7.89 g; P < 0.0001) and fewer suboptimal applications (8.02% vs. 27.73%; P < 0.0001). Conclusion: During PVI, several factors influence CF, which, despite optimization attempts, can be suboptimal in ∼20% of the applications. However, CF is higher in SR than in AF and this is strictly associated with a pulsatile pattern of instant CF values.

Clinical role of post-angioplasty hyperemic microvascular resistances in chronic ischemic left ventricular dysfunction.

AIMS: To investigate the impact of hyperemic microvascular resistances (HMRs) on myocardial perfusion and contractility after percutaneous coronary intervention (PCI) in chronic ischemic left ventricular dysfunction (CILVD). METHODS: The current retrospective study included 48 patients with CILVD of the left anterior descending territory undergoing HMRs assessment before and after PCI with a dual-sensor intracoronary pressure-flow wire. The severity of resting myocardial underperfusion and contractile dysfunction of the left anterior descending territory was scored as summed rest score (SRS-T) by single photon emission tomography, wall motion score index (WMSI-T) and left ventricular ejection fraction (LVEF) by transthoracic echocardiography before PCI and after 3 months. Patients were divided into two groups according to the mean post-PCI HMRs. RESULTS: Mean post-PCI HMRs were 2.05 ±â€Š0.43 mmHg/cm/s; increased HMRs (i.e. >2 mmHg/cm/s) were found in 17 patients (35.4%, group B) (3.29 ±â€Š0.77 mmHg/cm/s), whereas 31 patients (64.6%, group A) showed lower values (1.35 ±â€Š0.34 mmHg/cm/s; P < 0.001). Pre-PCI HMRs, WMSI-T and SRS-T were similar among groups.After PCI, a significant improvement of LVEF, WMSI-T and SRS-T was observed only in group A (6.6 ±â€Š7.4%, 0.44 ±â€Š0.42 and 3.9 ±â€Š2.9, respectively) compared with group B (1.3 ±â€Š1.9%, 0.02 ±â€Š0.07 and 1.1 ±â€Š1.9; P = 0.011, P < 0.001 and P = 0.028, respectively).Post-PCI HMRs predicted the absence of improvement of LVEF and WMSI-T at a cutoff value of 1.95 mmHg/cm/s (area under the curve 0.69 and 0.73; P = 0.038 and 0.017, respectively), with a positive predictive value of 96 and 100%, respectively. CONCLUSION: Increased post-PCI HMRs may predict the lack of functional improvement of the revascularized myocardium in CILVD.

Agenesia of the left atrial appendage: possible but very rare.

: Agenesia of the left atrial appendage in a patient with atrial fibrillation is shown. Although of interest, the prevalence of this abnormality is very low.

[Remarks on polyparametric assessment of sudden death risk for primary prevention ICD implantation in patients with left ventricular dysfunction of ischemic and non ischemic etiology. Italian Association of Hospital Cardiologists (ANMCO) Experts Position Paper]. / Considerazioni su una valutazione poliparametrica nella stratificazione del rischio di morte improvvisa per l'indicazione all'impianto di cardioverter-defibrillatore in prevenzione primaria, nella disfunzione ventricolare sinistra di origine ischemica e non ischemica. Position paper dell'Associazione Nazionale Medici Cardiologi Ospedalieri (ANMCO).

It is generally recognized that current guidelines, based on ejection fraction criteria, do not allow appropriate selection of patients for implantable cardioverter-defibrillator (ICD) therapy in the primary prevention of sudden death, thus hindering the optimal use of ICD in patients with left ventricular dysfunction of ischemic and nonischemic etiology. Ejection fraction alone has limitations in both sensitivity and specificity. Assessment of the risk for sudden death using a combination of multiple tests (ejection fraction associated with one or more different arrhythmic risk markers) could partially compensate for these limitations. In this position paper, the potential usefulness of a polyparametric assessment using some of the most investigated risk markers of sudden death is discussed, including late gadolinium enhancement cardiac magnetic resonance, programmed ventricular stimulation, T-wave alternans, autonomic tone, biomarkers, and genetic testing.

Prospective Use of Microvolt T-Wave Alternans Testing to Guide Primary Prevention Implantable Cardioverter Defibrillator Therapy.

BACKGROUND: We hypothesized that a negative microvolt T-wave alternans (MTWA) test would identify patients unlikely to benefit from primary prevention implantable cardioverter defibrillator (ICD) therapy in a prospective cohort. METHODS AND RESULTS: Data were pooled from 8 centers where MTWA testing was performed specifically for the purpose of guiding primary prevention ICD implantation. Cohorts were included if the ratio of ICDs implanted in patients who were MTWA "non-negative" to patients who were MTWA negative was >2:1, indicating that MTWA testing had a significant impact on the decision to implant an ICD. The pooled cohort included 651 patients: 371 MTWA non-negative and 280 MTWA negative. Among non-negative patients, 62% underwent ICD implantation whereas only 13% of MTWA-negative patients received an ICD (P<0.01). Despite a substantially lower prevalence of ICDs, long-term survival (6.9 years) was significantly better among MTWA-negative patients (68.2% non-negative vs. 87.1% negative, P=0.026). CONCLUSIONS: MTWA-negative patients had significantly better survival than MTWA non-negative patients, the majority of whom had ICDs. Despite a very low prevalence of ICDs, long-term survival among patients with left ventricular ejection fraction ≤40% and a negative MTWA test was better than in the ICD arm of any study to date that has demonstrated a benefit of ICDs. This provides further evidence that MTWA-negative patients are unlikely to benefit from primary prevention ICD therapy.

Invasive electrophysiological evaluation and ablation in patients with asymptomatic ventricular pre-excitation persistent at exercise stress test.

AIMS: In patients with asymptomatic ventricular pre-excitation (VPE) persistent at exercise stress test, this study evaluates the proportion of cases with adverse conduction properties of the atrioventricular accessory pathway (AP) at invasive electrophysiological study and the long-term follow-up after they received treatment according to pre-determined criteria. METHODS AND RESULTS: Over 10 years, asymptomatic patients with VPE persistent at exercise stress test referred for invasive electrophysiological evaluation including isoproterenol (IPN) infusion were included. Ablation was planned if they had at least one of the following criteria: (i) shortest pre-excited R-R interval (SPERRI) ≤250 ms and/or (ii) inducible atrioventricular re-entrant tachycardia (AVRT). Cryoablation was electively used in para-hisian and mid-septal APs. Patients non-eligible for ablation received no therapy. Sixty-three patients (45 males; mean age 26 ± 14 years) underwent electrophysiological evaluation: 7 had fasciculo-ventricular fibres and were excluded, whereas 56 had 58 APs. Thirty-one patients (55%) were eligible and underwent successful ablation: 87% had at least the SPERRI ≤ 250 ms and 61% had at least inducible AVRT. In 15 cases (48%) the ablation criteria were met only during IPN infusion. During follow-up (73 ± 33 months), one patient was successfully retreated for resumption of VPE in the ablation group, whereas no event was observed in the group of patients who received no treatment. CONCLUSION: In this subset of patients with asymptomatic VPE, invasive electrophysiological evaluation shows fast antegrade conduction over the AP and/or inducible AVRT in about half of the cases. Patients who received no therapy because of a benign electrophysiological profile had an event-free follow-up.

Takotsubo cardiomyopathy: an integrated multi-imaging approach.

Takotsubo cardiomyopathy (TTC) is a distinct clinical entity characterized by the presence of transient left ventricular wall dysfunction without significant culprit obstructive coronary artery disease. Invasive coronary angiography and ventriculography are the 'gold standard' for definitive diagnosis, with an integrated multi-modality imaging approach offering advantages in various clinical scenarios. Echocardiography is a widely available, first-line, non-invasive imaging technique appropriate both in emergency setting to confirm diagnosis, assess for various potential acute complications, and in serial follow-up to track myocardial recovery. Cardiac magnetic resonance (CMR) may be helpful to discriminate TTC from other acute cardiac syndromes with troponin elevation and ventricular dysfunction. Echocardiography, CMR, and nuclear imaging may also provide new insights into possible underlying pathophysiological mechanisms, and myocardial (123)I-metaiodobenzyl-guanidine imaging may have a role for retrospective diagnosis in the subacute phase of late-presenting cases. The potential diagnostic role of coronary computed tomography angiography in the emergency room requires a further study.

[Remarks on the guideline recommendations for cardioverter-defibrillator implantation for primary prevention of sudden cardiac Death in patients with severe ventricular dysfunction. Consensus Document of the Italian Association of Hospital Cardiologists (ANMCO)/Italian Society of Cardiology (SIC)/Italian Association of Arrhythmology and Cardiac Pacing (AIAC)]. / Considerazioni sulle raccomandazioni delle linee guida all'impianto del cardioverter-defibrillatore per la prevenzione primaria della morte cardiaca improvvisa nei pazienti con grave disfunzione ventricolare. Documento di Consenso dell'Associazione Nazionale Medici Cardiologi Ospedalieri (ANMCO)/Società Italiana di Cardiologia (SIC)/Associazione Italiana di Aritmologia e Cardiostimolazione (AIAC).

The indications for implantable cardioverter-defibrillator (ICD) therapy for the prevention of sudden cardiac death in patients with severe left ventricular dysfunction have rapidly expanded over the last 10 years on the basis of the very satisfying results of the numerous randomized clinical trials that have provided the framework for guidelines. However, the analysis of clinical practice in the real world has highlighted some important criticisms in the complex process of selection-management of those patients candidates for ICD therapy: 1) approximately one fourth of all ICD implantations is not justified by clinical evidence, 2) approximately one half of patients with an indication for ICD therapy do not undergo implantation, 3) the benefits from ICD therapy do not apply uniformly to all patients, 4) the relationship between the lifesaving benefit and the potential for harm of ICD therapy is still scarcely known. The main reason for this clinical scenario can be ascribed to the guideline recommendations that are based only on few standard cut-off criteria and therefore too generic and insufficiently detailed. This does not help cardiologists in their decision-making process, and results in fear, uncertainty, and sometimes emotional choices. The aim of this consensus document is to discuss current guideline recommendations and to provide the Italian cardiologists with the most updated information to optimize the selection of patients with severe left ventricular dysfunction who should receive ICD therapy.

A combined anatomic and electrophysiologic substrate based approach for sudden cardiac death risk stratification.

BACKGROUND: Although left ventricular ejection fraction (LVEF) is the primary determinant for sudden cardiac death (SCD) risk stratification, in isolation, LVEF is a sub-optimal risk stratifier. We assessed whether a multi-marker strategy would provide more robust SCD risk stratification than LVEF alone. METHODS: We collected patient-level data (n = 3355) from 6 studies assessing the prognostic utility of microvolt T-wave alternans (MTWA) testing. Two thirds of the group was used for derivation (n = 2242) and one-third for validation (n = 1113). The discriminative capacity of the multivariable model was assessed using the area under the receiver-operating characteristic curve (c-index). The primary endpoint was SCD at 24 months. RESULTS: In the derivation cohort, 59 patients experienced SCD by 24 months. Stepwise selection suggested that a model based on 3 parameters (LVEF, coronary artery disease and MTWA status) provided optimal SCD risk prediction. In the derivation cohort, the c-index of the model was 0.817, which was significantly better than LVEF used as a single variable (0.637, P < .001). In the validation cohort, 36 patients experienced SCD by 24 months. The c-index of the model for predicting the primary endpoint was again significantly better than LVEF alone (0.774 vs 0.671, P = .020). CONCLUSIONS: A multivariable model based on presence of coronary artery disease, LVEF and MTWA status provides significantly more robust SCD risk prediction than LVEF as a single risk marker. These findings suggest that multi-marker strategies based on different aspects of the electro-anatomic substrate may be capable of improving primary prevention implantable cardioverter-defibrillator treatment algorithms.

Left atrial diverticula in patients undergoing atrial fibrillation ablation: morphologic analysis and clinical impact.

INTRODUCTION: Left atrial diverticula (LAD) have been reported to be (1) at risk for intracavitary thrombosis and cardiac perforation during ablation and (2) sites of extrapulmonary vein foci. In atrial fibrillation (AF) ablation, their presence might undermine procedure safety and efficacy. This observational study evaluates the morphology and clinical impact of LAD in patients undergoing AF ablation. METHODS AND RESULTS: Consecutive patients undergoing computed tomography scan (Aquilion 64, Toshiba, Otawara, Japan) and AF ablation with imaging integration (CARTO 3 Merge, Biosense Webster, CA, USA) in our center were included. Morphologic analysis was performed by 2 independent radiologists. Ablation was obtained by irrigated radiofrequency energy (Navistar Thermocool or Thermocool SF, Biosense Webster). Out of 212 patients, 58 (27.3%) had LAD; 74.4% of LAD were located in the anterosuperomedial left atrium. In patients with and without LAD, the prevalence of prior cerebrovascular events was similarly low. The rate of major periprocedure complications did not differ significantly: 1.7% versus 2.6% (P = 1) in patients with and without LAD, respectively. However, 1 case of cardiac perforation occurred during ablation in a diverticulum. During follow-up, survival free from arrhythmia recurrences was comparable in the 2 groups. CONCLUSION: LAD are present in about one-fourth of patients undergoing AF ablation and, in general, they have no impact on its safety and efficacy. However, occasionally, radiofrequency energy delivery in a LAD can cause tissue overheating and perforation.

Simulator training reduces radiation exposure and improves trainees' performance in placing electrophysiologic catheters during patient-based procedures.

BACKGROUND: Currently, training in interventional electrophysiology is based on conventional methodologies, and a paucity of data on the usefulness of simulation in this field is available. OBJECTIVE: The purpose of this study was to evaluate the impact of simulator training on trainees' performance in electrophysiologic catheter placement during the early phase of their learning curve. METHODS: Inexperienced electrophysiology fellows were considered. A hybrid high-fidelity simulator (Procedicus VIST, version 7.0, Mentice AB Gothenburg, Sweden for Biosense Webster) was used. The following parameters were evaluated in 3 consecutive patient-based procedures before and after two training sessions of at least 1.5 hours on the simulator: (1) ability to place catheters in conventional recording/pacing sites (coronary sinus, His-bundle area, high right atrium, and right ventricular apex); (2) amount of help provided by the supervisor (scale from 1-3; 3 for maximal help); (3) fluoroscopy time; and (4) positioning time. RESULTS: Seven fellows performed 168 catheter placements during 42 patient-based procedures with no complications. Comparing parameters before and after simulator training, there was a significant reduction in the mean amount of help and in fluoroscopy and positioning times per placement: from 1.71 ± 1.24 to 0.42 ± 0.68 (P <.001), from 121 ± 88 seconds to 76 ± 54 seconds (P <.001), and from 175 ± 138 seconds to 102 ± 74 seconds (P <.001), respectively. Overall fluoroscopy time per patient decreased from 567 ± 220 seconds to 305 ± 111 seconds (P <.0001). Improvement appeared to be related to simulator training alone and not to the previously performed patient-based procedures. CONCLUSION: During the early phase of the trainees' learning curve, simulator training significantly improves the independent trainees' performance with reduction in radiation exposure.

Clinical utility of microvolt T-wave alternans testing in identifying patients at high or low risk of sudden cardiac death.

BACKGROUND: Previous studies have demonstrated that microvolt T-wave alternans (MTWA) testing is a robust predictor of ventricular tachyarrhythmias and sudden cardiac death (SCD) in at-risk patients. However, recent studies have suggested that MTWA testing is not as good a predictor of "appropriate" implantable cardioverter-defibrillator (ICD) therapy as it is a predictor of SCD in patients without ICDs. OBJECTIVE: To evaluate the utility of MTWA testing for SCD risk stratification in patients without ICDs. METHODS: Patient-level data were obtained from 5 prospective studies of MTWA testing in patients with no history of ventricular arrhythmia or SCD. In these studies, ICDs were implanted in only a minority of patients and patients with ICDs were excluded from the analysis. We conducted a pooled analysis and examined the 2-year risk for SCD based on the MTWA test result. RESULTS: The pooled cohort included 2883 patients. MTWA testing was positive in 856 (30%), negative in 1627 (56%), and indeterminate in 400 (14%) patients. Among patients with a left ventricular ejection fraction (LVEF) of ≤35%, annual SCD event rates were 4.0%, 0.9%, and 4.6% among groups with MTWA positive, negative, and indeterminate test results. The SCD rate was significantly lower among patients with a negative MTWA test result than in patients with either positive or indeterminate MTWA test results (P <.001 for both comparisons). In patients with an LVEF of >35%, annual SCD event rates were 3.0%, 0.3%, and 0.3% among the groups with MTWA positive, negative, and indeterminate test results. The SCD rate associated with a positive MTWA test result was significantly higher than that associated with either negative (P <.001) or indeterminate MTWA test results (P = .003). CONCLUSIONS: In patients without ICDs, MTWA testing is a powerful predictor of SCD. Among patients with an LVEF of ≤35%, a negative MTWA test result is associated with a low risk for SCD. Conversely, among patients with an LVEF of >35%, a positive MTWA test result identifies patients at significantly heightened SCD risk. These findings may have important implications for refining primary prevention ICD treatment algorithms.

Superiority of simulator-based training compared with conventional training methodologies in the performance of transseptal catheterization.

OBJECTIVES: This study aims to compare the performance of electrophysiology fellows in transseptal catheterization (TSP-C) after conventional (Conv-T) or simulator training (Sim-T). BACKGROUND: Current training for TSP-C, an increasingly used procedure, relies on performance on patients with supervision by an experienced operator. Virtual reality, a new training option, could improve post-training performance. METHODS: Fellows inexperienced in TSP-C were enrolled and randomly assigned to Conv-T or Sim-T. The post-training performance of each fellow was evaluated and scored in 3 consecutive patient-based procedures by an experienced operator blinded to the fellow's training assignment. RESULTS: Fourteen fellows were randomized to Conv-T (n = 7) or to Sim-T (n = 7) and, after training, performed 42 TSP-Cs independently. Training time was significantly longer for Conv-T than for Sim-T (median 30 days vs. 4 days; p = 0.0175). The Conv-T fellows had significantly lower post-training performance scores (median 68 vs. 95; p = 0.0001) and a higher number of recurrent errors (median 3 vs. 0; p = 0.0006) when compared with Sim-T fellows. CONCLUSIONS: The TSP-C training with virtual reality results in shorter training times and superior post-training performance.

Role of three-dimensional imaging integration in atrial fibrillation ablation.

Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form, catheter ablation aimed at electrically disconnecting the pulmonary veins (PVs) has proved more effective than use of antiarrhythmic drugs in maintaining sinus rhythm during follow-up. On the other hand, this ablation procedure is complex, requires specific training and adequate clinical experience. A main challenge is represented by the need for accurate sequential positioning of the ablation catheter around each veno-atrial junction to deliver point-by-point radiofrequency energy applications in order to achieve complete and persistent electrical disconnection of the PVs. Imaging integration is a new technology that enables guidance during this procedure by showing a three-dimensional, pre-acquired computed tomography or magnetic resonance image and the relative real-time position of the ablation catheter on the screen of the electroanatomic system. Reports in the literature suggest that imaging integration provides accurate visual information with improvement in the procedure parameters and/or clinical outcomes of the procedure.

Proportion of patients needing an implantable cardioverter defibrillator on the basis of current guidelines: impact on healthcare resources in Italy and the USA. Data from the ALPHA study registry.

AIMS: Implantable cardioverter defibrillators (ICD) improve survival in selected patients with left ventricular dysfunction or heart failure (HF). The objective is to estimate the number of ICD candidates and to assess the potential impact on public health expenditure in Italy and the USA. METHODS AND RESULTS: Data from 3513 consecutive patients (ALPHA study registry) were screened. A model based on international guidelines inclusion criteria and epidemiological data was used to estimate the number of eligible patients. A comparison with current ICD implant rate was done to estimate the necessary incremental rate to treat eligible patients within 5 years. Up to 54% of HF patients are estimated to be eligible for ICD implantation. An implantation policy based on guidelines would significantly increase the ICD number to 2671 implants per million inhabitants in Italy and to 4261 in the USA. An annual increment of prophylactic ICD implants of 20% in the USA and 68% in Italy would be necessary to treat all indicated patients in a 5-year timeframe. CONCLUSION: Implantable cardioverter defibrillator implantation policy based on current evidence may have significant impact on public health expenditure. Effective risk stratification may be useful in order to maximize benefit of ICD therapy and its cost-effectiveness in primary prevention.

Use of a novel sharp-tip, J-shaped guidewire to facilitate transseptal catheterization.

AIMS: Transseptal catheterization (TSP-C) is a demanding procedure and at the same time one of the key points of atrial fibrillation ablation, an increasingly diffused procedure. This study prospectively evaluates the usefulness of a novel sharp-tip, J-shaped 0.014'' transseptal guidewire (TSP-GW) to facilitate TSP-C in case of resistant atrial septum (AS). METHODS AND RESULTS: Consecutive patients undergoing TSP-C for arrhythmia ablation in a single centre were considered for the study. TSP-C was performed according to a standardized technique. The criterion to use the TSP-GW was a resistant AS, defined as inability to perforate the fossa ovalis by applying moderate pressure to a standard Brockenbrough needle. The TSP-GW was inserted in the needle lumen and advanced to puncture the AS and enter the left atrium; subsequently, the transseptal assembly was advanced over the TSP-GW. Double transseptal puncture was routinely performed for ablation of atrial fibrillation. Eighty-one patients (54 males, 27 females; mean age 54 +/- 17 years, range 12-81) undergoing TSP-C were enrolled; 132 TSP-C procedures were planned and accomplished. Nineteen patients (23%) in 27 procedures showed a resistant AS. In all these procedures, the TSP-GW was safely and successfully used to accomplish the TSP-C. In patients with a resistant AS, only a significantly lower prevalence of structural heart disease was observed when compared with controls. No complication related to TSP-C was observed. CONCLUSION: The TSP-GW facilitates TSP-C in 23% of the patients, in whom a resistant AS is encountered. In this population, there was no clinical predictor of such anatomy.

Electroanatomic mapping and ablation of macroreentrant atrial tachycardia: comparison between successfully and unsuccessfully treated cases.

INTRODUCTION: Ablation of macroreentrant atrial tachycardia (MRAT) is demanding and identification of predictors of failure may be of help in patient management. This study compares the characteristics of successfully versus unsuccessfully treated patients undergoing electroanatomic mapping (EAM) and ablation of MRAT. METHODS AND RESULTS: Consecutive patients undergoing EAM and ablation of MRAT were included. Ablation was linearly placed at the mid-diastolic isthmus (MDI) to achieve arrhythmia interruption and conduction block. Variables were analyzed for predictors of both procedural failure and cumulative failure (procedural failure + early recurrences). Fifty-two patients (37 M; age 64 +/- 16 years) with 56 MRATs were considered. The MRAT was in the right atrium in 25 morphologies (45%) and 32 (57%) showed a double-loop reentry. Fifty-one morphologies (91%) in 47 patients were successfully treated; 3 patients had early recurrences of the same MRAT. None of the clinical variables considered significantly differed in the successfully treated group as compared to the unsuccessfully treated. Conversely, there was a significant difference as to the EAM characteristics: successfully treated cases showed a narrower target isthmus with a lower voltage amplitude and slower conduction velocity (CV). In the MDI, a CV >60 cm/sec and a width >40 mm were the strongest predictors of procedural failure and cumulative failure, respectively. CONCLUSIONS: In this patient population, while the clinical variables did not differ significantly, there was a significant difference in the EAM characteristics between successfully and unsuccessfully treated cases. CV and width of the isthmus target for ablation were the strongest independent predictors of procedure outcome.

Predictors of mortality and hospitalization for cardiac causes in patients with heart failure and nonischemic heart disease: a subanalysis of the ALPHA study.

BACKGROUND: Several studies have searched for predictors of clinical outcome in patients with heart failure (HF). However, since they were collected in clinical trials, most data were subject to selection biases and do not specifically apply to patients with nonischemic heart disease. This study examined the impact of several variables on combined all-cause mortality and hospitalization for cardiac causes, in consecutive ambulatory patients with HF included in the ALPHA registry. METHODS AND RESULTS: This analysis included 446 patients with HF and nonischemic heart disease, in New York Heart Association functional class II or III, and a left ventricular (LV) ejection fraction below 40%. In 126 patients (73%) the disease was idiopathic dilated cardiomyopathy, in 72 (16%) hypertensive, in nine (2%) valvular, and in 39 (9%) of other etiologies. The median age was 61 years (range 51-69 years) and 349 (78%) patients were men. Over a median follow-up of 31 months (range 23-40), 82 patients (18%) died or were hospitalized for cardiac causes. In a proportional hazard (Cox) regression model, maximal oxygen consumption (HR 0.9, P = 0.001), LV end-diastolic diameter (HR 1.07, P < 0.001), resting systolic blood pressure (HR 0.97, P < 0.005), and hemoglobin (HR 0.86, P < 0.05) were independent predictors of the combined study endpoint. CONCLUSIONS: In an unselected population of patients with HF and nonischemic heart disease, a reduced exercise capacity, large LV end-diastolic diameter, low systolic blood pressure, and hemoglobin were correlated with long-term all-cause mortality or hospitalization for cardiac causes. These observations may help stratifying and tailoring the treatment of patients with HF and nonischemic heart disease.