[Radiofrequency transcatheter ablation of the left lateral Kent bundle in a premature newborn after 28 weeks of pregnancy with prenatal diagnosis of incessant tachycardia: 28-year follow-up]. / Ablazione transcatetere di fascio accessorio tipo Kent sinistro laterale in nato prematuro a 7 mesi di gestazione con diagnosi prenatale di tachicardia incessante: follow-up a distanza di 28 anni.

A case of incessant tachycardia diagnosed at the seventh month of pregnancy conditioning hydrops fetalis is described. Delivery was induced by caesarean section. Atrioventricular reciprocating tachycardia was due to the involvement of a left lateral accessory pathway refractory to multiple antiarrhythmic drugs and was often associated with ipsilateral left bundle branch block at a slower rate. To the best of our knowledge, this is the smallest premature infant in whom radiofrequency catheter ablation was necessary. There were no complaints of complications with recognizable clinical involvement but only a pericardial effusion diagnosed by echocardiography that reabsorbed within a few days. At 28 years old, the psycho-somatic development of this young man is optimal, with normal findings at cardiac imaging. This treatment modality has proven feasible but remains a procedure to be performed only in exceptional cases by very experienced operators.

Arterial hypertension in patients with takotsubo syndrome: prevalence, long-term outcome, and secondary preventive strategies: a report from the Takotsubo Italian Network register.

AIMS: The aim of this study was to investigate the long-term outcome of takotsubo syndrome (TTS) patients with and without hypertension (HT) and to evaluate the effectiveness of treatment with beta-blockers (BBs) and/or renin-angiotensin-aldosterone system inhibitors (RAASi). METHODS AND RESULTS: The study population includes a register-based, multicentre cohort of consecutive patients with TTS, divided into two groups according to the history of HT. Further stratification was performed for BB/RAASi prescription at discharge. The primary outcome was the composite of all-cause death and TTS recurrence at the longest available follow-up. The propensity score weighting technique was used to account for potential confounding. In the overall population (903 patients, mean age 70 ± 11 years), HT was reported in 66% of cases. At a median 2-year follow-up, there was no difference in the risk of the primary composite outcome between patients with and without HT. The adjusted Cox regression analysis showed a significantly lower risk for the primary outcome [adjusted hazard ratio (aHR): 0.69; 95% confidence interval (CI): 0.49-0.99] in patients who received BB vs. those who did not. Renin-angiotensin-aldosterone system inhibitors treatment was not associated with the primary study outcome. The lower risk for the primary outcome with BB treatment was confirmed in patients with HT (aHR: 0.37; 95% CI: 0.24-0.56) but not in patients without (aHR: 1.83; 95% CI: 0.92-3.64; Pinteraction < 0.001). CONCLUSION: In this TTS study, HT did not affect the long-term risk of adverse events but increased the probability of benefit from BB treatment after discharge. Owing to the favourable outcome impact of BB prescription in TTS patients with HT, a tailored pharmacological therapy should be considered in this cohort.

Although not associated with clinical outcomes, hypertension (HT) seems to modify the long-term effectiveness of pharmacological treatment in patients with takotsubo syndrome (TTS). Beta-blockers improved the overall survival of TTS patients with HT and should be considered as first-line therapy in this patient population. The effectiveness of renin­angiotensin­aldosterone system inhibitors on long-term outcome was not significant regardless of the history of HT.

Beta-blockers are associated with better long-term survival in patients with Takotsubo syndrome.

OBJECTIVE: The advantage of beta-blockers has been postulated in patients with Takotsubo syndrome (TTS) given the pathophysiological role of catecholamines. We hypothesised that beta-blocker treatment after discharge may improve the long-term clinical outcome in this patient population. METHODS: This was an observational, multicentre study including consecutive patients with TTS diagnosis prospectively enrolled in the Takotsubo Italian Network (TIN) register from January 2007 to December 2018. TTS was diagnosed according to the TIN, Heart Failure Association and InterTAK Diagnostic Criteria. The primary study outcome was the occurrence of all-cause death at the longest available follow-up; secondary outcomes were TTS recurrence, cardiac and non-cardiac death. RESULTS: The study population included 825 patients (median age: 72.0 (63.0-78.0) years; 91.9 % female): 488 (59.2%) were discharged on beta-blockers and 337 (40.8%) without beta-blockers. The median follow-up was 24.0 months. The adjusted Cox regression analysis showed a significantly lower risk for all-cause death (adjusted HR: 0.563; 95% CI: 0.356 to 0.889) and non-cardiac death (adjusted HR: 0.525; 95% CI: 0.309 to 0.893) in patients receiving versus those not receiving beta-blockers, but no significant differences in terms of TTS recurrence (adjusted HR: 0.607; 95% CI: 0.311 to 1.187) and cardiac death (adjusted HR: 0.699; 95% CI: 0.284 to 1.722). The positive survival effect of beta-blockers was higher in patients with hypertension than in those without (pinteraction=0.014), and in patients who developed cardiogenic shock during the acute phase than in those who did not (pinteraction=0.047). CONCLUSIONS: In this real-world register population, beta-blockers were associated with a significantly higher long-term survival, particularly in patients with hypertension and in those who developed cardiogenic shock during the acute phase.

Long-term outcome in patients with Takotsubo syndrome presenting with severely reduced left ventricular ejection fraction.

AIM: To evaluate the long-term outcome of patients with Takotsubo syndrome (TTS) and severely reduced left ventricular ejection fraction (LVEF ≤ 35%) at presentation. METHODS AND RESULTS: The study population included 326 patients (mean age 69.5 ± 10.7 years, 28 male) with TTS enrolled in the Takotsubo Italian Network, divided into two groups according to LVEF (≤ 35%, n = 131; > 35%, n = 195), as assessed by transthoracic echocardiography at hospital admission. In-hospital events were recorded in both groups. At long-term follow-up (median 26.5 months, interquartile range 18-33), composite major adverse cardiac events (MACE: cardiac death, acute myocardial infarction, heart failure, and TTS recurrence) and rehospitalization were investigated. Compared to patients with LVEF > 35%, patients with LVEF ≤ 35% were older (71.2 ± 10.8 vs. 68.4 ± 10.6 years; P = 0.026) and experienced more frequently cardiogenic shock (16% vs. 4.6%; P < 0.001), acute heart failure (28.2% vs. 12.8%; P = 0.001), and intra-aortic balloon pump support (11.5% vs. 2.6%; P = 0.001) in the acute phase. At long-term follow-up, higher rates of composite MACE (25.2% vs. 10.8%; P = 0.001) and rehospitalization for cardiac causes (26% vs. 13.3%; P = 0.004) were observed in these patients. LVEF ≤ 35% at admission [hazard ratio (HR) 2.184, 95% confidence interval (CI) 1.231-3.872; P = 0.008] and age (HR 1.041, 95% CI 1.011-1.073; P = 0.006) were independent predictors of MACE. Patients with LVEF ≤ 35% also had a significant lower freedom from composite MACE during long-term follow-up (χ2 = 11.551, P = 0.001). CONCLUSION: Left ventricular ejection fraction ≤ 35% at presentation is a key parameter to identify TTS patients at higher risk not only in the acute phase but also at long-term follow-up.

[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.

Epicardial and microvascular coronary vasomotor dysfunction and its relation to myocardial ischemic burden in patients with non-obstructive coronary artery disease.

AIM: To assess the relative contribution of epicardial endothelium-dependent (EDD) and microvascular endothelium-independent (EIMVD) coronary vasomotor dysfunction to the extent of myocardial ischemia in patients with normal angiograms or non-obstructive coronary artery disease (NOCAD). METHODS: Coronary vasomotion was evaluated by quantitative angiography and blood flow (CBF) measurements during intracoronary acetylcholine, nitroglycerine, and adenosine in 101 patients. Myocardial SPECT ischemic burden was evaluated by semi-quantitative scoring of summed stress (SSS) and summed ischemic (SDS) perfusion defect size. RESULTS: Coronary vasomotor dysfunction was found in most patients (83; 77%) with a divergent behavior of EDD and EIMVD in one half of them (52.4%). There was no significant difference in SDS between patients with and without EIMVD, whereas SDS was significantly greater in subjects with EDD as compared to patients with normal response to acetylcholine (4.31 ± 2.44 vs 1.35 ± 1.45; P < .0001). Patients with EDD, either alone or in combination with EIMVD, had significantly higher SSS as compared to patients with lone EIMVD or normal vasomotor function (8.50 ± 5.32; 5.55 ± 3.21; 2.60 ± 2.14; and 1.74 ± 1.66, respectively; P < .0001). Acetylcholine CBF correlated inversely with both SDS (r = -0.545; P < .001) and SSS (r = 0.538; P < .001). CONCLUSIONS: In NOCAD patients with symptoms and signs of myocardial ischemia, vasomotor dysfunction is common. EDD is associated with greater extent of ischemia as compared to isolated EIMVD. Thus, assessment of both EIMVD and EDD is needed to recognize mechanisms of ischemia and identify patients with greater ischemic burden.

Abnormal coronary vasoreactivity in transient left ventricular apical ballooning (tako-tsubo) syndrome.

BACKGROUND: The exact etiology and pathophysiologic mechanisms of tako-tsubo syndrome (TTS) remain controversial. OBJECTIVE: To further evaluate the abnormal coronary vasoreactivity and its possible anatomical substrate in TTS. METHODS: We studied 47 patients (46 women; age 67±12years) who underwent diagnostic cardiac catheterization and evaluation of coronary vasoreactivity by sequential acetylcholine (Ach), nitroglycerine and adenosine testing with angiographic and intracoronary pressure-Doppler flow monitoring. Coronary artery wall morphology was also evaluated by intravascular ultrasound (IVUS) imaging in 45 vessels of 43 patients. RESULTS: Abnormal coronary vasoconstriction to Ach stimulation was elicited in 40 patients (85%) involving the LAD artery and its branches in 39 (83%). Abnormal microvascular function was seen in 39 (83%) patients. Overall, hyperemic microvascular resistance index (HMR) was higher and Doppler coronary flow velocity reserve (CFVR) was lower in the LAD artery territory as compared to the reference territories (2.64±1.23 vs 2.05±0.56; p=0.008 and 1.95±0.7 vs 2.3±0.6; p=0.018, respectively). IVUS revealed no plaque rupture, dissection or thrombosis but occult plaque formation and myocardial bridging were found as a possible anatomical substrate of endothelial dysfunction in 67% and 48.8% patients respectively. CONCLUSIONS: A global failure of coronary vasomotor function was demonstrated in most TTS patients. These findings implicate abnormal vasoconstrictive response to the activation of the sympathetic system as a potential mechanism involved in the pathogenesis of myocardial stunning in TTS. PERSPECTIVES: Competency in medical knowledge: Abnormal coronary vasoconstriction secondary to endothelial dysfunction may actively contribute to the clinical manifestation of acute coronary syndromes in patients with non-obstructive coronary disease. Translational outlook 1: TTS patients reveal a global failure of vasomotor function with both vasoconstrictive response to acetylcholine and increased hyperemic microvascular resistances in the territory of myocardial stunning. They may also show occult coronary atherosclerosis and myocardial bridging as the anatomic substrates of endothelial dysfunction. Translational outlook 2: The cardiac phenotype of TTS includes a high prevalence of coronary vasomotor disturbances. These findings implicate abnormal vasoconstrictive response to the activation of the sympathetic system as a potential mechanism involved in the pathogenesis of TTS in post-menopausal women. Thus, a systematic evaluation of coronary vasoreactivity could better characterize the syndrome.

Risk Stratification Using the CHA2DS2-VASc Score in Takotsubo Syndrome: Data From the Takotsubo Italian Network.

BACKGROUND: The CHA2DS2-VASc score predicts stroke in patients with atrial fibrillation and has been reported to have a prognostic role even in acute coronary syndrome patients. The Takotsubo syndrome is a condition that mimics acute coronary syndrome and may present several complications including stroke. We sought to assess the ability of CHA2DS2-VASc score to predict adverse events in Takotsubo syndrome patients. METHODS AND RESULTS: Overall, 371 Takotsubo syndrome patients were enrolled in a prospective registry. Patients were divided into 3 groups according to the CHA2DS2-VASc score: Group A (≤1), B (2-3), and C (≥4). The median CHA2DS2-VASc score was 3 (interquartile range: 2-4). Overall, 9%, 42%, and 49% were included in Group A, B, and C, respectively. Follow-up length was 26±20 months. The mortality rate was 6%, 7%, and 17% in Group A, B, and C, respectively (P=0.011). The stroke rate was 3% and not different among the 3 groups. Estimated major adverse cardiac and cerebrovascular events (the composite of death, myocardial infarction, and stroke) rates in the 3 groups were 6%, 9%, and 17% in Group A, B, and C, respectively (P=0.033). The CHA2DS2-VASc score resulted as a predictor of major adverse cardiac and cerebrovascular events (odds ratio 2.1, 95% confidence interval, 1.2-3.6; P=0.01) and all-cause mortality (odds ratio 1.5, 95% confidence interval, 1.2-1.9; P=0.001). CONCLUSIONS: In Takotsubo syndrome, the CHA2DS2-VASc score allows prediction of cardiovascular events and mortality at long-term follow-up.

Revealing enterovirus infection in chronic human disorders: An integrated diagnostic approach.

Enteroviruses (EVs) causing persisting infection are characterized by minimal replication and genetic changes. Typing of these agents may complement disease assessment and shed light on pathogenesis. Here we report an integrated approach for EV detection in human samples that is based on pre-enrichment of virus in cell culture before search for the viral genome and viral antigens. Cases of post-polio syndrome, type 1 diabetes, and chronic cardiomyopathy were investigated. As tissue-based approaches require invasive procedures, information was mainly gleaned from virus in blood. Molecular assays targeting conserved genome regions of all EV types (5'UTR, 2 C, 3Dpol) were employed. As compared to direct assays of plasma or leukocytes, the EV detection rate was significantly enhanced by co-culture of leukocytes with cell lines prior to molecular and immunologic tests. Results of RT-PCR and sequencing were confirmed by staining cell cultures with a panel of EV-specific antibodies. Sequence and phylogenetic analysis showed that EVs of the C species (polioviruses) were associated with the post-polio syndrome, while members of the B species were found in type 1 diabetes and cardiomyopathy. The procedure may be used for investigating the possible association of different EVs with a variety of chronic neurologic, endocrine, and cardiac disorders.

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.

Clinical profile and in-hospital outcome of Caucasian patients with takotsubo syndrome and right ventricular involvement.

AIM: To determine the prevalence, clinical characteristics, in-hospital course and determinants of major adverse events in a cohort of Caucasian patients with Takotsubo syndrome (TTS) and right ventricular involvement (RVi), regardless of left ventricular variant forms. METHODS AND RESULTS: The study population consisted of 424 patients (mean age 69.1±11.5years; female 92.2%) with a diagnosis of TTS divided into two groups according to the presence or absence of RVi. RVi patients (n=57; 13.4%) showed a higher prevalence of comorbidities, especially respiratory diseases (p=0.011), and a higher Charlson comorbidity index (CCI; p=0.006) than non-RVi patients. In-hospital major adverse events (acute heart failure, cardiogenic shock and death) occurred more frequently in RVi patients (p<0.001). Heart rate and CCI, along with the echocardiographic parameters of wall motion score index, E/e' ratio, tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary artery pressure (sPAP) were associated with adverse in-hospital outcome. At multivariate analysis, CCI (HR: 1.871; 95% CI: 1.202-2.912; p=0.006), sPAP (HR: 1.059; 95% CI: 1.016-1.104; p=0.007) and TAPSE (HR: 0.728; 95% CI: 0.619-0.855; p<0.001) were independent correlates of the composite outcome in patients with RVi. CONCLUSION: Patients with RVi are characterized by distinct clinical profile and should undergo closely clinical and echocardiographic monitoring. The presence of echocardiographic signs of right ventricular failure along with substantial comorbidities burden identify a cohort at higher risk of in-hospital major adverse cardiovascular events.

Improving the appropriateness of sudden arrhythmic death primary prevention by implantable cardioverter-defibrillator therapy in patients with low left ventricular ejection fraction. Point of view.

It is generally accepted that the current guidelines for the primary prevention of sudden arrhythmic death, which are based on ejection fraction, do not allow the optimal selection of patients with low left ventricular ejection fraction of ischemic and nonischemic etiology for implantation of a cardioverter-defibrillator. Ejection fraction alone is limited in both sensitivity and specificity. An analysis of the risk of sudden arrhythmic death with a combination of multiple tests (ejection fraction associated with one or more arrhythmic risk markers) could partially compensate for these limitations. We propose a polyparametric approach for defining the risk of sudden arrhythmic death using ejection fraction in combination with other clinical and arrhythmic risk markers (i.e. late gadolinium enhancement cardiac magnetic resonance, T-wave alternans, programmed ventricular stimulation, autonomic tone, and genetic testing) that have been validated in nonrandomized trials. In this article, we examine these approaches to identify three subsets of patients who cannot be comprehensively assessed by the current guidelines: patients with ejection fraction of 35% or less and a relatively low risk of sudden arrhythmic death despite the ejection fraction value; patients with ejection fraction of 35% or less and high competitive risk of death due to evolution of heart failure or noncardiac causes; and patients with ejection fraction between 35 and 45% with relatively high risk of sudden arrhythmic death despite the ejection fraction value.

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.