Atsushi Kobori

Long-term clinical outcome of extensive pulmonary vein isolation-based catheter ablation therapy in patients with paroxysmal and persistent atrial fibrillation

Objective To examine the long-term clinical outcomes of patients undergoing catheter ablation (CA) for either paroxysmal (PAF) or persistent atrial fibrillation (PsAF) using an extensive pulmonary vein isolation (EPVI)-based strategy. Methods and results 574 patients (61±9 years; 449 men) with drug-refractory PAF or PsAF underwent CA. Ipsilateral pulmonary veins (PVs) were isolated with extensive antral ablation. A cavotricuspid isthmus line with bidirectional conduction block was created and all non-PV triggers of AF ablated at the index procedure. Left atrial linear ablation was performed in patients with PsAF if AF remained inducible. Patients with recurrent atrial arrhythmias had previous lesions assessed and consolidated. With mean follow up of 27±14 months after the final procedure, 480 patients (83.6%) were in sinus rhythm without antiarrhythmic drugs (1.4±0.6 procedures). The single procedure success rate without antiarrhythmic drugs was 65.5%. A late recurrence (>6 months after the initial procedure) and very late recurrence (>12 months) were seen in 1.6% and 1.7% of patients, respectively. All patients with a late recurrence had PV reconnection, with one patient also demonstrating a non-PV trigger. In comparison, non-PV triggers of AF accounted for 85.7% of very late recurrences with no evidence of PV reconduction. Conclusions EPVI-based CA is effective in maintaining sinus rhythm in patients with PAF and PsAF over the long term. Recurrent AF after 1 year is mainly due to non-PV triggers, suggestive of an ongoing pathological process.

Clinical Outcomes of Medical Therapy and Timely Operation in Initially Diagnosed Type A Aortic Intramural Hematoma: A 20-Year Experience

Background— The management of aortic intramural hematoma (IMH) involving the ascending aorta (type A) has not been well-established. The purpose of this study was to clarify the long-term clinical outcomes of patients with type A IMH who were treated with medical therapy and timely operation. Methods and Results— Clinical data including operative mortality, IMH-related events, and long-term survival were retrospectively reviewed in 66 patients with type A IMH, who were admitted to our institution from 1986 to 2006. Emergent surgical repair was performed in 16 (24%) patients because of severe complications, whereas 50 patients were treated with initial medical therapy. In medically treated patients, 15 (30%) patients who demonstrated progression to classic dissection or increase in hematoma size within 30 days underwent surgical repair except for 2 patients who refused surgery. The 30-day mortality rate was 6% with emergent surgery and 4% with supportive medial therapy. There were 7 late deaths and the actuarial survival rates of all patients were 96±3%, 94±3%, and 89±5% at 1, 5, and 10 years, respectively. In medically treated patients, maximum aortic diameter was the only predictor of early and late progression of ascending IMH (hazard ratio, 4.43; 95% CI, 2.04–9.64; P<0.001). Aortic diameter ≥50 mm predicted progression of ascending IMH with the positive and negative value of 83% and 84%, respectively. Conclusions— Combination of medical therapy and timely operation resulted in favorable long-term clinical outcomes in patients with type A IMH.

Adenosine triphosphate-guided pulmonary vein isolation for atrial fibrillation: the UNmasking Dormant Electrical Reconduction by Adenosine TriPhosphate (UNDER-ATP) trial.

AIMS Most of recurrent atrial tachyarrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation (AF) are due to reconnection of PVs. The aim of the present study was to evaluate whether elimination of adenosine triphosphate (ATP)-induced dormant PV conduction by additional energy applications during the first ablation procedure could reduce the incidence of recurrent atrial tachyarrhythmias. METHODS AND RESULTS We randomly assigned 2113 patients with paroxysmal, persistent, or long-lasting AF to either ATP-guided PVI (1112 patients) or conventional PVI (1001 patients). The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of Vaughan Williams class I or III antiarrhythmic drugs at 1 year with the blanking period of 90 days post ablation. Among patients assigned to ATP-guided PVI, 0.4 mg/kg body weight of ATP provoked dormant PV conduction in 307 patients (27.6%). Additional radiofrequency energy applications successfully eliminated dormant conduction in 302 patients (98.4%). At 1 year, 68.7% of patients in the ATP-guided PVI group and 67.1% of patients in the conventional PVI group were free from the primary endpoint, with no significant difference (adjusted hazard ratio [HR] 0.89; 95% confidence interval [CI] 0.74-1.09; P = 0.25). The results were consistent across all the prespecified subgroups. Also, there was no significant difference in the 1-year event-free rates from repeat ablation for any atrial tachyarrhythmia between the groups (adjusted HR 0.83; 95% CI 0.65-1.08; P = 0.16). CONCLUSION In the catheter ablation for AF, we found no significant reduction in the 1-year incidence of recurrent atrial tachyarrhythmias by ATP-guided PVI compared with conventional PVI.

Impact of New Development of Ulcer-Like Projection on Clinical Outcomes in Patients With Type B Aortic Dissection With Closed and Thrombosed False Lumen

Background— The purpose of this study was to investigate the clinical importance of newly developed ulcer-like projection (ULP) in patients with type B aortic dissection with closed and thrombosed false lumen (AD with CTFL), which is better known as aortic intramural hematoma. Methods and Results— A total of 170 patients with acute type B AD with CTFL were admitted to our institution from 1986 to 2008 and treated initially with medical therapy. There were 31 late deaths, including 9 cases of aortic rupture. The actuarial survival rates of all patients were 99%, 89%, 83% at 1, 5, and 10 years, respectively. A total of 62 (36%) patients showed new ULP development within 30 days from the onset. Patients who had ULP showed significantly poorer survival rates than patients who did not have ULP (P=0.037). Development of ULP was also associated with a significant increase in adverse aorta-related events (P<0.001). In addition, patients with ULP in the proximal descending thoracic aorta (PD) showed significantly higher aorta-related event rates than patients without ULP in the PD (P<0.001). Initial aortic diameter (hazard ratio, 3.55; P<0.001) and development of ULP in PD (hazard ratio, 3.79; P=0.003) were the strongest predictors of adverse aorta-related events. Conclusions— Initial aortic diameter and development of ULP in the PD are both strong predictors of adverse aorta-related events in patients with type B AD with CTFL. Patients with newly developed ULP should be more carefully followed up with close surveillance imaging than those without ULP.

Detection of Intimal Defect by 64-Row Multidetector Computed Tomography in Patients With Acute Aortic Intramural Hematoma

Background— Previous pathological and clinical studies demonstrated an intimal defect in patients with acute aortic intramural hematoma (IMH). The purpose of this study was to investigate the prevalence and clinical outcome of intimal defect detected by multidetector computed tomography (MDCT) in patients with IMH. Methods and Results— We retrospectively analyzed 38 consecutive patients with IMH in whom 64-row MDCT was performed during the acute phase (median, 5 days from the onset). Intimal defect was defined as continuity disruption of the inner layer of thrombosed false lumen, which could be detected by 1-mm axial and longitudinal interactive multiplanar reformation images. Clinical outcome of intimal defect was assessed in patients with type B IMH (n=32). A total of 48 lesions in 27 (71%) patients were recognized as intimal defects. The incidence of intimal defect was not affected by the timing of MDCT examination (1 to 3 days, 79%; 4 to 7 days, 58%; 8 to 14 days, 75%; P=0.56). In type B IMH, 16 (76%) of 21 patients with intimal defect showed progression (enlargement or progression to aortic aneurysm) in the chronic phase. In contrast, all 11 patients without intimal defect had complete resorption of hematoma. In lesion-based analysis, a depth of intimal defect of ≥5 mm predicted progression with sensitivity, specificity, and positive and negative predictive values of 84%, 95%, 94%, and 86%, respectively. Conclusions— A considerable portion of patients with IMH showed intimal defect detected by MDCT even in the very early stage, and defects frequently enlarged. Patients with intimal defect should be carefully followed up with serial imaging.

Efficacy of Antiarrhythmic Drugs Short-Term Use After Catheter Ablation for Atrial Fibrillation (EAST-AF) trial

AIMS Substantial portion of early arrhythmia recurrence after catheter ablation for atrial fibrillation (AF) is considered to be due to irritability in left atrium (LA) from the ablation procedure. We sought to evaluate whether 90-day use of antiarrhythmic drug (AAD) following AF ablation could reduce the incidence of early arrhythmia recurrence and thereby promote reverse remodelling of LA, leading to improved long-term clinical outcomes. METHODS AND RESULTS A total of 2038 patients who had undergone radiofrequency catheter ablation for paroxysmal, persistent, or long-lasting AF were randomly assigned to either 90-day use of Vaughan Williams class I or III AAD (1016 patients) or control (1022 patients) group. The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of class I or III AAD at 1 year, following the treatment period of 90 days post ablation. Patients assigned to AAD were associated with significantly higher event-free rate from recurrent atrial tachyarrhythmias when compared with the control group during the treatment period of 90 days [59.0 and 52.1%, respectively; adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.73-0.96; P = 0.01]. However, there was no significant difference in the 1-year event-free rates from the primary endpoint between the groups (69.5 and 67.8%, respectively; adjusted HR 0.93; 95% CI 0.79-1.09; P = 0.38). CONCLUSION Short-term use of AAD for 90 days following AF ablation reduced the incidence of recurrent atrial tachyarrhythmias during the treatment period, but it did not lead to improved clinical outcomes at the later phase.

Clinical outcomes in non-surgically managed patients with very severe versus severe aortic stenosis

Objective The management of asymptomatic severe and very severe aortic stenosis (AS) remains unestablished. This study aimed to investigate the clinical outcomes of severe versus very severe AS patients. Design A single centre, retrospective cohort study. Patients and Methods The study retrospectively reviewed 108 conservatively treated patients with severe AS (a maximal jet velocity ≥4.0 m/s, or mean aortic pressure gradient (MPG) ≥40 mm Hg, or an aortic valve area (AVA) <1.0 cm2) and 58 patients with very severe AS (a maximal jet velocity ≥5.0 m/s, or MPG ≥50 mm Hg or an AVA <0.6 cm2). Clinical outcomes were compared between the two groups, considering the existence of symptoms. Main Outcome Measures All-cause mortality and valve-related event, defined by a composite of cardiac death and hospitalisation because of heart failure. Results Mean follow-up was 5.5±3.1 years. Fifty-six patients (52%) with severe AS and 20 patients (34%) with very severe AS were asymptomatic. Very severe AS had poorer survival and valve-related event-free survival than severe AS at 3 years (77% vs 88%, p<0.01; 75% vs 88%, p<0.001, respectively). In addition, the 3-year survival and valve-related event-free survival of asymptomatic very severe AS were comparable with symptomatic severe AS, but they were significantly worse than asymptomatic severe AS (p<0.01 and p<0.001, respectively). Conclusions Surgery should always be considered in very severe AS regardless of symptoms, and particular attention needs to be paid to their extremely poor outcomes.

Left atrial volume predicts adverse cardiac and cerebrovascular events in patients with hypertrophic cardiomyopathy

AimsTo prospectively evaluate the relationship between left atrial volume (LAV) and the risk of clinical events in patients with hypertrophic cardiomyopathy (HCM).MethodsWe enrolled a total of 141 HCM patients with sinus rhythm and normal pump function, and 102 patients (73 men; mean age, 61 ± 13 years) who met inclusion criteria were followed for 30.8 ± 10.0 months. The patients were divided into two groups with or without major adverse cardiac and cerebrovascular events (MACCE), a composite of stroke, sudden death, and congestive heart failure. Detailed clinical and echocardiographic data were obtained.ResultsMACCE occurred in 24 patients (18 strokes, 4 congestive heart failure and 2 sudden deaths). Maximum LAV, minimum LAV, and LAV index (LAVI) corrected for body surface area (BSA) were significantly greater in patients with MACCE than those without MACCE (maximum LAV: 64.3 ± 25.0 vs. 51.9 ± 16.0 ml, p = 0.005; minimum LAV: 33.9 ± 15.1 vs. 26.2 ± 10.9 ml, p = 0.008; LAVI: 40.1 ± 15.4 vs. 31.5 ± 8.7 ml/mm2, p = 0.0009), while there were no differences in the other echocardiographic parameters.LAV/BSA of ≥ 40.4 ml/m2 to identify patients with cardiovascular complications with a sensitivity of 73% and a specificity of 88%.ConclusionLAVI may be an effective marker for detecting the risk of MACCE in patients with HCM and normal pump function.

Clinical characteristics of massive air embolism complicating left atrial ablation of atrial fibrillation: lessons from five cases.

AIMS This study aimed to elucidate the clinical characteristics of massive air embolism occurring during atrial fibrillation (AF) ablation. METHODS AND RESULTS Of 2976 patients undergoing AF ablation, 5 patients complicated by serious air embolism were examined. Atrial fibrillation ablation was performed with the use of three long sheaths for circular mapping and ablation catheters under conscious sedation. Two patients had air spontaneously introduced through a haemostasis valve of the long sheaths, at the end of long apnoea caused by the sedation, even though the catheters were placed within the long sheaths. The remaining three patients, all of whom also exhibited long apnoea, had air entry at the circular mapping catheter exchanges. Air accumulated in the right and left ventricles, left atrial appendage, right coronary artery, and ascending aorta. Haemodynamic collapse and hypoxaemia occurred in all and two patients, respectively, and supportive treatment and the accumulated air were aspirated. ST elevation, haemodynamic collapse, and hypoxaemia persisted for 10-35 min; however, all patients recovered completely. After we changed the sedative to one with less respiratory depressive effects and the timing of the saline flush at the circular mapping catheter exchanges, we never experienced such serious complications any further. CONCLUSION Serious air embolism can occur in patients with long apnoea under sedation during AF ablation with the use of long sheaths. Supportive therapy and air aspiration were effective in resolving the complication. A sedative that causes less respiratory depression and the timing of the saline flush were important for preventing air embolism.

Clinical utility of adenosine-infusion test at a repeat atrial fibrillation ablation procedure

BACKGROUND The majority of patients with recurrence of arrhythmia after the initial atrial fibrillation (AF) ablation procedure have resumption of pulmonary vein (PV) conduction. Adenosine-infusion test after PV isolation identifies acute dormant PV conduction during the index procedure. OBJECTIVE To evaluate the utility of adenosine-infusion test at a repeat AF ablation procedure. METHODS This study included 50 consecutive patients (38 men; mean age 65 ± 9 years) who underwent second ablation procedure for recurrent atrial tachyarrhythmia(s). At the index procedure, which was undertaken for paroxysmal AF, all patients underwent PV isolation and 48 of 50 (96%) underwent superior vena cava (SVC) isolation followed by adenosine infusion. PV and SVC were reisolated-if found reconnected-at the start of the second procedure. Thereafter, adenosine-infusion test was undertaken for all PVs in all patients. RESULTS At the index procedure, adenosine infusion revealed dormant PV conduction in 15 of 50 (30%) patients. At the second procedure, after 10 ± 10 months, PV and SVC reconnections were observed in 46 of 50 (92%) and 33 of 48 (68.8%) patients and they were reisolated. Subsequently, adenosine-infusion test revealed dormant PV conduction in 9 of 50 (18%) patients, including 3 of 50 (6%) who had no PV reconnection at the start of the procedure. In these 3 patients, transient AF resulted after adenosine infusion, and at mean 8.0 ± 3.4 months, they were free from any atrial arrhythmia after the elimination of dormant PV conduction alone. CONCLUSIONS Adenosine-infusion test reveals dormant thoracic vein conduction associated with arrhythmia recurrence in the chronic phase after the initial PV isolation.