Novel method to avoid serious injurious effects on the atrioventricular nodal (AVN) conduction during catheter ablation of the AVN slow pathway utilizing cryofreezing energy.

BACKGROUND: Slow pathway elimination of the atrioventricular node (AVN) is essential to treat AVN reentrant tachycardia (AVNRT). However, injury to the AVN conduction (IAVN) is one of the serious complications. Cryofreezing energy is expected to reduce the incidence of IAVN. This study aimed to investigate the usefulness of a novel method to avoid IAVN during cryoablation of AVNRT. METHODS: A total of 157 patients (average age, 65.8 years; male, 71) suffering from AVNRT were included. Once the AVNRT terminated during cryo-ablation, then rapid atrial constant pacing (RACP) was performed during freezing at a rate lower 10 bpm than that inducing Wenchebach AV block in 74 (47.1 %) patients (Group A). The RACP rate was decreasingly reduced by 10 bpm in case of the occurrence of IAVN. When the RACP reached 100 bpm, the cryoablation was prematurely terminated. Group B patients (83 = 52.9 %) underwent cryoablation during sinus rhythm. All patients were allocated in a randomized fashion. We compared the severity of the IAVN between Groups A and B. RESULTS: There were no significant differences at 12 months regarding the freedom from the AVNRT between Groups A and B. However, the duration of the IAVN was significantly longer in Group B than A (p = 0.02). There were no significant differences regarding the distance between the His recording sites and successful ablation sites between Groups A and B. No permanent IAVN requiring pacemaker implantation was provoked in either group. CONCLUSION: RACP was useful to avoid sustained and serious IAVN during cryoablation of AVNRT.

Feasibility, Safety, and Long-Term Outcomes of Zero-Contrast Percutaneous Coronary Intervention in Patients With Chronic Kidney Disease.

BACKGROUND: The long-term safety and utility of intravascular ultrasound (IVUS)-guided zero-contrast percutaneous coronary intervention (PCI) in patients with chronic kidney disease (CKD) are unknown.Methods and Results: A total of 698 consecutive patients treated with PCI (1,061 procedures) in our center were studied. Patients with acute coronary syndrome, who are on maintenance hemodialysis, and who had a planned rotational atherectomy were excluded. Finally, they were divided into 2 groups: zero-contrast PCI (n=55, 78 procedures) and conventional PCI (n=462, 670 procedures). After propensity score matching, 50 patients were matched for each group to evaluate long-term outcomes. Primary endpoints were major adverse cardiovascular events (MACE), including all-cause death, non-fatal myocardial infarction (MI), and clinically driven target lesion revascularization. All patients in the zero-contrast PCI group had stage 3-5 CKD with an estimated glomerular filtration rate of 38.3±14.8 mL/min/1.73 m2. Zero-contrast PCI was successful in all 78 procedures without renal events such as acute kidney injury or emergent hemodialysis and procedural complications such as coronary perforation or periprocedural MI. During a follow-up period of 32 months, 7 patients died (1 cardiac, 6 non-cardiovascular), and 4 patients were introduced to renal replacement therapy. The incidence of MACE was similar between the zero-contrast and conventional PCI groups (log-rank, P=0.95). CONCLUSIONS: IVUS-guided zero-contrast PCI might be safe and feasible in patients with CKD with satisfactory acute and long-term renal and cardiovascular outcomes.

Onset time and prognostic value of acute kidney injury in patients with acute myocardial infarction.

BACKGROUND: The mechanisms and clinical impact of acute kidney injury (AKI) after acute myocardial infarction (AMI) may differ depending on whether AKI develops during the early or late phase after AMI. The present study assessed the timing of AKI onset and the prognostic impact on long-term outcomes in patients hospitalized with AMI. METHODS: The present study enrolled consecutive AMI survivors who had undergone successful percutaneous coronary interventions at admission. AKI was defined as an increase in the serum creatinine level of ≥0.3 mg/dL above the admission value within 7 days of hospitalization. AKI patients were further divided into two subgroups (early-phase AKI: within 3 days vs. late-phase AKI: 4 to 7 days after AMI onset). The primary endpoint was all-cause death. RESULTS: In total, 506 patients were included in this study, with 385 men and a mean age of 69.5 ± 13.5 years old. The mean follow-up duration was 1289.5 ± 902.8 days. AKI developed in 127 patients (25.1%). Long-term mortality was significantly higher in the AKI group than in the non-AKI group (log-rank p < 0.001). Early-phase AKI developed in 98 patients (19.3%), and late-phase AKI developed in 28 patients (5.5%). In the multivariable analysis, early-phase AKI was significantly associated with all-cause mortality (HR 2.83, 95% CI [1.51-5.29], p = 0.0012), while late-phase AKI was not. CONCLUSION: Early-phase AKI but not late-phase AKI was associated with poor long-term mortality. Careful clinical attention and intensive care are needed when AKI is observed within 3 days of AMI onset.

Ultra-minimum contrast percutaneous coronary intervention for a patient with complex coronary artery disease and end-stage diabetic nephropathy.

A pivotal trial indicated that an initial invasive strategy did not improve the clinical outcomes in patients with moderate or severe ischemic heart disease and advanced chronic kidney disease (CKD) as compared with an initial conservative strategy. It is well known that contrast-induced nephropathy (CIN) is associated with worse prognosis after percutaneous coronary intervention (PCI). Minimum contrast PCI may lower the risk of CIN and improve the clinical outcomes of ischemic heart disease and advanced CKD. Here we report a case involving a 46-year-old woman with ischemic cardiomyopathy who was scheduled to start hemodialysis for end-stage diabetic nephropathy but exhibited improved renal function in accordance with the left ventricular function after PCI with an extremely low contrast dose. Accordingly, dialysis was not performed, and the patient did not require it for >2 years after coronary revascularization. The present case supports aggressive examination and revascularization for severe heart failure with an extremely low amount of contrast, even if the patient has complex coronary lesions and end-stage CKD. .

Clinical predictors for bradycardia and supraventricular tachycardia necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor.

BACKGROUND: Insertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known. HYPOTHESIS: This study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs. METHODS: We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox's stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT. RESULTS: One hundred thirty-two patients received ICMs to monitor unexplained syncope. During the 17-month follow-up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT. CONCLUSION: Syncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.

Permanent pacemaker implantation and its predictors in patients admitted for complete atrioventricular block: a report from the Tokyo Cardiovascular Care Unit Network multi-center registry.

Little is known about the permanent pacemaker implantation rate and predictors of permanent pacemaker implantation in patients admitted for complete atrioventricular block (cAVB). The present study was a retrospective analysis based on a multicenter cohort of 797 patients with cAVB (mean age: 79.6 ± 10.7 years; males: 48.4%) registered with the Tokyo Cardiovascular Care Unit Network multicenter registry between 2013 and 2016. Secondary cAVB due to acute coronary syndrome was excluded. The permanent pacemaker implantation rate was 82.9%. Multivariable logistic regression analysis revealed that systolic blood pressure (SBP) > 140 mmHg [odds ratio (OR) 2.10; 95% confidence interval (CI) 1.38-3.22; P < 0.001], male gender (OR 1.63; 95% CI 1.07-2.49; P = 0.023), and left ventricular ejection fraction (LVEF) ≥ 50% (OR 2.19; 95% CI 1.16-2.06; P = 0.016) were predictors of permanent pacemaker implantation while pre-admission ß-blocker use (OR 0.28; 95% CI 0.17-0.47; P < 0.001) was associated with a lower risk of permanent pacemaker implantation. Reversible cAVB was not rare in patients admitted for cAVB. Data on SBP on admission, gender, LVEF, and pre-admission ß-blocker use may be important for assessing the requirement for permanent pacemaker implantation in the emergency care setting.

Influence of sex on the incidence of potential coronary artery disease and long-term outcomes in asymptomatic patients with diabetes mellitus.

BACKGROUND: Diabetic patients often have coronary artery disease (CAD) without symptoms. It is known that females tend to have silent or less chest pain and worse prognoses when they develop acute coronary syndrome. Thus, sex differences may impact long-term outcomes in diabetes mellitus (DM) patients with silent myocardial ischemia (SMI). The present study aimed to assess the influence of sex on long-term outcomes in DM patients with SMI. METHODS: A total of 461 consecutive asymptomatic and self-sufficient DM patients seen at our hospital from 2011 to 2017 were prospectively reviewed. Patients underwent an ergometer exercise test. When the exercise test was positive or the patient could not achieve 90% of their target heart rate, coronary angiography was performed. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCEs), including death, non-fatal myocardial infarction, and stroke. RESULTS: SMI was diagnosed in 81 patients. The median follow-up duration from diagnosis was 35 (15-57) months. The incidence of SMI was similar in females and males [34/170 (20%) vs. 47/291 (16.2%), p = 0.36]. Enrolled patients were divided into four groups according to sex and the presence/absence of SMI. Female patients with SMI showed worse clinical outcomes. After adjustment for age and coronary risk factors, female SMI was independently associated with MACCEs [hazard ratio 2.59, 95% confidence interval 1.07-5.68, p = 0.024], while male SMI was not. CONCLUSIONS: Female SMI was associated with worse long-term outcomes in DM patients. Early diagnosis of potential SMI and appropriate care are required in female DM patients. (UMIN000038340).

Acute myocardial infarction caused by persistent coronary spasm associated with high-grade macrophage accumulation.

The mechanisms responsible for persistent and lethal coronary spasm remain incompletely understood. Our group treated a patient with non-ST-elevation myocardial infarction (MI) caused by a spontaneously persistent spasm associated with high-grade macrophage accumulation. A 48-year-old man was transferred to an emergency room because of persisted chest tightness. The patient's chest pain subsided without ST elevation when he arrived at the hospital, but he tested positive for fatty acid-binding protein. Emergent coronary angiography revealed a subtotal occlusion in the middle of the right coronary artery. The occluded lesion was released immediately after an injection of isosorbide dinitrate. No disruption, ulceration or erosion was observed at the culprit lesion segment on optical coherence tomography. The only finding was high-grade macrophage accumulation in the segment of the persistent focal coronary spasm. The present case suggests that the early stage of atherosclerosis with high-grade macrophage accumulation was associated with persistent coronary spasm resulting in acute MI.

Worsening renal failure due to renal steal by aortoiliac bypass.

Aortoiliac bypass surgery is the gold standard strategy for removing persistent ischaemia resulting from bilateral aortoiliac occlusive disease, a condition known as Leriche syndrome. However, the impact of aortoiliac bypass surgery on the blood flow of the renal artery is not fully understood. Here, we report a case of worsening renal failure caused by renal steal immediately after aortoiliac bypass for Leriche syndrome. The revascularisation of bilateral renal arteries dramatically improved the patient's renal function and allowed us to discontinue both haemodialysis and diuretics. This case demonstrates that in rare instances, haemodynamic change induced by aortoiliac bypass surgery affects the arteries feeding other organs. Careful preoperative evaluation for the corresponding branches of the aorta is indispensable. Optimal revascularisation should be performed to avoid serious complications after aortoiliac bypass if the patient is at risk of developing critical ischaemia.

Extended Posterior Leaflet Augmentation for Ischemic Mitral Regurgitation　- Augmented Posterior Leaflet Snuggling up to Anterior Leaflet.

BACKGROUND: The ideal surgical technique for ischemic mitral regurgitation (MR) is controversial. We introduced an extended posterior mitral leaflet (PML) augmentation technique for functional MR with severe tethering, which detached the PML from the annulus almost completely and augmented it with a large 3×6-cm oval pericardial patch. Methods and Results: A total of 17 mitral repairs using the new technique were performed for ischemic MR with no 30-day mortality and 2 hospital deaths. The NYHA class was III in 47% and IV in 13%. The EuroSCORE II was 9.7±4.9. The ring size was 32±1.4 mm. Concomitant coronary bypass was performed in 67% and left ventricular repair in 28%. The mechanism of leaflet closure was evaluated using transthoracic echocardiography in 15 survivors. MR decreased to none or trivial with a significant increase in coaptation length (Pre: 4.6±0.8 mm vs. Post: 9.8±2.5 mm; P<0.001). The PML flexibly moved forward and tightly contacted as if "snuggling up" to the anterior leaflet. There were no late deaths, heart failure readmissions or MR recurrences during follow-up (850±181 days). All patients remained in NYHA I or II. CONCLUSIONS: Extended PML augmentation for ischemic MR showed excellent early results with deep leaflet coaptation through a "snuggling up" phenomenon, which would help prevent late MR recurrence.

In-Hospital Electrical Storm in Acute Myocardial Infarction　- Clinical Background and Mechanism of the Electrical Instability.

BACKGROUND: Recurrent ventricular tachycardia (VT) and fibrillation (VF), the so-called "electrical storm" (ES) occurs at various stages of acute myocardial infarction (AMI), but its incidence, background, and short-term prognosis remain unclear. Methods and Results: A retrospective observational study was performed using the registry database of the Tokyo CCU Network. The individual data of 6,003 patients with AMI during 2011-2012 was corrected. ES was defined as more than 3 episodes of sustained VT/VF during a 24-h period as first documented after hospitalization. ES occurred in 55 patients after admission (0.9%). The ES(+) group had more severe heart failure (Killip class >III), more extensive MI (peak-CK), greater inflammatory reaction (CRP), history of diabetes, and more frequent application of hemodialysis as compared with the ES(-) group (n=5,865). When the ES patients were divided into Early-ES (n=37: ES occurred ≤48 h after the onset of MI) and Late-ES (n=15 >48 h after onset of MI) groups, logistic regression analysis revealed that Early-ES was associated with severity of MI, whereas Late-ES was related to systemic disorders, including inflammation, renal dysfunction, or diabetes. Late-ES was an independent predictor of in-hospital death. CONCLUSIONS: In-hospital ES was a rare clinical manifestation of AMI. The features and background of the ES varied as time elapsed after admission for MI.

Use of implantable and external loop recorders in syncope with unknown causes.

The gold standard for diagnosing syncope is to elucidate the symptom-electrocardiogram (ECG) correlation. The ECG recordings during syncope allow physicians to either confirm or exclude an arrhythmia as the mechanism of syncope. Many studies have investigated the use of internal loop recorder (ILR), while few studies have used external loop recorder (ELR) for patients with unexplained syncope. The aim of this review is to clarify the clinical usefulness of ILR and ELR in the diagnosis and management of patients with unexplained syncope. Many observational and four randomized control studies have shown that ILR for patients with unknown syncope is a useful tool for early diagnosis and improving diagnosis rate. ILR also provides important information on the mechanism of syncope and treatment strategy. However, there is no evidence of total mortality or quality of life improvements with ILR. The diagnostic yield of ELR in patients with syncope was similar to that with ILR within the same timeframe. Therefore, ELR could be considered for long-term ECG monitoring before a patient switches to using ILR. A systematic approach and selection of ECG monitoring tools reduces health care costs and improves the selection of patients for optimal treatment possibilities.

Predictors of Mortality, Rehospitalization for Syncope and Cardiovascular Events in Patients With Cardiovascular Syncope.

BACKGROUND: Predictors of poor outcomes remain unknown for cardiovascular syncope patients after discharge.Methods and Results:We reviewed the medical records of consecutive patients admitted to hospital with cardiovascular syncope. We then performed Cox stepwise logistic regression analysis to identify significant independent factors for death, rehospitalization for syncope, and cardiovascular events. The study group was 206 patients with cardiovascular syncope. Of them, bradycardia was diagnosed in 50%, tachycardia in 27%, and structural disease in 23%. During a 1-year follow-up period, 18 (8%) and 45 (23%) patients, respectively, were rehospitalized for syncope or a cardiovascular event, and 10 (4%) died. Independent predictors of cardiovascular events were systolic blood pressure <100 mmHg (odds ratio [OR] 3.25; 95%confidence interval [CI] 1.41-7.51, P=0.006) and implantation of a pacemaker (OR 0.19; 95% CI 0.05-0.51, P=0.0005) (inverse association). Drug-induced syncope (OR 4.57; 95% CI 1.54-12.8, P=0.007) was an independent risk factor for rehospitalization. Finally, a history of congestive heart failure (OR 11.0; 95% CI 2.78-54.7, P=0.0006) and systolic blood pressure <100 mmHg (OR 5.40; 95% CI 1.30-22.7, P=0.02) were identified as significant independent prognostic factors for death. CONCLUSIONS: Drug-induced syncope, hypotension, no indication for a pacemaker, and a history of congestive heart failure are risk factors post-discharge for patients with cardiovascular syncope and careful follow-up of these patients for at least 1 year is recommended.

Immediate discontinuation of ablation during pulmonary vein isolation remarkably decreases the incidence of esophageal thermal lesions even when using steerable sheaths.

BACKGROUND: Left atrial-esophageal fistulas (LAEFs) are serious complications with high mortality after atrial fibrillation radiofrequency ablation (AFRA). Decreasing the incidence of esophageal thermal lesions (EsoTLs) that may lead to LAEFs is important. The aim of this study was to suppress EsoTL development and determine the appropriate alarm setting for a temperature-monitoring probe by using steerable sheath (STS) methods. METHODS: We enrolled 82 consecutive patients (mean, 61.9±11.7 years; 75.6% men) who underwent AFRA, including pulmonary vein isolation for symptomatic, drug-refractory atrial fibrillation with esophageal temperature monitoring by using STS between January 2011 and April 2014. All patients underwent upper gastrointestinal endoscopy (UGE) 1-3 days after AFRA. The timing of ablation discontinuation in the first 17 patients was determined by each physician during AFRA (only monitoring group, OM). In the next 65 patients, physicians were to immediately discontinue ablation when an alarm set at 39 °C went off (instruction group, INS). We compared two groups with respect to the incidence of EsoTLs. RESULTS: Among the 82 patients, 5 (6.1%) had EsoTLs after AFRA. EsoTLs occurred in 3 of 17 patients (17.6%) and 2 of 65 patients (3.1%) in the OM and INS groups, respectively. The incidence of EsoTLs in the INS group was significantly lower than that in the OM group (p=0.0254). EsoTL did not occur at maximal temperature less than 39 °C, measured by using esophageal temperature-monitoring probe. CONCLUSIONS: Immediate discontinuation of ablation during pulmonary vein isolation remarkably decreased the incidence of EsoTLs, even when using STS.

Recurrence of atrial fibrillation within three months after pulmonary vein isolation for patients with paroxysmal atrial fibrillation: Analysis using external loop recorder with auto-trigger function.

BACKGROUND: Pulmonary vein isolation (PVI) via catheter ablation has been shown to be a highly effective treatment option for patients with symptomatic paroxysmal atrial fibrillation (AF). The recurrence of AF within 3 months after PVI is not considered to be the result of ablation procedure failure, because early recurrence of AF is not always associated with late recurrence. We examined the usefulness of an external loop recorder with an auto-trigger function (ELR-AUTO) for the detection of atrial fibrillation following PVI to characterize early recurrence and to determine the implications of AF occurrence within 3 months after PVI. METHODS: Fifty-three consecutive symptomatic patients with paroxysmal AF (age 61.6±12.6 years, 77% male) who underwent PVI and were fitted with ELR-AUTO for 7±2.0 days within 3 months after PVI were enrolled in this study. RESULTS: Of the 33 (62.2%) patients who did not have AF recurrence within 3 months after PVI, only 1 patient experienced AF recurrence at 12 months. Seven (35%) of the 20 patients who experienced AF within 3 months of PVI experienced symptomatic AF recurrence at 12 months. The sensitivity, specificity, positive predictive value, and negative predictive value of early AF recurrence for late recurrence were 87.5%, 71.1%, 35.0%, and 96.9%, respectively. CONCLUSIONS: AF recurrence measured by ELR-AUTO within 3 months after PVI can predict the late recurrence of AF. Freedom from AF in the first 3 months following ablation significantly predicts long-term AF freedom. ELR-AUTO is useful for the detection of symptomatic and asymptomatic AF.

J-Wave in Patients With Syncope.

BACKGROUND: Syncope is a common occurrence. The presence of J-wave, also known as early repolarization, on electrocardiogram is often seen in the general population, but the relationship between syncope and J-wave is unclear. METHODS AND RESULTS: After excluding 67 patients with structural heart disease from 326 with syncope, we classified 259 patients according to the presence or absence of J-wave (≥1 mm) in at least 2 inferior or lateral leads. Head-up tilt test (HUT) was performed for 30 min. If no syncope or presyncope occurred, HUT was repeated after drug loading. Before tilt, 97/259 (37%) had J-wave (57 male, 47.6±22.5 years) and 162 patients had no remarkable change (89 male, 51.1±21.2 years). HUT-positive rate was higher in patients with J-wave, compared with patients without (P<0.0001). The combination of J-wave and descending/horizontal ST segment in the inferior leads was more strongly associated with positive HUT than J-wave with ascending ST segment (odds ratio, 3.23). CONCLUSIONS: Prevalence of J-wave in the inferior or lateral leads was high in patients with syncope and was associated with HUT-induced neurally mediated reflex syncope (NMRS). Furthermore, the combination of J-wave and descending/horizontal ST segment in the inferior leads could be associated with a much higher risk of NMRS.

Single center experience in Japanese patients with syncope.

BACKGROUND AND PURPOSE: The present diagnostic method and features of syncope in Japan are unclear. Implantable loop recorder (ILR) and head-up tilt tests have recently become available for diagnosing syncope. The examination method and rates of diagnosing syncope may vary. This study aimed to clarify the present diagnostic method and features of syncope in a single Japanese medical center. METHODS AND RESULTS: We retrospectively reviewed the medical records of consecutive patients who were seen at our hospital from January 1, 2009, to December 31, 2012. A total of 547 patients (328 men, 60.4±21.5 years) with syncope were seen at our hospital. Reflex syncope was diagnosed in 29.1% of the cases, orthostatic hypotension in 11.7%, cardiac syncope in 34.0%, and unexplained syncope in 23.9% by initial and early evaluations. The number of patients with situational syncope and orthostatic hypotension that could be diagnosed in the initial evaluation of the first examination was significantly greater than that in subsequent evaluations. Forty-three percent of the unexplained syncope patients received an ILR. The consent rate for ILR implantations in the unexplained syncope patients with a suspected arrhythmia nature was 53.1%. The cumulative ILR diagnostic rates were 47% and 65% at 1 and 2 years after the ILR implantation, respectively. The estimated ILR diagnostic rates were significantly greater than that for conventional test without using an ILR. When patients with unexplained syncope could be diagnosed, the recurrent symptoms were greatly reduced. CONCLUSIONS: Syncope is induced by various causes in Japan. It is important that we understand the characteristics of each syncope cause. The consent rate for implanting an ILR in appropriate unexplained syncope patients is low. We need to educate these patients about the importance of making a diagnosis of syncope.