Emiko Nakashima

Differences in catheter ablation of paroxysmal atrial fibrillation between males and females

BACKGROUND Catheter ablation (CA) has become a standard treatment for patients with atrial fibrillation (AF). However, gender-related differences associated with CA of paroxysmal AF (PAF) remain unclear. METHODS We compared 1124 consecutive patients (mean age, 61 ± 10 years; male, n=864) with PAF scheduled for CA between the genders. RESULTS Females were significantly older (p<0.0001), and had a lower body-mass-index (p=0.02), smaller left atrial dimension (LAD; p=0.04), larger LAD indexed by the body-surface-area (LADI; p<0.0001) and better left ventricular ejection fraction (p<0.0001) at baseline. Ischemic heart disease (p=0.007) was more frequent in males, whereas hypertrophic cardiomyopathy (p=0.007) and mitral stenosis (p=0.001) were more frequent in females. More additional procedures were performed to eliminate non-pulmonary vein foci in females than males (p<0.05), but those locations were similar between the genders. The incidence of procedure-related complications was similar between genders (p=0.73). Sinus rhythm was similarly maintained between females and males after the first CA (56.4% vs. 59.3% at 5 years, p=0.24), but was significantly lower in females after the last CA (76.5% vs. 81.3% at 5 years, p=0.007). More females did refuse multiple CA procedures (especially a second one) than males (37.8% in females vs. 27.4% in males, p=0.02). The age (HR, 0.98/y, p=0.01), duration of AF (HR, 1.04/y, p=0.0001), number of failed anti-arrhythmic-drugs (HR, 1.10, p=0.03) and LADI (HR, 1.89 per 10mm/m(2), p=0.001) were significantly associated with AF-recurrence in males, but not in females. CONCLUSIONS Specific differences and similarities between the genders were observed in PAF patients undergoing CA.

Renal Function After Catheter Ablation of Atrial Fibrillation

Background— Kidney function is a known predictor of cardiovascular morbidity and mortality. Although patients with atrial fibrillation (AF) often have kidney dysfunction, less is known about the association between AF and kidney function. We sought to assess changes in kidney function after catheter ablation of AF. Methods and Results— Patients who underwent catheter ablation of AF were recruited for the present prospective study. Estimated glomerular filtration rate (eGFR) was evaluated before and 1 year after the ablation. Three hundred eighty-six patients (paroxysmal AF, 135; persistent AF, 106; longstanding persistent AF, 145) were studied. Their baseline eGFR was 68±14 mL · min−1 · 1.73 m−2. Sixty-six percent and 26% of patients had eGFR of 60 to 89 and 30 to 59 mL · min−1 · 1.73 m−2, respectively. Overall, 278 patients (72%) were arrhythmia free over a 1-year follow-up. In patients free from arrhythmia, eGFR increased 3 months later and was maintained until 1 year, whereas in patients with recurrences, eGFR had decreased over 1 year. Changes in eGFR over 1 year in patients free from arrhythmia differed significantly compared with those with recurrences (3±8 versus −2±8 mL · min−1 · 1.73 m−2; P<0.0001). In all quartiles of baseline eGFR, changes in eGFR over 1 year after the ablation were greater in patients free from arrhythmia compared with those with recurrences. Conclusion— Elimination of AF by catheter ablation was associated with improvement of kidney function over a 1-year follow-up in patients with mild to moderate kidney dysfunction.

Oesophageal cooling with ice water does not reduce the incidence of oesophageal lesions complicating catheter ablation of atrial fibrillation: randomized controlled study

AIM Atrial fibrillation (AF) ablation can result in oesophageal injuries that lead to atrio-oesophageal fistulae, a life-threatening complication. This study aimed to evaluate whether oesophageal cooling could prevent oesophageal lesions complicating AF ablation. METHODS AND RESULTS We randomly assigned 100 patients with drug-resistant AF to an oesophageal cooling group or a control group. In the oesophageal cooling group, we injected 5 mL of ice water into the oesophagus prior to radiofrequency (RF) energy delivery adjacent to the oesophagus. If the oesophageal temperature reached 42°C, the RF energy delivery was stopped, and the ice water injection was repeated. In the control group, oesophageal cooling was not applied. Oesophageal endoscopy was performed 1 day after the catheter ablation, and lesions were qualitatively assessed as mild, moderate, or severe. The numbers of ablation sites with an oesophageal temperature of >42°C were 1.7 ± 1.4 and 2.6 ± 1.7 in the oesophageal cooling group and the control group, respectively (P = 0.04), and the maximal oesophageal temperature at those sites was 43.0 ± 0.6 and 44.7 ± 0.9°C (P < 0.0001). Oesophageal lesions occurred almost equally between the oesophageal cooling group [10 of 50 patients (20%)] and the control group [11 of 50 patients (22%)]. However, the severity of the oesophageal lesions was slightly milder in the oesophageal cooling group (three moderate, seven mild) than in the control group (three severe, one moderate, seven mild). CONCLUSION Oesophageal cooling may alleviate the severity of oesophageal lesions but does not reduce the incidence of this complication under the specific protocol evaluated here.

Lipoprotein(a) is an important factor to determine coronary artery plaque morphology in patients with acute myocardial infarction.

BackgroundLipoprotein(a) [Lp(a)] can influence the development and disruption of atherosclerotic plaques through its effect on lipid accumulation. The purpose of this study was to evaluate the relationship between serum Lp(a) levels and plaque morphology of an infarct-related lesion and non-infarct-related lesion of the coronary artery in acute myocardial infarction (AMI). Methods and resultsCoronary plaque morphology was evaluated in 68 patients (age 62.1±12.1 years, mean±SD; men n=58, women n=10) with AMI by intravascular ultrasound with radiofrequency data analysis before coronary intervention and by 64-slice computed tomography angiography within 2 weeks. Patients were divided into a group with an Lp(a) level of 25 mg/dl or more (n=20) and a group with an Lp(a) level of less than 25 mg/dl (n=48). Intravascular ultrasound with radiofrequency data analysis identified four types of plaque components at the infarct-related lesion: fibrous, fibrofatty, dense calcium, and necrotic core. The necrotic core component was significantly larger in the group with an Lp(a) level of 25 mg/dl or more than in the group with an Lp(a) level of less than 25 mg/dl (27.6±8.0 vs. 15.7±10.0%, P=0.0001). Coronary plaques were classified as calcified plaques, noncalcified plaques, mixed plaques, and low-attenuation plaques on 64-slice computed tomography angiography. Computed tomography indicated that the group with an Lp(a) level of 25 mg/dl or more had a greater number of total plaques, noncalcified plaques, and low-attenuation plaques in whole coronary arteries than did the group with an Lp(a) level of less than 25 mg/dl (5.3±1.8 vs. 3.7±2.2, P=0.0061; 4.0±2.0 vs. 1.2±1.3, P=0.0001; 2.2±2.1 vs. 0.5±0.7, P=0.0001, respectively). ConclusionElevated serum Lp(a) levels are associated with the number of plaques and plaque morphology. Patients with a high Lp(a) level during AMI require more intensive treatment for plaque stabilization.

Impact of statin use before the onset of acute myocardial infarction on coronary plaque morphology of the culprit lesion.

Statins favorably stabilize coronary plaque. We evaluated the impact of statin use before the onset of acute myocardial infarction (AMI) on culprit lesion plaque morphology. Patients (n = 127) with AMI were divided into either a statin group (n = 31) or a nonstatin group (n = 96) based on statin use before the onset of AMI. Coronary plaque morphology of the culprit lesion was evaluated using intravascular ultrasound virtual histology (IVUS-VH) with radiofrequency data analysis before coronary intervention. The IVUS-VH identified 4 types of plaque components: fibrous, fibrofatty, dense calcium, and necrotic core. The IVUS-VH showed less percentage of necrotic area, greater percentage fibrous area, and greater percentage of fibrofatty area of the culprit lesion in the statin group. In conclusion, statin use before the onset of AMI might have effects on coronary plaque morphology of the AMI culprit lesion with less necrotic core and greater fibrous and fibrofatty component.

Long-term outcome after catheter ablation of paroxysmal atrial fibrillation: Impact of different atrial fibrillation foci

BACKGROUND We aimed to determine whether differing foci in paroxysmal atrial fibrillation (PAF) affected the long-term outcome of catheter ablation (CA). METHODS A total of 865 consecutive PAF patients (age, 61±10years; 670 male) undergoing initial AF ablation were included. After pulmonary vein (PV) isolation, superior vena cava (SVC) isolation was performed for SVC foci; other non-PV foci were focally ablated. Long-term outcomes were compared among patients with SVC foci (Group SVC), other non-PV foci (Group Non-PV), and those without these foci (Group PV). RESULTS Groups PV, SVC, and Non-PV contained 740 (85.8%), 57 (6.6%), and 68 (7.6%) patients, respectively. Structural heart disease (P=0.01) and duration of AF history (P=0.04) were significantly associated with Group Non-PV, and female sex (P=0.0002) was significantly associated with Group SVC. AF recurrence-free rates at 5years in Group PV, SVC, and Non-PV were 62.0%, 66.3%, and 49.3%, respectively (P=0.03), after the initial CA, and 84.7%, 83.9%, and 77.0%, respectively (P=0.02), after the final CA. The duration of AF history (HR, 1.04, P<0.0001) and left atrial dimension (HR, 1.37 per 10mm increase, P=0.0003) were significant predictors of AF recurrence after the initial CA. Although Group Non-PV was weakly associated (HR 1.38, P=0.08) with AF recurrence, Group SVC was not associated with AF recurrence. CONCLUSIONS Long-term outcome of CA of PAF was significantly worse in patients with non-PV foci other than SVC foci. These foci may affect the outcome not independently but as an aspect of atrial remodeling.

Simultaneous isolation of superior and inferior pulmonary veins on both the left and right sides could yield better outcomes in patients with paroxysmal atrial fibrillation

AIMS This study investigated whether disappearance patterns of pulmonary vein (PV) potentials (PVPs) during PV isolation (PVI) affect the outcome of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS Extensive PVI was performed in 1149 PAF patients (age, 61 ± 10 years). Clinical and demographic characteristics, ablation data, and follow-up outcomes were prospectively collected. During an initial CA, simultaneous disappearance of superior and inferior PVPs in both right and left PVs was observed in 464 (40.4%) patients (Group S). Atrial fibrillation-recurrence free rates at 1, 3, and 5 years after the initial CA in Group S were 78.9, 71.9, and 68.1%, respectively, which were higher than those in Group Non-S (P = 0.004). However, those were similar after the final CA between both groups. The incidence of PV-left atrium (LA) electrical reconnection was significantly lower in Group S than in Group Non-S in the second (Group S, 65.6% vs. Group Non-S, 82.1%; P = 0.004) and third (Group S, 8.3% vs. Group Non-S, 47.6%; P = 0.03) CAs. Furthermore, the reconnections more frequently occurred on the side of PVs where simultaneous PVP elimination had not been achieved at the initial CA. Simultaneous disappearance of superior and inferior PVPs in both right and left PVs independently reduced the risk of AF recurrence after the initial CA by 26%. CONCLUSIONS The simultaneous disappearance of superior and inferior PVPs in both right and left PVs is associated with less frequent PV-left atrium reconnection and may yield a better clinical outcome after the initial CA.

Differential characteristics of inflammatory responses to stent implantation between de novo and intrastent restenosis lesion in patients with stable angina.

Mechanical plaque rupture of coronary atherosclerotic plaque during stent implantation can increase serum levels of high-sensitivity C-reactive protein (hsCRP). Patients with stable angina pectoris were divided into 2 groups: one group included 186 patients with de novo lesion who underwent stent implantation (de novo group); the other group included 40 patients with intrastent restenosis (ISR) undergoing stent implantation (ISR group). The de novo group had a significant increase in hsCRP levels post stenting, while the ISR group showed no increase in hsCRP post stenting. Intravascular ultrasound with radiofrequency data analysis showed that the de novo group had larger percentage of both necrotic core area and fibrofatty area at the target lesion than the ISR group, while the ISR group had a larger percentage of fibrous area. Differential inflammatory response to stent implantation between the de novo plaque and in ISR lesion is related to lesion morphology.

Airway support using a pediatric intubation tube in adult patients with atrial fibrillation: A simple and unique method to prevent heart movement during catheter ablation under continuous deep sedation

The present study aimed to elucidate the safety and effectiveness of a noble and unique airway management technique in which a pediatric intubation tube is used in adult patients with atrial fibrillation (AF) undergoing catheter ablation (CA) under continuous deep sedation.

The proportion of asymptomatic recurrence after catheter ablation of atrial fibrillation in patients with a pacemaker for sick sinus syndrome

Background Catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) is an effective treatment. However, the frequency of asymptomatic AF recurrence after CA in patients with PAF and sick sinus syndrome (SSS) is not clear. The aim of this study was to elucidate the real AF recurrence after CA in patients with PAF and a pacemaker for SSS. Methods and results Fifty-one consecutive patients (mean age 66.6 ± 7.0 years, male 34) with PAF and SSS and pacemakers underwent CA. All patients were followed at 1, 3, 6, 9, and 12 months after the CA using a 12-lead ECG, Holter-ECG, and 1-month event recorder as a conventional follow-up. In addition, the pacemakers were interrogated every 12 months. During a 5-year follow-up after the final CA procedure, AF recurrences were observed in 7 patients (13.7%) with a conventional follow-up, including 1 (2.0%) asymptomatic patient. Pacemaker-interrogation revealed another 10 patients (19.6%) with asymptomatic AF recurrences. Ultimately, the conventional follow-up plus pacemaker-interrogation provided a higher incidence of AF recurrences (P = 0.009). Multiple CA procedures contributed to a significant increase in the AF-free survival rate at 5 years: 58.6% after a single CA and 86.0% after multiple CA procedures with a conventional follow-up, but which decreased to 40.6% and 60.9% with a conventional follow-up plus a pacemaker interrogation, respectively. Conclusions One-third of PAF patients with SSS and pacemakers recurred after multiple CA sessions. However, 65% of them were asymptomatic and difficult to be identified with conventional follow-up. Pacemaker interrogation significantly increased the detection rate of AF-recurrence.