Mamoru Nanasato

A Randomized Controlled Trial of Dabigatran versus Warfarin for Periablation Anticoagulation in Patients Undergoing Ablation of Atrial Fibrillation

We aimed to evaluate the feasibility of an oral direct thrombin inhibitor, dabigatran, as a periprocedural anticoagulant for use with ablation of atrial fibrillation (AF).

Arterial remodeling influences the development of intimal hyperplasia after stent implantation

OBJECTIVES We examined whether preinterventional arterial remodeling influenced the interventional results after stenting. BACKGROUND Arterial remodeling is seen in atherosclerotic lesions, and it may play an important role in the early stage of atherosclerosis. METHODS We examined 113 lesions that underwent elective stenting using tubular slotted stents under intravascular ultrasound guidance. The lesions were divided into three groups--adequate, intermediate and inadequate remodeling group--according to preinterventional arterial remodeling. The patients were subjected to coronary angiography and intravascular ultrasound evaluation on average 6.4 months after stenting. RESULTS At baseline and immediately after stenting, there were no differences in quantitative angiographic analysis among remodeling groups. However, the plaque cross-sectional area (CSA) in the minimal lumen CSA at preintervention and intimal hyperplasia CSA at follow-up were significantly larger in the adequate remodeling group than in the inadequate remodeling group. The restenosis rate of stenting for the lesions with inadequate arterial remodeling was very low (9.4%). A significant positive correlation was found between preinterventional plaque CSA and intimal hyperplasia CSA at follow-up (r = 0.47, p < 0.0001). Moreover, remodeling index significantly correlated with relative intimal hyperplasia CSA (r = 0.28, p < 0.01). CONCLUSIONS Preinterventional arterial remodeling influenced the development of intimal hyperplasia after stenting.

The Effect of Sitagliptin on Carotid Artery Atherosclerosis in Type 2 Diabetes: The PROLOGUE Randomized Controlled Trial

Background Experimental studies have suggested that dipeptidyl peptidase-4 (DPP-4) inhibitors provide cardiovascular protective effects. We performed a randomized study to evaluate the effects of sitagliptin added on to the conventional therapy compared with conventional therapy alone (diet, exercise, and/or drugs, except for incretin-related agents) on the intima-media thickness (IMT) of the carotid artery, a surrogate marker for the evaluation of atherosclerotic cardiovascular disease, in people with type 2 diabetes mellitus (T2DM). Methods and Findings We used a multicenter PROBE (prospective, randomized, open label, blinded endpoint) design. Individuals aged ≥30 y with T2DM (6.2% ≤ HbA1c < 9.4%) were randomly allocated to receive either sitagliptin (25 to 100 mg/d) or conventional therapy. Carotid ultrasound was performed at participating medical centers, and all parameters were measured in a core laboratory. Of the 463 enrolled participants with T2DM, 442 were included in the primary analysis (sitagliptin group, 222; conventional therapy group, 220). Estimated mean (± standard error) common carotid artery IMT at 24 mo of follow-up in the sitagliptin and conventional therapy groups was 0.827 ± 0.007 mm and 0.837 ± 0.007 mm, respectively, with a mean difference of −0.009 mm (97.2% CI −0.028 to 0.011, p = 0.309). HbA1c level at 24 mo was significantly lower with sitagliptin than with conventional therapy (6.56% ± 0.05% versus 6.72% ± 0.05%, p = 0.008; group mean difference −0.159, 95% CI −0.278 to −0.041). Episodes of serious hypoglycemia were recorded only in the conventional therapy group, and the rate of other adverse events was not different between the two groups. As it was not a placebo-controlled trial and carotid IMT was measured as a surrogate marker of atherosclerosis, there were some limitations of interpretation. Conclusions In the PROLOGUE study, there was no evidence that treatment with sitagliptin had an additional effect on the progression of carotid IMT in participants with T2DM beyond that achieved with conventional treatment. Trial Registration University Hospital Medical Information Network Clinical Trials Registry UMIN000004490

Three-Year Clinical Outcomes of Everolimus-Eluting Stents From the Post-Marketing Surveillance Study of Cobalt-Chromium Everolimus-Eluting Stent (XIENCE V/PROMUS) in Japan

BACKGROUND The Cobalt-Chromium Everolimus-Eluting Stent (CoCr-EES) Post-marketing Surveillance (PMS) is a prospective multicenter registry designed to evaluate the safety and efficacy of XIENCE V/PROMUS everolimus-eluting stents in routine clinical practice at 47 centers representative of the clinical environment in Japan. METHODSANDRESULTS We enrolled 2,010 consecutive patients (2,649 lesions) who underwent PCI using CoCr-EES. Clinical outcomes were evaluated for up to 3 years. Clinical follow-up was available in 1,930 patients (96%) at 3 years. Major adverse cardiovascular events (MACE) occurred in 6.8% of patients, including cardiac death (1.7%), myocardial infarction (1.5%), and clinically driven target lesion revascularization (CD-TLR, 4.2%). Late CD-TLR rate was 0.8% from 1 to 2 years, and 0.5% from 2 to 3 years. Definite or probable stent thrombosis occurred in 7 patients (0.3%) up to 1 year. There was no very late definite or probable stent thrombosis from 1 to 3 years. Significant independent predictors for MACE were hemodialysis, prior coronary intervention, triple-vessel coronary artery disease, and age >70 years. CONCLUSIONS Three-year clinical outcomes from the CoCr-EES PMS demonstrated a low incidence of clinical events. There was no major concern about very late stent thrombosis or late catch-up phenomenon in patients treated with EES in routine clinical practice in Japan.

Incremental predictive value of myocardial scintigraphy with 123I-BMIPP in patients with acute myocardial infarction treated with primary percutaneous coronary intervention

PurposeIt is unclear whether 123I-labelled β-methyl iodophenyl pentadecanoic acid (123I-BMIPP) myocardial scintigraphy adds further predictive value for future cardiac events compared with the variables obtained during cardiac catheterisation in patients with acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention (PCI). We therefore investigated whether 123I-BMIPP imaging in patients with AMI treated by primary PCI was useful in predicting future cardiac events.MethodsOne hundred and fifty-nine patients with AMI who were treated with primary PCI and underwent left ventriculography (LVG) on admission underwent 201Tl and 123I-BMIPP myocardial scintigraphy. Scintigrams were visually classified, and the total defect score (TDS) was calculated. Major adverse cardiac events (MACE) were defined as cardiac death including sudden death, congestive heart failure and recurrence of acute coronary syndrome. Patients were followed up for a mean of 34.5 months (12–63 months).ResultsTwenty-six patients had MACE. Kaplan-Meier analysis indicated that patients with the top 50% of 123I-BMIPP TDSs had a significantly higher rate of MACE (P=0.007). Patients with mismatch between 201Tl and 123I-BMIPP images also had significantly more MACE (P=0.02). In the prediction of MACE, the global chi-square value was 5.2 (P=0.001) based on LVEF (<45%) and the number of diseased vessels (two or three). Adding 123I-BMIPP TDS and the mismatch improved the global chi-square value (χ2=7.2)Conclusion Myocardial scintigraphy using 201Tl and 123I-BMIPP predicts future cardiac events in patients with AMI treated with primary PCI, and provides additional predictive value compared with the variables obtained with cardiac catheterisation alone.

The incidence and clinical significance of non-isolation of the pulmonary vein carina after encircling ipsilateral pulmonary veins isolation for paroxysmal atrial fibrillation: a pitfall of the double-Lasso technique

AIMS Encircling ipsilateral pulmonary veins (PVs) isolation (EIPVsI) with the double-Lasso technique has proven to be effective to cure atrial fibrillation (AF). However, in this technique, PV mapping with circular catheters may miss a non-isolation of the PV carina. The purpose of this study was to reveal the incidence and clinical significance of a non-isolation of the PV carina after EIPVsI. METHODS AND RESULTS We studied 81 consecutive paroxysmal AF patients (age 61 ± 12 years, 56 men), in whom EIPVsI was successfully performed in one encircling line with the endpoint of the demonstration of bidirectional conduction block between the PVs and left atrium (LA) with the double-Lasso technique. After a successful EIPVsI, pacing from the PV carina was performed and it captured the LA in 17 (21.0%) patients. During a mean follow-up period of 19 ± 13 months, AF recurred in 13 (16.0%) patients. A multivariate Cox proportional analysis revealed that a non-isolation of the PV carina after the EIPVsI was a significant predictor (hazard ratio = 3.91, 95% confidence interval = 1.13-14.16, P = 0.03) of AF recurrence. CONCLUSIONS Pulmonary vein mapping with the double-Lasso technique did miss the non-isolation of the PV carina after a successful EIPVsI, which was an independent predictor of AF recurrence after the EIPVsI. Pacing from the PV carina may be required to confirm the electrical isolation of the PV carina after EIPVsI with the double-Lasso technique.

Renin‐Angiotensin System Blocker Use May Be Associated with Suppression of Atrial Fibrillation Recurrence after Pulmonary Vein Isolation

Introduction: An additional approach may be essential to reduce recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI). We examined the efficacy of renin‐angiotensin system blockers (RAS‐B) in suppressing AF recurrences after PVI.

Outcomes of ablation of paroxysmal atrial fibrillation in patients on chronic hemodialysis.

AF Ablation in HD Patients. Introduction: It is not common for patients on chronic hemodialysis (HD) to undergo catheter ablation of atrial fibrillation (AF). We aimed to show the outcomes of AF ablation in the HD patients.

High-frequency stimulation of the atria increases early recurrence following pulmonary vein isolation in patients with persistent atrial fibrillation

BACKGROUND High-frequency stimulation (HFS) of the atria induces atrial fibrillation (AF) when applied during sinus rhythm and elicits a parasympathetic response when delivered at sites where ganglionated plexi (GPs) are located. However, little is known about its impact after an electrophysiological study. OBJECTIVE To evaluate the impact of HFS on the short-term and long-term outcomes after the ablation of persistent AF. METHODS Thirty consecutive patients with persistent or long-standing persistent AF were randomly assigned to either receive HFS of the left atrium (n = 15) or not (n = 15) during their electrophysiological studies. Patients receiving HFS were examined to determine whether or not a vagal response was elicited by the HFS at sites where GPs were located before and after conventional pulmonary vein isolation without any ablation targeting the GPs. Patients not receiving the HFS underwent the ablation procedure alone. The rate of recurrence of AF within 3 months of the procedure (early recurrence [ER]) and the frequency of that occurring after that period (late recurrence) were compared between the patient groups. RESULTS The incidence of ER occurred more frequently in patients with HFS than in those without (80% vs 40%; P = .015), whereas the occurrence of late recurrence was similar between the 2 groups (27% vs 33%; P = .73). In the HFS group, the number of GPs decreased from 3.4 ± 1.1 to 1.5 ± 0.8 after the pulmonary vein isolation (P < .0001), and the decrease was smaller in the patients experiencing ER than in those without. CONCLUSION HFS increases the incidence of ER in patients with persistent AF despite a partial GP modification resulting from the pulmonary vein isolation.

Clinical significance of sleep-disordered breathing induced by sedatives during ablation of atrial fibrillation.

BACKGROUND Sleep-disordered breathing (SDB) frequently is induced by sedation during ablation of atrial fibrillation (AF). We tested whether or not sedative-induced SDB is associated with clinical sleep apnea syndrome (SAS). METHODS We examined SDB observed during intra-ablation sedation with a novel portable respiratory monitor (PM), SD-101, in 140 patients undergoing AF ablation without any known SAS. A sleep study was repeated the next night of the ablation with the simultaneous use of the SD-101 and type 3 PM, APNOMONITOR V. RESULTS The respiratory disturbance index (RDI) during sedation (20.0±7.8 events/h) was significantly correlated with the RDI measured by the SD-101 during the night (15.8±13.7 events/h; r=0.50) and the RDI assessed by the APNOMONITOR V during the night (12.7±12.3 events/h; r=0.55). An excellent agreement was found between the RDIs simultaneously measured with the 2 PMs (intraclass correlation coefficient, 0.84), especially for an RDI of ≥30 events/h (κ statistic value, 0.82). The area under the receiver-operating characteristic curve for the RDI with the use of the SD-101 during sedation to identify the patients with an RDI of ≥30 events/h by both PMs during the night was 0.92. A left atrial diameter of >40 mm (odds ratio [OR], 4.10) and an RDI during sedation of >20 events/h (OR, 17.75) were independently associated with having an RDI of ≥30 events/h with both PMs during the night. CONCLUSIONS Frequent episodes of sedative-induced SDB may have a diagnostic value for SAS in patients with AF.