Takayuki Ishihara

Classification and Clinical Impact of Restenosis After Femoropopliteal Stenting

OBJECTIVES The purpose of this study was to investigate the relationship between angiographic patterns of in-stent restenosis (ISR) after femoropopliteal (FP) stenting and the frequency of refractory ISR. BACKGROUND In-stent restenosis after FP stenting is an unsolved problem. The incidence and predictors of refractory restenosis remain unclear. METHODS This study was a multicenter, retrospective observational study. From September 2000 to December 2009, 133 restenotic lesions after FP artery stenting were classified by angiographic pattern: class I included focal lesions (≤50 mm in length), class II included diffuse lesions (>50 mm in length), and class III included totally occluded ISR. All patients were treated by balloon angioplasty for at least 60 s. Recurrent ISR or occlusion was defined as ISR or occlusion after target lesion revascularization. Restenosis was defined as >2.4 of the peak systolic velocity ratio by duplex scan or >50% stenosis by angiography. RESULTS Sixty-four percent of patients were male, 67% had diabetes mellitus, and 24% underwent hemodialysis. Class I pattern was found in 29% of the limbs, class II in 38%, and class III in 33%. Mean follow-up period was 24 ± 17 months. All-cause death occurred in 14 patients; bypass surgery was performed in 11 limbs, and major amputation was performed in 1 limb during the follow-up. Kaplan-Meier survival curves showed that the rate of recurrent ISR at 2 years was 84.8% in class III patients compared with 49.9% in class I patients (p < 0.0001) and 53.3% in class II patients (p = 0.0003), and the rate of recurrent occlusion at 2 years was 64.6% in class III patients compared with 15.9% in class I patients (p < 0.0001) and 18.9% in class II patients (p < 0.0001). CONCLUSIONS Restenotic patterns after FP stenting are important predictors of recurrent ISR and occlusion.

Low left atrial appendage flow velocity predicts recurrence of atrial fibrillation after catheter ablation of persistent atrial fibrillation

BACKGROUND Recurrence after catheter ablation of persistent atrial fibrillation (AF) remains an unsolved issue. This study aimed to explore the association between the left atrial appendage peak flow velocity (LAAV) and AF recurrence after ablation in persistent AF patients. METHODS Fifty-three consecutive patients who underwent an initial catheter ablation of persistent AF were enrolled [age, 65±10 years; male, 42 (79%)]. The LAAV was obtained by transesophageal echocardiography before ablation. All the patients underwent pulmonary vein isolation and were followed up for 12 months. The LAAV and other clinical factors (AF duration, CHA2DS2VASc score, left atrial diameter, left atrial volume, and left ventricular ejection fraction) were tested using a Cox proportional hazards regression analysis as predictors of AF recurrence during the 1-year follow-up. RESULTS AF recurrence occurred in 16 (30%) patients. The patients with AF recurrences had lower LAAVs (23.3±7.2cm/s vs. 33.3±15.1cm/s, p=0.002) than those without AF recurrence. In the multivariable analysis, a low LAAV independently predicted AF recurrence (hazard ratio, 3.04; 95% confidence interval, 1.05-8.79; p=0.040). A Kaplan-Meier analysis also demonstrated a lower survival rate free from AF recurrence in the low LAAV group than in the high LAAV group (p=0.030). CONCLUSION A low LAAV was associated with AF recurrence after the initial catheter ablation of persistent AF.

Influence of underlying substrate on atrial tachyarrhythmias after pulmonary vein isolation

BACKGROUND Recurrent atrial tachyarrhythmias occur as a result of residual atrial arrhythmogenic substrates after atrial fibrillation (AF) ablation. In patients with AF, electrograms with reduced amplitudes indicate diseased myocardium. OBJECTIVE The purpose of this study was to investigate the association between the distribution of low-voltage areas and the type of induced atrial tachyarrhythmias. METHODS Our prospective observational study enrolled 152 consecutive AF patients scheduled for an initial ablation (46% persistent AF). After pulmonary vein isolation, voltage mapping was performed during sinus rhythm, and regions with reduced electrogram amplitudes (<0.5 mV) were defined as low-voltage areas. Burst pacing was performed to investigate the inducibility of atrial tachyarrhythmias. RESULTS Low-voltage areas were more frequently observed in patients with persistent AF than paroxysmal AF (50% vs. 34%, P = .048). A higher proportion of patients with low-voltage areas presented with inducibility of atrial tachyarrhythmias than those without, as follows: AF 70% vs. 16% (P = .0001); perimitral macroreentrant atrial tachycardia (AT) 18% vs. 0% (P = .0001); and roof-dependent macroreentrant AT 13% vs. 0% (P = .01). Investigation into the regional distribution of low-voltage areas revealed that patients with perimitral macroreentrant AT more frequently coincided with low-voltage areas than those without in the septal (100% vs. 18%, P <.0001) and anterior regions (55% vs. 11%, P = .001), and those with roof-dependent AT in the roof (75% vs. 15%, P <.0001) and posterior regions (75% vs. 15%, P = .0001). CONCLUSION Low-voltage areas are associated with high inducibility of atrial tachyarrhythmias after pulmonary vein isolation. In addition, the distribution of low-voltage areas is specific for each type of macroreentrant AT.

Left atrial low-voltage areas predict atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation

BACKGROUND Association between the presence of left atrial low-voltage areas and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been shown mainly in persistent AF patients. We sought to compare the AF recurrence rate in paroxysmal AF patients with and without left atrial low-voltage areas. METHODS This prospective observational study included 147 consecutive patients undergoing initial ablation for paroxysmal AF. Voltage mapping was performed after PVI during sinus rhythm, and low-voltage areas were defined as regions where bipolar peak-to-peak voltage was <0.50mV. RESULTS Left atrial low-voltage areas after PVI were observed in 22 (15%) patients. Patients with low-voltage areas were significantly older (72±6 vs. 66±10, p<0.0001), more likely to be female (68% vs. 32%, p=0.002), and had higher CHA2DS2-VASc score (2.5±1.5 vs. 1.8±1.3, p=0.028). During a mean follow-up of 22 (18, 26) months, AF recurrence was observed in 24 (16%) and 16 (11%) patients after the single and multiple ablation procedures, respectively. AF recurrence rate after multiple ablations was higher in patients with low-voltage areas than without (36% vs. 6%, p<0.001). Low-voltage areas were independently associated with AF recurrence even after adjustment for the other related factors (Hazard ratio, 5.89; 95% confidence interval, 2.16 to 16.0, p=0.001). CONCLUSION The presence of left atrial low-voltage areas after PVI predicts AF recurrence in patients with paroxysmal AF as well as in patients with persistent AF.

Comparable 2-Year Restenosis Rates Following Subintimal and Intraluminal Drug-Eluting Stent Implantation for Femoropopliteal Chronic Total Occlusion.

Purpose: To report midterm outcomes after subintimal vs intraluminal drug-eluting stent (DES) implantation for femoropopliteal (FP) chronic total occlusion (CTO). Methods: This subanalysis of the prospective, multicenter ZEPHYR study (ZilvEr PTX for tHe Femoral ArterY and Proximal Popliteal ArteRy) included 176 patients (mean age 74±8 years; 130 men) with 192 de novo FP CTOs that were evaluated by intravascular ultrasound after successful guidewire crossing. The primary outcome was the 2-year restenosis rate after subintimal (n=73) or intraluminal (n=119) DES implantation. Propensity score matching extracted 61 matched pairs (mean age 75 years; 49 men) for patency analysis to minimize baseline intergroup differences. Restenosis rates are reported with the 95% confidence interval (CI). Results: The 1-year restenosis rates in the groups with subintimal and intraluminal DES implantation were 45% (95% CI 32% to 59%) and 35% (95% CI 22% to 49%), respectively (p=0.352), whereas the corresponding rates at 2 years were not significantly different (p=0.648) at 56% (95% CI 41% to 71%) and 51% (95% CI 34% to 68%). Baseline characteristics had no significant interaction effect on the association of subintimal angioplasty with restenosis risk. Conclusion: In FP CTO, 2-year restenosis rates were comparable after subintimal or intraluminal DES implantation.

Severity of Coronary Artery Disease Affects Prognosis of Patients With Peripheral Artery Disease

It remains unclear whether severity of coronary artery disease (CAD) affects the prognosis of patients with peripheral artery disease (PAD). In this retrospective, multicenter study, we analyzed 537 consecutive patients with symptomatic PAD who underwent both peripheral artery revascularization and coronary angiography (CAG) prior to revascularization. We classified patients into 3 groups based on CAG: no-CAD group, intermediate CAD group (1-2 diseased vessels), and triple-vessel disease (TVD) group. We evaluated clinical outcome including all-cause death, major adverse cardiac events (MACEs), and amputation. The no-CAD, intermediate CAD, and TVD groups comprised 204, 268, and 65 patients, respectively. Mean follow-up duration was 952 ± 497 days. Freedom from any adverse outcome was highest in the no-CAD group and lowest in the TVD group (all-cause death: 86% vs 77% vs 65%, P = .043; MACE: 95% vs 87% vs 78%, P = .044; amputation: 96% vs 92% vs 83%, P = .0015). Severity of CAD affected prognosis of patients with PAD.

Indications and outcomes of excimer laser coronary atherectomy: Efficacy and safety for thrombotic lesions—The ULTRAMAN registry

BACKGROUND Excimer laser coronary atherectomy (ELCA) recently became available in Japan, but ELCAs effectiveness and safety are not clear. METHODS AND RESULTS We enrolled consecutive patients who underwent ELCA and were registered in the Utility of Laser for Transcatheter Atherectomy-Multicenter Analysis around Naniwa (ULTRAMAN) registry comprising six Japanese medical centers around Naniwa in Japan with patients registered from April 2006 to June 2015. We evaluated the catheter sizes used and compared the success rate, thrombolysis in myocardial infarction (TIMI) flow, blush score, and complications between the rich-thrombus (RT) group [acute coronary syndrome (ACS) and saphenous vein graft (SVG)] and the poor-thrombus (PT) group [in-stent restenosis (ISR), chronic total occlusion (CTO), calcification, and long or bifurcation (L&B) lesions]. Of the 328 patients, 6 (1.8%) were treated for an SVG, 175 (53.4%) were treated for ACS, 18 (5.5%) for CTO, 106 (32.4%) for ISR, 8 (2.4%) for calcification, and 15 for L&B lesions (4.6%). A 1.7-mm (concentric)-diameter ELCA catheter was used most frequently (59.4%). High success rates were achieved in both the RT and PT groups, but the TIMI flow grade and blush score were significantly lower and the complications rate was significantly higher in the RT group (n=181). CONCLUSIONS In Japan, the major indications for ELCA have been ACS and ISR. ELCA can provide a safe and effective treatment even for RT lesions.

The identification of conduction gaps after pulmonary vein isolation using a new electroanatomic mapping system

BACKGROUND The reconnection of left atrial-pulmonary vein (LA-PV) conduction after the initial procedure of pulmonary vein (PV) isolation is not rare, and is one of the main cause of atrial fibrillation (AF) recurrence after PV isolation. OBJECTIVE We investigated feasibility of a new ultrahigh-resolution mapping system using a 64-pole small basket catheter for the identification of LA-PV conduction gaps. METHODS This prospective study included 31 consecutive patients (20 with persistent AF) undergoing a second ablation after a PV isolation procedure with LA-PV reconnected conduction at any of the 4 PVs. An LA-PV map was created using the mapping system, and ablation was performed at the estimated gap location. RESULTS The propagation map identified 54 gaps from 39 ipsilateral PV pairs, requiring manual electrogram reannotation for 23 gaps (43%). Gaps at the anterior and carinal regions of left and right ipsilateral PVs required manual electrogram reannotation more frequently than the other regions. The voltage map could identify the gap only in 19 instances (35%). Electrophysiological properties of the gaps (multiple gaps in the same ipsilateral PVs, conduction time, velocity, width, and length) did not differ between those needing and not needing manual electrogram reannotation. During the gap ablation, either the activation sequence alteration or elimination of PV potentials was observed using a circular catheter placed in the PV, suggesting that all the identified gaps were correct. CONCLUSION This new electroanatomic mapping system visualized all the LA-PV gaps in patients undergoing a second AF ablation.

Long-Term Prognostic Implications of the Admission Shock Index in Patients With Acute Myocardial Infarction Who Received Percutaneous Coronary Intervention

The admission shock index (SI) enables prediction of short-term prognosis. This study investigated the prognostic implications of admission SI for predicting long-term prognoses for acute myocardial infarction (AMI). The participants were 680 patients with AMI who received percutaneous coronary intervention. Shock index is the ratio of heart rate and systolic blood pressure. Patients were classified as admission SI <0.66 (normal) and ≥0.66 (elevated; 75th percentile). The end point was 5-year major adverse cardiac events (MACEs). Elevated admission SI was seen in 176 patients. Peak creatine kinase levels were significantly higher and left ventricular ejection fraction was lower in the elevated SI group, which had a worse MACEs. In multivariate Cox regression analysis, SI ≥0.66 was a risk factor for MACE. Elevated admission SI was associated with poorer long-term prognosis.

Impact of Calcification on Clinical Outcomes After Endovascular Therapy for Superficial Femoral Artery Disease Assessment Using the Peripheral Artery Calcification Scoring System

Purpose: To investigate whether the severity of lesion calcification assessed by the novel peripheral artery calcification scoring system (PACSS) was associated with clinical outcomes after endovascular therapy (EVT) for superficial femoral artery (SFA) lesions. Methods: A retrospective analysis was conducted of 394 consecutive patients (mean age 72±8 years; 290 men) with intermittent claudication [223 (57%) with diabetes, 81 (21%) on hemodialysis] who underwent successful EVT for de novo SFA lesions [length 152.1±95.7 mm; 199 (50%) TransAtlantic Inter-Society Consensus II class C/D] between January 2010 and December 2013. The patients were retrospectively categorized using the PACSS classification (grades 0–4: no visible calcification of the target lesion, unilateral wall calcification <5 cm, unilateral calcification ≥5 cm, bilateral wall calcification <5 cm, and bilateral calcification ≥5 cm, respectively). The main outcome was primary patency, while the secondary outcome measures were mortality and major adverse limb events [MALE: any intervention (repeat EVT or surgical revision) or major (above ankle) amputation]. Cox proportional hazards analysis was used to explore whether the PACSS classification was an independent predictor of clinical outcomes. Results are presented as the hazard ratio (HR) and 95% confidence interval (CI). Results: The distribution of PACSS grades was 0 in 54%, grade 1 in 16%, grade 2 in 12%, grade 3 in 9%, and grade 4 in 9%. The 2-year primary patency rates in these grades, respectively, were 70.0%, 66.6%, 72.1%, 55.6%, and 36.3% (p<0.001). After multivariate analysis, PACSS grade 4 (HR 2.74, 95% CI 1.56 to 4.83, p<0.001), diabetes (HR 1.52, 95% CI 1.06 to 2.20, p=0.022), lesion length (HR 1.04, 95% CI 1.01 to 1.07, p=0.006), and vessel diameter (HR 0.80, 85% CI 0.65 to 0.98, p=0.038) were associated with loss of primary patency. PACSS grade 4 was also associated with MALE and mortality (p=0.048 and 0.011, respectively). Bare metal stent use (HR 0.47, 95% CI 0.30 to 0.73, p<0.001) was positively associated with primary patency. Conclusion: PACSS grade 4 calcification was independently associated with clinical outcomes after EVT for de novo SFA lesions.