Yusuke Miyashita

Angioplasty for chronic total occlusion by using tapered-tip guidewires

Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is still technically challenging. The use of tapered‐tip guidewires in these lesions may improve the success rate of PCI. In order to avoid the needless radiation exposure or contrast consumption, we have to determine a guideline for the termination of procedures in these lesions. We retrospectively analyzed the data of 182 patients between April 1997 and December 1999 (phase 1) and 80 patients between January and August 2001 (phase 2) who underwent angioplasty for CTO lesions ≥ 3 months. There were no significant differences in clinical or lesion characteristics except the use of tapered‐tip guidewires. Tapered‐tip guidewires were used in 60% of patients in phase 2 period but no patients in phase 1 period. The overall success rate of PCI was improved from 67% in phase 1 to 81% in phase 2 (P = 0.019). In the phase 2 period, the success rate was higher in tapered‐type occlusion (P = 0.002) and shorter length of occlusion (P = 0.004). Total procedure time was 46 ± 17 min and total volume of contrast dye was 180 ± 63 ml. The success rate was higher in patients treated by transradial coronary intervention (TRI) than transfemoral coronary intervention (89% vs. 64%; P = 0.008). The use of tapered‐tip guidewires can improve the success rate of PCI in CTO lesions. The following guideline for the termination of the procedures is reasonable: time from arterial access to successful penetration of a guidewire through occlusion ≤ 30 min; total procedure time ≤ 90 min; and total dye volume ≤ 300 ml. TRI can achieve a high success rate even in CTO lesions provided that the case selection is adequate. Cathet Cardiovasc Intervent 2003;59:305–311.

Comparative study on transradial approach vs. transfemoral approach in primary stent implantation for patients with acute myocardial infarction: Results of the test for myocardial infarction by prospective unicenter randomization for access sites (TEMPURA) trial

Transradial coronary intervention (TRI) can be performed in elective patients with low incidence of access site complications. However, the feasibility of primary stent implantation by TRI is still not clear in patients with acute myocardial infarction (AMI). We prospectively randomized 149 patients out of 213 patients with AMI within 12 hr from onset into two groups: 77 patients treated by TRI (TRI group) and 72 patients by transfemoral coronary intervention (TFI; TFI group). We compared the incidences of major adverse cardiac events (MACE; repeat MI, target lesion revascularization, and cardiac death) during the initial hospitalization and 9‐month follow‐up periods in both groups. There were one patient who crossed over to the opposite arm, and two patients with severe bleeding complications in the TFI group. Background characteristics of patients were similar between the two groups. The success rate of reperfusion and the incidence of in‐hospital MACE were similar in both groups (96.1% and 5.2% vs. 97.1% and 8.3% in TRI and TFI groups, respectively). In selected patients with AMI, primary stent implantation by TRI is feasible as compared to TFI. Cathet Cardiovasc Intervent 2003;59:26–33.

Long-term results of direct and indirect endovascular revascularization based on the angiosome concept in patients with critical limb ischemia presenting with isolated below-the-knee lesions

OBJECTIVE We compared clinical outcomes between limbs with and without achievement of feeding artery flow by endovascular therapy (EVT) based on the angiosome concept in critical limb ischemia (CLI) patients with isolated below-the-knee (BTK) lesions and assessed factors influencing major amputation (MA). METHOD We analyzed 369 limbs from 329 consecutive patients (224 men; age, 70 ± 11 years) with ischemic ulceration or gangrene, or both, presenting with isolated BTK lesions (Rutherford class 5, 270 limbs; class 6, 99 limbs) with a pretreatment ankle-brachial index of 0.79 ± 0.26. Patients underwent successful EVT, without bypass surgery. Limbs were classified into direct (n = 200) and indirect (n = 169) groups by whether feeding artery flow to the site of ulceration or gangrene was successfully achieved, based on the angiosome concept. Unadjusted and adjusted (by propensity score matching) between-group rates of amputation-free survival (AFS) and freedom from major amputation (MA) and major adverse limb event (MALE) were compared by Kaplan-Meier analysis and the log-rank test. The independent determinants of MA in the direct and indirect groups were explored by multivariable analysis. RESULTS During follow-up (mean, 18 ± 16 months), the overall limb salvage rate was 81% (300 of 369), death occurred in 36% (119 of 329), and the reintervention rate was 31% (114 of 369). After propensity score adjustment, the estimated (± standard error) rates for AFS (49% ± 8% vs 29% ± 6%; P = .0002), freedom from MALE (51% ± 8% vs 28% ± 8%, P = .008), and major amputation (82% ± 5% vs 68% ± 5%, P = .01) were significantly higher in the direct group than in the indirect group for up to 4 years after the index procedure. After multivariable Cox proportional analysis, the independent factors associated with major amputation were hemoglobin A(1c) level (hazard ratio [HR], 1.4; 95% confidential interval [CI], 1.1-1.9; P = .006) and cilostazol administration (HR, 0.28; 95% CI, 0.11-0.70; P = .006) in the direct group, and C-reactive protein level (HR, 1.2; 95% CI, 1.1-1.4; P = .002) in the indirect group. CONCLUSION Achieving direct flow by angioplasty based on the angiosome concept in CLI patients with isolated BTK lesions is clinically important for AFS and freedom from MA and MALE. Limb salvage factors appear to differ between patients with and without direct flow from the feeding artery after EVT.

New method to increase a backup support of a 6 French guiding coronary catheter.

A 6 Fr guiding catheter is commonly used in the percutaneous coronary intervention (PCI). However, one of the limitations of the 6 Fr guiding catheter is its weak backup support compared to a 7 or an 8 Fr guiding catheter. In this article, we present a new system for PCI called the five‐in‐six system. Between March 2003 and September 2003, this system was tried on eight chronic total occlusion cases. The advantage of the five‐in‐six system is that it increases backup support of a 6 Fr guiding catheter. Catheter Cardiovasc Interv 2004;63:452‐456.

Endovascular Treatment for Infrainguinal Vessels in Patients With Critical Limb Ischemia OLIVE Registry, a Prospective, Multicenter Study in Japan With 12-Month Follow-up

Background—Recent technical advances have made endovascular treatment (EVT) an alternative first-line treatment for critical limb ischemia. Methods and Results—A prospective multicenter study was conducted to evaluate the clinical outcomes of 314 Japanese critical limb ischemia patients (mean age, 73±10 years) with infrainguinal arterial lesions who underwent EVT. Patients were enrolled from December 2009 to July 2011 and were followed-up for 12 months. The primary end point was amputation-free survival (AFS) at 12 months. Secondary end points were anatomic, clinical, and hemodynamic measures, including 12-month freedom from major adverse limb events. The 12-month AFS rate was 74%, with body mass index <18.5 (hazard ratio [HR], 2.22; P=0.008), heart failure (HR, 1.73; P=0.04), and wound infection (HR, 1.89; P=0.03) associated with a poor prognosis for AFS. The 12-month major adverse limb event-free rate was 88%, with hemodialysis (HR, 1.98; P=0.005), heart failure (HR, 1.69; P=0.02), and Rutherford classification 6 (HR, 2.25; P=0.002) associated with a poor prognosis for major adverse limb events. The median time for wound healing was 97 days, with body mass index <18.5 (HR, 0.54; P=0.03) and wound infection (HR, 0.60; P=0.04) being significant risk factors for unhealed wounds after EVT. At 12 months, 34% had undergone reintervention (bypass surgery, 2.6%; repeat EVT, 31.7%), and 73% were major adverse event–free. Conclusions—The high reintervention rate notwithstanding, EVT was an effective treatment for Japanese critical limb ischemia patients with infrainguinal disease, with satisfactory AFS and major adverse limb event-free rates. The results of this study will be helpful for the future evaluation of critical limb ischemia therapy. Clinical Trial Registration—URL: http://www.umin.ac.jp/ctr. Unique identifier: UMIN000002830.

Angiographic Restenosis and Its Clinical Impact after Infrapopliteal Angioplasty

OBJECTIVE To assess 3- and 12-month angiographic restenosis rates and their clinical impact after infrapopliteal angioplasty. DESIGN Prospective multicenter study. MATERIALS AND METHODS We analyzed 68 critical ischemic limbs (tissue loss: 58 limbs) from 63 consecutive patients due to isolated infrapopliteal lesions who underwent angioplasty alone. Primary endpoint was 3-month angiographic restenosis rate; secondary endpoints were 12-month angiographic restenosis rate, and 3- and 12-month rates of mortality, major amputation and reintervention. Three- and 12-month frequency of ambulatory status and of freedom from ischemic symptoms, and time to wound healing in the ischemic wound group, were compared between restenotic and non-restenotic groups. Angiographic restenosis predictors were assessed by multivariable analysis. RESULTS 95% of cases had 3-month angiography; restenosis rate was 73%: 40% restenosis and 33% re-occlusion. Twelve-month follow-up angiography was conducted for the patients without 3-month angiographic restenosis, and restenosis rate at 12 months was 82%. Non-administration of cilostazol and statin, and chronic total occlusion were 3-month angiographic restenosis predictors. Three- and 12-month mortality was 5% and 12%, respectively. Despite no patients having undergone amputation, 15% had persistent ischemic symptoms, and 48% of limbs underwent reintervention within 12 months. During the same study period, ambulatory status and limbs with complete healing were more frequently observed in the non-restenosis group than in the restenosis group. In the tissue loss group, time to wound healing in the restenosis group was longer than in the non-restenosis group (127 days vs. 66 days, p = 0.02). CONCLUSION The extremely high angiographic restenosis rate after infrapopliteal angioplasty may adversely impact clinical status improvement.

Cilostazol Reduces Angiographic Restenosis After Endovascular Therapy for Femoropopliteal Lesions in the Sufficient Treatment of Peripheral Intervention by Cilostazol Study

Background— It remains unclear whether cilostazol, which has been shown to improve the clinical outcomes of endovascular therapy for femoropopliteal lesions, also reduces angiographic restenosis. Methods and Results— The Sufficient Treatment of Peripheral Intervention by Cilostazol (STOP-IC) study investigated whether cilostazol reduces the 12-month angiographic restenosis rate after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions. Two hundred patients with femoropopliteal lesions treated from March 2009 to April 2011 at 13 cardiovascular centers were randomly assigned 1:1 to receive oral aspirin with or without cilostazol. The primary end point was 12-month angiographic restenosis rate. Secondary end points were the restenosis rate on duplex ultrasound, the rate of major adverse cardiac events, and target lesion event-free survival. Researchers evaluated all follow-up data and assessed the end points in a blinded fashion. The mean lesion length and reference vessel diameter at the treated segment were 128±86 mm and 5.4±1.4 mm, respectively. The frequency of stent used was similar between groups (88% versus 90% in the cilostazol and noncilostazol group, respectively, P=0.82). During the 12-month follow-up period, 11 patients died and 152 patients (80%) had evaluable angiographic data at 12 months. The angiographic restenosis rate at 12 months was 20% (15/75) in the cilostazol group versus 49% (38/77) in the noncilostazol group (P=0.0001) by intention-to-treat analysis. The cilostazol group also had a significantly higher event-free survival at 12 months (83% versus 71%, P=0.02), although cardiovascular event rates were similar in both groups. Conclusions— Cilostazol reduced angiographic restenosis after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00912756; and URL: https://www.umin.ac.jp. Unique identifier: UMIN000002091.

A new radiofrequency thermal balloon catheter for pulmonary vein isolation

OBJECTIVES We sought to evaluate whether porcine pulmonary vein (PV) isolation (PVI) can be produced by ablation using our novel radiofrequency (RF) thermal balloon catheter (RBC). BACKGROUND It has been proposed that PVI can prevent focal atrial fibrillation (AF) originating in or close to the PV. METHODS The RBC is composed of a 12F main shaft, a 4F inner tube and a balloon. Inside the balloon, there is a unipolar coil electrode with a thermocouple sensor mounted along the tube, the former to deliver RF energy (13.56 MHz) and the latter to monitor the temperature. After the presence of a PV potential was confirmed, the RBC was safely inserted into the left atrium (LA) by the trans-septal approach. Once the balloon was inflated and optimally wedged at the junction between the PV and LA, RF energy was applied for 5 min. Radiofrequency catheter ablation (RFA) was repeated up to three times, until elimination of the PV potential or dissociation between the LA and PV was observed. Finally, each heart was examined histologically. RESULTS In 18 PVs that had PV potentials, PVI was performed, resulting in success in 15 (success rate 83%, 95% confidence interval [CI] 58.0% to 96.3%; failure rate 17%, 95% CI 3.7% to 42.0%). After successful PVI, the PV potentials completely disappeared and the histologic examination revealed circumferential, transmural necrosis around the PV trunks. No major complications, such as PV stenosis or macroscopic thrombosis, were observed. CONCLUSIONS The RBC was useful for PVI.

Torsion analysis in the early detection of anthracycline-mediated cardiomyopathy

AIMS Anthracyclines have profound consequences on the structure and function of the heart, which over time cause a cardiomyopathy that leads to congestive heart failure. Early detection of subclinical left ventricular (LV) dysfunction following a low dose of anthracyclines may be a preventive strategy. The aim of this study was to determine torsion analysis using two-dimensional speckle-tracking imaging (STI), useful for detecting early anthracycline-mediated cardiotoxicity. METHODS AND RESULTS Conventional and Doppler echocardiography images were obtained from 25 patients (mean age 58 ± 11 years) before chemotherapy and 1 and 3 months after treatment. The cumulative anthracycline doses were 98 ± 59 and 170 ± 87 g/m(2) at 1 and 3 months, respectively. After standard echocardiography, LV torsion and twisting velocity profiles from apical and basal short-axis images were analysed using STI. LV dimensions and ejection fraction did not change throughout follow-up. Although isovolumic relaxation time showed prolongation 3 months after chemotherapy, other Doppler indices did not show significant changes. However, significant deteriorations in torsion (P < 0.0001 by ANOVA), twisting rate (P < 0.0001 by ANOVA), and untwisting rate (P < 0.001 by ANOVA) were found 1 month after chemotherapy. A significant negative correlation was observed between cumulative anthracycline doses and torsion (r = -0.524, P < 0.0001). CONCLUSION LV torsion analysis could be a useful non-invasive approach for early detection of subclinical anthracycline cardiotoxicity.

Prognosis of Critical Limb Ischemia in Hemodialysis Patients After Isolated Infrapopliteal Balloon Angioplasty: Results From the Japan Below-the-Knee Artery Treatment (J-BEAT) Registry

Purpose To evaluate the long-term clinical results after isolated infrapopliteal balloon angioplasty for critical limb ischemia (CLI) in end-stage renal disease patients on hemodialysis. Methods Between April 2004 and October 2010, 406 CLI consecutive patients (275 men; mean age 71±11 years) who underwent balloon angioplasty for primary treatment of isolated infrapopliteal artery lesions in 465 limbs were enrolled in a multicenter, nonrandomized registry. The patients were classified into 2 groups, those on hemodialysis (242 patients with 283 limbs) and those not (164 patients with 182 limbs), for a retrospective comparative study of clinical outcomes [target extremity revascularization (TER), major amputation (MA), and survival] at an average 3.4±1.9 years. Results Freedom from TER at 5 years was lower in the hemodialysis patients (48.3% vs. 65.4% in non-hemodialysis patients, p<0.001); 9.9% of hemodialysis patients had undergone bypass surgery in contrast to 3.8% of non-hemodialysis patients (p=0.011). Freedom from MA was 77.1% in hemodialysis patients and 85.1% in non-hemodialysis patients at 5 years (p=0.058). Hemodialysis patients had significantly poorer survival (24.3% vs. 48.0%, p<0.001) and MA-free survival (20.8% vs. 42.9%, p<0.001) than non-hemodialysis patients at 5 years. Multivariate predictors of MA or all-cause death were non-ambulatory status (p<0.001), gangrene (p=0.036), and higher C-reactive protein levels (p=0.048). Conclusion Although hemodialysis patients have a higher TER rate compared to the general population, the long-term limb salvage rate after balloon angioplasty for isolated infrapopliteal lesions is acceptable; nevertheless, the MA-free survival rate is very low.