Naoto Tama

Repeated occurrence of slow flow phenomenon during and late after sirolimus-eluting stent implantation

A 78-year-old man with unstable angina showed 90xa0% stenosis in the proximal left anterior descending artery. Pre-procedural intravascular ultrasound revealed ruptured plaque and attenuated plaque in the lesion. Under these conditions, two overlapping sirolimus-eluting stent (SES) implantation in this lesion resulted in slow flow which was recovered by intracoronary nitrates, nicorandil, and nitroprusside without further complications. When the patient showed up again 5xa0years later with recurrence of angina pectoris, angiography revealed a hazy ulcerated in-stent restenosis (ISR) at the site of the SES. Pre-procedural optical coherence tomography (OCT) imaging revealed multiple intimal ruptures, cavity formation behind the stent struts, a thin-cap fibroatheroma containing neointima surrounded by signal-poor, lipid-rich area in the proximal SES, suggesting the progression of neoatherosclerosis within SES. Importantly, there occurred slow flow again after balloon angioplasty for this lesion. We would suggest careful OCT examination is warranted to confirm development of neoatherosclerosis within the stent, and distal protection device should be considered to prevent slow flow phenomenon even in a patient with very late ISR.

Serial cardiac influence of volume overload induced by interventional therapy for central venous stenosis or occlusion in chronic hemodialysis patients.

BACKGROUNDnUpper arm swelling and venous hypertension at arteriovenous fistula sites, and insufficiency of hemodialysis are induced by central venous lesions in chronic hemodialysis patients. Percutaneous transluminal angioplasty (PTA) for central venous lesions is first-choice treatment. Cardiac function can be evaluated by measuring the acute increase in venous return volume after PTA.nnnMETHODSnWe studied 6 cases of successful PTA for central venous stenotic or occluded lesions, and evaluated cardiac function by Swan-Ganz (SG) catheter and ultrasound echocardiography (UCG) at pre-, post-PTA, and on the following day.nnnRESULTSnEjection fraction (EF) in 6 cases was 71.0 ± 5.5% on UCG. Two cases of subclavian venous stenosis, one case of subclavian venous occlusion, and three cases of brachiocephalic venous occlusion were enrolled. The reference diameter (RD) was 10.2 ± 4.9 mm, % diameter-stenosis (%DS) was 92.2 ± 12.2% at pre-PTA, and %DS at post-PTA was 21.7 ± 20.7%. There were no significant differences in pulmonary capillary-wedge, pulmonary artery, and right ventricular end-diastolic pressure in SG at pre- and post-PTA. The pressure of right atrium (RA) and cardiac output (CO) were significantly increased by PTA (RA pressure at pre-/post-PTA, 9.7 ± 2.9/11.7 ± 3.6 mmHg, p<0.05, CO at pre-/post-PTA 5.09 ± 2.07/5.45 ± 2.25 l/min, p<0.05). There were no significant differences in serial EF, left atrial and left ventricular diameters on UCG. However, the short-diameter of right ventricle (RV) and RA were significantly increased at post-PTA and recovered on the following day (RV short-diameter at pre-/post-/following-day PTA, 26.7 ± 3.5/32.5 ± 1.9/29.1 ± 1.7 mm, p<0.05; RA short-diameter at pre-/post-/following-day PTA, 30.2 ± 4.2/36.3 ± 2.4/32.1 ± 3.6mm, p<0.05).nnnCONCLUSIONSnVolume overload after PTA for central venous stenotic or occluded lesions in chronic hemodialysis patients resulted in increased RA and RV diameters. These changes were transient and completely recovered by the following day. PTA for central venous lesions in patients with normal EF can be performed without clinical cardiac problems.

Impaired myocardial microcirculation in the flow-glucose metabolism mismatch regions in revascularized acute myocardial infarction.

AbstractBackgroundIn successfully revascularized acute myocardial infarction (AMI), microvascular function in a myocardial flow-glucose metabolism mismatch pattern has not been reported. nWe aimed to elucidate myocardial flow reserve (MFR) and myocardial viability in mismatch segments.Methods18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and adenosine stress 13N-ammonia PET were performed in eighteen AMI patients to evaluate myocardial glucose metabolism, myocardial blood flow (MBF), and MFR. Infarct segments were classified into 3 groups: normal (preserved resting MBF), mismatch (preserved FDG uptake but reduced resting MBF), and match (reduced FDG uptake and resting MBF). Regional wall motion score (WMS) was assessed immediately after reperfusion and recovery periods.ResultsMFR in the mismatch group was significantly lower than that in non-infarct-related segments (1.655xa0±xa00.516 vs 2.282xa0±xa00.629, Pxa0<xa0.01) and similar to that in the match group (1.635xa0±xa00.528, Pxa0=xa0.999). WMS in the mismatch group was significantly improved (3.07xa0±xa00.48 vs 2.07xa0±xa01.14, Pxa0=xa0.003); however, in recovery periods, WMS in the mismatch group was significantly higher than that in the normal group (1.05xa0±xa01.04, Pxa0<xa0.01).ConclusionsIn successfully revascularized AMI, microvascular function is impaired despite preserved myocardial glucose metabolism in mismatch segments.

Which DES is the most appropriate for very small target vessels? Experimental study of stent expandable performance with SES, PES, ZES and EES

The restenosis rate of coronary stent has significantly decreased by implantation of the drug-eluting stent (DES). We often experienced the DES implantation for very small target vessels. The minimum size of DES in Japan and USA is 2.5xa0mm-diameter, but there were no reports of the expandability of DESs for the very small target vessels with reference diameter <2.2xa0mm. We clarify the expandable performance of 2.5xa0mm-DESs for very small target vessels with reference diameter <2.2xa0mm in vitro and vivo study. We studied 3 pieces in each kind of DES (Sirolimus-eluting stent; SES, Paclitaxel-eluting stent; PES, Zotarolimus-eluting stent; ZES and Everolimus-eluting stent; EES) in vitro and vivo study of the porcine coronary artery with reference diameter <2.2xa0mm. By using the delivery balloon, each stent was initially dilated with 3.5xa0atm. And the pressure of 0.5xa0atm. was applied until it reached the maximum pressure of 12xa0atm. The minimum pressure of the full expanded stent balloon was estimated as the minimum expandable pressure. The stent-inner diameter and area on each pressure were measured by IVUS. The average minimum expandable pressure (atm.) in vitro/vivo was 4.7/4.5 in SES, 7.2/6.8 in PES, 4.3/4.5 in ZES and 3.8/3.8 in EES. The inner diameter (mm) in vitro/vivo at minimum expandable pressure was 1.81xa0±xa00.07/1.84xa0±xa00.05 in SES, 2.31xa0±xa00.10/2.13xa0±xa00.13 in PES, 2.41xa0±xa00.13/1.98xa0±xa00.31 in ZES and 2.13xa0±xa00.11/1.88xa0±xa00.22 in EES. The stent inner-diameter (mm) of DESs at 8xa0atm. in vivo was 2.16/2.21/2.45/2.25 in SES/PES/ZES/EES. All kinds of DES could be delivered to very small target vessels with reference diameter <2.2xa0mm at the minimum expandable pressure in vivo study, but the stent which presented adequate stent inner-diameter at 8xa0atm. was only SES. We have to implant the 2.5xa0mm-DESs for very small target vessels according to the data based on this expandability of DESs to bail out threatening occlusion due to coronary dissection or elastic recoil.

Endothelial damage and thromboembolic risk after pulmonary vein isolation using the latest ablation technologies: a comparison of the second-generation cryoballoon vs. contact force-sensing radiofrequency ablation

Experimental data suggest that cryoenergy is associated with less endothelial damage and thrombus formation than radiofrequency energy. This study aimed to compare the impact of pulmonary vein isolation (PVI) on the endothelial damage, myocardial damage, inflammatory response, and prothrombotic state between the two latest technologies, second-generation cryoballoon (CB2) and contact force-sensing radiofrequency catheter (CFRF) ablation. Eighty-six paroxysmal atrial fibrillation (AF) patients (55 men; 65u2009±u200912xa0years) underwent PVI with either the CB2 (nu2009=u200964) or CFRF (nu2009=u200922). Markers of the endothelial damage (l-arginine/asymmetric dimethylarginine [ADMA]), myocardial injury (creatine kinase-MB [CK-MB], troponin-T, and troponin-I), inflammatory response (high-sensitive C-reactive protein), and prothrombotic state (D-dimer, soluble fibrin monomer complex, and thrombin–antithrombin complex) were determined before and up to 24-h post-procedure. The total application time was shorter (1,460u2009±u2009287 vs. 2,395u2009±u2009571 [sec], pu2009<u20090.01) and total procedure time tended to be shorter (199u2009±u200937 vs. 218u2009±u200938 [min], pu2009=u20090.06) with CB2 than CFRF ablation. The amount of myocardial injury was greater (CK-MB: 45u2009±u200917 vs. 11u2009±u20093 [IU/l], pu2009<u20090.01) with CB2 than CFRF ablation. The l-arginine/ADMA ratio was lower (160u2009±u200951 vs. 194u2009±u200938, pu2009=u20090.028) after CB2 than CFRF ablation. Inflammatory and all prothrombotic markers were significantly elevated post-ablation; however, the magnitude was similar between the two groups. During a mean follow-up of 20u2009±u20096xa0months, the single-procedure AF freedom was similar between the CB2 and CFRF groups (60/64 vs. 20/22, pu2009=u20090.82). CB2-PVI produces significantly lesser endothelial damage with greater myocardial injury than CFRF-PVI; however, similar anticoagulant regimens are required during the peri-procedural periods in both technologies.

Initial and late efficacy of everolimus-eluting stents for small and non-small coronary lesions from evaluating delayed late loss study

The aim of the present study was to evaluate the long-term outcomes at 2xa0years in patients in whom everolimus-eluting stents (EESs) were implanted in small and non-small vessels. A small vessel is an important risk factor for restenosis with BMSs, even in the first generation DESs. The 690 patients with 690 lesions implanted with an EES were enrolled and divided into two groups by vessel reference diameter (RD): >2.5xa0mm for non-small vessels (Non-S-group) and ≤2.5xa0mm for small vessels (S-group). Two years later, the 365 patients with no restenosis at 8xa0months who underwent angiography were enrolled into the late catch-up study. At the initial 8-month follow-up, the rates of restenosis and target lesion revascularization (TLR) of both groups were not significantly different (restenosis 3.9 vs 6.5%, pxa0=xa00.17; TLR 3.9 vs 6.5%, pxa0=xa00.17). At the late 2-year follow-up, there were no significant differences in the late loss (0.36xa0±xa00.66 vs 0.34xa0±xa00.50xa0mm, pxa0=xa00.14), net gain (1.50xa0±xa00.75 vs 1.26xa0±xa00.60xa0mm, pxa0=xa00.39), late catch-up restenosis rate (5.1 vs 3.4%, pxa0=xa00.38), TLR (4.9 vs 2.7%, pxa0=xa00.40), and delayed late loss (0.14xa0±xa00.58 vs 0.15xa0±xa00.49xa0mm, pxa0=xa00.10) between both groups. There is no correlation between delayed late loss and RD in all patients(rxa0=xa0−0.009) and in AMI patients (rxa0=xa0−0.004). These results demonstrate that the initial and late catch-up restenosis rates of small coronary vessels with EES placement were excellent, the same as for non-small coronary vessels. We suggest that involvement of small coronary arteries may not be a risk factor for restenosis and results of stenting for small coronary arteries with EES placement were excellent.

ASSOCIATIONS OF BODY MASS INDEX, WASTING SYNDROME AND PROGNOSIS IN PATIENTS WITH CHRONIC HEART FAILURE

Chronic heart failure is one of a number of disorders associated with the development of a wasting syndrome. In patients with chronic heart failure (CHF), previous studies have reported reduced mortality rates in patients with increased body mass index (BMI). The potentially protective effect of

Effect of postprandial hyperglycaemia on coronary flow reserve in patients with impaired glucose tolerance and type 2 diabetes mellitus

Background: This study investigated whether postprandial hyperglycaemia has an adverse effect on coronary microvascular function and left ventricular diastolic function. Methods: In all, 28 patients with type 2 diabetes mellitus with no significant stenosis in left anterior descending artery were enrolled. In all subjects, plasma 1,5-anhydroglucitol was measured, and coronary flow reserve in the left anterior descending artery was evaluated using a Doppler wire. Membrane type-1 matrix metalloproteinase expression on circulating peripheral blood mononuclear cells was measured by flow cytometry. Correlation analyses were performed for coronary flow reserve and 1,5-anhydroglucitol, other coronary risk factors, membrane type-1 matrix metalloproteinase and E/e′. Results: Strong correlations were found only between 1,5-anhydroglucitol and coronary flow reserve and membrane type-1 matrix metalloproteinase. On multiple regression analysis, 1,5-anhydroglucitol remained an independent predictor of coronary flow reserve (βu2009=u20090.38, pu2009=u20090.048). Conclusion: Postprandial hyperglycaemia appears to have an adverse effect on coronary microvascular function, suggesting that improvement of postprandial hyperglycaemia may contribute to the improvement of coronary microvascular dysfunction.

IMPACT OF PATIENTS' CHARACTERISTICS, PROCEDURAL, ANGIOGRAPHIC, AND IVUS FINDINGS ON NEOATHEROSCLEROSIS AFTER STENT IMPLANTATION: INSIGHTS FROM OPTICAL COHERENCE TOMOGRAPHY STUDY

background: Recent studies have reported that the development of neoatherosclerosis (NA) inside the stents is associated with late complications such as very late stent thrombosis and late catch up. However, few data exist regarding clinical background of NA after stenting. Therefore, we evaluate the impact of patients’ characteristics, procedural, angiographic, and IVUS findings on development of stent-related NA which was detected by optical coherence tomography (OCT).

TCT-463 Impact of Late Catch-up Phenomenon on Delayed Restenosis After Sirolimus-Eluting Stent and Bare-Metal Stent Implantation

Background: There are limited data on whether delayed late catch-up exists in sirolimus-eluting stents (SES) and bare-metal stents (BMS). We sought to compare differences in time course of late loss (LL) between SES and BMS. Methods: Serial (8-months, 2-years, and over 3-years) angiographic examination was performed in 598 lesions treated with SES (n1⁄4353) or BMS (n1⁄4245). Lesions with 8months and 2-years instent-restenosis (>50% of angiographic diameter stenosis) were excluded. LL was categorized as early (between post-procedure and 8-months), delayed (between 8-months and 2-years), further delayed (between 2-years and over 3years) or overall (between post-procedure and over 3-years). Results: Whereas early LL was significantly smaller in SES than in BMS, delayed LL was significantly greater in SES than in BMS. On the other hand, further delayed LLwas comparable between the 2 stents. Consequently, overall LL was significantly smaller in SES than in BMS. Moreover, the incidence of over 3-year instent-restenosis was similar between the 2 stents (1.13 and 0.82% in SES and BMS, p1⁄40.70). In multivariate analysis, stent type predicted delayed LL but did not predict further delayed LL. Conclusions: SES lumen diameter progressively narrowed in delayed phase compared with BMS. However, the narrowing rate was similar among SES and BMS over 2 years. This evidence may raise the possibility that the impact of late catch-up phenomenon on SES restenosis over 2 years is minimal.