Intravascular ultrasound catheter entrapment after coronary artery stenting.

Intracoronary ultrasound (IVUS) facilitates optimal stent deployment in the treatment of coronary artery disease, which may favorably improve long-term outcome after stenting. Complications associated with IVUS include coronary vasospasm and rarely more serious adverse events such as vessel perforation or stent deformation. We report an IVUS catheter tip entrapment within a self-deploying nitinol stent.     

Intravascular ultrasound findings after excimer laser coronary angioplasty

Intravascular ultrasound (IVUS) was used to study 104 lesions in 98 patients after excimer laser coronary angioplasty (ELCA). Lesion site external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque + media (P + M = EEM − lumen) CSA and percentage of cross-sectional narrowing (CSN = P + M CSA/EEM CSA) were calculated; and the results were compared to a reference site. The lumen CSA (2.6 ± 1.0 mm²) averaged 24% larger than the cross-sectional area of the largest laser catheter used, and 64 lesions (62%) fit the definition of arterial expansion (lesion EEM CSA > reference site EEM CSA). The residual percentage of cross-sectional narrowing averaged 83.8 ± 8.8%. Dissections were present in 44% of lesions, and were more common in lesions with superficial calcium (59%) than in lesions with only deep calcium (31%) or no calcium (20%, P = 0.0102). Dissections of superficial calcified plaque had an unusual “shattered” or “fragmented” appearance. These findings suggest that excimer laser angioplasty causes forced vessel expansion with dissection, but limited atheroablation. © 1996 Wiley-Liss, Inc.     

Evaluation of intermediate coronary stenosis with intravascular ultrasound and fractional flow reserve: Its use and abuse

Clinical decision making in patients with intermediate coronary stenosis is still debated. Intravascular ultrasound (IVUS) examination and/or functional assessment of coronary stenosis by fractional flow reserve (FFR) are currently used to define the severity of such lesions. There are very few studies with a small sample size that have a head‐to‐head comparison between IVUS and FFR in the evaluation of angiographically de novo intermediate lesions. There are no randomized, controlled trials to demonstrate the superiority of IVUS versus FFR in providing improved clinical outcomes in comparison with angiography alone. However, the issue of superiority might be irrelevant, because IVUS and FFR could be complementary techniques to be used in the catheterization laboratory to provide critical anatomic and functional data that permit more accurate decisions in the management of the patient. © 2009 Wiley‐Liss, Inc.     

Use of intravascular ultrasound in evaluating repeated balloon rupture during coronary stenting

Balloon rupture during coronary angioplasty is a well-recognized complication of PTCA. Coronary angiography commonly fails to elicit the cause of balloon perforation. We present a case with multiple balloon rupture during additional high-pressure inflations of a Palmaz-Schatz stent where intravascular ultrasound was useful in revealing a calcified lesion protruding through the struts of the stent. Cathet Cardiovasc Diagn 40:52–54, 1997. © 1997 Wiley-Liss, Inc.     

Effects of atorvastatin on coronary flow reserve in patients with slow coronary flow

BACKGROUND: Statins improve endothelial functioning in patients with coronary artery disease and hypercholesterolemia, while substantially little is known about induced changes in myocardial microcirculation. However, although previous studies have suggested that microvascular abnormalities and endothelial dysfunction is responsible for slow coronary flow (SCF), there is no study investigating possible effects of statins on coronary microvascular function in patients with SCF. HYPOTHESIS: We prospectively investigated the effects of short-term lipid-lowering therapy with atorvastatin on coronary flow reserve (CFR) reflecting coronary microvascular function in patients with SCF assessed by transthoracic Doppler echocardiography (TTDE). METHODS: In an open clinical trial, CFR was studied in 20 subjects with SCF. TTDE was used to assess CFR at baseline as well as after 8 weeks of atorvastatin therapy. Coronary flow was quantified according to TIMI frame count (TFC). Coronary diastolic peak flow velocities were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocities. RESULTS: CFR was independently correlated with TFC. After 8 weeks of atorvastatin therapy, CFR values increased significantly (1.95 +/- 0.38 vs. 2.54 +/- 0.56, (p < 0.001). No change in hemodynamic parameters was noted during the entire study. The improvement in CFR was not correlated to the amount of lipid-lowering effect of atorvastatin. CONCLUSIONS: These findings suggest that short-term lipid-lowering therapy with atorvastatin improved CFR, which reflects coronary microvascular functioning in patients with SCF.     

Extramural vessel wall hematoma causing a reduced vessel diameter after coronary stenting: Diagnosis by intravascular ultrasound and treatment by stent implantation

An extramural vessel wall hematoma occured immediately after implanting a coronary stent in an in-stent-restenosis of the intermedius branch. Angiography showed a significant luminal reduction distal to the intervention site. Intravascular ultrasound revealed an extramural echolucent zone compressing the vessel lumen. Stent implantation compressed the hematoma and allowed adequate myocardial perfusion. This demonstrates the value of intravascular ultrasound (IVUS) in cases of unusual angiographic results which can help to manage complications after coronary intervention. Cathet. Cardiovasc. Diagn. 43:438–443, 1998. © 1998 Wiley-Liss, Inc.     

Comparison of myocardial fractional flow reserve and intravascular ultrasound for the assessment of slotted-tube stents.

Intravascular ultrasound (IVUS) and myocardial fractional flow reserve (FFR) have been reported to provide similar results for assessment of coil stent deployment. Their relative value in slotted-tube stents has not been investigated. Fourteen patients subjected to coronary angioplasty and IVUS-guided elective stenting with a slotted-tube stent underwent IVUS assessment and FFR measurement following stent implantation at inflation pressures of 12 and 18 atm. FFR values (mean +/- SD) preangioplasty, postangioplasty, and poststenting at 12 atm and 18 atm, were 0.58 +/- 0.07, 0.83 +/- 0.05, 0.94 +/- 0.02, and 0.94 +/- 0.02, respectively. After inflation at 12 atm, the area under the receiver operating characteristic (ROC) curve for the concordance of IVUS and FFR measurements was 0.89 (P = 0.02). Six patients had either an abnormal IVUS (n = 2) or FFR < 0.94 (n = 1) or both abnormal IVUS and FFR < 0.94 (n = 3) after the first inflation and had a second inflation at 18 atm. The area under the ROC curve for the concordance between IVUS and FFR final measurements was 0.855 (P = 0.10). Perfect concordance between IVUS and FFR was seen only for FFR values less than 0.91 or larger than 0.94. Overall, IVUS and FFR have substantial concordance with respect to slotted-tube stent deployment. However, FFR values between 0.91 and 0.94 after inflation are difficult to interpret.     

应用血管内超声指导冠状动脉临界病变介入治疗

目的 探讨应用血管内超声(IVUS)检查与定量冠状动脉造影(QCA)方法在冠状动脉临界病变介入治疗中的应用价值。方法 选择经冠状动脉造影(CAG)检查显示冠状动脉狭窄程度在40％～70％的临界病变患者60例,根据检查方法不同将患者分为QCA组和IVUS组,分别应用QCA和IVUS测量两组病变血管的参考管腔直径、最小管腔直径、直径狭窄率、管腔面积狭窄率及最小管腔面积并进行比较。比较观察两组患者住院期间、随访1月、6月和12月的主要不良心血管事件(再发心绞痛、心肌梗死、靶病变再次冠状动脉成形术、死亡)的发生情况。结果 IVUS组冠状动脉的管腔直径狭窄率[(57.80％±8.18％)比(51.73％±7.91％)]及面积狭窄率[(67.01％±10.41％)比(57.07％±10.71％)]均高于QCA组(P＜0.05),而最小管腔面积[(3.90±0.79) mm²比(4.14±0.60) mm²]则低于QCA组(P＜0.05)。住院期间两组患者均无主要不良心血管事件发生,但自随访第1月开始至12月随访结束,IVUS组的主要不良心血管事件发生率显著低于QCA组(7.7％比26.7％,P＜0.05)。结论 IVUS检查与QCA相比对冠状动脉临界病变检测出的狭窄率更显著,并能更有效地发现“不稳定性”病变并指导冠状动脉临界病变支架的植入,减低心血管事件发生,改善预后。     

瑞舒伐他汀对冠状动脉慢血流患者冠状动脉贮备功能和超敏C反应蛋白的影响

目的:探讨长期瑞舒伐他汀治疗对冠状动脉慢血流患者冠脉贮备功能(CFR)和超敏C反应蛋白(hsCRP)的影响。方法:选择冠状动脉造影正常但存在冠脉慢血流的患者48例,所有患者随机分为试药组和对照组,对照组(22例)予常规治疗,试药组(26例)在常规治疗基础上加用瑞舒伐他汀20 mg/d,治疗期为6个月。治疗前后测定两组患者的血脂,hsCRP,利用腺苷负荷超声记录左前降支远端血流频谱评评价CFR。结果:经过6个月瑞舒伐他汀的治疗后,试药组总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)较对照组明显下降,[TC:(3.2±0.9)mmol/Lvs.(5.4±1.2)mmol/L,P<0.05;LDL-C:(2.1±0.7)mmol/L vs.(3.4±0.8)mmol/L,P<0.05]。hsCRP较对照组明显下降[(2.1±1.4)mg/L vs.(3.7±2.1)mg/L,P<0.05]。试药组静息冠脉血流速度(bCFV)较对照组和治疗前显著下降[(21±6)cm/s vs.(26±5)cm/s和(21±6)cm/s vs.(25±7)cm/s,P<0.05],而最大冠状动脉扩张状态hCFV较对照组和治疗前增加[(71±9)cm/s vs.(56±8)cm/s和(71±9)cm/s vs.(56±10)cm/s,P<0.05],冠状动脉血流储备CFR较对照组和治疗前明显增加[(3.2±0.6)cm/s vs.(2.1±0.5)cm/s和(3.2±0.6)cm/s vs.(2.2±0.4)cm/s,P<0.05)]。结论:冠状动脉慢血流患者经过瑞舒伐他汀治疗可以有效改善冠脉贮备功能。     

Adiponectin produced in coronary circulation regulates coronary flow reserve in nondiabetic patients with angiographically normal coronary arteries

BACKGROUND: Epicardial adipose tissue expresses adiponectin protein, and its expression is significantly lower in patients with severe coronary artery disease (CAD) than in those without CAD. Transcoronary adiponectin levels are significantly decreased in nondiabetic but not in diabetic patients with CAD. Adiponectin is also an important adipocytokine that is linked to insulin resistance and reduces coronary microvascular function. HYPOTHESIS: Adiponectin may play a significant role in the localized coronary circulation. The present study examines the local dynamics of adiponectin in the coronary circulation in nondiabetic individuals with normal coronary arteries and the relationship between adiponectin and coronary microvasculature function. METHODS: We examined 22 consecutive nondiabetic patients whose coronary arteries were angiographically normal. Plasma levels of adiponectin were measured in blood samples that were simultaneously collected from the orifice of the left coronary artery (LCA) and the great cardiac vein (GCV). To evaluate the function of the coronary microcirculation, we measured coronary flow velocity at maximal hyperemia using a Doppler wire. Coronary flow reserve (CFR) was obtained from the ratio of hyperemia to the baseline coronary flow velocity. RESULTS: Plasma adiponectin levels in the GCV (median 6.95 microg/ml) were significantly higher than those in the LCA (median 6.60 microg/ml, p < 0.0005). The difference in plasma adiponectin levels between GCV and LCA significantly correlated with CFR (R = 0.451, p < 0.05). CONCLUSIONS: Adiponectin is locally produced in the coronary circulation. This protein may participate in modulating the coronary circulation of nondiabetic patients with angiographically normal coronary arteries.     

A warm footbath improves coronary flow reserve in patients with mild-to-moderate coronary artery disease

Backgrounds: Recent studies have shown that thermal therapy by means of warm waterbaths and sauna has beneficial effects in chronic heart failure. However, a comprehensive investigation of the hemodynamic effects of thermal vasodilation on coronary arteries has not been previously undertaken. In this study, we studied the effect of a warm footbath (WFB) on coronary arteries in patients with coronary artery disease (CAD), as well as any adverse effect. Methods: We studied 21 patients (33.3% men, mean age 60.8 ± 13.5 years) with CAD. Coronary flow Doppler examination of the left anterior descending coronary artery and coronary flow reserve (CFR) were performed and measured using adenosine before and after a WFB. Results: Systolic and diastolic blood pressure and heart rate did not change with the WFB. Mean velocity of diastolic coronary flow significantly increased (diastolic mean flow velocity: 18.3 ± 7.1 cm/sec initial, 21.5 ± 8.0 cm/sec follow‐up, P = 0.002) and CFR significantly improved (1.6 ± 0.4 vs. 2.2 ± 0.5, P < 0.001) after WFB. The WFB was well accepted and no relevant adverse effects were observed. The change of CFR after WFB correlated well with diastolic function (E’, r = 0.51, P = 0.031; E/E’, r =–0.675, P = 0.002). Conclusions: A WFB significantly improved CFR without any adverse effects in patients with mild‐to‐moderate CAD and can be applied with little risk of a coronary artery event if appropriately performed. (Echocardiography 2011;28:1119‐1124)     

阿托伐他汀对冠状动脉血流缓慢患者冠状动脉血流储备的影响

目的 探讨冠状动脉血流缓慢患者冠状动脉血流储备(CFR)的改变以及阿托伐他汀对这类患者CFR的影响.方法 入选有胸痛症状但冠状动脉造影结构正常的冠状动脉血流缓慢患者91例,分为治疗组(51例)和无治疗组(40例).治疗组给予阿托伐他汀20 mg治疗8周.另选26例冠状动脉造影正常且运动试验阴性的无心脏疾患者为正常对照组.治疗前后测定治疗组和无治疗组的血脂以及利用腺苷负荷超声记录左前降支远端血流频谱,并评价CFR.结果 (1)冠状动脉血流缓慢者接受阿托伐他汀8周治疗后总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)较无治疗组及正常对照组明显减低[TC:(3.83±0.80)mmol/L比(5.30±1.18)mmol/L和(5.32±1.17)mmol/L,均P＜0.05:LDL=C:(2.26±0.64)mmol/L比(3.28±0.85)mmol/L和(3.30±0.82)mmol/L,均P＜0.05].(2)给予阿托伐他汀前,治疗组与无治疗组CFR(分别为2.32±0.30和2.25±0.33)均低于正常对照组(3.15±0.34,P＜0.05);8周后,治疗组冠状动脉血流速度(CFV)[(26.06±3.22)cm/s]较无治疗组[(29.02±3.36)cm/s]及治疗前静息状态[(28.43±3.40)cm/s]低(均P＜0.05),最大冠状动脉扩张状态CFV高于无治疗组和对照组[分别为(77.63±8.96)、(65.17±7.22)和(64.58±6.26)cm/s,P＜0.05],CFR低于治疗前和无治疗组(分别为3.07±0.29、2.28±0.35和2.32±0.30,P＜0.05),且与正常对照组差异均无统计学意义.结论 冠状动脉血流缓慢患者CFR明显减低,短期阿托伐他汀在调脂的同时可以有效改善其CFR.     

Assessment of regional coronary flow reserve by digital angiography in patients with coronary artery disease

Summary Digital angiography provides a convenient means to quantify the progression of a contrast medium bolus injected into a coronary artery throughout the myocardium, which in turn yields information on myocardial perfusion. Sixteen patients presenting a single critical proximal stenosis (estimated diameter reduction >80%) on either the left anterior descending coronary artery (LAD) or the left circumflex coronary artery (LCX) were studied. First, 12 consecutive end-diastolic images of an ECG-triggered intracoronary injection of 4 ml of iopamidol were acquired on 60° left anterior oblique projection under basal conditions. This was repeated 30 s after intracoronary injection of 12 mg of papaverine. For each image sequence, a densogram was computed in each pixel by fitting a curve through its 12 consecutive intensity values. The time of maximal pixel opacification (T_MAX) and the mean ascending time (T_MAT), expressed in cardiac cycles, were determined from each curve. Two myocardial regions of interest (ROI) were defined for each patient, one in the perfusion bed of the LAD, the other in the bed of the LCX. The mean values of T_MAX and T_MAT in each ROI were computed, at rest and during hyperemia. At rest, the mean values of T_MAX and T_MAT obtained from the ROI associated to the stenosis artery were not significantly different from the values obtained in the ROI associated with the intact artery. During hyperemia, a significant decrease of the mean T_MAX and T_MAT was observed in the normally perfused regions (p<0.001). The rest to hyperemia ratios of both T_MAX and T_MAT mean values were considered to be indices of coronary flow reserve. Due to the decrease of T_MAX and T_MAT during hyperemia, the two indices were significantly higher in the normal ROI than in the ischemic ROI (p<0.001).In conclusion: Intracoronary injection of papaverine produces an acceleration of blood flow in normally perfused myocardium despite the increase of vascular volume. This acceleration is absent in regions supplied by a severely stenosed coronary artery. Thus, a differentiation between normally and abnormally perfused myocardial regions is possible by use of indices of coronary flow reserve derived from time parameters of the myocardial circulation.Supported by a grant of the Swiss National Science Foundation.     

Two years experience of a simple technique of precise ostial coronary stenting

Objective: To evaluate a new technique of precise ostial coronary stenting without relying solely on angiography. Background: Precise stent positioning at ostial coronary stenosis is difficult because angiography may not be able to profile the coronary ostium, due to vessel overlap and/or foreshortening. This problem is compounded by bobbing or to and fro movement of the stent with cardiac contraction. Methods: A new technique of precise ostial stenting not dependant on angiography was utilized. A guidewire in a side branch was threaded through the most proximal stent cell and the stent was advanced into the target vessel until it was stopped at the carina. The stent was deployed and the side guidewire withdrawn. All results were documented by intravascular ultrasound (IVUS). Results: From October 2005 to October 2007, 58 patients with significant ostial coronary stenosis required stenting. Seventeen patients were treated in the conventional manner and the remaining 41 patients with the new technique. The ostial locations included 8 left main, 25 left anterior descending, 3 circumflex, 1 obtuse marginal, 3 right coronary, and 1 posterior descending artery. Success, as confirmed by IVUS, was achieved in 40 patients (97.6%). Failure occurred in a right coronary ostial stenosis, which was subsequently treated by the conventional method. There were no complications. Conclusion: This new technique is highly successful in cases of difficulty in stenting ostial stenosis guided solely by conventional angiography. © 2008 Wiley‐Liss, Inc.