Measurement of transstenotic pressure gradient during percutaneous transluminal coronary angioplasty

Obstruction to blood flow is accompanied by a pressure gradient across the obstructed site. In certain clinical settings, magnitude of pressure gradient has been used to judge severity of obstruction, and gradient reduction to judge success of an interventional procedure. In percutaneous transluminal coronary angioplasty (PTCA) the relationships between transstenotic pressure gradient, diameter stenosis, and lesion length are imprecisely known. We therefore examined 4263 sets of measurements in patients who underwent PTCA on single, discrete coronary arterial lesions. Multivariate regression analysis demonstrated that pressure gradient was artifactually elevated by about 12 mm Hg at low values of diameter stenosis but increased by the 4th power of stenosis as expected from fluid dynamics models. Pressure gradient was dampened and relatively constant at values of diameter stenosis of 60% or higher, probably because of total or near-total occlusion of the artery. Lesion length was not found to influence pressure gradient. Reductions in diameter stenosis (delta D) and pressure gradient (delta G) were related nonlinearly, with delta D proportional to the square root of delta G, suggesting that a reduction in gradient is directly proportional to an increase in cross-sectional area of the stenosis. The predictive value of final post-PTCA pressure gradients was found: a final gradient of 15 mm Hg or less predicted a final post-PTCA diameter stenosis of 30% or less, with 75% sensitivity and 29% specificity (p less than .01). The results of this study suggest that (1) pressure gradient as currently measured during PTCA is related to diameter stenosis but not to lesion length (2) reductions in pressure gradient and diameter stenosis are nonlinearly related.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of coronary artery stenosis during PTCA by measurement of the trans-stenotic pressure gradient: Comparison with quantitative coronary angiography

A fibreoptic pressure sensor mounted on an 0 018 inch guidewire(Pressure Guide®, RadiMedical Systems, Uppsala, Sweden)was used to measure the trans-stenotic pressure gradient in20 patients admitted for percutaneous transluminal coronaryangioplasty (PTCA) of a single, discrete stenosis. Pressuremeasurements were made both at rest and during maximal vasodilatationinduced by intracoronary injection of papaverine. From the ratioof distal coronary pressure divided by the proximal pressure,the relative coronary flow reserve was calculated. The aim ofthe study was to compare the different pressure-derived parametersby correlating them to stenosis geometry estimated by quantitativecoronary angiography. There was a moderate correlation betweenbaseline pressure gradient and percent area stenosi r= 0.64,P<0.001 and minimal cross-sectional area; r= 0.45, P<0005.A higher correlation was found between hyperaemic pressure gradientand area stenosis (r= 080, P<0001) and minimal cross-sectionalareas, respectively (r= 0.55, P<0 005). The best correlationwas found between relative coronary flow reserve and area stenosis(r= 0.86, P<0.001) and minimal cross-sectional area (r= 0.70,P<0001). In conclusion, pressure measurement using a pressure guidewireis useful as a complement to angiography in evaluation of coronarystenoses during PTCA. Pressures should be measured during maximalvasodilatation. Relative coronary flow reserve calculated fromthe pressure measurements provides additional information aboutthe fraction of normal maximal flow possible in the presenceof a stenosis.     

Coronary artery perforation during coronary angioplasty

In one patient percutaneous transluminal coronary angioplasty was complicated by coronary artery perforation of the left anterior descending coronary artery with light pericardial effusion. The outcome was favorable without either pericardiocentesis or emergency surgery.     

Is short-stay coronary angioplasty safe?

Percutaneous transluminal coronary angioplasty (PTCA) is usually performed as an inpatient procedure and the patients are monitored for several days afterward. Over a 13-month period, in 91 of 373 PTCA procedures, the clinical condition of the patient did not necessitate inpatient status before PTCA. PTCA was done the day of admission and discharge planned the following. Overall hospital stay was planned as less than 24 hours. PTCA was done in one vessel in 62 patients, two vessels in 24, three vessels in 3, and four vessels in 2 patients. PTCA was initially successful (less than 50% residual stenosis) in 85 patients (93%). In one of these, acute occlusion occurred the next morning and urgent bypass surgery was done. PTCA failed in 6 patients who left the catheterization laboratory with unchanged coronary anatomy. Bypass surgery was performed that day in 2 patients, on another admission in 1 patient, and medical therapy continued in the other 3 patients. Of the 88 patients not receiving same admission bypass surgery, 84 (95%) were discharged in less than 24 h. Hospitalization was prolonged (1-5 days) in 4 patients. This was because of nonobstructive dissection treated with heparin for approximately 24 h in 2 patients; a catheterization site hematoma in 1 patient, and post-PTCA noncardiac chest pain in another. No patient had inhospital myocardial infarction or death. The only late complication was in a patient treated with heparin and monitored for 2 days; 3 weeks later angina returned and he died suddenly. These data suggest PTCA can safely be done in selected patients with both single and multivessel disease in a short stay inhospital setting.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary angioplasty of anomalous right coronary arteries

We report 2 cases of successful angioplasty of anomalous right coronary arteries originating above the sinotubular line at the junction of the right and left sinus of Valsalva. The use of Amplatz left guiding catheters provided optimal support for performing angioplasty. © 1993 Wiley-Liss, Inc.     

Coronary artery vasomotion after percutaneous transluminal coronary angioplasty

Substantial evidence of postangioplasty vasoconstriction is available, both at the dilated site and distal to balloon injury, demonstrating its frequent occurrence. It is likely that even mild or moderate vasoconstriction at the site of balloon injury may create flow turbulence, promoting platelet aggregation and contributing to thrombotic vessel closure. The regulation of arterial smooth muscle tone is a complex process and should be distinguished from elastic recoil, which occurs at the site of balloon injury due to passive elastic properties of the artery, generally immediately after balloon deflation. The contribution of a variety of messengers generated by humoral, neurogenic, myogenic, and endothelium-derived factors in this regulatory process has been implicated. The possible mechanisms of post-percutaneous transluminal coronary angioplasty vasoconstriction at the dilated site (local) and in segments of coronary artery beyond the dilated site (distal) are reviewed in this article.     

Acute closure during coronary excimer laser angioplasty and conventional balloon dilatation: a comparison of management outcome and prediction

Of 523 consecutive patients undergoing elective percutaneoustransluminal coronary angioplasty (PTCA) and 83 patients treatedwith coronary excimer laser angioplasty (ELCA), 17 (3.3%) hadin-laboratory occlusion following PTCA and 25 (30%)followingELCA; they were enrolled into a prospective study. Successfulmanagement (reopened vessel, patency at repeat angiography within24 h, no death, no myocardial infarction (MI), no emergencybypass surgery) including repeat lasing, subsequent PTCA, useof intracoronary nitroglycerin or streptokinase was achievedin 24 (96%) of the 25 patients with acute occlusion during ELCA.An anterior MI occurred in one patient of the laser group. Repeatballoon dilatation was successfully performed in seven of the17 patients (41%) with acute closure during PTCA. Among the10 patients with persistent occlusion after PTCA, five developeda limited myocardial infarction (35%). One patient requiredemergency CABG, and died peri-operatively. Severe spasm priorto occlusion defined by a new coronary flow depression withoutevidence of dissection or thrombus showed a significant positiveassociation with acute occlusion during ELCA (P =0.0008). Thus, in contrast to occlusion during PTCA, subsequent balloondilatation was successfully performed in the majority of patientswith acute occlusion during ELCA, implying that different underlyingmechanisms are responsible for this complication. In this limitedpatient group, occlusion after excimer laser angioplasty wasmuch more frequent than closure during PTCA, but was infrequentlyassociated with major events such as myocardial infarction ordeath.     

Comparison of angioplasty and bypass surgery in multivessel coronary artery disease

The role of coronary angioplasty in the treatment of patient with multivessel coronary artery disease has not been fully established. We compared immediate and 1-year follow-up results in 60 patients undergoing coronary angioplasty for multivessel coronary disease in 1982 with 41 patients anatomically suitable for angioplasty but who underwent elective coronary bypass surgery during the same time period. Baseline variables were similar in both groups except for number of vessels diseased which was higher in the surgical group. Angioplasty was initially successful in 70% of cases. There were no deaths. Mean initial hospital days were lower in the angioplasty group. At follow-up there were no significant differences in survival, functional class, occurrence of subsequent myocardial infarction or use of cardiac medications. However, 33% of the successfully dilated patients required either repeat dilatation or subsequent bypass surgery because of restenosis or inadequate initial revascularization. The statistical power of the study was limited due to the small sample sizes. While demonstrating that angioplasty can be successfully performed in patients with multivessel disease, definitive conclusions about the comparability of the two treatments are hampered by possible selection bias and small patient numbers. This issue could be better addressed by a multicenter prospective randomized trial.     

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.     

Recurrence of coronary artery spasm after successful percutaneous transluminal coronary angioplasty

A 47-year-old man presented with angina, and coronary angiograms showed a significant organic stenosis with spasm in the left anterior descending coronary artery. Percutaneous transluminal coronary angioplasty was successfully performed for the organic lesion in the left anterior descending coronary artery. Symptom of angina due to coronary artery spasm recurred, even without restenosis at the site of successful angioplasty.     

Successful excimer laser angioplasty following unsuccessful primary balloon angioplasty

We report five patients where excimer laser coronary angioplasty facilitated successful balloon dilatation of heavily calcified lesions that could not be dilated by conventional angioplasty techniques alone. In each case, the lesion was crossed successfully with a guide wire. Conventional angioplasty failed because of inability to cross the lesion with a balloon (four lesions) or inability to dilate the lesion with balloon inflation (two lesions). These cases illustrate an indication for excimer laser coronary angioplasty as an adjunctive procedure in heavily calcified coronary stenoses. © 1993 Wiley-Liss, Inc.     

冠状动脉旋磨术及经皮冠状动脉成形术在复杂病变介入治疗中的应用

目的　探讨冠状动脉旋磨术 (Rotational atherectomy)及经皮腔内冠状动脉成形术 (Percutaneous translum i-nal coronary angioplasty PTCA)治疗复杂冠脉病变的临床效果。方法　对 15例患者的 2 0处病变行冠脉旋磨术及经皮腔内冠状动脉成形术 (PTCA)治疗 ,部分病例并在血管内超声指导下进行 ,观察其治疗的即刻成功率及并发症率。结果　 15例施行冠状动脉旋磨术的患者 ,旋磨头均成功地通过了病变 ,平均狭窄程度由 88.30 %± 7.5 4 %降至15 .6 0 %± 10 .75 %。其中 6 0 .0 0 %的病例选择了 1.5 mm的旋磨头 ,13.33%的病例使用了 2个旋磨头。全部病例均联合应用了 PTCA,13例在行旋磨术后置入冠脉内支架 (余下 2例为支架内再狭窄病例 )。 1例患者术中发生较严重的冠状动脉痉挛 ,经冠状动脉内给予硝酸甘油后缓解 ;2处 (10 .0 0 % )病变出现了 B型以上的内膜撕裂 ,出现缓慢血流现象发生率为 3.8%。无急诊冠状动脉搭桥及死亡病例。结论　冠状动脉旋磨术及 PTCA可选择性用于复杂冠状动脉病变 ,尤其是严重钙化病变 ,小血管长节段病变     

Erroneous pressure measurement due to artificially deformed vessel during angioplasty

Percutaneous transluminal angioplasty is a commonly performed procedure. The clinical success of such a procedure is determined by the combination of the post-procedure angiographic appearance and the pressure gradient across the lesion. This case demonstrates the importance of recognizing the anatomical variation if proper pressure measurements are to be obtained. Cathet. Cardiovasc. Diagn. 40:281–282, 1997. © 1997 Wiley-Liss, Inc.     

Coronary artery rupture during transluminal coronary recanalization and angioplasty in a case of acute myocardial infarction and shock

Percutaneous transluminal coronary angioplasty (PTCA) is a widely performed and effective therapy for coronary artery disease. Evolution of the dilatation instruments during the last decade has led to an increased success rate of PTCA and to the development of newer techniques such as recanalization of totally occluded coronary arteries. We report a case of coronary artery recanalization complicated by fatal coronary artery rupture.     

Double loop guiding catheter: A primary catheter for angioplasty of the right coronary artery

Double loop guiding catheters have been used for percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery (RCA) in 42 consecutive cases. A catheter with a 90- degree primary curve was used when the proximal RCA had horizontal or inferior orientation. When the proximal segment of the RCA was oriented superiorly (shepherd's crook), the catheter with a 75-degree primary curve was used. Catheters were fabricated with short (1.5 cm) or long (2.3 cm) (USCI, C.R. Bard, Inc., Billerica, MA) distal tips. Short-tip catheters were satisfactory in the majority of cases. When the RCA had a complex course and more backup was necessary or when the ascending aorta was wide, long-tip catheters were found to be the best choice. Angioplasty of 49 lesions was attempted in 42 consecutive patients. In 39 patients successful dilatation was achieved (93%). In three patients the procedure was unsuccessful. In one patient, the lesion could not be crossed with the guidewire despite an excellent backup. In another patient, two of three stenoses were dilated successfully; the distal lesion was crossed with a guidewire but could not be crossed with the balloon catheter in spite of a good backup. The lack of a satisfactory engagement and inadequate backup were responsible for the failure in only one patient. There were no complications related to these guiding catheters. We conclude that double loop guiding catheters are safe and can be the primary choice in all right coronary angioplasties. These catheters provide an excellent backup with consequent high success rate.     

Use of coronary angioplasty, bypass surgery, and conservative therapy for treatment of coronary artery disease over the past decade

Aims There is a continuous increase in the number of percutaneoustransluminal coronary angioplasty pro-cedures performed peryear per population in most industrialised countries. This analysissearches for trends in treatment decisions after diagnosticcoronary angiography. Methods and Result The degree of coronary artery disease and the therapeutic strategywere determined retro-spectively in consecutive patients undergoingcoronary angiography at a Swiss university hospital during threedifferent time periods in the past 11 years (n=750 in 1994,n=500 in 1990, and n=545 in 1983). The indication for coronaryangioplasty rose from 45% in 1983 to 78% in 1990 and 87% in1994 in patients with one-vessel disease, from 25% to 38% and71% in patients with two-vessel disease, and from 10% to 24%and 29% in patients with three-vessel disease. In contrast,the use of conservative therapy declined with time, independentof the severity of coronary artery disease. Indications forcoronary artery bypass grafting decreased in patients with two-vesseldisease, but did not change in patients with three-vessel diseaseover the 11-year period. Conclusions The use of coronary angioplasty, bypass surgery, and conservativetherapy changed drastically over the past decade, with an increasinguse of angioplasty and a decreasing use of conservative therapyin one-vessel and multivessel disease, and of bypass surgeryin two-vessel disease. The expansion of coronary angioplastyis mainly related to increased use in patients previously treatedconservatively.     

Contained rupture following percutaneous transluminal coronary angioplasty: Long-term outcome

Coronary artery aneurysm formation can occur as a complication of balloon angioplasty. We present a case of a contained rupture of the left circumflex artery following angioplasty which resulted in an unusual pseudoaneurysm on angiography at 3-year follow-up. © 1993 Wiley-Liss, Inc.     

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty (PTCA)—with an autoperfusion balloon or active system—facilitates prolonged balloon inflation. Prolonged inflations may tack up intimal dissections and improve the primary angioplasty result in complex lesions. Additionally, distal perfusion may reduce the likelihood of cardiogenic shock during high-risk PTCA. Autoperfusion balloons are most frequently used to treat acute or threatened closure. There currently is no prospective clinical study showing that stent implantation for this complication is more successful and more cost-effective. The blood flow rates through autoperfusion balloons may not abolish myocardial ischemia, and higher flow rates can often be achieved with pumps. Therefore, during high-risk PTCA, pumps may be preferred to prevent hemodynamic collapse. Clinical application of perfusion pumps is hampered by the risk for mechanical hemolysis during prolonged perfusion and the high velocity of the bloodstream that exits the PTCA catheter, causing distal vessel wall trauma. © 1996 Wiley-Liss, Inc.     

冠心病患者经皮穿刺冠状动脉内血管成型术前后的心脏功能评价

通过运动负荷试验评价PTCA术的即刻效果,为患者进一步康复提供参考.方法:所有患者行常规PTCA术,达到完全或基本完全血管重建,患者于PTCA术前及术后1周分别进行亚极量自行车运动试验.结果:34例患者成功的进行了PTCA术并分别于手术前后进行了运动试验,PTCA术后患者运动中最大心率(HRmax)非常明显提高(P<0.0001),运动最大负荷明显增加(P<0.0001).运动所诱发的病变冠状动脉相应导联心电图ST段压低明显改善(P<0.002).运动中每分钟通气量(VE)、二氧化碳的产生(VCO_2)明显增加(P均<0.002).运动中最大氧耗量(VO_2max)明显提高(P<0.02).结论:PTCA成功后可使患者运动时VO_2max、HRmax、VE、VCO_2明显提高,运动诱发的心肌缺血明显改善,运动耐量明显增加,从而提高患者的生活质量.     

经桡动脉行复杂冠状动脉病变的介入治疗

目的探讨经桡动脉行复杂冠状动脉病变介入治疗的可行性。方法将178例左主干开口病变、分叉病变、慢性闭塞病变、长度≥30mm的长病变、纡曲成角病变及严重钙化病变等复杂冠状动脉病变患者经桡动脉途径进行PCI。结果经桡动脉PCI完成率97.2%。因导引导管支撑力不够,采用双导丝技术18例,采用子母导管技术5例,微导管技术6例,锚技术3例。左主干开口病变8处即刻全部成功。左主干分叉病变双支架置入17例,单支架置入9例。其他分叉病变67处,单支架置入47处,双支架置入20处。双支架置入后对吻球囊扩张成功率100%。34处慢性闭塞病变PCI成功27处。长度≥30mm的长病变91处、纡曲成角病变23处、严重钙化病变27处全部PCI成功。术中支架内血栓2例,住院期间亚急性血栓形成2例。死亡1例。穿刺处并发症:桡动脉闭塞8例,前臂肿胀4例,无血肿及神经损伤。结论经桡动脉途径进行冠状动脉复杂病变的PCI有较高的成功率。