Coronary stenting for acute coronary dissection after coronary angioplasty: implications of residual dissection

Spontaneous coronary artery dissection: new insights into diagnosis and treatment

Spontaneous coronary artery dissection (SCAD) remains an infrequent, elusive, and challenging clinical entity of unknown etiology eight decades after its initial description. Our understanding of the pathophysiology of SCAD, initially limited to information from early pathological studies, case reports, and very short series, has been enriched recently by relatively large contemporary series of patients studied prospectively. The typical presentation involves a young woman without coronary risk factors suffering an acute coronary syndrome but, actually, most patients are middle-aged and have coronary risk factors. A high number of conditions have been related to SCAD, but fibromuscular dysplasia has shown a major intriguing association with potential pathophysiological implications. SCAD may present (a) with an intimal tear and the classic angiographic 'flap' leading to the appearance of two lumens (true and false), or (b) without an intimal rupture, as an intramural hematoma. An increased clinical awareness together with new diagnostic tools have led to a major surge in the diagnosis of SCAD. High-resolution intracoronary techniques provide unique diagnostic insights into the underlying pathophysiology and facilitate identification of the disease in patients misdiagnosed previously. After the initial acute ischemic insult, most patients stabilize and have a benign clinical course and eventually experience spontaneous healing of the vessel wall during follow-up. However, recurrences may still occur in up to 10-20% of cases. Accordingly, a conservative medical management (watchful waiting strategy) has been recommended as the initial approach. Revascularization remains particularly challenging and may be associated with suboptimal results, acute complications, and poor long-term outcome. Nevertheless, in patients with ongoing or refractory ischemia and adequate anatomy, revascularization should be attempted. Some novel and attractive coronary interventions have been proposed in this uniquely challenging anatomic scenario. This review aims to present a comprehensive and contemporary update on this elusive and intriguing clinical entity.

Spontaneous Coronary Artery Dissection/Intramural Haematoma in Young Women with ST-Elevation Myocardial Infarction: "It Is Not Always a Plaque Rupture Event"

Spontaneous coronary artery dissection (SCAD) is an unusual, but increasingly recognized, cause of ST-elevation myocardial infarction (STEMI), especially among younger patients without conventional risk factors for coronary artery disease (CAD). Although dissection of the coronary intima or media is a hallmark finding, hematoma formation within the vessel wall is often present. It remains unclear whether dissection or hematoma is the primary event, but both may cause luminal stenosis and occlusion. The diagnosis of SCAD is made principally with invasive coronary angiography, although adjunctive intracoronary imaging modalities may increase the diagnostic yield. In STEMI patients, the decision whether to pursue primary percutaneous coronary intervention (PCI) or appropriate conservative medical therapy is based on clinical presentation, the extent of the dissection, the critical anatomy involvement, and the amount of ischaemic myocardium at risk. In this case report, we present two cases of young women with SCAD and STEMI, successfully treated with primary PCI. We briefly illustrate the characteristic aspects of the angiographic presentation and intravascular ultrasound-guided treatment. SCAD should always be considered in young STEMI patients without conventional risk factors for CAD with primary angioplasty to be required in patients with ongoing myocardial ischemia.

Diagnosis of Dissection of the Coronary Artery Dissection by Multidetector Computed Tomography: A Comparative Study With Coronary Angiology

OBJECTIVES

This study was to assess the diagnostic performance of multidetector computed tomography (MDCT) angiographic protocol for dissection of the coronary artery (DCA) detection compared with coronary angiology (CAG).

METHODS

Intravascular ultrasound was used as the gold standard for DCA diagnosis. Thirty-six DCA patients and 34 non-DCA (control) participants were retrospectively reviewed. The CAG and MDCT angiography images were separately reviewed by 4 independent observers, and a 5-point grading scale was used for DCA diagnosis. Diagnostic performance was compared using receiver operating characteristic analysis. Sensitivity, specificity, and negative predictive values were calculated.

RESULTS

The MDCT performed significantly better than that of CAG (AZ = 0.9943 ± 0.0034 vs AZ = 0.8411 ± 0.0274, respectively) for DCA detection. The sensitivity (98.6%), specificity (89.7%), and negative predictive value (98.4%) of MDCT for DCA were higher than those of CAG (77.8%, 79.4%, and 77.1%, respectively).

CONCLUSIONS

Multidetector computed tomography angiography was a more sensitive and specific technique for the diagnosis of DCA compared with CAG.

Spontaneous coronary artery dissection: long-term follow-up of a large series of patients prospectively managed with a "conservative" therapeutic strategy

OBJECTIVES

This study sought to assess the long-term clinical outcome of patients with spontaneous coronary artery dissection (SCD) managed with a conservative strategy.

BACKGROUND

SCD is a rare, but challenging, clinical entity.

METHODS

A prospective protocol, including a conservative management strategy, was followed. Revascularization was only considered in cases with ongoing/recurrent ischemia. Inflammatory/immunologic markers were systematically obtained.

RESULTS

Forty-five consecutive patients (incidence 0.27%) were studied during a 6-year period. Of these, 27 patients (60%) had "isolated" SCD (I-SCD), and 18 had SCD associated with coronary artery disease (A-SCD). Age was 53 ± 11 years, and 26 patients were female. Most patients presented with an acute myocardial infarction. SCD had a diffuse angiographic pattern (length: 31 ± 23 mm). In 11 patients, the diagnosis was confirmed by intracoronary imaging techniques. Sixteen patients (35%) required revascularization during initial admission. One patient died after surgery, but no additional patient experienced recurrent myocardial infarction. No significant inflammatory/immunologic abnormalities were detected. At follow-up (median 730 days), only 3 patients presented with adverse events (1 died of congestive heart failure, and 2 required revascularization). No patient experienced a myocardial infarction or died suddenly. Event-free survival was similar (94% and 88%, respectively) in patients with I-SCD and A-SCD. Notably, at angiographic follow-up, spontaneous "disappearance" of the SCD image was found in 7 of 13 (54%) patients.

CONCLUSIONS

In this large prospective series of consecutive patients with SCD, a "conservative" therapeutic strategy provided excellent long-term prognosis. Clinical outcome was similar in patients with I-SCD and A-SCD. The natural history of SCD includes spontaneous healing with complete resolution.

Diagnosis of spontaneous coronary artery dissection by optical coherence tomography

OBJECTIVES

This study sought to assess the diagnostic value of optical coherence tomography (OCT) in patients with suspected spontaneous coronary artery dissection (SCAD).

BACKGROUND

SCAD is a rare but challenging clinical entity.

METHODS

Following a prospective protocol, OCT was performed in 17 consecutive patients with a clinical and angiographic suspicion of SCD from a total of 5,002 patients undergoing coronary angiography. A conservative management strategy was followed.

RESULTS

OCT ruled out the diagnosis of SCAD in 6 patients with coronary artery disease (atherosclerotic plaques and/or intracoronary thrombus). In 11 patients (age 48 ± 9 years, 9 female), OCT confirmed the presence of SCAD. A double-lumen or intramural hematoma image was visualized in all cases. However, only 3 patients presented an intimal "flap" on angiography. OCT readily identified the intimal rupture site (n = 7), the thickness (348 ± 84 μm) and length (31 ± 9 mm) of the intimomedial membrane, the area of the true (1.1 ± 0.5 mm(2)) and false lumen (5.9 ± 2.1 mm(2)), the associated intramural hematoma (n = 9), and thrombi in the true or false lumens (n = 11). Most of these findings were angiographically silent. After stenting (n = 4), OCT disclosed adequate stent coverage, expansion, and apposition, but also residual intramural hematoma at the stented site (abluminal) and at the distal vessel.

CONCLUSIONS

OCT provides unique insights in patients with SCAD that allow an early diagnosis and adequate management. Most of these findings are undetectable by angiography.

Impact of female gender and transradial coronary stenting with maximal antiplatelet therapy on bleeding and ischemic outcomes

BACKGROUND

Female gender has been associated with poorer outcomes after percutaneous coronary intervention (PCI) and femoral approach. However, no data are available on the impact of gender and transradial PCI with maximal antiplatelet therapy on bleeding and ischemic outcomes.

METHODS

In the EArly discharge after Stenting of coronarY arteries (EASY) trial, 1,348 patients with acute coronary syndrome underwent transradial PCI. All patients were pretreated with aspirin and clopidogrel. After sheath insertion, 70 U/kg heparin was administered and a bolus of abciximab was given before first balloon inflation. Major adverse cardiac events including death, myocardial infarction, and target vessel revascularization; major bleeding; and local hematomas were evaluated at 30 days, 6 months, and 12 months.

RESULTS

Women (n = 298, 22%) were older, had more hypertension, more family history, and less previous PCI than men. Weight, baseline hemoglobin, and creatinine clearance were significantly lower in women. The number of dilated sites, complex lesions, and procedure duration was similar, but 5F sheath size was more frequent in women. Major adverse cardiac events remained similar at 30 days (3.4% vs 3.9%, P = .86), at 6 months (11.5% vs 7.8%, P = .06), and at 1 year (14.1% vs 12.6%) in both groups. There was no significant difference in the incidence of major bleeding between the 2 groups, but female gender was the only independent predictor of hematomas (odds ratio 4.40, 95% confidence interval 2.49-7.81, P < .0001).

CONCLUSION

Despite more comorbidities, female gender was not a predictor of adverse clinical outcomes after transradial PCI with maximal antiplatelet therapy. Still, female gender remained associated with a higher risk of local hematomas. Efforts should continue to identify modifiable factors to reduce procedural bleeding in women, regardless of the access site.

Drug-eluting stents for the treatment of bifurcation lesions: a randomized comparison between paclitaxel and sirolimus stents

BACKGROUND

Drug-eluting stents have been shown to reduce restenosis in many types of lesions. The purpose of this article is to assess the efficacy of sirolimus- and paclitaxel-eluting stents in patients with bifurcation lesions.

METHODS

Between June 2003 and October 2004, 205 patients were enrolled in a prospective randomized trial; 103 patients were assigned to sirolimus stents and 102 patients to paclitaxel stents. All patients were treated by provisional T-stenting.

RESULTS

There were no differences between groups in terms of age, risk factors, clinical condition, location of the bifurcation lesion, or other technical factors. Angiographic data and immediate results were also similar in both groups. Three patients developed inhospital non-Q-wave acute myocardial infarction (2 from the sirolimus group and 1 from the paclitaxel group). Follow-up angiography was obtained in 109 patients (53%). In the sirolimus group, 5 patients developed restenosis (9%): 1 at the main vessel, 2 at the side branch, and 2 in both branches. In contrast, 16 patients from the paclitaxel group had restenosis (29%): 6 at the main vessel, 5 at the side branch, and 5 in both branches. Target lesion revascularization at 24 +/- 5 months post stenting occurred in 4 patients from the sirolimus group (4%) and in 13 from the paclitaxel group (13%) (P < .05). Late loss at the main vessel in the sirolimus group patients was 0.31 +/- 0.59 versus 0.60 +/- 0.77 mm in patients from the paclitaxel group (P < .05).

CONCLUSIONS

Patients with bifurcation lesions treated by sirolimus showed significantly lower rates of late loss, restenosis and target lesion revascularization than patients treated with paclitaxel-eluting stents.

Delayed spontaneous recanalization of a totally occluded right coronary artery following failed percutaneous coronary intervention with associated Type F dissection: case report and review

Coronary artery dissection is a well-known and frequent complication of percutaneous coronary intervention (PCI). We report the first case of a Type F dissection following PCI of the distal right coronary artery causing total vessel occlusion that could not be stented but was associated with late spontaneous recanalization and a favorable outcome.

Long-term clinical outcomes of dissections after intracoronary beta-radiation with rhenium-188-diethylene triamine penta-acetic acid-filled balloon system

BACKGROUND

Intracoronary radiation with a rhenium-188 ((188)Re)-filled balloon is safe and efficiently reduces restenosis, but there is a potential risk of a (188)Re-filled balloon induced dissection. Little is known about the effect of radiation on dissection resolution and the late clinical outcome of dissection after brachytherapy.

METHODS

After successful catheter-based treatments of de novo or restenotic lesion, 256 patients were randomly assigned to the radiation or control group. The (188)Re-filled balloon system was designed to deliver 17.6 Gy in 1.0-mm tissue depth.

RESULTS

Dissections were identified in 15 patients among the 138 patients of the radiation group (10.9%). Additional stents were deployed in 10 patients to cover the flow-limiting dissection. Binary restenosis rate (53.3% vs. 16.3%, p=0.001) and target vessel revascularization (TVR) rate (53.3% vs. 11.1%, p<0.001) were significantly higher in patients with the dissection at 9 months. Geographic miss (GM) was identified in 4 of the 10 patients who underwent additional stenting. Binary restenosis rate in the GM group (100%; 4 of 4 patients) was significantly higher than the non-GM group (33.3%; 2 of 6 patients, p=0.02). Long-term follow-up of the patients with dissections who had not undergone TVR (n=7, mean follow-up duration: 640.7+/-387.3 days) has demonstrated persistent unhealed dissections.

CONCLUSIONS

Intracoronary radiation impairs the healing process after vessel injury and residual dissection after brachytherapy leads to adverse clinical outcomes, which was mainly due to GM in case of stent implantation.

Percutaneous coronary stenting in guide-induced aortocoronary dissection: angiographic and CT findings

We report here on a case of accidental aortocoronary dissection that occurred during the engagement of a guiding catheter. This resulted in an antegrade dissection into the right coronary artery, and a retrograde extension of the dissection into the Sinus of Valsalva and the ascending aorta up to the aortic arch. It was successfully treated with a stent deployment at the RCA ostium; this restored optimal coronary blood flow and there was a complete resolution of the aortic dissection as was documented by coronary angiography and the follow-up CT scan.

Percutaneous Treatment of Dissection of the Ascending Aorta Occurring as a Complication During Coronary Angioplasty of a Saphenous Vein Bypass Graft

Aortocoronary dissection can occur as a complication of angioplasty of native coronary arteries. This case report is of aortic dissection occurring as a complication of percutaneous coronary intervention of proximal anastomoses of a saphenous vein bypass graft. The aortic dissection that had progressed retrogradely into the ascending aorta was treated percutaneously by stenting in the saphenous vein graft with a membrane-covered stent.

Findings of intravascular ultrasound during acute stent thrombosis

OBJECTIVE

To evaluate the potential role of intravascular ultrasound (IVUS) in evaluating patients experiencing an episode of acute stent thrombosis.

DESIGN AND SETTING

Prospective observational study in a cardiac catheterisation laboratory in a university teaching hospital.

PATIENTS AND INTERVENTIONS

IVUS was used to examine 12 patients undergoing coronary interventions for stent thrombosis to gain further mechanistic insights and to guide treatment. IVUS studies were obtained before and after intervention with a motorised pullback device.

MAIN OUTCOME MEASURES

Qualitative and volumetric IVUS analyses.

RESULTS

Angiographically, 10 patients had occluded vessels and two patients had intraluminal filling defects within the stent. IVUS showed an occlusive thrombus in all patients. Thrombus volume was 90 (77) mm3, which was 51 (21)% of total stent volume. There was evidence of severe stent underexpansion in most patients and no patient fulfilled standard criteria for optimal stent implantation. Stent malapposition was detected in four patients, edge dissections were seen in two patients, and significant inflow-outflow disease was present in 11 patients. During interventions IVUS findings led to the use of higher pressures or larger balloons than those used during initial stenting in 10 patients. In addition, four patients required additional stenting, whereas a thrombectomy device alone was selected for one patient. After the procedure final minimum stent area (7.1 (2.1) v 5.3 (2) mm2, p < 0.005) and stent expansion (83.2 (17) v 62.1 (15)%, p < 0.005) improved compared with pre-interventional values. However, residual lining thrombus was still visualised in eight patients (25 (19) mm3, accounting for a 17% of final stent volume).

CONCLUSIONS

IVUS provides an attractive technique to characterise fully the pattern of stent thrombosis, to identify readily the underlying mechanical predisposing factors, and to guide repeated coronary interventions.

Predictors and implications of residual plaque burden after coronary stenting: an intravascular ultrasound study

BACKGROUND

Residual plaque burden after coronary stenting may be visualized by use of intravascular ultrasound. Determinants and implications of residual atherosclerotic plaque burden after coronary stenting are not well established. In particular, the implications of residual plaque burden, after adjusting for confounding factors, are still unknown.

METHODS

Sixty-two consecutive patients (age 56 +/- 9 years) undergoing coronary stenting under intravascular ultrasound imaging guidance were prospectively studied. A total of 616 slices were analyzed (every 2 mm of stent length) from motorized pull-back recordings. Residual plaque burden was calculated as residual plaque/vessel area x 100.

RESULTS

In 565 slices (89%), both residual plaque area and stent area could be measured. Mean residual plaque burden was 46.5% +/- 6%. By use of multiple regression analysis, lesion plaque area and reference segment plaque burden were identified as independent predictors of residual plaque burden after stenting. In addition, a significant correlation was found between residual plaque burden and most relevant angiographic parameters at follow-up (including minimal lumen diameter, percent diameter stenosis, and loss index), which persisted after adjustment. Furthermore, stents with a residual plaque burden >or=46% had higher a restenosis rate (relative risk [RR] 4.4, 95% CI 1.09-18.2, P =.03). On logistic regression analysis, residual plaque burden (RR 4.8, 95% CI 4.1-5.6, P =.01) and diabetes (RR 4.3, 95% CI 3.6-5.1, P =.03) emerged as the only independent predictors of restenosis.

CONCLUSIONS

The amount of residual plaque burden after coronary stenting plays an independent role on the late angiographic outcome of these patients.

Fate of stent-related side branches after coronary intervention in patients with in-stent restenosis

OBJECTIVES

We sought to assess the fate of stent (ST)-related side branches (SB) after coronary intervention in patients with in-ST restenosis.

BACKGROUND

In-ST restenosis constitutes a therapeutic challenge. Although the fate of lesion-related SB after conventional angioplasty or initial coronary stenting is well established, the outcome of ST-related SB in patients with in-ST restenosis undergoing repeat intervention is unknown.

METHODS

One hundred consecutive patients (age 61 +/- 11 years, 22 women) undergoing repeat intervention for in-ST restenosis (101 ST) were prospectively studied. Two hundred and twenty-six SB spanned by the ST were identified. The SB size, type, ostium involvement, location within the ST and take-off angle were evaluated. The SB TIMI (Thrombolysis in Myocardial Infarction trial) flow grade was studied in detail before, during, immediately after the procedure, and at late angiography.

RESULTS

Occlusion (TIMI flow grade = 0) was produced in 24 (10%) SB, whereas some degree of flow deterioration (> or = 1 TIMI flow grade) was observed in 57 SB (25%). The SB occlusion was associated with non-Q wave myocardial infarction in two patients (both had large and diseased SB). Side-branch occlusion at the time of initial stenting (RR [relative risk] 11.1, 95% CI [confidence interval] 3.5-35.5, p < 0.001), diabetes (RR 3.5, 95% CI 1.1-10.5, p = 0.02), SB ostium involvement (RR 5.0, 95% CI 1.4-17.2, p = 0.004), baseline SB TIMI flow grade <3 (RR 5.5, 95% CI 1.7-18.1, p = 0.005), and restenosis length (RR 1.05 95% CI 1.01-1.11, p = 0.03) were identified as independent predictors of SB occlusion. Late angiography in 19 initially occluded SB revealed that 17 (89%) were patent again. The long-term clinical event-free survival (81% vs. 82% at two years) in patients with and without initial SB occlusion was similar.

CONCLUSIONS

Occlusion or flow deterioration of SB spanned by the ST is relatively common during repeat intervention for in-ST restenosis. Several factors (mainly anatomic features) are useful predictors of this event. However, most SB occlusions are clinically silent and frequently reappear at follow-up.

[One-year clinical and angiographic follow-up after primary stenting]

INTRODUCTION AND OBJECTIVES

The late reocclusion or restenosis rate of the infarct related artery is frequent after primary angioplasty. An implanted stent may be able to improve the coronary angioplasty results and long-term outcome of these patients. We present the clinical and angiographic outcome of a cohort of patients treated with primary stenting.

PATIENTS AND METHODS

A group of 74 consecutive patients with acute myocardial infarction treated with primary angioplasty and stenting were followed for one year. An angiographic control was performed at the 6th month of follow-up in 91% of patients to assess the restenosis and reocclusion rates of the infarct-related artery.

RESULTS

There were eight in-hospital deaths and three during follow-up (mortality rate 14.8%) and one non-fatal reinfarction (1.5%). The cumulative rate of recurrent ischemia was 6% at 3 months and 15% at 6 months, without any further increment at one-year follow-up. A new angioplasty was performed in 7 patients and three patients underwent surgical revascularization. Thus 80% of patients after discharge were free of events. The angiographic control showed only one reocclusion of the infarct related artery and a restenosis rate of 27%.

CONCLUSIONS

These results show that primary stenting is an effective procedure in treating non-selected patients with acute myocardial infarction with a low long-term incidence of adverse events and a low restenosis rate.

Stenting the stent: initial results and long-term clinical and angiographic outcome of coronary stenting for patients with in-stent restenosis

Stent restenosis constitutes a therapeutic challenge affecting an increasing number of patients. Conventional angioplasty and debulking techniques are currently used in these patients. However, the potential role of a second stent implantation in this setting (stenting the stent) remains unknown. Therefore, 65 consecutive patients (12 women, aged 62 +/- 11 years) undergoing stent implantation (42 elective and 23 unplanned) for the treatment of in-stent restenosis (diffuse [> 10 mm] in 39 [60%]) were studied. Angiographic success was obtained in all patients. Three patients developed hospital complications: 1 died from refractory heart failure and 2 suffered non-Q-wave myocardial infarctions. During follow-up (mean 17 +/- 11 months) 1 patient died (noncardiac cause) and only 9 (14%) required target vessel revascularization. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and target vessel revascularization) at 1 year was 84%. Using Cox analysis, patients with unstable symptoms, a short time to stent restenosis, nonelective stenting, and B2-C lesions tended to have poorer prognosis. After adjustment, nonelective stenting was associated (adjusted RR 2.9, 95% confidence interval [CI] 0.82 to 10.3, p = 0.09) with an adverse clinical outcome. On quantitative angiography (core lab) restenosis was found in 13 of 43 patients (30%) (75% of those eligible). Logistic regression analysis identify restenosis length (adjusted RR 1.43, 95% CI 1.04 to 2.14, p = 0.04), and time to restenosis (adjusted RR 0.67, 95% CI 0.47 to 0.94, p = 0.01) as the only independent predictors of recurrent restenosis. Thus, repeat coronary stenting is a safe and efficacious strategy for the treatment of patients with in-stent restenosis. Both elective and nonelective stenting provide excellent initial results. The long-term clinical and angiographic outcome of these patients is also favorable.

[Spontaneous dissection of the coronary arteries: a rare cardiologic diagnosis]

A 55-year-old woman who was admitted to hospital with acute chest pain as a case of emergency suffered from an acute anteroseptal myocardial infarction. Four weeks later coronary angiography revealed a long dissection of the left anterior descending artery (LAD) as well as a significant stenosis of the left main and the proximal circumflex. Cardiovascular surgery was done subsequently. In addition to myocardial revascularization using coronary artery bypass grafts a readaptation of the dissecting artery walls and a proximal ligation of the LAD before anastomosis were performed. Clinical data, pathogenesis, and indications for medical and surgical treatment of spontaneous artery dissection are presented.

Initial results and long-term clinical and angiographic implications of coronary stenting in elderly patients

Results of 378 consecutive elderly patients (> or = 65 years) undergoing coronary stenting were compared with those of 601 younger patients. Although the restenosis rate was similar in the 2 groups, age > or = 65 years was an independent predictor of in-hospital mortality (relative risk 5.4, 95% confidence interval 1.2 to 20.1) and follow-up mortality (relative risk 2.8, 95% confidence interval 1.3 to 6.1).

Long-term outcome and determinants of event-free survival in patients treated with balloon angioplasty for in-stent restenosis

Long-term prognosis and predictors of event-free survival were studied in 56 consecutive patients with in-stent restenosis successfully treated with balloon angioplasty. Most patients sustained prolonged clinical benefit, but during follow-up, those with diabetes or with a short time interval (<4 months) from stenting to repeat angioplasty experienced adverse cardiac events more often.

Pathology of bailout coronary stenting in human beings

OBJECTIVES

The aim of this study was to perform detailed postmortem analysis of bailout coronary stenting to gain insights into the mechanism of success or failure of the procedure. Bailout stenting is increasingly used for acute or threatened arterial closure after angioplasty. Few pathologic data from bailout stenting have been reported.

METHODS AND RESULTS

The coronary arteries from 6 cases of bailout stenting were analyzed at autopsy. All stents were placed for extensive coronary dissection or abrupt vessel closure after balloon angioplasty. Twenty stents (11 Palmaz-Schatz and 9 Gianturco-Roubin stents) were placed in 8 coronary arteries, ranging from 1 to 5 stents per artery. After stenting, angiography showed good coronary flow in 3 of 6 cases. All patients died secondary to acute myocardial infarction. Histologically, in all cases, the stents were well opposed to the coronary artery wall, with a focally widely patent lumen by compression of the dissection plane. However, in 4 of 6 cases, there was residual dissection present in the nonstented portion of the arteries proximal, proximal to, and between stents or distal to the stented segment, resulting in focal luminal compression or obstruction. In 2 cases, bailout stenting effectively covered the dissection and prevented luminal compression.

CONCLUSIONS

Bailout stenting for dissection after balloon angioplasty restores lumen patency in the stented segment. Residual dissection in nonstented segments adversely affects outcome and supports the need for continued development of new stents with increased trackability and tapering designs to more effectively treat major coronary dissections.

Value of intravascular ultrasound in the assessment of coronary pseudostenosis during coronary interventions

Coronary pseudostenosis (PS) are increasingly visualized during coronary interventions. In many patients PS are readily recognized by a characteristic angiographic pattern, but in other cases the diagnosis remains difficult. The value of intravascular ultrasound (IVUS) in the study of PS remains unknown. In this study, IVUS was used to assess the morphologic appearance of the vessel wall in 10 consecutive patients showing images of PS during coronary interventions. Mean age of the group was 60+/-12 years and two patients were female. IVUS was performed with a motorized pullback system to assess lumen, plaque, and total vessel cross-sectional areas. Measurements were performed both at the site of PS and at the distal reference segment. PS were always located on angled coronary segments. In one patient no lumen narrowing was detected with IVUS at the site of PS. In the remaining nine patients, however, a very localized elliptic-shaped lumen narrowing was demonstrated. As compared with the distal reference segment, coronary lumen (6.3+/-2.2 vs. 12.7+/-4.8 mm2, P < 0.001) and total vessel area (11.9+/-3.3 vs. 16.1+/-6.1 mm2, P < 0.05) were smaller at the site of PS. Severe lumen asymmetry was also documented at this site. In addition, a characteristic image of a flattened, three-layered wall, overlying a hypoechogenic space, was visualized in five patients. This unique pattern was considered the correlate of a partial coronary intussusception. PS induced some resistance to the advancement of catheters in two patients and temporary flow impairment in two additional patients. However, in every case, the image of PS disappeared once the guidewire was removed. Thus, at sites with PS, IVUS allows ruling out severe atherosclerosis and coronary dissections. In addition, IVUS also provides important diagnostic clues, including the image of intussusception, for making the correct diagnosis of this benign entity.

Therapeutic repositioning of a Gianturco-Roubin II coronary stent after initial deployment

Movement of coronary stents after deployment can produce complications. We report a case of stent migration that led to stent coverage of a distal dissection, obviating the need for placement of a second stent. In this case, stent movement was therapeutic.

Aortic dissection occurring during coronary angioplasty: angiographic and transesophageal echocardiographic findings

A localized acute aortic dissection was produced in 2 patients, complicating coronary angioplasty. In both cases a coronary dissection provided the entry door, with subsequent retrograde progression of the dissection into the aortic root. After sealing the entry door, both patients could be managed conservatively using transesophageal echocardiography to accurately define the location of the intimal flap and to rule out dissection progression.

Pharmacologic prevention of acute ischemic complications of coronary angioplasty

The risk of acute coronary occlusion following percutaneous transluminal coronary angioplasty (PTCA) has remained high despite the traditional use of heparin and aspirin. Interest has focused on newer strategies for preventing intracoronary thrombus formation, which is an important mechanism of abrupt vessel closure. Pretreatment with thrombolytic agents has failed vigorous testing in double-blind trials. Retrospective and observational studies have indicated that pretreatment with intravenous heparin is of benefit in patients with unstable symptoms, but prolonged infusion after angioplasty increases bleeding complications without improving outcomes. Subcutaneous heparin may be safer, but has not proved more effective. Oral dipyridamole has shown no advantage over aspirin, although there is evidence to suggest a benefit when given intravenously. Direct thrombin inhibitors (such as hirudin and hirulog) are associated with fewer early complications compared with heparin, but have yielded no apparent long-term benefit. The use of the antiplatelet drug ticlopidine is increasing, although long-term data are lacking. A great deal of recent interest has focused on newer antiplatelet agents, particularly the glycoprotein IIB/IIIa receptor inhibitor c7E3 Fab. In a large-scale trial, c7E3 significantly reduced the 30-day rate of mortality and cardiac events, and these benefits were maintained at 6 mo. This drug, unlike other antiplatelet agents, inhibits the final common pathway of platelet aggregation, which influences not only acute closure but has lasting effects for at least 6 mo. This may reflect a reduction in restenosis, although this remains to be proven. This article gives a brief overview of the pharmacologic agents available for the prophylaxis and treatment of acute ischemic complications of PTCA.

Clinical and angiographic implications of balloon rupture during coronary stenting

Balloon rupture was detected in 66 consecutive patients (5.8%) during coronary stenting. This rare phenomenon usually does not have clinical or angiographic sequelae, but in some cases, it may induce new coronary dissections that can be managed with additional stenting, but also may cause clinical complications.

Abrupt vessel closure: changing importance, management, and consequences

Percutaneous coronary interventions have been performed for 20 years. Despite the success and progress of these interventions, abrupt vessel closure has been a dramatic adverse event of coronary interventions. Closure has frequently led to the major complications of death, myocardial infarction, and emergency coronary artery bypass. Because of the fear of this adverse event and its subsequent complications, the applicability of coronary interventions is sometimes limited. The pathologic characteristics of abrupt vessel closure have been recognized as predominantly caused by dissection, with vessel recoil and thrombus formation playing important secondary roles. The recognition of the lesions at risk for abrupt vessel closure has led to a strategy of lesion-specific device therapy to reduce complications. Similarly the role of antiplatelet and antithrombotic therapies have reduced complications. The earliest methods of dealing with abrupt closure was emergency coronary artery bypass surgery with significant rates of morbidity and mortality. With the advent of second-generation devices and techniques, particularly stents, the management of abrupt vessel closure has been simplified and alternatives to emergency coronary bypass are more available. This article will review the history and current status of the prevention and management of abrupt vessel closure and demonstrate that anticipation and management of this complication have been facilitated with reduction of subsequent complications and increased applicability of coronary interventions.

Safety and efficacy of angiography-guided stent placement in small native coronary arteries of < 3.0 mm in diameter

BACKGROUND AND HYPOTHESIS

Increased operator experience, greater insight in stent deployment techniques, and improved poststent medication regimen have significantly reduced the risk of thrombotic stent closure following stent placement in large coronary arteries (> or = 3.0 mm in diameter). Whether equally favorable results are afforded by stent placement in small vessels (< 3.0 mm), however, remains unclear. Accordingly, the aim of this study was the specific examination of the risk of stent placement in small native coronary vessels, using stent deployment technique consisting of supplementary dilatations with larger balloons or high-pressure inflations, and aggressive aspirin-ticlopidine and short-term oral anticoagulation poststent therapy.

METHODS

Forty-seven balloon-expandable stents (20 Gianturco-Roubin, 21 NIR, 6 Palmaz-Schatz) were successfully implanted without intravascular guidance in 45 native coronary arteries (mean reference diameter of 2.5 mm) in 44 consecutive patients (31 men, 13 men), the majority of whom (87%) were stented for the treatment of failed or suboptimal balloon angioplasty outcome.

RESULTS

Successful stent placement reduced the lesion diameter stenosis from 91 +/- 9% to 3 +/- 7% (p = 0.0001). There were no early stent thrombosis or major cardiovascular events prior to hospital discharge. During a 12-month follow-up period, most patients remained symptomatically improved and no myocardial infarction, stroke, or death was observed. Five-month angiographic reassessment revealed an in-stent restenosis rate of 41%, which was higher in vessels < or = 2.5 mm in size (47 vs. 33% for vessels > 2.5 mm, p = 0.2747).

CONCLUSIONS

In selected patients with small native coronary vessels < 3.0 mm in diameter, angiography-guided optimal stent placement is associated with a low risk of stent thrombosis and bleeding complications. However, the in-stent restenosis rate is high with the stents used in this study.

Clinical and angiographic implications of coronary stenting in thrombus-containing lesions

OBJECTIVES

This study sought to determine the results of coronary stenting in thrombus-laden lesions.

BACKGROUND

The angiographic evidence of intracoronary thrombus has classically been considered a formal contraindication to stent implantation. However, with increasing use of stenting, the indications for this technique have widened to include treatment of patients who have an acute coronary syndrome or lesions with adverse anatomic features.

METHODS

We studied 86 consecutive patients (mean age +/- SD 61 +/- 11 years, 14 women) undergoing coronary stenting of a thrombus-containing lesion; the procedure was performed electively in 39% and after angioplasty failure in 61%. Sixty-four patients (75%) were treated for unstable angina, and 19 (22%) underwent the procedure during an acute myocardial infarction. A specific protocol that included clinical and late angiographic follow-up was used.

RESULTS

Angiographic success was obtained in 83 patients (96%). Five patients (6%) died during the hospital stay despite angiographic success; four of these had cardiogenic shock, and one (1%) had subacute stent thrombosis. Non-Q wave myocardial infarction developed in five additional patients (6%), and four of these five had data consistent with distal embolization. Of the 78 patients discharged with angiographic success, 67 (86%) were event-free and clinically improved at last follow-up visit (12 +/- 11 months). During the follow-up period, eight patients required repeat angioplasty, one patient required heart transplantation, and two patients died. Quantitative angiography demonstrated excellent angiographic results after stenting (minimal lumen diameter 0.31 +/- 0.4 vs. 2.77 +/- 0.6 mm). Late angiographic follow-up (5.5 +/- 1 months) was obtained in 50 patients with 54 lesions (93% of eligible), revealing a minimal lumen diameter of 2.0 +/- 1 mm and restenosis (lumen narrowing > 50%) in 18 lesions (33%).

CONCLUSIONS

Coronary stenting constitutes an effective therapeutic strategy for patients with thrombus-containing lesions, either after failure of initial angioplasty or electively as the primary procedure. Coronary stenting in this adverse anatomic setting results in a high degree of angiographic success, a low incidence of subacute thrombosis and an acceptable restenosis rate.

Arterial perforation during optimization of coronary stents using high-pressure balloon inflations

Angiographic optimization of coronary stents, using high-pressure balloon inflation, was complicated by vessel rupture in 3 patients. The risk of this potentially life-threatening complication should be considered during stent optimization.

Stent embolization during intracoronary stenting

Nine patients with systemic embolization complicating intracoronary stenting (incidence 1.8%) are described. Although this rare complication was not associated with any clinical sequelae, great care should be taken to prevent this possibility, especially in patients with unfavorable anatomic characteristics, including lesions in the left circumflex artery, at bend points, and calcified lesions.

Role of polymers in improving the results of stenting in coronary arteries

This article is a review of recent developments of polymer-related stents mainly employed in the coronary arteries, including polymer-coated stents, biostable stents and biodegradable stents. Polymer paving is covered as well. The problems with the stents currently investigated and the development of new stents are discussed.

Stents for intracoronary placement: current status and future directions

The technique of intracoronary stenting has achieved remarkable progress over the last few years. Improved stent deployment techniques and optimization of postprocedural management have dramatically improved the safety of intracoronary stent placement. At present, the incidence of early vessel closure after stenting is even lower than that after standard angioplasty and, as most operators no longer prescribe aggressive anticoagulation, bleeding complications are uncommon. Stenting has become an extremely effective treatment for abrupt or threatened vessel closure or for any suboptimal angiographic result during conventional angioplasty. Furthermore, large prospective trials have demonstrated that its efficacy is superior to that of conventional angioplasty for primary restenosis prevention in focal lesions of some native coronary arteries. Ongoing trials tend to extrapolate these conclusions to saphenous vein graft lesions. Mechanical support of the vessel wall explains the sustained angiographic benefit observed after stenting. Future developments may include the use of stents as a vehicle for local drug delivery in an attempt to further reduce the incidence of restenosis. In view of these results, coronary stents should be considered a new standard therapeutic modality in interventional cardiology.

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.

Bail-out stenting for flow limiting dissections after rotational atherectomy in complex coronary lesions

Flow limiting dissection may occur after rotational atherectomy and require urgent management. Important questions about the safety and effectiveness of bail-out stenting in this setting remain to be answered. We have observed that emergent stenting after rotational atherectomy can be accomplished successfully in most patients, high pressure stent dilatation is both necessary and well tolerated, and lesion debulking facilitates movement of stents into diseased arterial segments.