Results of coronary angioplasty of chronic total occlusions (the National Heart, Lung, and Blood Institute 1985-1986 Percutaneous Transluminal Angioplasty Registry)

Retrograde endovascular revascularization for chronic total occlusion of the internal carotid artery: a case report

Endovascular revascularization of a chronically occluded internal carotid artery (ICA) is challenging because the occlusive segment can be long and tortuous. A case is presented of a successful recanalization of a chronically occluded ICA by retrograde passing of a guidewire from the intracranial ICA to the cervical ICA via the posterior communicating artery. This case suggests that a retrograde approach for reopening an occluded artery may be useful during neurovascular interventions, similar to percutaneous coronary interventions. In this patient, daily transient ischemic attacks disappeared after successful recanalization of the ICA.

Iteration of Reverse Controlled Antegrade and Retrograde Tracking for Coronary Chronic Total Occlusion Intervention: a Current Appraisal

Coronary chronic total occlusion (CTO) remains one of the most challenging subsets for percutaneous coronary intervention (PCI). The retrograde recanalization is one of the most significant amendments of the technique that remains critical to improved success of CTO PCI. Currently the reverse controlled antegrade and retrograde tracking (CART) is the most dominant retrograde technique. With emergence of new equipment and important iterations, this approach has become safer, faster and more successful. In this review, the author proposes the iteration and standardization of this technique which would further facilitates its adoption with more efficacy and safety.

A step-by-step guide to mastering retrograde coronary chronic total occlusion intervention in 2018: The author's perspective

Chronic total occlusion remains one of the most challenging subsets and represents the "last frontier" of percutaneous coronary intervention. Retrograde recanalization is one of the most significant amendments of the technique and has become an important complement to the classical antegrade approach. It yields a high success rate even in most complex patients. With emergence of important iterations, this approach has become safer, faster, and more successful. The author proposes a step-by-step guide to the retrograde approach with alternatives to various steps for operators wishing to embark on this strategy.

Retrograde Coronary Chronic Total Occlusion Intervention

Coronary chronic total occlusion (CTO) is a frequent finding in patients with coronary artery disease. It remains one of the most challenging subsets, accounting for 10-20% of all percutaneous coronary interventions (PCI). Although remarkable progress in PCI has been made, it is reasonable to state that successful recanalization of CTO represents the “last frontier" of PCI. PCI of CTOs has been limited historically by technical success rates of 50-70%. The introduction of enhanced guidewires, microcatheter, channel dilatator with increasing operator experience, and innovative techniques such as the retrograde approach have raised hopes for better outcomes. This article goes into depth into various strategies of retrograde approach in CTO.

Training Standards and Recommendations for Intervention on Chronic Total Occlusions

Despite major advances in coronary intervention, the recanalization of a chronic total occlusion (CTO) remains a challenge for many interventional cardiologists. Complex anatomy and lesion characteristics demand a special set of skills for procedural success.

Provided patient selection is appropriate, CTO intervention can confer a variety of benefits including relief of angina, improvement in left ventricular function and reduction in ischemic burden. The chances of procedural success are enhanced by having a dedicated CTO program. This involves adequate training of staff, quality control and availability of equipment. A diverse toolkit allows variation in strategy and increases procedural success. Further, skills and equipment are required to manage complications like vessel dissection, perforation and the resultant ischemic or mechanical complications. These procedures can often be lengthy and giving careful consideration to peri-procedural issues like radiation exposure and contrast dose plays a vital role in ensuring optimal patient outcomes and radiation hygiene.

In this article we review the evidence behind indications for CTO intervention and discuss the development of a CTO program.

Rationale for Percutaneous Intervention of CTO

Chronic total occlusion accounts for 15% of cases during diagnostic angiography with higher referral rate to surgical revascularization. With contemporary strategies and techniques, the success rate with experienced operators can exceed 90%. Currently available observational studies in carefully selected patient populations show evidence of a trend toward symptom relief; improvement in quality of life, left ventricular function, and mortality; and improved tolerance toward future ischemic events. Lack of randomized controlled trials comparing current optimal medical management with percutaneous coronary intervention for chronic total occlusion is a major barrier to widespread adaptation of this advanced complex interventional technique.

Current percutaneous recanalization of coronary chronic total occlusion

Although successful recanalization rates of coronary chronic total occlusions have remained suboptimal in percutaneous coronary interventions, evolving techniques, including the retrograde approach, have raised hopes for better outcomes. With the advent of antiplatelet therapy and drug-eluting stents, along with conventional antegrade approaches, further progress can be expected in the "last frontier" of interventional cardiology. The article focuses on contemporary recanalization strategy in percutaneous coronary intervention of coronary chronic total occlusions.

A novel modification of the retrograde approach for the recanalization of chronic total occlusion of the coronary arteries intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking

OBJECTIVES

The study evaluates the feasibility and efficacy of the novel modification of the retrograde recanalization of the chronic total occlusion (CTO) of the coronary arteries by using intravascular ultrasound (IVUS)-guided reverse controlled antegrade and retrograde tracking (CART).

BACKGROUND

Despite improvement in the techniques and materials, CTO recanalization is still suboptimal. The CART procedure has improved success rates, but there are certain inherent technical uncertainties and risk with this procedure.

METHODS

This first series involves 31 patients, with 22 patients having previous failed attempts at CTO recanalization. All patients were treated with bilateral approach and using IVUS-guided reverse CART concept.

RESULTS

Successful recanalization of the CTO was achieved in all cases (100%). The access route was septal collateral in 20 (70%) cases and epicardial collateral in 11 (30%) cases. IVUS guidance was used successfully in 30 cases, and the channel dilator (microcatheter) was used in 27 cases. Guidewire injury and grade 1 perforation was seen in 3 (9%) cases, which were managed conservatively. There was no death, coronary artery bypass surgery, or pericardiocentesis in this group of patients. Mean fluoroscopy time was 65.84 +/- 23.16 min, ranging from 31 to 106 min and total contrast volume used 321.32 +/- 137.77 ml (range 115 to 650 ml).

CONCLUSIONS

This first series describes a high success rate of CTO recanalization with IVUS-guided reverse CART in selected patients performed by an experienced operator.

Effect of preoperative evaluation by multidetector computed tomography in percutaneous coronary interventions of chronic total occlusions

BACKGROUND

The prevalence of success of percutaneous coronary interventions (PCIs) of chronic total occlusions (CTOs) remains relatively low. We determined the effect of preoperative multidetector computed tomography coronary angiography (CTCA) in PCIs of CTOs.

METHODS

The study population was 100 consecutive patients who underwent PCIs of CTOs from January 2005 to December 2007 at Keio University School of Medicine. They were divided into two groups according to the absence (non-CT group, n=60) or presence (CT group, n=40) of preoperative CTCA. The effect of preoperative CTCA was assessed in the prevalence of success of the procedure, prevalence of complications, irradiation time, and the dose of contrast agents.

RESULTS

The prevalence of procedural success was similar in both groups (non-CT group vs CT group 80.0% vs 77.5%, p=0.76). Irradiation time and the dose of contrast agents were also similar between these groups. The prevalence of complications was significantly reduced in the CT group (23.3% vs 7.5%, p=0.039), especially coronary perforations, which required treatment only in the non-CT group (10.0% vs 0.0%, p=0.039). Multiple logistic regression analysis revealed that use of a rotablator (odds ratio [OR]: 4.40, 95% confidence interval [CI]: 1.19-16.27, p=0.027) and absence of preoperative CTCA (OR: 4.26, 95% CI: 1.04-17.49, p=0.044) were independent determinants of complications.

CONCLUSION

Preoperative CTCA does not affect the prevalence of procedural success, irradiation time and the dose of contrast agents, but may be useful to reduce the prevalence of complications during PCIs of CTOs.

Computed tomography angiography-guided percutaneous coronary intervention in chronic total occlusion

OBJECTIVE

The aim of this study is to investigate if dual-source computed tomography (DSCT) could guide the percutaneous coronary intervention (PCI) of chronic total occlusion (CTO).

METHODS

We enrolled patients who were confirmed to have at least one native coronary artery CTO by DSCT before they underwent selective PCI in the period from December 2007 to October 2008. A CTO was defined as an obstruction of a native coronary artery with no luminal continuity. The CT-guided PCI procedure involved placing CT and fluoroscopic images side-by-side on the screen. DSCT images were analyzed for location, segment, plaque characteristics, calcification, and proximal lumen diameter of the CTO before PCI. The guidewire was advanced and manipulated under CT guidance. The PCI was carried out and the results were compared.

RESULTS

Seventy-four CTOs were assessed. PCI was successful in 57 cases of CTOs (77.0%). According to the results, CTOs were divided into two groups: successful-PCI and failed-PCI. All coronary artery paths of CTOs were clearly recognized by DSCT. In the successful-PCI group, soft plaques were detected much more often than those in the failed-PCI group, but fibrous and calcified plaques were seen more often in the failed-PCI group. Calcification severity in CTO segments showed a significant difference between the groups (P=0.014). Calcified plaques were detected in 20 (35.1%) lesions in the successful-PCI group. More than 70% of the failures were calcified plaques, of which there were two arc-calcified and one circular-calcified lesions. Occlusions were longer in the failed-PCI group than those in the successful-PCI group [(38.8+/-25.0) vs. (18.0+/-15.3) mm, respectively, P<0.01]. Fewer guidewires were used in the successful-PCI group compared with the failed-PCI group (1.7+/-1.0 vs. 2.5+/-0.9, respectively, P<0.01). The logistic regression analysis indicated that predictors of recanalization of CTOs included occlusion length (P=0.0035, risk ratio (RR)=0.93) and calcification severity (P=0.05, RR=0.27). Multi-linear trends analysis showed that the factors affecting procedural time were CTO location (P=0.0141) and occlusion length (P=0.0035).

CONCLUSIONS

DSCT could delineate the path of CTOs and characterize plaques. The outcomes of PCI were related to thrombolysis in myocardial infarction (TIMI) flow grade, CTO characteristics, severity of calcified plaques, and the length of occlusive segments. Occlusion length and calcification severity were independent predictors of CTOs. Occlusion length and CTO segments could also help to estimate the duration of interventional procedures.

[Why perform PCI of coronary chronic occlusion and how?]

Angioplasty of coronary chronic total occlusion (CTO), defined by complete occlusion of coronary vessel with TIMI 0 flow greater than 3 months, has been avoided for many years, single vessel diseases being medically treated and multivessel diseases sent to surgeons mainly because a low success and high restenosis rates. Major improvements in devices and techniques mainly coming from Japan created a new concern about when and how to perform PCI of CTO. Clearly CTO are stable lesions but during the last years it was demonstrated that while comparing success and failure of recanalization, success improved symptoms, ischemia, left ventricular function, and even survival. Reopening CTOs can also decrease the risk of death and cardiogenic shock associated with a future acute coronary event. Selection of cases for PCI is based on well-known predictors of failure (calcifications, tortuosities, length of occluded segment and age of occlusion), on operator's experience and on a proof of viability and ischemia of the myocardium depending from occluded vessel (MRI). Many specific devices (powerful wires, microcatheters and coaxial balloons, specific guiding catheters, Tornus) and techniques (anterogrades and retrogrades through trans-septal collateral vessels) have been developed to increase success rate (70 to 90% in high volume operator hands). Outside of coronary perforations which are no more frequent in CTO lesions, some specific problems are important limitations: X-Ray exposure, contrast medium volume, and cost. With the success rate these complications are good reasons to have these procedures (or the most complex) performed by specialists.

Clinical and research issues regarding chronic advanced coronary artery disease: part I: Contemporary and emerging therapies

The following report is based on a working group meeting about advanced coronary artery disease for patients with refractory ischemia who cannot receive revascularization. The aims were to review currently available treatment strategies, define unmet clinical needs, explore clinical trial design issues, and identify promising novel therapeutic targets and approaches for patients with chronic ischemia. The Working Group brought together medical experts in the management of refractory angina with representatives from regulatory agencies, Centers for Medicare and Medicaid Services, and industry. The meeting began with presentations reviewing the limitations of the current medical therapies and revascularization strategies and focused on lessons learned from past therapeutic attempts to optimize outcomes and on what are considered to be the most promising new approaches. Perspectives from clinical experts and from regulatory agencies were juxtaposed against needs and concerns of industry regarding development of new therapeutic strategies. This report presents the considerations and conclusions of the meeting on December 4-5, 2006. This document has been developed as a 2-part article, with contemporary and emerging therapies for advanced coronary artery disease reviewed first. Trial design, end points, and regulatory issues will be discussed in the second part of the article.

Trends in outcomes after percutaneous coronary intervention for chronic total occlusions: a 25-year experience from the Mayo Clinic

OBJECTIVES

The aim of our study was to examine the trends in procedural success, in-hospital, and long-term outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) over the last 25 years from a single PCI registry and to examine the impact of drug-eluting stents.

BACKGROUND

The percutaneous treatment of CTO remains a major challenge. Past studies have used variable definitions of CTO, and there are limited data available from contemporary practice.

METHODS

We evaluated the outcomes of 1,262 patients from the Mayo Clinic registry who required PCI for a CTO. The patients were divided into 4 groups according to the time of their intervention: group 1 (percutaneous transluminal coronary angioplasty era), group 2 (early stent era), group 3 (bare-metal stent era), and group 4 (drug-eluting stent era).

RESULTS

Procedural success rates were 51%, 72%, 73%, and 70% (p < 0.001), respectively, in the 4 groups. In-hospital mortality (2%, 1%, 0.4%, and 0%, p = 0.009), emergency coronary artery bypass grafting (15%, 3%, 2%, and 0.7%, p < 0.001), and rates of major adverse cardiac events (8%, 5%, 3%, and 4%, p = 0.052) decreased over time. During follow-up, the combined end point of death, myocardial infarction, or target lesion revascularization, was significantly lower in the 2 most recent cohorts compared with those patients treated before (p = 0.001 for trend). Technical failure to treat the CTO was not an independent predictor of long-term mortality (hazard ratio 1.16 [95% confidence interval 0.90 to 1.5], p = 0.25).

CONCLUSIONS

Procedural success rates for CTO have not improved over time in the stent era, highlighting the need to develop new techniques and devices. Compared with the prestent era, in-hospital major adverse cardiac events and 1-year target vessel revascularization rates have declined by approximately 50%.

Recent trends in the percutaneous treatment of chronic total coronary occlusions

Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has a lower success rate than PCI for non-CTO lesions. We sought to determine trends in the treatment of CTOs within the current interventional era. Using 4 sequential recruitment waves of the National Heart, Lung, and Blood Institute Dynamic Registry, we assessed the relative prevalence and success rates in treating CTO (n=371) versus non-CTO (n=4,802) lesions over a 7-year period (1997 to 2004). Characteristics of attempted lesions and factors associated with PCI outcome were evaluated. CTO lesion attempts decreased by 41% over time, from 9.6% (1997 to 1998) to 5.7% (2004, p<0.0001 for trend). More contemporary CTO lesions were longer (22.4 vs 17.0 mm, p=0.006 for trend), had thrombus less often (21.3% vs 35.4%, p=0.03 for trend), and were more often treated with stents (69.8% vs 45.4% p=0.02). The rate of successful intervention for CTO lesions decreased nonsignificantly during this time, from 79.7% to 71.4% (p=0.18). Using multivariable analysis, female gender (adjusted odds ratio 0.42, 95% confidence interval 0.20 to 0.88, p=0.02), and thrombus (adjusted odds ratio 0.31, 95% confidence interval 0.15 to 0.61, p=0.0008) were associated with higher success rates, whereas the presence of severe noncardiac disease (adjusted odds ratio 1.91, 95% confidence interval 1.05 to 3.45, p=0.03) was associated with a higher risk for PCI failure. Recruitment wave and patient age were not independently related to lesion success. In conclusion, during the PCI period of 1997 to 2004, CTO lesions were attempted less frequently and success rates did not increase, indicating a need for new operator techniques or device technologies to treat this important lesion subset by a percutaneous approach.

Human-grade purified collagenase for the treatment of experimental arterial chronic total occlusion

PURPOSE

Chronic total occlusions (CTO) remain a major limitation of percutaneous interventions. Procedural failure is usually due to the inability to cross the lesion with a guide wire. We have previously shown that local administration of a laboratory-grade collagenase followed by a 72-h waiting period may facilitate guide-wire crossing. The aim of the present study was to evaluate the efficacy and toxicity of a human-grade purified collagenase, suitable for clinical use, in facilitating guide-wire crossing in a rabbit model of femoral artery CTO.

METHODS AND RESULTS

A chronic total arterial occlusion was constructed in femoral arteries of New Zealand white rabbits. The local administration of purified collagenase solution (150 microg) via an over-the-wire balloon system was performed in 10 CTO. Guide-wire crossing was attempted after 24 h and was successful in all cases. Different doses (50-500 microg) were administered to an additional 17 rabbits to assess collagenase effects. Local subcutaneous bruising was observed at higher doses. Histological evaluation showed no damage to the arterial wall structure. Arterial extracts from collagenase-treated arteries showed increased MMP-2 and MMP-9 activities and higher levels of local MMP-1 and degraded collagen.

CONCLUSIONS

Local administration of a human-grade purified collagenase degrades collagen in CTO and is highly effective for the facilitation of guide-wire crossing in CTO.

Effect of percutaneous coronary intervention of nonacute total coronary artery occlusions on QT dispersion

BACKGROUND

Myocardial ischemia is one of several potential causes of increased QT dispersion (QTd) in patients with nonacute total coronary artery occlusions (TCOs). We sought to assess the effect of percutaneous revascularization (PCI) of TCO on QTd and the relationship between QTd and long-term vessel patency.

METHODS

Seventy patients enrolled in the TOSCA were analyzed. Patients were undergoing PCI of a TCO > 72 hours' duration. Two independent reviewers measured QTd from electrocardiograms done immediately before PCI (PRE), 12 to 18 hours after PCI (POST), and then at 6 months (6M). Follow-up angiography was performed at 6 months.

RESULTS

Mean QTd decreased from PRE (77 +/- 29 milliseconds) to POST (66 +/- 26 milliseconds, P < .001) and 6M (65 +/- 25 milliseconds, P < .001). Patients with the same or longer QTd at 6 months compared with POST (POST < or = 6M) had significantly higher risk of failed target-vessel patency (odds ratio 10.3, 95% CI 1.24-84.8) than patients with QTd reduction at 6M versus POST values.

CONCLUSION

Revascularization of TCO resulted in a decrease in QTd, which was sustained at 6M. This suggests that PCI to a TCO has a beneficial effect on stabilization of the underlying ischemic substrate. Furthermore, absence of QTd reduction at 6M versus POST was associated with increased risk of failed target-vessel patency.

Intracoronary Fibrin-Specific Thrombolytic Infusion Facilitates Percutaneous Recanalization of Chronic Total Occlusion

OBJECTIVES

We sought to investigate the benefit, predictors of procedural success, and safety of pre-procedural intra-coronary fibrin-specific lytic infusion (ICL) in patients with failed prior percutaneous coronary intervention (PCI) for chronic total occlusions (CTO).

BACKGROUND

Percutaneous coronary intervention for CTO remains a challenge with a high incidence of procedural failure secondary to inability to cross the occlusion with the guidewire.

METHODS

Eighty-five patients who underwent unsuccessful PCI procedures of CTO (more than three months' duration) had a repeat attempt of recanalization with the use of pre-procedural ICL. Patients received a weight-adjusted dose of either alteplase (tPA) (2 to 5 mg/h) or tenecteplase (TNK) (0.5 mg/h) for a total of 8 h. The total dose of ICL therapy was infused split between the guiding catheter and an intracoronary infusion catheter. A step-down multivariate logistic regression analysis was completed to determine the best predictors of procedural success. In-hospital major adverse cardiac events (MACE) including myocardial infarction, acute reocclusion, stroke, and death, as well as bleeding complications, were also examined.

RESULTS

The procedure was successful in 46 of 85 cases (54%). Four of 85 (5%) contained dissections that did not result in perforations, tamponade, or MACE. The incidence of groin complications was 7 of 85 (8%) and of bleeding complications requiring transfusions was 3 of 85 (3.5%). On multivariate analysis, predictors of success were tapering morphology (odds ratio, 15.5; 95% confidence interval, 3.73 to 63; p = 0.0002) and lack of bridging collaterals (odds ratio, 5.08; 95% confidence interval, 1.53 to 17; p = 0.008).

CONCLUSIONS

Intracoronary infusion of fibrin-specific thrombolytic therapy may provide a valuable and safe option for facilitating percutaneous revascularization of CTO.

Success, safety, and mechanisms of failure of percutaneous coronary intervention for occlusive non-drug-eluting in-stent restenosis versus native artery total occlusion

We compared the procedural success, mechanism of failure, and safety of percutaneous coronary intervention in 235 procedures for de novo chronic total occlusions with 78 procedures for chronic occlusive in-stent restenosis. Despite similar rates of procedural success and safety profile, angiographic predictors of successful percutaneous coronary intervention for de novo chronic total occlusions played a limited role in patients who had chronic occlusive in-stent restenosis, and the mechanisms of failure were different.

Utility of the Safe-Cross-guided radiofrequency total occlusion crossing system in chronic coronary total occlusions (results from the Guided Radio Frequency Energy Ablation of Total Occlusions Registry Study)

The Safe-Cross radiofrequency guidewire (IntraLuminal Therapeutics, Carlsbad, California) combines 3 capabilities: (1) steerability of a conventional 0.014-in intermediate-stiffness guidewire, (2) optical coherence reflectometry to warn the operator when the wire tip approaches within 1 mm of the vessel wall, and (3) delivery of radiofrequency energy pulses to the wire tip to facilitate passage through an occluded segment. The Guided Radio Frequency Energy Ablation of Total Occlusions Registry was a prospective, nonrandomized, multicenter registry that enrolled 116 patients who had long-term coronary total occlusions and in whom a >10-minute good-faith attempt to cross the occlusion using conventional guidewires had failed. The median known duration of occlusion was 22 months (32%; >1 year), and the median length of the occluded segment was 25 mm (25%; >30 mm). Device success was achieved in 63 of 116 of patients (54.3%), and major adverse events occurred in 6.9%, consisting predominantly of isolated increases in cardiac enzymes with no procedure-related deaths, Q-wave myocardial infarctions, or emergency bypass operations. Clinical perforation occurred in 2.6% of patients; of these, perforation in only 1 patient (0.9%) was adjudicated to be directly related to the Safe-Cross radiofrequency wire rather than to the stiff and/or hydrophilic wires used after an inability to advance with the Safe-Cross. Based on these data, the device has been approved in Europe and was recently (January 2004) granted 510K clearance by the Food and Drug Administration.

Simple detection of occluded coronary artery using retrograde flow in septal branch and left anterior descending coronary artery by transthoracic doppler echocardiography at rest

BACKGROUND

We hypothesized that coronary flow assessment by transthoracic Doppler echocardiography (TTDE) for both intramyocardial collateral channel and epicardial channels would be useful for identifying occluded left anterior descending coronary artery (LAD).

METHODS

We assessed flow direction in the LAD and the septal branch (SEP) by TTDE in 302 consecutive patients who were suggested to have ischemic heart disease. We defined antegrade LAD flow as a direction from the base to the apex of the left ventricle in the anterior groove area, and antegrade SEP flow as a direction from anterior to inferior in the anterior interventricular septum. By contrast, we defined retrograde LAD and SEP flow as an inverse direction. We performed angiography on all patients.

RESULTS

Retrograde flow was detected in 22 (LAD, 16 patients; SEP, 6 patients) of 23 patients with occluded LAD, and antegrade flow was detected in all patients without occluded LAD. The sensitivity and specificity for identification of occluded LAD by TTDE were 96% and 100%, respectively.

CONCLUSIONS

Assessment of flow direction in both LAD and SEP by TTDE is a useful method in identification of occluded LAD.

Immediate results and one-year clinical outcome after percutaneous coronary interventions in chronic total occlusions: data from a multicenter, prospective, observational study (TOAST-GISE)

OBJECTIVES

We sought to investigate the success rate and the acute and 12-month clinical outcome of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in the contemporary era.

BACKGROUND

The technique of PCI involving CTO has improved over time. However, limited data on acute and follow-up results in patients treated with PCI on CTO in recent years are available.

METHODS

Four hundred nineteen consecutive patients scheduled for PCI of CTO of > or =30 days of duration were enrolled in 29 centers; 390 CTOs were confirmed in 376 patients in an independent core laboratory. The end points were technical and procedural success, in-hospital and 12-month major adverse cardiac events (MACE) occurrence, and 12-month symptomatic status.

RESULTS

Technical and procedural success was obtained in 77.2% and 73.3% of lesions, respectively. In-hospital major adverse cardiac events occurred in 5.1% of patients. Multivariate analysis identified CTO length >15 mm or not measurable, moderate to severe calcifications, duration > or =180 days, and multivessel disease as significant predictors of PCI failure. At 12 months, patients with a successful procedure experienced a lower incidence of cardiac deaths or myocardial infarction (1.05% vs. 7.23%, p = 0.005), a reduced need for coronary artery bypass surgery (2.45% vs. 15.7%, p < 0.0001), and were more frequently free of angina (88.7% vs. 75.0%, p = 0.008) compared with patients who had an unsuccessful procedure.

CONCLUSIONS

Successful PCI was achieved in a high percentage of CTOs with a low incidence of complications. At one-year follow-up, patients with successful PCI of a CTO had a significantly better clinical outcome than those whose PCI was unsuccessful.

Differential response of coronary collateral channels to atrial pacing and balloon occlusion at angioplasty

BACKGROUND

Collateral channels can protect from infarction, even in the presence of a total or sub-total occlusion. Acute re-occlusion following restoration of flow may still lead to ischaemia or infarction. It is unclear whether collaterals respond differently to tachycardia-induced stress and balloon inflation. This study compared the response of collateral-dependent viable myocardium to repetitive atrial pacing with the response to multiple balloon occlusions during percutaneous transluminal coronary angioplasty (PTCA).

METHODS AND RESULTS

Fifteen patients undergoing elective single vessel PTCA with well-developed collateral channels supplying the target vessel were recruited. Patients underwent two periods of incremental atrial pacing (P(1); P(2)) followed by two 90-s balloon inflations (I(1); I(2)). Collateral flow velocity was assessed by Doppler flow wire across the target lesion. Evidence of ischaemia was obtained from monitoring of surface ST-segments and by chest pain scores recorded on a visual analogue scale. Retrograde and 'aggregate' flow velocities were significantly lower during I(1) and I(2) than either P(1) or P(2). Reduction in flow velocity was most marked during I(1) compared with P(1) or P(2). Chest pain score was lower during P(2) than P(1) (3.8 +/- 3.5 versus 5.5 +/- 3.0, P < 0.02), although flow velocity was unchanged.

CONCLUSION

Collateral flow velocity is significantly higher during tachycardia-induced stress than balloon occlusion. Restoration of antegrade flow by balloon inflation results in a further reduction in flow during a second inflation, suggesting a functional down-regulation of the collateral channels. Ischaemic symptoms are attenuated with repetitive pacing independent of collateral flow, suggesting an additional preconditioning response.

[Recanalization of chronic coronary occlusions]

Recanalization of occluded coronary arteries is the aim of percutaneous interventions with acute myocardial infarction. Moreover, chronic coronary occlusion is a common finding during diagnostic coronary angiography and is often a contributing factor in the choice of revascularisation by surgery rather than by percutaneous coronary interventions (PCI). An occluded coronary artery with some degree of collateral supply is functionally comparable to a severe coronary stenosis. Therefore, recanalization of chronic occluded coronary arteries results in less angina and often in improvement of left ventricular function. Success is limited in particular in longer lasting occlusions. Characterization of lesions, where recanalization can performed successfully is warranted. We correlated primary success rates of attempted coronary recanalizations with localisation of lesions and procedural characteristics. We analyzed records of 124 consecutive patients, who underwent attempted coronary recanalization of chronically occluded coronary arteries at our institution in 1998. Revascularisation was successful in 84 (64 male, 20 female) of 124 (92 male, 32 female) patients. Therefore, success rate was 67.7% (69.9% in men, 62.5% in women, p = 0.42). Target vessel was the left anterior descending artery (LAD) in 49 cases. Success rate in the LAD did not differ significantly from that in "non-LAD"-vessels (65.3% versus 69.3%; p = 0.35). Successful recanalizations were performed using only one guide-wire in 77.3%. More than one guide-wires were used during procedures without success in 44.5% and exceeded use in successful interventions (p < 0.05). Procedures, failing to be successful after an attempt with a first guide-wire, could be performed successfully using at least a second wire in 50%. Coronary stenting after recanalization has been performed in 84.4% in the LAD and in 59.7% in non-LAD vessels (p < 0.01). Success rate of attempted recanalizations of chronic occluded coronary arteries in unselected patients is high. Most procedures can be performed successfully using only one guidewire. Additional use of other wires can increase success rates in procedures with primary failure to pass the occlusion. Stenting has been performed in three out of four patients with successful recanalization of chronically occluded coronary arteries.

Acute success rates of percutaneous transluminal coronary angioplasty in the treatment of chronic complete occlusions with use of the 0.014 magnum Meier wire

The 0.014 inch magnum Meier wire was used as the primary tool for recanalization of chronic total coronary artery occlusions in 230 consecutive patients treated by a single operator over a 3-year period. Exclusive use of the magnum wire resulted in an acute success rate of 80.9% in all occlusions and 64.7% in occlusions with a duration of >6 months. The complication rate of this procedure was extremely low with only one nontransmural myocardial infarction occurring. There were no vessel perforations, no in-hospital deaths, and no need for acute surgery. After failure to recanalize with the magnum wire, various other devices (conventional stiff guidewires, jagwire, crosswire) were used resulting in only six additional successful recanalizations but also in two vessel perforations with spontaneous closure of the perforation hole. Therefore, the 0.014-inch magnum Meier recanalization wire is highly effective for recanalization of chronic coronary artery occlusions, if used as the primary tool by an experienced operator, and is associated with an extremely low complication rate.

Effect of plaque debulking and stenting on short- and long-term outcomes after revascularization of chronic total occlusions

OBJECTIVES

We evaluated the effect of plaque burden modification (debulking) on the short- and long-term clinical outcomes of patients with a totally occluded native coronary artery undergoing successful stent deployment.

BACKGROUND

Although the primary success rate of crossing a chronic totally occluded coronary artery has improved with the development of new interventional devices and guidewires, the rate of acute reocclusion and restenosis remains high.

METHODS

The in-hospital and late clinical outcomes of 150 patients who had undergone successful stenting of 176 chronic total occlusions were analyzed. After successful crossing of the lesion, 44 patients with 50 lesions underwent debulking by laser angioplasty, rotational or directional atherectomy followed by stenting, whereas 106 patients with 126 lesions underwent stent implantation without prior debulking.

RESULTS

Baseline clinical and angiographic characteristics were similar for the two groups, except for a higher incidence of left anterior descending coronary artery location and longer lesions in the group of patients who underwent debulking prior to stenting. In-hospital mortality, myocardial infarction and repeat angioplasty rates were similar for the two groups. At a mean 14 +/- 8 months follow-up time, there were no deaths in either group, and target lesion revascularization rates were the same (16.3% in the debulking plus stent group vs. 14.4% in the stent alone group, p = NS).

CONCLUSIONS

Treatment of chronic total native coronary artery occlusions with stent deployment with and without lesion modification (debulking) results in a favorable in-hospital outcome, with relatively low long-term target lesion revascularization rates.

Stent or angioplasty after recanalization of chronic coronary occlusions? (The SARECCO Trial)

This study tests whether stent implantation without anticoagulation after catheter recanalization of coronary occlusions can improve outcome compared with balloon angioplasty alone. One hundred ten patients were randomly assigned to angioplasty alone (no stent group) or stent implantation (stent group) after successful recanalization and balloon angioplasty. The type of stent and angioplasty technique utilized were decided by the operator. The acute procedural success in both groups was 100%. The acute minimal lumen diameter (MLD) was 1.85 +/- 0.44 mm in the no stent group versus 2.54 +/- 0.53 mm in the stent group (p <0.01). The diameter stenosis was 21 +/- 13% versus 3 +/- 14% (p <0.01). This was achieved not only by the stent implantation itself but primarily by a larger maximum balloon diameter in the stent group after stent implantation (3.32 +/- 0.55 mm vs 2.86 +/- 0.4 mm, p <0.05). After 4 months, the MLD was 1.15 +/- 0.73 mm in the no stent group versus 1.81 +/- 0.9 mm in the stent group (p <0.01). The diameter stenosis was 56 +/- 29% versus 34 +/- 28% (p <0.01). After 2 years, event-free survival was 26% in the no stent group and 52% in the stent group (p <0.05). Thus, acute and long-term procedural and angiographic success of stent implantation without anticoagulation after recanalization of total coronary occlusions is superior to that of balloon angioplasty alone. This beneficial effect is mainly the result of the larger balloon diameters, which may be used after stent implantation.

Early recovery of wall motion abnormalities after recanalization of chronic totally occluded coronary arteries: a dobutamine echocardiographic, prospective, single-center experience

BACKGROUND

Patients with symptomatic myocardial ischemia from a chronic totally occluded coronary (TOC) artery are usually referred for coronary artery bypass surgery. Because guide wire technology has improved considerably in recent years, percutaneous coronary angioplasty has become a useful technique in opening chronic TOC arteries. We evaluated the early functional results of successful percutaneous recanalization by performing dobutamine stress echocardiography (DSE).

METHODS

Fifteen patients with a chronic TOC artery who underwent a successful recanalization were prospectively studied. Each patient had a DSE within 24 hours before and 48 hours after the procedure. Wall motion was scored according to a 16-segment/5-point model. A clinical and angiographic follow-up of 6 months was obtained.

RESULTS

The wall motion score index at rest improved from 1.26+/-0.23 before to 1.22+/-0.21 after the procedure (P < .05). Of those 10 segments that improved at rest, 7 were collateral recipients and 3 were collateral donors. The number of ischemic segments decreased from 46 before to 4 after the procedure (P < .0001). Wall motion score index at peak stress improved from 1.34+/-0.20 before to 1.15+/-0.12 after the procedure (P < .05). DSE was positive for ischemia in 15 patients before and 2 patients after the procedure (P < .0001). Angina was present in 12 patients before and in 2 patients after recanalization (P < .0001). Two patients (13%) had angiographic reocclusion and 5(33%) restenosis after 6 months of follow-up.

CONCLUSIONS

Successful percutaneous recanalization of chronic TOC artery results in an early improvement of both clinical status and resting or stress-induced wall motion abnormalities, as detected by DSE.

Crosswire for recanalization of total occlusive coronary arteries

Coronary angioplasty of total occlusions is technically difficult and is associated with limited success rates. The procedural outcome is mainly determined by the underlying pathological process. Recanalization of total occlusions is aimed at finding the passage with least resistance, without causing dissection or perforation. Several techniques have been advocated to improve the overall success rate. Recently, a new 0.014" Nitinol wire (Crosswire, Terumo) has been introduced as a tool, to achieve higher success rates for total occlusion angioplasty. The wire consists of an extremely flexible Nitinol-core, a platinum/iridium coil at the distal tip, and a hydrophilic polymer coating. Balloon angioplasty was attempted in 30 totally occluded coronary arteries with mean age of occlusion being 5 +/- 4 months (range 2-14 months). The initial five procedures were performed following failure of the conventional angioplasty guidewires. Subsequently, Cross-wire was used electively in all the cases. The lesion was crossed successfully in 90% (27/30) cases. Dissection of the coronary artery with subintimal entry was seen in two (7%) cases, and the rest (three cases) could not be crossed. Balloon angioplasty and stenting (n = 21) were performed with good immediate angiographic results. There were no myocardial infarctions or deaths. Fourteen of 16 patients, who had completed 6 months follow-up, were asymptomatic. Angiographic evidence of in-stent restenosis was demonstrable in one case. Successful recanalization of total coronary occlusions by using Cross-wire can be expected in 83% cases, with reasonable safety.

Clinical and angiographic outcome after stent placement for chronic coronary occlusion

A consecutive series of 132 patients with total chronic coronary occlusions were compared with 1,966 patients with stenotic lesions in terms of angiographic and clinical outcome. We concluded that patients with chronically occluded coronary lesions present a higher rate of target lesion revascularizations and angiographic restenosis than patients with stenotic lesions.

Beyond stents: third-generation coronary devices

Despite extraordinary growth in percutaneous transluminal coronary angioplasty (>400,000 cases in United States in 1997) patients are still routinely referred for bypass grafting in large numbers. Why? Second-generation devices (directional coronary atherectomy, high-speed rotational atherectomy [Rotablator], and stents) have expanded the application of percutaneous catheter treatment of coronary disease. Specifically, highly eccentric lesions in large vessels, heavily calcified lesions, and coronary dissections can be effectively treated with these devices. Stents have substantially reduced the incidence of restenosis, but this benefit is largely confined to vessels more than 3 mm in diameter and stenoses less than 20 mm in length. A third generation of coronary devices has evolved in the late 1990s in response to continuing failures of conventional balloon angioplasty, atherectomy, and stenting. The failures of the 1990s were (1) restenosis, including in-stent restenosis, (2) chronic total occlusions, (3) diffuse small-vessel disease, and (4) aged vein graft disease. In response to these challenges novel devices are being developed: (1) for restenosis, intracoronary radiation therapy (brachytherapy); (2) for chronic total occlusions, Prima Laser wire; (3) for diffuse small-vessel disease, percutaneous myocardial laser revascularization; and (4) for aged vein grafts, antiembolization devices. Each of these new catheter technologies will need to be economically and clinically reconciled with the multitude of minimally invasive surgical revascularization techniques that are rapidly evolving.

Laser wire for crossing chronic total occlusions: "learning phase" results from the U.S. TOTAL trial. Total Occlusion Trial With Angioplasty by Using a Laser Wire

The Prima laser guidewire system (Spectranectics Corp., Colorado Springs, CO) consists of an 0.018" hypotube containing a bundle of 45-microm optical fibers coupled to a pulsed excimer laser operating at a tip fluence of 60 ml/mm2 and a repetition rate ranging from 25-40 Hz. This laser guidewire was specifically designed to cross total occlusions refractory to passage with conventional wires. The Prima wire was evaluated in a feasibility study at 15 U.S. centers. Following failure to cross a total occlusion with approved guidewires, the Prima wire was utilized in 179 patients. Average age of subjects was 61 yr. Lesion locations included left anterior descending (36%), right (45%), and circumflex (19%) coronary arteries. Mean angiographic age of total occlusions was 70 wk (range, 2-1,020 wk, median, 14 wk). The use of the Prima wire either solely or in combination with conventional guidewires resulted in successful crossing in 61% of these previously impenetrable occlusions. Failure of the device was commonly related to length of the occlusion and tortuosity along the occluded pathway. Major complications included myocardial infarction in 7 patients (3.9%), tamponade in 3 (1.7%), and death in 2 (1.1%). This "learning phase" pilot study confirmed the feasibility of a laser guidewire in chronic total occlusions that are resistant to passage of conventional guidewires. An extended registry at these investigative sites is planned.

Recanalization of chronic coronary occlusions using a new hydrophilic guidewire

Chronic total occlusion remains a relative contraindication and the main cause of failure of coronary angioplasty. Previously available hydrophilic guidewires had numerous limitations. The Crosswire is a new 0.014" hydrophilic nitinol guidewire which can be accommodated by very-low-profile balloon catheters and has a shapeable and highly radiopaque platinum-iridium coiled tip. This guidewire was used in 55 patients with 56 chronic coronary occlusions in which recanalization by conventional guidewires had failed. Clinical success was 79%. Coronary perforation occurred in two cases, one of them requiring pericardiocentesis for tamponade. These results illustrate the usefulness of this new guidewire in the treatment of chronic total occlusions.

Mechanical recanalization of total coronary occlusions with the use of a new guide wire

The mechanical approach in the recanalization of total coronary occlusions consisted of the use of a new 0.014-inch standard coronary guide wire with jointless spring coil design that improves steering characteristics and tip stiffness. In addition, a 0.014-inch soft tip wire with hydrophilic coating and low-profile 1.5 mm over-the-wire balloons were used. The first wire was used selectively in 86 patients to treat 95 total occlusions, of which 51 (54%) were older than 3 months. Unfavorable angiographic characteristics were present in 79 (83%) of 95 lesions. Overall crossing success was 71% (67 of 95 lesions). Complications were one coronary perforation with cardiac tamponade necessitating emergency bypass surgery. In conclusion, the mechanical approach with the use of the standard coronary guide wire with jointless spring coil design provides a high success rate in the recanalization of unfavorable total occlusions.

Randomised trial of elective stenting after successful percutaneous transluminal coronary angioplasty of occluded coronary arteries

BACKGROUND

The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly.

OBJECTIVES

To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery.

METHODS

Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months.

RESULTS

Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%)).

CONCLUSIONS

Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

Chronic total occlusions of coronary arteries--medical versus surgical treatment

Coronary artery bypass grafting (CABG) is an established treatment of patients with angina pectoris and chronic total coronary occlusion of major coronary arteries. However, in patients with mild or absent angina and chronic total coronary occlusion, optimal treatment is unsettled. We compared the prognosis of patients with chronic total coronary occlusion treated medically because of mild or absent angina with a matched group of patients undergoing CABG. In a retrospective design we evaluated all coronary angiographies performed in our department over a 5-year period. We identified 77 patients with chronic total occlusion of major coronary arteries eligible for CABG but treated medically because of mild or absent angina. The medically treated patients were matched on age, sex and ejection fraction with 77 patients with occluded major coronary arteries and angina pectoris who were treated surgically. The main outcome measures were death, acute myocardial infarction (AMI) and CABG. At baseline, CABG patients demonstrated an increased duration and severity of angina pectoris and an increased consumption of anti-anginal drugs. No differences were found with regard to angiographic parameters. The 5-year event rates (medically treated versus CABG) were: death, 14% vs 7% (p = 0.08); death or AMI; 27% vs 16% (p = 0.10); death, AMI or CABG, 34% vs 16% (p = 0.03) (log-rank statistics). In conclusion, our data indicate that patients with chronic total coronary occlusions and mild or absent anginal symptoms may benefit from surgical treatment.

Short-term results and intermediate-term follow-up of laser wire recanalization of chronic coronary artery occlusions: a single-center experience

OBJECTIVES

This study sought to elucidate the short-term efficacy and intermediate-term outcome of excimer laser recanalization of chronic coronary artery occlusions in patients in whom attempts at mechanical revascularization had failed.

BACKGROUND

Recanalization of chronic coronary occlusions with the use of a mechanical guide wire fails in 30% to 50% of cases, mostly because of inability to pass the wire through the lesion. The value of using excimer laser energy in this setting has not yet been determined.

METHODS

The study group comprised 66 consecutive patients with 68 chronic coronary occlusions. Patients were eligible for inclusion in the study if a previous attempt at mechanical revascularization had failed and if their angiographic status was such that 1) the vessel segment distal to the occlusion could be visualized by way of collateral vessels, 2) the entry point of the occlusion was clearly outlined, and 3) not more than one anatomic bend was expected within the occlusion. Excimer laser energy was applied to the lesion through a 0.018-in. (0.046 cm) fiber-optic guide wire. Adjunctive balloon angioplasty and stenting were performed in all successfully treated patients but one.

RESULTS

Thirty-four occlusions (50%) in 32 patients (48%) could be crossed with the laser wire. Location and age of the occlusion had no adverse influence on the outcome of laser wire recanalization, nor did the presence of bridging collateral vessels, a major side branch at the site of the lesion or a blunt stump of the occlusion. An inverse relation was found between the success rate and the length of the occlusion, such that a 19% reduction of the success rate accompanied each 10-mm increment of the mean occlusion length. Thus, the success rate was 68% for lesions < or = 10 mm but only 25% for lesions > 30 to < or = 40 mm. The presence of a bend in the lesion exceeding 60 degrees was strongly related to procedural failure. During a median angiographic follow-up period of 18 weeks, restenosis > 50% (n = 6) or reocclusion (n = 4) was found in 10 of the 32 successfully treated patients, for an intermediate-term success rate of 33% (22 of 66). Clinical follow-up revealed improved anginal status in 21 patients (66%) after a median of 24 weeks. Major complications (death, myocardial infarction, emergency operation) were not encountered.

CONCLUSIONS

Successful recanalization of a chronic coronary occlusion by using currently available laser wires can be expected in 50% of selected patients in whom attempts at mechanical revascularization fail. Restenosis or reocclusion accounts for an overall 6-month success rate of 35%.

Histologic correlates of angiographic chronic total coronary artery occlusions: influence of occlusion duration on neovascular channel patterns and intimal plaque composition

OBJECTIVES

Age-related changes in histologic composition and neovascular channel (NC) pattern of angiographic chronic total coronary artery occlusions (CTOs) were studied to define histologic correlates of age-related revascularization profiles and neovascular channel formation.

BACKGROUND

Revascularization of CTOs is frequently characterized by inability to cross or dilate the lesion and a high incidence of reocclusion or restenosis but low periprocedural ischemic complication rates. Little is known about the histopathologic basis of these observations.

METHODS

Ninety-six angiographic CTOs from autopsy studies in 61 patients who had undergone coronary angiography within 3 months of death were studied. Abrupt plaque rupture was excluded. Occlusion segments were analyzed for 1) histologic composition as a function of lesion age; and 2) NC pattern as a function of lesion age and intimal plaque (IP) composition.

RESULTS

Cholesterol and foam cell-laden IP was more frequent in younger lesions (p = 0.0007), whereas fibrocalcific IP increased with CTO age (p = 0.008). IP NCs arose directly from adventitial vasa vasorum and were anatomically and quantitatively related in terms of number and size (p = 0.0001) to the extent of IP cellular inflammation. IP cellular inflammation exceeded that found in the adventitia (p < 0.001) or media (p = 0.0001) across all CTO ages. In CTOs < 1 year old, the adventitia was associated with a larger number and size of NCs relative to the IP (p = 0.0006 and p = 0.009), media (p = 0.0001 and p = 0.002) and recanalized lumen (p = 0.0001 and p = 0.001). In CTOs >1 year old, the adventitia and IP NC numbers were similar and exceeded NC numbers found in the media (p = 0.0001) and recanalized lumen (p = 0.0001 and p = 0.003).

CONCLUSIONS

Angiographic CTO frequently corresponds to less than complete occlusion by histologic criteria. Age-related changes in IP composition from cholesterol laden to fibrocalcific may explain the adverse revascularization profile of older CTOs. IP NC growth derived from the adventitia increases with age and is strongly associated with IP cellular inflammation. IP NC formation may protect against the flow-limiting effects of IP growth.

The appropriateness of intention to treat decisions for invasive therapy in coronary artery disease in The Netherlands

OBJECTIVE

To determine the appropriateness of intention to treat decisions concerning coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) for patients with coronary artery disease in The Netherlands.

DESIGN

Prospective study of intention to treat decisions using a computerised expert system.

SETTING

"Presentation" sessions in 10 tertiary referral heart centres in 1992.

PATIENTS

3207 consecutive patients: 1618 CABG and 1589 PTCA candidates.

MAIN OUTCOME MEASURE

Percentage of invasive treatment decisions rated appropriate, uncertain, or inappropriate by the expert system.

RESULTS

PTCA decisions were common for patients with one-vessel disease and CABG decisions for patients with three-vessel and left main disease. PTCA decisions outnumbered CABG decisions in acute myocardial infarction. Of CABG decisions, 84% were rated appropriate, 12% uncertain, and 4% inappropriate. The proportions for PTCA decisions were 39% appropriate, 31% uncertain, and 29% inappropriate. Type C lesion was the main determinant of inappropriateness of PTCA decisions. If type C lesions were downgraded to type A/B lesions the rate of inappropriate PTCA decisions dropped to 6%.

CONCLUSIONS

Clinicians in tertiary referral centres in The Netherlands favoured CABG if vessel disease was extensive or involved the left main artery, and PTCA for patients with less extensive disease and with acute myocardial infarction. Few CABG decisions were inappropriate. The main determinant of inappropriateness of PTCA decisions was its intended use in patients with type C lesions.

Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty

OBJECTIVES

This study investigated whether stenting improves long-term results after recanalization of chronic coronary occlusions.

BACKGROUND

Restenosis is common after percutaneous transluminal coronary angioplasty (PTCA) of chronic coronary occlusions. Stenting has been suggested as a means of improving results, but its use has not previously been investigated in a randomized trial.

METHODS

We randomly assigned 119 patients with a satisfactory result after successful recanalization by PTCA of a chronic coronary occlusion to 1) a control (PTCA) group with no other intervention, or 2) a group in which PTCA was followed by implantation of Palmaz-Schatz stents with full anticoagulation. Coronary angiography was performed before randomization, after stenting and at 6-month follow-up.

RESULTS

Inguinal bleeding was more frequent in the stent group. There were no deaths. One patient with stenting had a myocardial infarction. Subacute occlusion within 2 weeks occurred in four patients in the stent group and in three in the PTCA group. At follow-up, 57% of patients with stenting were free from angina compared with 24% of patients with PTCA only (p < 0.001). Angiographic follow-up data were available in 114 patients. Restenosis (> or = 50% diameter stenosis) developed in 32% of patients with stenting and in 74% of patients with PTCA only (p < 0.001); reocclusion occurred in 12% and 26%, respectively (p = 0.058). Minimal lumen diameter (mean +/- SD) at follow-up was 1.92 +/- 0.95 mm and 1.11 +/- 0.78 mm, respectively (p < 0.001). Target lesion revascularization within 300 days was less frequent in patients with stenting than in patients with PTCA only (22% vs. 42%, p = 0.025).

CONCLUSIONS

Stent implantation improved long-term angiographic and clinical results after PTCA of chronic coronary occlusions and is thus recommended regardless of the primary PTCA result.

Prospective, randomized trial of prolonged intracoronary urokinase infusion for chronic total occlusions in native coronary arteries

OBJECTIVES

The purpose of this study was to determine the safety and efficacy of three dosing regimens of intracoronary urokinase for facilitated angioplasty of chronic total native coronary artery occlusions.

BACKGROUND

Percutaneous transluminal coronary angioplasty of chronically occluded (>3 months) native coronary arteries is associated with low initial success secondary to an inability to pass the guide wire beyond the occlusion.

METHODS

Patients were enrolled if a chronic total occlusion >3 months old could not be crossed with standard angioplasty equipment. Of the 101 patients enrolled, 41 had successful guide wire passage and were excluded from urokinase treatment. The remaining 60 patients were randomized to receive one of three intracoronary dosing regimens of urokinase over 8 h (group A = 0.8 million U; group B = 1.6 million U; group C = 3.2 million U), and angioplasty was again attempted after completion of the urokinase infusion in 58 patients.

RESULTS

Coronary angioplasty was successful in 32 patients (53%) (group A 52%, group B 50%, group C 59%, p = 0.86). This study had a 90% power to detect at least a 50% difference between dosing groups at alpha 0.05. Bleeding complications requiring blood transfusion did not differ significantly among the dosing groups (A 0%, B 15%, C 6%, p = 0.14), although major bleeding episodes were less common in group A (p < 0.05). There were no major procedural or in-hospital complications. Angiographic follow-up in 69% of the patients with successful angioplasty revealed target vessel patency in 91% but an angiographic restenosis rate of 59%.

CONCLUSIONS

A prolonged supraselective intracoronary infusion of urokinase can be safely administered and may facilitate angioplasty of chronic total occlusions. Lower doses of urokinase are equally effective and result in fewer bleeding complications than do higher dosage regimens. Vessel patency is frequently maintained, but restenosis remains a problem.

Percutaneous revascularization of chronic coronary occlusions: an overview

Patients with a chronic coronary occlusion often undergo coronary angiography after weeks to months of occlusion. The published reports underestimate the extent of this problem because such patients are often arbitrarily assigned to receive medical therapy or undergo bypass surgery as a result of poor success with percutaneous revascularization and substantial restenosis. Thus, there is controversy about the role of angioplasty in this patient cohort. The goal of this overview was to evaluate the available information about angioplasty in chronic coronary occlusions. The primary indication for attempted recanalization of a chronic coronary occlusion has been symptomatic angina pectoris. Anginal status often improves after successful procedures (70% vs. 31% with a failed procedure); left ventricular function may improve; and subsequent referral for coronary artery bypass graft surgery is uncommon (3% vs. 28% in unsuccessful cases). Successful recanalization is achieved in approximately 65% of attempted procedures. Inability to cross the stenosis with a guide wire is the most common cause of procedural failure. Statistically significant predictors of procedural success include older occlusions (75% < 3 months old vs. 37% > or = 3 months old), absence of any anterograde flow through the occlusion (76% with vs. 58% without), angiographically abrupt-appearing occlusions (50% vs. 77% with tapered occlusions), presence of bridging collateral vessels (23% with vs. 71% without) and lesions > 15 mm. Procedural complications occur at a slightly lower incidence than in angioplasty of high grade subtotal stenoses. Long-term success is limited, and restenosis can be expected in > 50% of the patients. The experience with chronic total occlusions of saphenous vein bypass grafts is small, but there appear to be limited procedural success and significant procedural complications, particularly associated with distal emboli. The role of new pharmacologic agents has yet to be defined and that of new devices has been disappointing so far, but further technologic advances are on the horizon.

Balloon angioplasty versus rotational angioplasty in chronic coronary occlusions (the BAROCCO study)

Chronic total coronary occlusion remains one of the limitations of percutaneous transluminal coronary angioplasty, and few therapeutic devices are specifically designed to address this problem. Among such devices, low-speed rotational angioplasty could improve the primary success rate of the procedure but has never been studied in a controlled trial. One hundred consecutive patients with total coronary occlusion (duration 10 days to 1 year) and an indication for myocardial revascularization were randomized to either rotational or conventional angioplasty if the occlusion morphology was judged suitable for either technique. All baseline variables were evenly distributed among the 2 groups. The primary success rate in the rotational angioplasty groupø was 66% (33 of 50) compared with 52% (26 of 50) in the conventional angioplasty group before crossover to the rotational technique (p=NS). According to lesion morphology, the respective primary success rates were 77% (10 of 13) versus 92% (11 of 12) for tapered occlusions (p=NS), and 61% (22 of 36) versus 38% (14 of 37) for "stump-like" occlusions (p < 0.05). After taking into account the crossovers after failed conventional angioplasty, there was no benefit in performing rotational angioplasty first versus conventional angioplasty first (primary success rates 66% vs 60%, p=NS). Thus, in chronic coronary occlusions of tapered morphology, rotational angioplasty is not superior to conventional angioplasty. In stump-like occlusions, the primary success rate is higher with the rotational angioplasty technique; however ther is a disadvantage in using rotational angioplasty as a second-line device if the conventional technique is unsuccessful.