Percutaneous recanalization of chronically occluded coronary arteries: a consensus document: part II

The feasibility and safety of applying the Magnetic Navigation System to manage chronically occluded vessels: a single centre experience

AIMS

Applying the Magnetic Navigation System (MNS) to manage chronic total occlusions (CTOs). The MNS precisely directs a magnetised guidewire in vivo through two permanent external magnets.

METHODS AND RESULTS

The first 43 consecutive MNS treated CTOs were retrospectively evaluated. Computed tomography coronary angiography (CTCA) co-integration with the MNS provided a virtual road map through the occlusion. Unsuccessful MNS cases were managed with bailout conventional guidewire techniques. Experienced CTO and MNS operators had unrestricted access to CTO devices and equipments. The MNS crossing success increased from 40% to 56% over 52 months and averaged 44.2% (19/43 patients). In 58.3% (14/24) of failed MNS cases the conventional wire approach was successful, giving an overall procedural success rate of 76.6%. Of those conventionally treated, two patients required pericardiocentesis. On average, 1.8 ± 0.9 stents (lengths 44.7 ± 21.4 mm and diameter 2.8 ± 0.4 mm) were implanted. Procedural times were lengthy (125.0 ± 35.3 min) requiring high fluoroscopy dosage (11980.2 ± 6457.9 Gy/cm2) and contrast media usage (388.8 ± 170.2 ml). Operators persevered less with magnetic wires (20.9 ± 12.4 min vs. 27.7 ± 24.4 min), and preferentially used the least stiff wire as first choice (53.5%). CTCA co-integration did not influence procedural outcome. As with conventional wires, higher magnetic wire successes occurred in low calcified lesions, those with a central stump and without bridging collaterals.

CONCLUSIONS

In unselected CTOs, the magnetic wires are safe and feasible. Current modest success rates with a high procedural bailout rate implicate the need for improved magnetic guidewire technology comparable to available sophisticated conventional CTO wires. Randomised studies are needed to clarify the value of magnetic guided recanalisation.

Contemporary success and complication rates of percutaneous coronary intervention for chronic total coronary occlusions: results from the ALKK quality control registry of 2006

AIMS

Despite successful prevention of lesion recurrence by drug-eluting stents (DES), and the advancement in procedural techniques in the treatment of chronic total coronary occlusions (CTO), the number of CTOs treated by percutaneous coronary intervention (PCI) is still low as compared to their prevalence. This study aims to assess the outcome of PCI for CTOs in a contemporary survey of PCI in interventional centres in Germany.

METHODS AND RESULTS

The basis of this analysis is the 2006 quality assessment database of PCI conducted by the ALKK (working group of cardiology centres). Thirty-five centres contributed to this database, representing about 10% of all interventional centres of Germany. From a total of 20,502 patients, 8,882 patients with stable angina were selected. Of these 674 patients (7.6%) underwent PCI for a CTO. Their procedural characteristics and the hospital outcome were compared with patients treated for non-occlusive lesions. As compared to non-occlusive lesions, less patients underwent ad hoc PCI for a CTO. The fluoroscopy time was almost double of that in non-occlusive lesions, and contrast usage was significantly higher. The success rate was 60.1% as compared to 97.3% (p<0.001). Severe intraprocedural and in-hospital complications were similar for CTO and non-CTO lesions. Almost all patients with a CTO received a stent; DES were used in 53.4%, which was higher than the rate in non-CTO lesions (38.9%; p<0.001).

CONCLUSIONS

Although the success rate for PCI in CTOs is still well below that in non-occlusive lesions, this procedure is safe, encouraging its wider application. The low rate of DES use did not reflect the evidence for DES in CTOs.

Changes in myocardial ischemic burden following percutaneous coronary intervention of chronic total occlusions

OBJECTIVES

We assessed the potential for percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) to decrease myocardial ischemia and established objective criteria to predict post-procedure improvement.

BACKGROUND

Optimal treatment for CTO of coronary arteries is controversial, and selection criteria for PCI of CTO are subjective.

METHODS

All patients undergoing CTO PCI at a single center between 2002 and 2007 were included if myocardial perfusion imaging (MPI) was performed within 12 ± 3 months before and a follow-up study within 12 ± 3 months after PCI. Average summed difference scores were calculated and converted to percent ischemic myocardium to classify patients as having normal/minimal, mild, moderate, or severe ischemia. A significant improvement in ischemia following PCI was classified as an absolute ≥5% decrease in ischemic myocardium. Receiver operating characteristic (ROC) curves were used to identify ischemic thresholds predictive of decreased and increased ischemic burden on follow-up MPI.

RESULTS

In 301 patients, average baseline ischemic burden was 13.1% ± 11.9% and decreased to 6.9% ± 6.5% (P < 0.001) during follow-up. Overall, 53.5% of patients met criteria for improvement following PCI. These patients were more likely to be male, without diabetes, with CTO in the left anterior descending artery, and classified as having high ischemic burden at baseline. ROC analysis identified a baseline 12.5% ischemic burden as optimal in identifying those most likely to have a significantly decreased ischemic burden post-PCI. Those with a baseline ischemic burden less than 6.25% were more likely to have an increased ischemic burden post-PCI.

CONCLUSIONS

Ischemic burden is reduced following CTO PCI, and the decrease is greater at high ischemic burden. A threshold of 12.5% ischemic burden is suggested as a criterion for performing PCI in the setting of CTO.

Short- and long-term follow-up of percutaneous coronary intervention for chronic total occlusion through transradial approach: tips for successful procedure from a single-center experience

BACKGROUND

 There are limited data regarding transradial percutaneous coronary intervention (PCI) for chronic total occlusion (CTO).

OBJECTIVE

 To assess the feasibility and safety of transradial coronary intervention (TRI) for CTO lesions, we analyzed our experience in PCI treatment of CTO lesion through transradial approach for the past 6 years.

METHODS

 From January 2003 to May 2009, among 134 CTO lesions, on which we performed PCI, 120 lesions were performed from transradial approach.

RESULTS

 Technical success for transradial CTO was 80%. Complication of access bleeding was zero. The most commonly selected guiding wire was Wave 3 for right coronary artery (RCA) lesions (82%) and Voda left for Left Coronary Artery (LCA) lesions (91%). The average number of wires used during procedure was 2.2 ± 0.8. Tapered wire was used in 8% of the cases, Rotablator was performed in 4.1% of cases, and Tornus catheter was performed in 12.5% of cases. The mean procedure time was 83 ± 39 minutes. The mean volume of contrast medium used was 228 ± 92 mL. There were two coronary artery perforations during procedure and one in-hospital cardiac death. Patients were followed up for 36 ± 21 months; restenosis rate was 19.5%-26.7% for bare metal stent (BMS) and 9.8% for drug-eluting stents (DES). Overall major adverse cardiac events (MACE) rate was 11.7%.

CONCLUSION

 It was demonstrated that transradial PCI for CTO lesions is safe, minimizing vascular complications without increasing procedural time and contrast use.

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.

The role of coronary CT angiography in chronic total occlusion intervention

Revascularisation by percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is often a technically challenging procedure. The manipulation of wires and devices through a CTO during PCI without any means to visually identify vessel-wall boundaries involves an inherent risk of complications such as arterial dissection, perforation and cardiac tamponade. With the tremendous advances in multidetector CT technology and the popularity of utilising coronary CT angiogram (CCTA) for a workup of chest pain patients, an increasing number of CTO cases are being encountered. Therefore, the primary goal of CCTA for imaging in CTOs involves identifying the presence and locations of CTO as well as predicting the potential clinical benefits derived from revascularisation of the occluded segment. The secondary goal includes preprocedural planning to shorten procedure times, visualisation of the procedure in predicting the ease with which a CTO can be crossed and the frequency of procedure-related complications such as contrast nephropathy and radiation skin injury. Apart from these, CCTA also plays a role in postprocedural assessment of the revascularised arterial segments and long-term follow-up on the patency of coronary stents.

Peri-procedural myocardial injury during percutaneous coronary intervention: an important target for cardioprotection

Percutaneous coronary intervention (PCI) has become the predominant procedure for coronary revascularization in patients with both stable and unstable coronary artery disease (CAD). Over the past two decades, technical advances in PCI have resulted in a better and safer therapeutic procedure with minimal procedural complications. However, about 30% of patients undergoing elective PCI sustain myocardial injury arising from the procedure itself, the extent of which is significant enough to carry prognostic importance. The peri-procedural injury which accompanies PCI might therefore reduce some of the beneficial effects of coronary revascularization. The availability of more sensitive serum biomarkers of myocardial injury such as creatine phosphokinase MB isoenzyme (CK-MB), Troponin T, and Troponin I has enabled the quantification of previously undetectable myocardial injury. Peri-procedural myocardial injury (PMI) can also be visualized by cardiac magnetic resonance imaging, a technique which allows the detection and quantification of myocardial necrosis following PCI. The identification of CAD patients at greatest risk of sustaining PMI during PCI would allow targeted treatment with novel therapies capable of limiting the extent of PMI or reducing the number of patients experiencing PMI.

A prospective multicenter registry of 0.010-inch guidewire and compatible system for chronic total occlusion: the PIKACHU registry

OBJECTIVES

The aim of this study was to evaluate the safety and effectiveness of a 0.010-inch guidewire and a balloon catheter for treatment of chronic total occlusion (CTO).

BACKGROUND

Pathological studies have shown that 60-70% of CTO lesions have microchannels of sizes equal to or less than 0.010 inch.

METHODS

The PIKACHU registry is a prospective, multicenter registry study. A 0.010-inch guidewire had to be used as the first guidewire to attempt to pass the CTO lesion. The primary endpoint was device success using a 0.010 system.

RESULTS

A total of 141 patients with 141 lesions were enrolled. The median duration of occlusion was 9 months (range 3-156). Average guiding catheter size was 5.8 +/- 0.7 Fr. and TRI was 76.6 %. CTOs were mostly between 10-20 mm long, observed in 53 occlusions. There were 107 lesions (75.9%) with bending of more than 45 degrees. Calcification was seen in 91 lesions (64.5%). A 0.010-inch guidewire was successfully passed through in 97 of 141 lesions (68.8%). A 0.010-inch guidewire compatible balloon catheter was passed in 87 of the 97 lesions (88.7%) and final PCI success was achieved in all the cases. The overall clinical success rate was 87.9% (124/141). No MACE or bleeding complications were observed.

CONCLUSION

The PIKACHU registry data suggest that the 0.010-inch system is safe and practicable for treatment of CTO lesions.

Antegrade, retrograde, and combination strategies for chronic total occlusions

Chronic total occlusion (CTO) represents one of the most challenging lesion subsets faced by the interventional cardiologist. CTO is a common problem, being present in more than 30% of patients undergoing coronary angiography. Over the past 10 years, the success rate of recanalization has increased from approximately 50-85%. Developments in guidewire technology, imaging technique, and coronary devices have contributed to the improved prognosis of patients affected by a CTO lesion. Enhancement in antegrade and retrograde techniques of recanalization also result in improved outcomes. Benefits of CTO recanalization may include symptom relief, decreased need for coronary artery bypass graft surgery, improved left ventricular ejection fraction, and in some cases an improved survival.

Real-time 3D imaging in the cardiac catheterization laboratory

Worldwide experience in coronary catheterization and angiography for the detection and evaluation of lumen narrowing is extensive. Conventional coronary angiography analysis is complex since these arteries are of relatively small caliber and in constant movement, while being synchronized with the movement of the heart chambers and respiratory system. Moreover, atherosclerotic plaques in the coronary tree are themselves very intricate and frequently positioned in eccentric locations. The last decade has witnessed significant advances as novel data acquisition and processing techniques have been introduced. Researchers have developed novel processing systems that make it possible to construct 3D images in real-time during coronary intervention. The most common solutions are rotational imaging and reconstruction from multiple single-plane images. These techniques produce real-time 3D images of the coronary arteries in the catheterization laboratory. This article describes these state-of-the-art imaging methods and other specific novel applications in clinical practice, such as stent enhancement, guidance during transcatheter aortic valve implantation and advanced geometrical analysis with computational fluid dynamics.

Effectiveness of recanalization of chronic total occlusions: a systematic review and meta-analysis

BACKGROUND

Chronic total occlusion (CTO) recanalizations remain extremely challenging procedures. With improvements in technology and techniques, success rates for recanalization of CTO continue to improve. However, the clinical benefits of this practice remain unclear. The aim of the study was to determine the effectiveness of CTO recanalization on clinical outcomes.

METHODS

We performed a systematic review and meta-analysis of published studies comparing CTO recanalization to medical management. Data were extracted in duplicate and analyzed by a random effects model.

RESULTS

We did not identify any randomized controlled trials or observational studies comparing CTO recanalization to a planned medical management. We did identify 13 observational studies comparing outcomes after successful vs failed CTO recanalization attempt. These studies encompassed 7,288 patients observed over a weighted average follow-up of 6 years. There were 721 (14.3%) deaths of 5,056 patients after successful CTO recanalization compared to 390 deaths (17.5%) of 2,232 patients after failed CTO recanalization (odds ratio [OR] 0.56, 95% CI 0.43-0.72). Successful recanalization was associated with a significant reduction in subsequent coronary artery bypass graft surgery (CABG) (OR 0.22, 95% CI 0.17-0.27) but not in myocardial infarction (OR 0.74, 95% CI 0.44-1.25) or major adverse cardiac events (OR 0.81, 95% CI 0.55-1.21). In the 6 studies that reported angina status, successful recanalization was associated with a significant reduction in residual/recurrent angina (OR 0.45, 95% CI 0.30-0.67).

CONCLUSIONS

In highly selected patients considered for CTO recanalization, successful attempts appear to be associated with an improvement in mortality and with a reduction for the need for CABG as compared to failed recanalization. However, given the observational nature of the reviewed evidence, randomized clinical trials are needed to confirm these findings.

Impact of Aggressive Endovascular Recanalization Techniques on Success Rate in Chronic Total Arterial Occlusions (CTOs)

Purpose: To report experience with aggressive recanalization approaches in chronic total arterial occlusion (CTO). Methods: Chronic total arterial occlusion recanalization was attempted on 112 limbs in 99 consecutive patients between January 1999 and December 2006. Results: There were 63 iliac arteries, 45 femoropopliteal arteries, and 4 occluded stents. Mean occlusion length was 8.7 ± 4.7 cm. Conventional recanalization was attempted first and was successful in 71 limbs (70%). Probing with the guidewire’s stiff end was attempted in 33 of the 41 procedures where conventional techniques failed and was successful in 18 (54%), improving the overall procedural success rate to 80%. For the remaining 15 limbs, home-made directional sharp needle recanalization was attempted in 11 and was successful in 9 (82%), further improving the overall recanalization success to 88%. Procedural complications were self-limited or managed nonoperatively. Conclusions: Aggressive recanalization techniques in CTO following failure of traditional means are safe and can substantially improve procedural success rates.

Percutaneous coronary intervention in the Occluded Artery Trial: procedural success, hazard, and outcomes over 5 years

BACKGROUND

The Occluded Artery Trial (OAT) was a 2,201-patient randomized clinical trial comparing routine stent-based percutaneous coronary intervention (PCI) versus optimal medical therapy alone in stable myocardial infarction (MI) survivors with persistent infarct-related artery occlusion identified day 3 to 28 post MI. Intent-to-treat analysis showed no difference between strategies with respect to the incidence of new class IV congestive heart failure, MI, or death. The influence of PCI failure, procedural hazard, and crossover on trial results has not been reported.

METHODS

Study angiograms were analyzed and adjudicated centrally. Factors associated with PCI failure were examined. Time-to-event analysis using the OAT primary outcome was performed by PCI success status. Landmark analysis (up to and beyond 30 days) partitioned early hazard versus late outcome according to treatment received.

RESULTS

Percutaneous coronary intervention was adjudicated successful in >87%. Percutaneous coronary intervention failure rates were similar in US and non-US sites, and did not significantly influence outcome at 60 months (hazard ratio for success vs fail 0.79, 99% CI 0.45-1.40, P = .29). Partitioning of early procedural hazard revealed no late benefit for PCI (hazard ratio for PCI success vs medical therapy alone 1.06, 99% CI 0.75-1.50, P = .66).

CONCLUSIONS

Percutaneous coronary intervention failure and complication rates in the OAT were low. Neither PCI failure nor early procedural hazard substantively influenced the primary trial results.

Anchor wire technique improves device deliverability during PCI of CTOs and other complex subsets

INTRODUCTION

The DES era has increased the demand on PCI-based revascularization and lesion complexity. One of the technical problems still limiting success rates in complex PCI is limited device deliverability. This work describes a new technique to improve deliverability.

METHODS

When deliverability was limited during PCI, a second 0.014-inch guide wire was inserted into the non-target artery. Then, another attempt was made to deliver the device to the target lesion.

RESULTS

The technique was attempted in 13 consecutive cases with difficulties in delivering a device; five of CTO (38.5%), five of diffuse calcifications (38.5%), two of direct stenting (15.3%) and one case (7.7%) of dilated aortic root. The anchor wire technique was the only maneuver needed in eight (61.5%) cases. Additional technique was needed in four (30.7%) cases. In four out of five (80%) CTO cases, the anchor wire technique allowed successful PCI and to deliver a balloon across a CTO. Final procedural success was achieved in 12 (92.3%) cases.

CONCLUSIONS

The anchor wire technique can be very useful in increasing success rates in CTOs and various complex PCI's and has the advantage of being simple to use, without a need to re-cross the target lesion or to exchange PCI system.

Chronic total coronary occlusion in patients with intermediate viability: value of low-dose dobutamine and contrast-enhanced 3-T MRI in predicting functional recovery in patients undergoing percutaneous revascularisation with drug-eluting stent

PURPOSE

Myocardial viability was evaluated by magnetic resonance imaging (MRI) in patients with chronic total coronary occlusion (CTO) treated with a drug-eluting stent. Change in left ventricular ejection fraction (LVEF) was analysed.

MATERIALS AND METHODS

Twenty-three patients with CTO underwent delayed-enhancement (DE) and low-dose dobutamine MRI (LD). Diastolic wall thickness (DWT), dobutamine-induced systolic wall thickening (SWT) and DE transmural extension were quantitatively assessed in vessel-related segments, calculating the contribution of viable tissue to SWT, expressed as viability index (VI)=[SWTx(100 - DE)]/100. Patients with transmural enhancement were excluded from revascularisation. At 6 months follow-up, patients underwent coronary angiography (CA) and MRI. Functional recovery was defined as a 2-mm increase in SWT.

RESULTS

Transmural enhancement (mean DE 62.88+/-37.18] was present in three patients. Mean DWT, SWT, VI and DE of recanalised patients were 8.03+/-2.35, 2.64+/-1.56, 1.77+/-1.48 mm and 41.97+/-30.32. Revascularisation was successful in 14/16. Follow-up CA showed patency of treated vessels. Functional recovery was achieved in 13 patients. Functional recovery showed significant correlation with SWT (beta 1,779, p=0.015), and even higher correlation with VI (beta 2.032, p=0.011). LVEF improved significantly [Delta 95% confidence interval (CI) -4.47, p=0.0203).

CONCLUSIONS

Invasive CTO treatment has beneficial effects on myocardial contractility that can be predicted by VI, and on LVEF.

Chronic total coronary occlusions in patients with stable angina pectoris: impact on therapy and outcome in present day clinical practice

BACKGROUND

Chronic total coronary occlusions (CTOs) represent a subgroup of coronary lesions with a low procedural success and high recurrence rate. However, there is evidence for a prognostic benefit of revascularizing a CTO.

OBJECTIVE

This study assessed the prevalence of CTOs among patients with stable angina pectoris and its impact on therapeutic strategies.

METHODS

Between 2001 and 2003, a survey was conducted in 64 sites to analyze the outcome of the first diagnostic angiography in patients presenting with stable angina pectoris (STAR registry). The clinical characteristics, initial angiographic findings, therapeutic strategy and outcome within the first year were analyzed.

RESULTS

A total of 2,002 patients were entered into the registry. One-third had at least one CTO. At 1 year, the mortality in patients with a CTO was significantly higher than in those without a CTO (5.5 vs. 3.1%; P = 0.009). This excess mortality was related to a higher prevalence of confounding factors in patients with a CTO such as diabetes and more severe LV dysfunction. Patients with a CTO were more likely to undergo surgery or being treated medically, whereas patients without a CTO were more likely to undergo PCI. If a CTO was treated by PCI the periprocedural and long-term outcome was similar to those with PCI for a non-occlusive lesion. However, periprocedural MACE was higher for patients treated for a non-occlusive lesion without first treating the CTO.

CONCLUSIONS

The prevalence of CTOs in patients with stable angina pectoris is high, and it influences the clinical outcome within the first year. The therapeutic strategy is influenced towards a rather conservative approach and lower rates of interventional therapy.

Subintimal tracking and re-entry technique with contrast guidance: a safer approach

OBJECTIVES

To assess the procedural and clinical outcomes from a modified subintimal tracking and re-entry (STAR) procedure performed using contrast guidance.

BACKGROUND

Previous data showed that recanalizing a chronic total occlusion (CTO) with the STAR technique was possible. However, this technique was considered difficult and therefore has only been adopted by a limited number of experienced operators.

METHODS

Patients (n = 68) with a CTO of a native coronary artery treated by a single operator with this technique were included.

RESULTS

The right coronary artery was involved in 79.4%, the morphology was blunt in 77.9%, and CTO length was longer than 20 mm in 67.6%. Angiographic success rate was 80.9% with a 70.6% rate of complete recanalization. Stent implantation was performed in 82.3% of cases, with drug-eluting stents (DES) implanted in the majority (92.7%). Procedural complications occurred in 10.3% of cases. There were no episodes of myocardial infarction during follow-up, with 1 case (1.5%) of cardiac death. There were no cases of definite or probable stent thrombosis, and there was 1 (1.5%) possible stent thrombosis. The overall rate of in-segment binary restenosis was 44.7%, and target lesion revascularization (TLR) was performed in 25% of lesions. The rate of TLR in lesions treated with DES was 29.4% and in those treated with bare-metal stents was 50%.

CONCLUSION

The contrast-guided STAR technique appears to be feasible and relatively safe. However, this procedure is limited by a high rate of restenosis even with DES, and a second procedure may be necessary to obtain a definitive result.

Comparison of safety, efficacy, and outcome of successful versus unsuccessful percutaneous coronary intervention in "true" chronic total occlusions

Despite improving techniques for opening chronic total occlusions (CTOs), the benefit of successful recanalization of the artery remains unclear. The aims of this study were to investigate the safety and efficacy of percutaneous coronary intervention for "true" CTO, defined by Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 and duration > or =3 months, and to compare the outcome of successful versus failed procedures. A cohort of 172 consecutive patients with de novo CTOs of native vessels confirmed by angiographic review in which percutaneous coronary interventions were attempted was studied. End points included angiographic success, in-hospital complications, and long-term major adverse cardiac events. Technical success was obtained in 73.8% of CTO lesions (127 of 172). No deaths or nonfatal Q-wave myocardial infarctions occurred in the hospital. Repeat percutaneous coronary interventions in the hospital were required in 1.6% of patients (2 of 127) in whom the CTOs were initially opened. Perforation during the initial failed attempts occurred in 6.7% of patients (3 of 45). One patient required operative repair. After an average follow-up period of 2 years, patients with successful procedures experienced similar incidences of cardiac death and nonfatal Q-wave myocardial infarctions as did patients with failed procedures (5.3% and 4.9%, respectively, p = 0.3). Patients with successfully opened arteries required target vessel revascularization more frequently, but this did not reach statistical significance (18.8% vs 0%, p = 0.06). In conclusion, attempts to open CTOs with the devices available at the time of this registry were accompanied by a significant risk for perforation. Furthermore, successful recanalization did not translate into a reduction in 2-year mortality or nonfatal Q-wave myocardial infarctions compared with patients with failed procedures.

Clinical use of sirolimus-eluting stents

Drug-eluting stents, or intracoronary stents that combine the local delivery of antirestenotic pharmacologic therapies while maintaining the mechanical advantage of bare metal stents over balloon angioplasty alone, are a highly complex technology that have profoundly affected the practice of percutaneous coronary intervention over the last 5 years. These devices were designed specifically to treat the neointimal hyperplasia occurring after conventional bare metal stent placement, and have been remarkably successful in this regard. However, recent concerns have been raised regarding the long-term safety of these devices, particularly when used outside of the specific patient and lesion subsets studied in the pivotal randomized trials that led to device approval by regulatory bodies within the United States and abroad. This review aims to present a brief description of the sirolimus-eluting stent device platform and its mechanism of action, followed by an overview of current data regarding efficacy and safety regarding the clinical use of sirolimus-eluting stent technology.

Utility of drug-eluting stents in complex lesions and high-risk patients

Drug-eluting stents represent a breakthrough technology designed to deliver high concentrations of a bioactive agent locally to an atherosclerotic lesion, thereby minimizing systemic side effects of the drug. The safety and efficacy of drug-eluting stents have clearly been demonstrated in noncomplex lesions. This article presents an evidence-based analysis of the current experience with CYPHER sirolimus-eluting stents (Cordis Corp., Miami Lakes, FL) and TAXUS paclitaxel-eluting stents (Boston Scientific, Natick, MA) in a broad spectrum of high-risk and/or complex subsets of patients and lesions, including those with diabetes mellitus, multivessel disease, diffuse disease, very small vessels, lesions in saphenous vein grafts, chronic total occlusions, in-stent restenosis, ostial and bifurcation lesions, unprotected left main disease, and acute myocardial infarction. Emerging data in several of these subsets suggest that drug-eluting stents are safe and effective, and their use may currently be recommended, whereas in other groups of patients and lesions the efficacy and/or safety of drug-eluting stents remains to be determined, thus warranting caution. It is anticipated that penetration of drug-eluting stents will continue to increase, and fewer patients will require surgical revascularization to achieve sustained event-free survival.

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.

Evaluation of left ventricular function three years after percutaneous recanalization of chronic total coronary occlusions

We investigated early and late effects of percutaneous revascularization for chronic total coronary occlusion on left ventricular (LV) function and volumes. Magnetic resonance imaging was performed in 21 patients before and 5 months and 3 years after recanalization. Global LV function and volumes and segmental wall thickening (SWT) were quantified on cine images. The 2 viability indexes used were the transmural extent of infarction (TEI) on delayed contrast enhancement images and end-diastolic wall thickness at baseline. Significant decreases in mean end-diastolic (86 +/- 14 to 78 +/- 15 ml/m2; p = 0.02) and mean end-systolic volume indexes (35 +/- 13 to 30 +/- 13 ml/m2; p = 0.03) were observed 3 years after recanalization. Mean ejection fraction tended to improve (60 +/- 9% to 63 +/- 11%; p = 0.11). SWT significantly increased at 5-months' follow-up (p <0.001), and an additional improvement was found at 3 years' (p = 0.04) follow-up in segments with TEI <25%. In segments with TEI of 25% to 75%, SWT was unchanged at 5-month follow-up (p = 0.89), but improved at 3 years (p = 0.04). SWT was unchanged in segments with transmural scars. For segmental functional recovery, TEI was a better predictor than end-diastolic wall thickness at baseline (odds ratio 5.6, 95% confidence interval 1.5 to 21.1, p = 0.01 vs odds ratio 2.5, 95% confidence interval 0.7 to 8.3, p = 0.14). In conclusion, a positive effect on LV remodeling and ejection fraction was observed up to 3 years after recanalization. Both early and late improvements in regional LV function were observed in the perfusion territory of chronic total coronary occlusion and were related to the transmural extent of infarction on pretreatment magnetic resonance imaging.