Procedural implications of intravascular ultrasound morphologic features of chronic total coronary occlusions

A large post-stenting intramural hematoma in the left anterior descending artery caused by a small intimal calcium spur; should we respect the calcium shape?

Coronary heavy calcification (HC) poses a sturdy challenge to percutaneous coronary intervention (PCI). Scores considering calcification length, thickness, or circumferential extent, are widely accepted to dictate upfront calcium modification to improve PCI outcomes. Although often marginalized, calcification shape (morphology) may require consideration during procedure planning in selected cases. This case demonstrates how a focal but spur-shaped calcification led to a massive proximal left anterior descending (LAD) dissecting intramural hematoma.

The role of intravascular imaging in chronic total occlusion percutaneous coronary intervention

Chronic total occlusions (CTOs) represent the most complex subset of coronary artery disease and therefore careful planning of CTO percutaneous coronary recanalization (PCI) strategy is of paramount importance aiming to achieve procedural success, and improve patient's safety and post CTO PCI outcomes. Intravascular imaging has an essential role in facilitating CTO PCΙ. First, intravascular ultrasound (IVUS), due to its higher penetration depth compared to optical coherence tomography (OCT), and the additional capacity of real-time imaging without need for contrast injection is considered the preferred imaging modality for CTO PCI. Secondly, IVUS can be used to resolve proximal cap ambiguity, facilitate wire re-entry when dissection and re-entry strategies are applied and most importantly to guide stent deployment and optimization post implantation. The role of OCT during CTO PCI is currently limited to stent sizing and optimization, however, due to its high spatial resolution, OCT is ideal for detecting stent edge dissections and strut malapposition. In this review, we describe the use of intravascular imaging for lesion crossing, plaque characterization and wire tracking, extra- or intra-plaque, and stent sizing and optimization during CTO PCI and summarize the findings of the major studies in this field.

Contemporary issues of percutaneous coronary intervention in heavily calcified chronic total occlusions: an expert review from the European CTO Club

Severe calcification is frequent in coronary chronic total occlusions (CTO), and its presence has been associated with increased procedural complexity and poor long-term outcomes following percutaneous coronary intervention (PCI) in an already challenging anatomical setting. The diagnostic characterisation of heavily calcified CTOs using non-invasive and invasive imaging tools can lead to the application of different therapeutic options during CTO PCI, in order to achieve adequate lesion preparation and optimal stent implantation. In this expert review, the European Chronic Total Occlusion Club provides a contemporary, methodological approach, specifically addressing heavily calcified CTOs, suggesting an integration of evidence-based diagnostic methods to tailored, up-to-date percutaneous therapeutic options.

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.

The Clinical Effects of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion: A Meta-Analysis

Background

The clinical effects of intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) lesions remain unclear.

Methods

We identified all full-text published studies that compared the effects of IVUS-guided CTO-PCI with angiography-guided CTO-PCI by searching electric databases including PubMed, Embase, Cochrane Library, and ISI Web of Science from the establishment to Nov 2021. There was no language limitation. The endpoints included the incidence of major adverse cardiac events (MACE), cardiac death, all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR).

Results

Five studies involving a total of 2320 patients were included in this meta-analysis. Compared to the angiography-guided group, IVUS-guided PCI showed no significant reduction in the incidence of MACE (I² = 27.4%, P = 0.239; RR 0.929, 95% CI 0.765 to 1.128, P = 0.457), cardiac death (I² = 0.0%, P = 0.459; RR 0.574, 95% CI 0.299 to 1.103, P = 0.096), all-cause death (I² = 0.0%, P = 0.964; RR 0.677, 95% CI 0.395 to 1.163, P = 0.158), MI (I² = 46.7%, P = 0.131; RR0.836, 95% CI 0.508 to 1.377, P = 0.482), and TVR (I² = 21.2%, P = 0.279; RR 0.929, 95% CI 0.679 to 1.272, P = 0.648).

Conclusions

IVUS-guided PCI demonstrated no significant benefit on MACE, cardiac death, all-cause death, MI, and TVR in patients with CTO lesions. However, given the study's limitations, additional high-quality RCTs are needed.

Plaque modification in calcified chronic total occlusions: the PLACCTON study

INTRODUCTION AND OBJECTIVES

Severe calcification is present in> 50% of coronary chronic total occlusions (CTOs) undergoing percutaneous intervention. We aimed to describe the contemporary use and outcomes of plaque modification devices (PMDs) in this context.

METHODS

Patients were included in the prospective, consecutive Iberian CTO registry (32 centers in Spain and Portugal), from 2015 to 2020. Comparison was performed according to the use of PMDs.

RESULTS

Among 2235 patients, wire crossing was achieved in 1900 patients and PMDs were used in 134 patients (7%), requiring more than 1 PMD in 24 patients (1%). The selected PMDs were rotational atherectomy (35.1%), lithotripsy (5.2%), laser (11.2%), cutting/scoring balloons (27.6%), OPN balloons (2.9%), or a combination of PMDs (18%). PMDs were used in older patients, with greater cardiovascular burden, and higher Syntax and J-CTO scores. This greater complexity was associated with longer procedural time but similar total stent length (52 vs 57mm; P=.105). If the wire crossed, the procedural success rate was 87.2% but increased to 96.3% when PMDs were used (P=.001). Conversely, PMDs were not associated with a higher rate of procedural complications (3.7 vs 3.2%; P=.615). Despite the worse baseline profile, at 2 years of follow-up there were no differences in the survival rate (PMDs: 94.3% vs no-PMDs: 94.3%, respectively; P=.967).

CONCLUSIONS

Following successful wire crossing in CTOs, PMDs were used in 7% of the lesions with an increased success rate. Mid-term outcomes were comparable despite their worse baseline profile, suggesting that broader use of PMDs in this setting might have potential technical and prognostic benefits.

Collagenase to facilitate guidewire crossing in chronic total occlusion PCI-The Total Occlusion Study in Coronary Arteries-5 (TOSCA-5) trial

BACKGROUND

Chronic total occlusions (CTO) are common and are associated with lower percutaneous coronary intervention (PCI) success rates, often due to failure of antegrade guidewire crossing. Local, intralesional delivery of collagenase (MZ-004) may facilitate guidewire crossing in CTO.

AIMS

To evaluate the effect of MZ-004 in facilitating antegrade wire crossing in CTO angioplasty.

METHODS

A total of 76 patients undergoing CTO PCI were enrolled at 13 international sites: 38 in the randomized training stage (collagenase [MZ-004] 900 or 1200 μg) and 38 in the placebo-controlled stage (MZ-004 900 or 1200 μg or placebo). Patients received the MZ-004 or identical volume saline (placebo group) in a double-blind design, injected via microcatheter directly into the proximal cap of the CTO. The following day patients underwent CTO PCI using antegrade wire techniques only.

RESULTS

Patients were generally similar except for a trend for higher Japanese chronic total occlusion (J-CTO) score in the MZ-004 group (MZ-004 J-CTO score 1.9 vs. 1.4, p = 0.07). There was a numerical increase in the rates of guidewire crossing in the MZ-004 groups compared to placebo (74% vs. 63%, p = 0.52). Guidewire crossing with a soft-tip guidewire (≤1.5 g tip load) was significantly higher in the MZ-004 groups (0% in placebo, 17% in 900 μg, and 29% in 1200 μg MZ-004 group, p = 0.03). Rates of the major adverse cardiovascular event were similar between groups.

CONCLUSION

Local delivery of MZ-004 into coronary CTOs appears safe and may facilitate CTO crossing, particularly with softer tipped guidewires. These data support the development of a pivotal trial to further evaluate this agent.

Stent visualization methods to guide percutaneous coronary interventions and assess long-term patency

Evaluation of acute percutaneous coronary intervention (PCI) results and long-term follow-up remains challenging with ongoing stent designs. Several imaging tools have been developed to assess native vessel atherosclerosis and stent expansion, improving overall PCI results and reducing adverse cardiac events. Quantitative coronary analysis has played a crucial role in quantifying the extent of coronary artery disease and stent results. Digital stent enhancement methods have been well validated and improved stent strut visualization. Intravascular imaging remains the gold standard in PCI guidance but adds costs and time to the procedure. With a recent shift towards non-invasive imaging assessment and coronary computed tomography angiography imaging have shown promising results. We hereby review novel stent visualization techniques used to guide PCI and assess stent patency in the modern PCI era.

Intravascular Ultrasound in Chronic Total Occlusion Percutaneous Coronary Intervention: Solving Ambiguity and Improving Durability

Chronic total occlusions remain among the most technically challenging lesions to treat percutaneously. Limitations of 2-dimensional angiography may further hinder successful treatment of these lesions. Intrasvascular ultrasound has a key role in percutaneous recanalization for a chronic total occlusion by providing key lesion characteristics, facilitating guidewire crossing, elucidating the intraplaque or extralaque path of the guidewire, optimizing lesion preparation, guiding stenting and identifying suboptimal results. Live visualization of the guidewire during crossing may reduce extraplaque wire tracking. This review describes the practical uses of intravascular imaging for commonly encountered scenarios when treating chronic total occlusions.

Clinical and angiographic outcomes of true vs. false lumen stenting of coronary chronic total occlusions: Insights from intravascular ultrasound

OBJECTIVES

The clinical implications of subintimal stenting (SS) of the recanalized chronic total occlusion (CTO) segment have not been characterized. We evaluated the in-hospital and the long-term clinical and angiographic outcomes of drug-eluting stents (DESs) deployed in true vs. false lumen of successfully recanalized CTO.

METHODS AND RESULTS

Two independent reviewers analyzed the intravascular ultrasound (IVUS) images of 173 successfully recanalized CTO lesions (157 patients), between August 2011 and October 2012. After successful guidewire (GW) crossing, lesions were classified according to IVUS evaluation into two groups: (1) true lumen (TL) stenting group and (2) SS group; and compared with regards to in-hospital and long-term clinical outcomes. In 154 lesions, DESs were deployed in the TL; and in 19 (11%) lesions, DESs were deployed in the subintimal space (95% confidence interval: 6.3-15.6%). False GW tracking in the SS group resulted in increased rates of IVUS-detected dissection flaps (84% vs. 42.6%, P ≤ 0.001), intramural hematoma (32 vs. 11%, P = 0.01), and minor perforations 6/19 (31.6% vs. 8.4%, P = 0.002). At 1-year follow-up, both groups had similar cumulative rates of binary restenosis and target lesion revascularization (P = 0.73 and P = 0.97, respectively). Six patients (4.6%, 6/129 patients) in the TL group and none in the subintimal group died at 1 year.

CONCLUSIONS

Acknowledging some limitations, our observations may suggest that, subintimal stent deployment in a recanalized CTO segments, using second generation DES and IVUS guidance, might have a comparable success rate and long-term angiographic and clinical outcomes as TL stenting.

Coronary chronic total occlusion intervention: A pathophysiological perspective

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is the last frontier in coronary intervention. PCI of CTO carries multiple advantages, such as significant improvement in symptoms, improvement in abnormal wall motion and left ventricular function and, possibly, increased long-term survival. As of today the procedural success is markedly improved because of technical innovations and is limited to highly experienced operators. To enhance the overall success rate from a worldwide perspective, a thorough understanding of its pathophysiology is critical to further development of newer techniques and technologies. In this review, the author outlines in-depth the evidence that underpins our understanding of CTO pathophysiology and its insight into CTO intervention that incorporates various steps and techniques to cross the lesion.

Utility of adjunctive modalities in Coronary chronic total occlusion intervention

Coronary chronic total occlusion (CTO) intervention remains one of the most challenging domains in interventional cardiology. Due to the technical challenges involved and potential procedural complications, CTO percutaneous coronary intervention (PCI) attempt and success rates remain less than standard PCI. However, the use of several adjunctive tools such as intravascular ultrasound, optical coherence tomography, rotational atherectomy, orbital atherectomy, excimer laser coronary atherectomy and percutaneous left ventricular assist device may contribute to improved CTO PCI success rates or provide better hemodynamic assessment of CTO lesion (i.e., using fractional flow reserve). In this review we present the current literature describing the utility and efficacy of these adjunctive modalities in CTO intervention.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

BACKGROUND

Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention.

METHODS AND RESULTS

We examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade-only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time.

CONCLUSIONS

Intravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Clinical Impact of Intravascular Ultrasound-Guided Chronic Total Occlusion Intervention With Zotarolimus-Eluting Versus Biolimus-Eluting Stent Implantation: Randomized Study

BACKGROUND

There have been no randomized studies comparing intravascular ultrasound (IVUS)-guided versus conventional angiography-guided chronic total occlusion (CTO) intervention using new-generation drug-eluting stent Therefore, we conducted a prospective, randomized, multicenter trial designed to test the hypothesis that IVUS-guided CTO intervention is superior to angiography-guided intervention.

METHODS AND RESULTS

After successful guidewire crossing, 402 patients with CTOs were randomized to the IVUS-guided group (n=201) or the angiography-guided group (n=201) and secondarily randomized to Resolute zotarolimus-eluting stents or Nobori biolimus-eluting stents. The primary and secondary end points were cardiac death and a major adverse cardiac event defined as the composite of cardiac death, myocardial infarction, or target-vessel revascularization, respectively. After 12-month follow-up, the rate of cardiac death was not significantly different between the IVUS-guided group (0%) and the angiography-guided group (1.0%; P by log-rank test=0.16). However, major adverse cardiac event rates were significantly lower in the IVUS-guided group than that in the angiography-guided group (2.6% versus 7.1%; P=0.035; hazard ratio, 0.35; 95% confidence interval, 0.13-0.97). Occurrence of the composite of cardiac death or myocardial infarction was significantly lower in the IVUS-guided group (0%) than in the angiography-guided group (2.0%; P=0.045). The rates of target-vessel revascularization were not significantly different between the 2 groups. In the comparison between Resolute zotarolimus-eluting stent and Nobori biolimus-eluting stent, major adverse cardiac event rates were not significantly different (4.0% versus 5.7%; P=0.45).

CONCLUSIONS

Although IVUS-guided CTO intervention did not significantly reduce cardiac mortality, this randomized study demonstrated that IVUS-guided CTO intervention might improve 12-month major adverse cardiac event rate after new-generation drug-eluting stent implantation when compared with conventional angiography-guided CTO intervention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01563952.

Intravascular imaging of coronary calcification and its clinical implications

Calcium impacts the natural history and treatment of coronary artery disease in many ways. Intravascular imaging studies, mostly intravascular ultrasound, but more recently studies using optical coherence tomography, have been instrumental in increasing our understanding of the relationship between calcium and coronary atherosclerosis, the predictors, the natural history of this relationship, and the impact on treatment. On one hand, stable coronary lesions are associated with more calcium than unstable lesions; and the amount of calcium may affect the success of percutaneous coronary intervention. On the other hand, calcium correlates with plaque burden; unstable lesions are associated with focal calcium deposits; and calcific nodules are one of the morphologies of vulnerable plaque. This review focuses on more than 20 years of intravascular imaging studies of the relationship between calcium and coronary atherosclerosis.

Comparison of second- and first-generation drug eluting stent for percutaneous coronary chronic total occlusion intervention

BACKGROUND

The performance of contemporary second-generation drug-eluting stents (DESs) for percutaneous chronic total occlusion (CTO) intervention is not well established. The present study compared the efficacy and safety outcomes of second-generation DESs with those of first-generation DESs in CTO-percutaneous coronary intervention (PCI).

METHODS

This retrospective analysis included 1049 consecutive CTO patients who underwent successful DES implantation (first-generation; 487 vs. second-generation; 562 patients) between March 2003 and August 2014. The primary endpoint was the composite of all-cause death, Q-wave myocardial infarction (MI), or target-vessel revascularization (TVR).

RESULTS

During a follow-up of 3 years, the primary endpoint incidence was 10.1% for second- and 7.7% for first-generation DES (p=0.30). After multivariable adjustment, there was no significant difference between these groups in terms of the risk of composite of death, Q-wave MI, or TVR (Hazard ratio [HR] 1.42, 95% confidence interval [CI] 0.88-2.28, p=0.15) nor in the individual risks of death (adjusted HR 1.33, 95% CI 0.69-2.56, p=0.39), Q-wave MI (adjusted HR 1.15, 95% CI 0.30-4.47, p=0.84) and TVR (adjusted HR 1.06, 95% CI 0.52-2.15, p=0.87). The incidence of definite/probable stent thrombosis was relatively low (0.5% vs.0.9%, p=0.17) throughout the follow-up period.

CONCLUSION

The 3-year clinical outcomes of patients treated with second-generation DESs are comparable to those treated with first-generation DESs for CTO-PCI.

Applied Pathology for Interventions of Coronary Chronic Total Occlusion

Percutaneous coronary intervention of chronically occluded vessels can result in significant improvement in symptoms, relieve myocardial ischemia, and affect a reduction in major adverse cardiac events. Likelihood of achieving successful revascularization can be significantly enhanced with a thorough understanding of the pathology of these occluded coronary arteries. In this chapter, various steps and techniques to cross the CTO lesion and recanalize it are discussed in details.

CTO pathophysiology: how does this affect management?

Chronic total occlusion (CTO) pathophysiology has been described in a few, small studies using post mortem histology, and more recently, in vivo intravascular ultrasound (IVUS) to analyse the constituents of occluded segments. Recent improvements in equipment and techniques have revealed new insights into physical characteristics of occluded coronaries, which in turn enable predictable procedural success. The purpose of this review is to consider the published evidence describing CTO pathophysiology from the perspective of the hybrid algorithm approach to CTO PCI.

Methods: Literature searches using “Chronic Occlusion”, “angioplasty”, and” pathology” as keywords. Further searches on “coronary” “collateral”, “Viability”. Bibliographies were scrutinised for further key publications in an iterative process. Papers describing animal models were excluded.

Lumen enlargement of the coronary segments located distal to chronic total occlusions successfully treated with drug-eluting stents at follow-up

AIMS

Chronic total occlusions (CTO) are the final stage of atherosclerosis. Occluded coronary arteries have large plaque burden and negative remodelling. The aim of this study was to assess lumen and vessel changes of segments located distal to successfully recanalised CTO.

METHODS AND RESULTS

Ninety-one CTO treated with drug-eluting stents underwent quantitative coronary angiography (QCA) at baseline and at 12-18 months; 31 underwent serial intravascular ultrasound (IVUS) imaging. Angiographic changes were assessed with QCA as differences in minimal, mean and maximal lumen diameter (MinLD, MeanLD and MaxLD, respectively). Vessel changes were assessed with IVUS as changes in plaque and vessel volume. At follow-up, angiographic MinLD increased 23.9% (from 0.88±0.32 to 1.09±0.35 mm; p<0.01), MeanLD 16.4% (from 1.59±0.44 to 1.85±0.45 mm; p<0.01) and MaxLD 11.7% (from 2.39±0.67 to 2.67±0.70 mm; p<0.01). Lumen enlargement was greater in non-restenotic lesions, small lumen area at the end of the index procedure and low LDL-cholesterol levels during the study. By IVUS, lumen volume increased 26.9% (from 108.1±89.2 to 137.3±115.3 mm3; p<0.01), vessel volume increased 12.1% (from 207.1±170.2 to 232.2±196.0 mm3; p<0.01) and plaque volume tended to decrease 3.9% (from 98.9±88.7 to 94.9±89.3 mm3; p=0.07). Small lumen at baseline was related to greater lumen enlargement.

CONCLUSIONS

Segments distal to recanalised CTO showed a notable lumen and vessel enlargement with a trend toward mild plaque regression. Low LDL-cholesterol levels increase lumen enlargement.

The role for adjunctive image in pre-procedural assessment and peri-procedural management in chronic total occlusion recanalisation

Non invasive coronary angiography with multislice computed tomography has exquisite sensitivity to detect calcium and even the faintest late contrast filling of the distal vessel. Calcium burden and occlusion length are still valuable markers of duration, complexity and success of the recanalisation procedure. The ability to visualise the vessel also in the occluded segment, especially if calcified, can also help the operator to understand where to pierce the proximal cap in stumpless occlusions and to predict unusual courses, especially in very tortuous arteries. Imaging side by side CT images and angiography during the recanalisation procedure is an established practice in many active CTO laboratories and algorithms for co-registration are designed to overcome the challenges of systo-diastolic and respiratory motion. Intravascular ultrasound is used in almost all cases by the experienced Japanese CTO operators but most of the times its main use is a better identification of the diseased segment after predilatation to ensure complete stent cover and appropriate stent expansion, an application similar to other complex non occlusive lesions. The specificity of IVUS during CTO recanalisation is the identification of the vessel path in stumpless occlusions and the guidance of wire reentry especially during reverse Controlled Retrograde Anterograde Tracking. Optical coherence tomography has limitations in the setting of CTO recanalisation because of the need of forceful contrast flushing to clear blood, contraindicated in the presence of anterograde dissections, and the limited penetration. The variability in the use of both non-invasive and invasive imaging during CTO recanalisation is immense, going from more than 90% in Japan to less than 20% in Europe and intermediate penetration in the USA. Probably the explanation is almost only in availability and cost because all countries see a progressive increase of use suggesting that these methods are becoming an established tool for guidance of CTO recanalisation.

Thrombotic Occlusion during Intravascular Ultrasonography-Guided Percutaneous Coronary Intervention of Stumpless Chronic Total Occlusion

Percutaneous coronary intervention (PCI) of stumpless chronic total occlusion (CTO) lesions with a side branch stemming from the occlusion have a significantly lower treatment success rate because physicians cannot identify an accurate entry point with only conventional angiographic images. An intravascular ultrasonography (IVUS)-guided wiring technique might be useful for the penetration of stumpless CTO. We recently experienced thrombotic occlusion during an IVUS-guided stumpless CTO procedure. The cause of the thrombosis is not completely understood; the thrombosis may have been associated with the long use of the IVUS catheter. Special precautions should be taken to prevent thrombus in such cases.

A case of intra- and extra-mural hematomas during recanalization for chronic total occlusion

An intramural hematoma is an accumulation of blood between the internal and external elastic membranes within the medial space, whereas an extramural hematoma is a dilution and/or dissemination of blood throughout the adventitia. Intra- and extra-hematomas are observed by intravascular ultrasound during percutaneous coronary intervention (PCI). The patient described herein presented with angina pectoris. Her coronary angiogram showed diffuse narrowing of the mid-left anterior descending artery and total occlusion of the distal right coronary artery (RCA). Intra- and extra-mural hematomas developed during PCI of the RCA; however, the lesions were covered successfully using long drug-eluting stents.

Value of intravascular ultrasound in the management of coronary chronic total occlusions

Failure of guide wire crossing is the commonest reason for failed procedure in chronic total occlusion (CTO) of the coronary arteries. Intravascular ultrasound can be useful in some cases to achieve. Successful guide wire crossing into the distal true lumen of the coronary artery. We describe two cases demonstrating the role of intravascular ultrasound in successful recannalization of the CTO.

Heavily calcified coronary lesions preclude strut apposition despite high pressure balloon dilatation and rotational atherectomy: in-vivo demonstration with optical coherence tomography

Heavily calcified lesions (HCL) continue to present challenges that are not always solved by modern low-profile, non-compliant high-pressure balloons, or bladed balloons. Uncrossable or unexpandable lesions need lesion modification, using ablating devices such as rotational atherectomy. Three cases of HCL treated with drug-eluting stents, using a new intravascular imaging device, Optical Coherence Tomography with 10-fold superior resolution and fewer artifacts compared with conventional intravascular ultrasound, are presented. Insights from using this highly sensitive imaging technique outline the high prevalence of persistent stent strut malapposition in this group, despite the use of high-pressure dilatation or rotational atherectomy.

CT coronary angiography predicts the outcome of percutaneous coronary intervention of chronic total occlusion

BACKGROUND

The success rate of percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) is relatively low. Further evaluation of CTO lesion with CT coronary angiography (CT-CA) may help to better select patients that would benefit from percutaneous revascularization. We aimed to test the possible association between failed PCI and transluminal calcification of CTO as assessed by CT-CA.

METHODS

Patients with CTO awaiting PCI were scanned with a 16-slice CT. A cardiologist and a radiologist assessed transluminal calcification of CTO lesions on CT images while an interventional cardiologist at a core laboratory assessed conventional variables of invasive fluoroscopic coronary angiography (FCA) associated with failed PCI of CTO. The significance of CT and FCA variables in association with failed PCI were analyzed.

RESULTS

In a cohort of 39 patients with 43 CTO lesions, 24 lesions were successfully revascularized. Transluminal calcification > or =50% as assessed on CT-CA was strongly associated with failed PCI (odds ratio [OR] of PCI success = 0.10, 95% confidence interval [CI]: 0.02-0.47, P = 0.003). Blunt stump as seen on FCA was also associated with failed PCI (OR of PCI success = 0.24, 95% CI: 0.07-0.86, P = 0.029). There was no significant evidence to support that the duration of CTO, presence of side branch and bridging collaterals, and the absence of microchannels as assessed with FCA were associated with failed PCI. On multivariate analysis, transluminal calcification > or =50% on CT-CA was the only significant predictor of failed PCI.

CONCLUSIONS

Heavy transluminal calcification as assessed with CT-CA is an independent predictor of failed PCI of CTO. CT-CA may have a role in the work-up of CTO patients prior to PCI.