A Coronary computed Tomography Angiography assisted CHIP-PCI: large Ectasia, multiple Narrowings and Chronic total Occlusion

Case-Report | DOI: https://doi.org/10.31579/2641-0419/080

A Coronary computed Tomography Angiography assisted CHIP-PCI: large Ectasia, multiple Narrowings and Chronic total Occlusion

  • Alfredo Marchese 1,2*
  • Antonio Tito 2
  • Fabrizio Resta 3
  • Giuseppe Speziale 3

*Corresponding Author: Alfredo Marchese, Chief of Interventional Cardiology Ospedale Santa Maria, Bari, Italy

Citation: Marchese A., Tito A., Resta F., Speziale G., (2020) A Coronary computed Tomography Angiography assisted CHIP-PCI: large Ectasia, multiple Narrowings and Chronic total Occlusion. J. Clinical Cardiology and Cardiovascular Interventions, 3(8); Doi:10.31579/2641-0419/080

Copyright: © 2020 Alfredo Marchese, This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Received: 07 September 2020 | Accepted: 14 September 2020 | Published: 22 September 2020

Keywords: Coronary Ectasia- Guide extension catheter - Complex higher-risk and indicated patients - Coronary computed tomography angiography- Complex percutaneous coronary intervention

Abstract

Background - Complex higher-risk and indicated patients (CHIP) percutaneous coronary interventions (PCI) still challenge interventionalists. Coexistence of coronary atherosclerotic ectasia, narrowings and chronic total occlusion (CTO), represents a unique complex scenario where no evidence could support a standard treatment.

Case summary - A 67-year-old man, hypertensive, diabetic, and with recent kidney transplantation with ongoing anti-rejection therapies, presented a complex three-vessel disease, in which the triad of ectasia, stenosis and chronical total occlusion became linked in a continuous pathological arterial remodelling process. The patient was successfully treated with CHIP-PCI integrating endovascular devices, drugs and imaging modalities.

Discussion - If revascularization is clinically warranted, procedural challenges and thrombotic issues could be overcome with advanced devices and effective antithrombotic therapies. Moreover, coronary computed tomography angiography (CCTA) represents one of the most promising procedures to predict the likelihood of success during CTOs recanalization and to overcome the absence of some objective means on invasive angiography. If narrowings, CTO and lesion-containing thrombus coexist, coronary imaging combined with modern technical devices and new antithrombotic drugs need to be combined in a tailored complex procedure.

Abbreviations

CHIP- complex high risk and indicated patients

PCI- percutaneous coronary intervention

CTO- chronic total occlusion

CCTA- coronary computed tomography angiography

GCE- guide extension catheter

GPI- glycoprotein IIb/IIIa inhibitor

Introduction

The coronary artery ectasia is attributed to atherosclerosis in 50% of cases and, in the great majority of these patients, it coexists with severe coronary artery narrowings. When sluggish blood flow and enhanced thrombogenicity (ectasia) are concomitant with severe blood flow reduction (coronary stenosis), the risk of angina up to the occurrence of an acute coronary syndrome is consistently high (1). However, despite interventions are mandatory depending on certain high-risk clinical or anatomic features, both percutaneous and antithrombotic treatments are significantly complicated by the lower procedural success rate with a higher incidence of no-reflow, distal embolization and/or early and late stent thrombosis. In fact, the role of aggressive anti-platelets or anticoagulation is still an area of ongoing debate. Moreover, the high thrombus burden, the landing zone sizing and the stiff and high-profile of the devices used, make these procedures demanding.

Above all, if a CTO occurs contemporarily it represents the major challenge for percutaneous intervention.

In this scenario, a variety of modern imaging modalities combined with the conventional invasive angiography and improved techniques and devices have been developed in an effort to overcome the aforementioned difficulties encountered in percutaneous treatment of CHIP lesions.

Mainly, considerable interest in the context of pre-procedural planning for revascularization of CTOs has increased in relation to the ability of CCTA to visualize and characterize the plaque, as well as to highlight coronary vessel trajectories and calcifications.

In fact, CCTA is reliably able to visualize many features that influence the success rate of PCI for CTOs and that are not easily visible on invasive angiography such as: extent of calcification and tortuosity, blunt or tapered stump shape, multiple occlusion and ectatic and/or aneurysmatic segment. Moreover, these procedures may be facilitated by an off-line integration of 3-dimensional CCTA data and fluoroscopic images in the cath-lab.

Case Presentation

A 67-year-old man, hypertensive, diabetic and on dialysis in the last 15th years, recently received a kidney transplantation with ongoing anti-rejection therapies.

After a six-months history of dyspnoea, he was referred for recent onset of effort angina and a reversible perfusion defect in the anterolateral and inferior wall territories.

Coronary angiography showed both a large and diffuse ectasia of the prox-mid left anterior descending artery (LAD) and a severe stenosis on its tortuous mid-distal segment (Figure 1d).

The left circumflex artery (LCx) showed both a flap of dissection and a narrowing at the ostium followed by a large ectasia in the mid segment. Also, the LCx had a distal Medina 0,1,0 bifurcation lesion (Figure 1: a, b, c)

An epicardial collateral filling for the distal right coronary artery (RCA) was evident (Figure 1: a,d).

Finally, the RCA showed a long sub-occlusive lesion on the mid-segment followed by a large ectasia resulting in a chronical total occlusion (CTO) (Figure 1 e).

Figure 1a) LAD: ectasia (arrows), distal stenosis (arrow). LCx: side branch narrowing (arrow).b) LCx: ostial flap and stenosis (arrow).c) Tortuous and narrowed mid-distal LAD (arrow).d) RCA sub-occlusive stenosis, large ectasia and distal CTO stump (arrows).

Percutaneous treatment was agreed during a Heart Team discussion.

An elective multivessel PCI of the LAD and of the LM-LCx with distal marginal branches was first planned.

The anti-thrombotic strategy was the administration of pre-treatment aspirin and cangrelor at the beginning of the procedure.

After a troublesome wiring of the distal LAD segment through the very large ectasia, a guide extension catheter (GEC) was advanced and the distal stenosis on the tortuous segment was prepared. Then, a 2.75/22mm stent was implanted and post-dilated at 22 atm (Figure 2: a,b,c).

With the same GEC, the large proximal LCx ectasia was crossed and the distal lesion pre-dilated; then a 3.0/26mm stent was carefully positioned, from the normal main to the side branch, with minimal proximal stent protrusion into the ectatic segment and optimized at high-pressure (Figure 2: d,e).

Finally, a jailed wire was left in the LAD and a 4.5/28mm stent was ensured from the LM ostium up to the proximal neck of the mid-LCx coronary ectasia to seal the LM-LCx ostial flap. A proximal optimization at high-pressure with two 4.5 and 5.0/8mm balloons (Figure 2: f,g,h) was performed. At the end of Cangrelor infusion (2 hours), the patient was administered with Ticagrelor 180mg.

Figure 2a,b,c) Safe stent delivery through GEC and final result(arrows).d,e) Bifurcation stent implantation with final result(arrows).f,g,h) LM-LCx stenting with POT and final angiogram.

A CCTA was performed before the RCA CTO-index procedure and after 24-hours of a specific hydration protocol for kidney protection. It offered detailed information about the stump, the intra-thrombus enhancement, and, above all, it unmasked a second hidden calcified ectasia in the occluded segment (Figure 3: a,b,c).

Figure 3a) CCTA of the calcific ectasia of the LAD(arrows).b) Hidden ectasia in the occluded segment(arrows).c) Collateral opacification and huge calcification in the occluded segment(arrows)   

Three days after the first PCI patient underwent the CTO procedure on the RCA; the set up was the right femoral access with a 6 Fr EBU 3.75 guiding catheter (GC) for bilateral injection and the left femoral access for RCA cannulation with a 6 Fr AL 2 GC (Figure 4: a, b).

Off-line CCTA datasets were directly integrated on the fluoroscopy screen in order to select the most suitable fluoroscopic projection and to minimize contrast use during angiography. Moreover, it was particularly useful to verify the direction and the advancement of the stiff flat guidewire through the large ectatic and occluded segment below the re-entry point.

Multiple attempts with single wire escalation failed with a Fielder XT and a Gaia 1 (Asahi Intecc, Nagoya, Japan) then, supported by a FineCross microcatheter advanced at the end of the first large ectasia, parallel wire using a further escalation to a Gaia 2, crossed successfully (Figure 4: c, d, e). Combined collateral injection and CCTA images were particularly useful to gradually correct, the angulations of the wire in the occluded saccular ectasia and through two consecutive shrinkages unmasked by CT-scan.

Once the guidewire re-entered into the true lumen, the occluded segment was prepared with multiple low-profile balloons and overlapped stents were implanted covering all the occluded segments with the proximal edge slightly encroaching into the distal segment of the first patent coronary ectasia.

Finally, the sub-occlusive lesion was treated with an optimal final angiographic result (Figure 4: f, g).

Figure 4a) RCA proximal sub-occlusion, ectasia and CTO(arrows).b) contralateral injection.c,d,e) Wiring with microcatheter and Gaia 2(arrows). f,g) Final angiographic result.

The patient was pain-free with an un-complicated post-procedural recovery and rise of I-Troponine to 0.37 ng/ml (normal values: <0.16 ng/ml).

Discussion 

Management of CHIP affected by coexisting coronary artery ectasia, LM coronary lesions and chronically total occlusions remain uncertain.

These specific lesion types, mostly exacerbating clinical comorbidities, are typically associated with higher recurrence of in-hospital and late thrombotic events.

The endovascular treatment of complex PCI often means difficulties during wire crossing, delivery of balloons and stents and, above all, higher risk of procedural complications.

The following aspects specific to this case need to be highlighted:

  • Mechanistically, both stenosis and ectasia slows coronary flow velocity and increases blood viscosity promoting thrombosis
  • The enhanced thrombogenicity suggests a potential benefit of more aggressive and effective antiplatelet agents. 
  • The more the procedure is challenged the more detailed imaging information before PCI are essential to optimize the procedural planning.
  • Marked advances in endovascular techniques and device technology are effective in lowering the risks of distal embolization, no-reflow and huge perforation when delivering through thin-wall, angulated and thrombus containing lesions.

For the aforementioned reasons, we intentionally opted for the administration of aspirin and cangrelor in catheterization laboratory instead of the clopidogrel pre-loading in order to obtain the safest and most effective platelet inhibition during the first highly risky PCI.

Cangrelor not only resulted more effective than clopidogrel particularly in elective complex PCI (2) but, its safety profile related to the immediate reversibility of its effect makes it particularly useful in special subsets of CHIP-PCI as the one described.

Conversely, the effects of GPI, often routinely used in an off-label or in a bail-out fashion, cannot be reversed safely and immediately if bleeding complications and/or perforation would occur and a coronary artery bypass graft urgently needed.

Moreover, this case highlights the safety and the usefulness of micro- and guide extension catheters to facilitate PCI in particularly complex anatomies (3). In fact, not only it has been proven that their effectiveness reduces contrast-dye and to deliver bulky devices distally over tortuous and angulated vessels, but also to avoid excessive manipulations through lesions containing-thrombus at high risk of huge coronary complications.

Finally, CCTA is a pivotal imaging modality providing valuable information complementary to conventional angiography for a careful diagnostic and technical work-up of a CTO procedure (4).

Evidence highlights the reliability of CCTA to enable vessel mapping and to select the most optimal device based on the morphological and anatomical features of the occlusion such as the exact trajectory during the “hit-or-miss” wire manipulations (5). In fact, in our case CCTA represented a great diagnostic tool in directing the wire along the correct track of the ectatic occluded segment just below the CTO stump.

Conclusions 

CHIP-PCIs, hampered by low success rate and high risk of severe complications, are facilitated by the use of safer and more effective antiplatelet therapies combined with contemporary techniques supported by multiple devices and non-invasive modalities of imaging.   

Firstly, in stable patients undergoing complex PCI, compared with the current recommendation of a loading dose of clopidogrel, cangrelor reduces major adverse cardiac events occurring within 48h after PCI regardless of baseline lesion complexity, thus suggesting a greater benefit/risk profile in patients with complex coronary anatomy. Secondly, by reducing the thrombotic complications in the peri-procedural period, it may result in less need for bailout GPI use, thus improving the safety profile of a cangrelor-based antiplatelet therapy. Thirdly, cangrelor also avoids postponing PCI to allow for sufficient platelet inhibition after oral P2Y12 inhibitor administration hence increasing the safety and efficacy of the anti-thrombotic therapy needed during complex ad hoc PCI performed in catheterization laboratories with high turnover.

With regards to the usefulness of the GECs, they are most frequently used to deliver the devices distally over the calcified lesions, in tortuous or angulated vessels and/or when it may be difficult to negotiate through previously deployed stents. Further, the GEC could accommodate various bulky devices without any resistance, such as PTFE-covered stents and multiple wires and balloons, thus reducing the risk of stent dislodgment, coronary dissection and thrombosis, and the distal embolization of thrombus-containing plaque.

Finally, preprocedural non-invasive CCTA imaging may predict the difficulty of CTO PCI reasonably. Most studies have consistently reported blunt entries tortuous or long occlusions, side branches, and calcifications as anatomic predictors of failure. CCTA can evaluate these parameters reasonably and has an advantage over coronary angiography for direct visualization of CTO vessel trajectory, the burden of calcification, the presence of any ectatic segment and visualization of artery from any arbitrary angle.

Conflict of Interest

The authors declare that there was no conflict of interest. 

Acknowledgement

Endorsed by the Italian Society of Interventional Cardiology – GISE

References

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