Full Metal Jacket

JACC: CARDIOVASCULAR INTERVENTIONS

VOL.

PUBLISHED BY ELSEVIER ON BEHALF OF THE AMERICAN

-, NO. -, 2017

ISSN 1936-8798/$36.00

COLLEGE OF CARDIOLOGY FOUNDATION

http://dx.doi.org/10.1016/j.jcin.2017.06.006

EDITORIAL COMMENT

Full-Metal Jacket Is it En Vogue?* Subhash Banerjee, MD, Emmanouil S. Brilakis, MD, PHD

T

he article entitled “Full Metal Jacket With

adds to the validity of their findings. The overall fre-

Drug-Eluting Stents for Coronary Chronic

quency of FMJ stenting in w37% of successful CTO

Total Occlusion” by Lee et al. (1) provides

PCIs and a clear increase in such procedures between

important insights into treatment of coronary chronic

2011 and 2015 is representative of the current clinical

total occlusions (CTO) with multiple overlapping

practice in the United States and world-wide. This

drug-eluting stents (DES). Although, it is focused on

clear trend has been fostered by the progress made

CTO lesions, its findings may be relevant to the percu-

on many fronts: improved CTO recanalization tech-

taneous coronary interventions (PCI) of both CTO

niques, operator experience, a more standardized

and diffusely diseased non-CTO stenoses, because

approach, access to specialized guidewires, crossing

these lesions are being increasingly tackled during

and re-entry devices, and improved deliverability

multivessel PCI in contemporary clinical practice (2).

and performance of coronary balloon catheters and

However, clinical outcomes data, both immediate

DES platforms. As expected, the majority of FMJ

and long-term, and determinants of treatment failure

PCIs were performed in the right coronary artery,

have been scarce (3–5). This report from a prospec-

which is known to require extensive treatment once

tively enrolled single-center CTO registry in South

recanalized. However, many FMJs were performed in

Korea involving 1,126 successful CTO procedures in

the left anterior descending artery (LAD) (almost 40%),

1,107 consecutive patients with long-term follow-up

with very few circumflex CTOs, which are associ-

(median 5.1 years, interquartile range: 2.4 to 7.1 years)

ated with lower success rates (6). Many operators

is one of the largest reports to date on full-metal

hesitate creating FMJ in the LAD, as it may preclude

jacket (FMJ) stenting of coronary CTO lesions.

subsequent coronary bypass graft surgery and may

The investigators represent an experienced group of

compromise important side branches, such as di-

operators with an established track record in per-

agonals and septals. A hybrid FMJ approach involving

forming complex PCI procedures. Similar to prior

stenting of the LAD with overlapping metal DES and

studies, FMJ was defined as $60-mm stent length

bioresorbable

without gaps (3). Inclusion of established clinically

Although, this approach offers some putative advan-

scaffolds

has

been

described

(7).

meaningful definitions of CTO, endpoints, and anti-

tages in terms of preserving future left internal mam-

platelet therapy regimen, along with an independent

mary artery anastomosis option for surgical bypass,

adjudication of angiographic data and clinical events,

its technical feasibility, safety, and durability are yet to be rigorously tested in well-designed clinical studies. The reported target lesion failure (TLF) of 16% and

*Editorials published in JACC: Cardiovascular Interventions reflect the

target lesion revascularization or occlusion rates of

views of the authors and do not necessarily represent the views of JACC:

8.6% over a median of 5 years are well within the

Cardiovascular Interventions or the American College of Cardiology. From the Veterans Affairs North Texas Health Care System, Dallas, Texas; the University of Texas Southwestern Medical Center, Dallas, Texas; and

accepted range for complex PCI with contemporary DES. The same can be said about periprocedural

the Minneapolis Heart Institute, Minneapolis, Minnesota. Dr. Banerjee

myocardial infarction (2.5%), overall stent thrombosis

has received honoraria from Medtronic, Gore, and AstraZeneca; and has

(1.2%), cardiovascular death (5.7%), and nonfatal

received (institutional) research grants from Boston Scientific Corpora-

spontaneous myocardial infarction (2.2%) rates re-

tion and Merck. Dr. Brilakis has received consulting/speaker honoraria

ported in this study. These findings may provide

from Abbott Vascular, Asahi, Cardinal Health, Elsevier, GE Healthcare, and St Jude Medical; and research support from InfraRedx and Boston

reassurance and alleviate concerns regarding FMJ

Scientific. His spouse is an employee of Medtronic.

stenting, which include potential loss of side branches,

2

Banerjee and Brilakis

JACC: CARDIOVASCULAR INTERVENTIONS VOL.

-, NO. -, 2017 - 2017:-–-

Full-Metal Jacket

especially with dissection re-entry, implantation of

whether the operators were overzealous in treating

additional stent layers to treat TLF, loss of coronary

distal coronary bed disease, which has been chroni-

bypass surgery options, and associated high TLF and

cally underperfused and could increase in diameter

stent thrombosis rates. Finally, 2 independent pre-

over time, or a >90% intravascular ultrasound–

dictors of TLF were identified: number of target vessel

guided PCI attributed to distal vessel stent oversizing.

DES (per 1 increment; multivariable hazard rate: 1.72,

Many CTO operators recommend avoiding over-

95% confidence interval 1.16 to 2.54) and persistent

treatment of distal lesions because they often

distal luminal narrowing ($50% narrowing compared

improve over time after restoration of antegrade flow

with distal stent edge and $20 mm in length; hazard

(8). Developing and validating criteria about when

rate 2.73, 95% confidence interval 1.66 to 4.47).

(and when not) to stent diseased distal segments

The authors (1) report that persistent distal luminal

during CTO PCI remains an “unmet need” and should

narrowing was present at the conclusion of nearly

be the focus of future investigations. Three- to

one-third of successful CTO PCI procedures. First,

6-month follow-up angiography could potentially be

whether the distribution of such distal narrowing was

of value for CTOs with diffusely diseased distal

disproportionately observed in a select coronary ar-

segments to allow early detection of restenosis

tery distribution is not disclosed. Second, the selec-

and treatment before progression and reocclusion

tion of $2.5-mm reference vessel CTO lesions and

occurs. Last, but not least, the inclusion of total stent

treatment with an average 3.2  0.4 mm in diameter

length instead of the number of stents as a predictor

DES are representative of CTO PCI of medium- to

of TLF would be more meaningful. Understandably,

large-caliber vessels. Thus, the persistent distal

the inclusion of both these variables in the multi-

luminal narrowing rate of 31.3% at the end of a suc-

variable regression model might be precluded by

cessful procedure may seem high; however, the lack

multicollinearity. However, using number of stents

of a non-FMJ group in the analysis deprives us of a

in this analysis does not preclude the effect of

much needed comparative assessment. This number

stent overlaps on this adverse outcome measure.

should also be considered in light of relatively low

In summary, the results of the present study pro-

use of dissection re-entry (2.7% patients), which has

vide reassurance regarding the safety and long-term

been associated with longer stented segments (6).

durability of FMJ stenting of CTO and possibly

A J-CTO score for the enrolled lesions has been pro-

non-CTO diffusely diseased vessels with DES. This

vided (2.3  1.1) and is representative of a more

information can be used for informed decision mak-

complex CTO cohort, but no information regarding

ing by both patients and operators performing CTO

the quality of the distal target vessel is provided.

PCI. These decisions hinge on the balance between

Because small-caliber distal vessels are associated

anticipated benefits and risks (both immediate and

with higher CTO recanalization failures and greater

long-term) prior to undertaking the now “en vogue”

use of retrograde techniques and/or dissection re-

FMJ stenting of coronary CTOs.

entry, it would seem that the current study might be biased toward more favorable and comparatively

ADDRESS

larger-caliber distal vessels (6). In view of these as-

Banerjee, 4500 South Lancaster Road (111a), Dallas, Texas

FOR

CORRESPONDENCE:

sumptions, albeit speculative, we are left to wonder

75230. E-mail: [email protected].

Dr. Subhash

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implantation. Catheter Cardiovasc Interv 2014;84: 361–5.

procedural outcomes: insights from a multicenter US registry. Can J Cardiol 2014;30:1588–94.

4. Yamamoto K, Sakakura K, Adachi Y, et al. Comparison of mid-term clinical outcomes between “complete full-metal jacket strategy” versus “incomplete full-metal jacket strategy” for

7. Rigatelli G, Zuin M, Frigato J, et al. Hybrid metal/scaffold-jacket versus full-metal jackets in

diffuse right coronary artery stenosis with drugeluting stents. J Cardiol 2017;69:823–9. 5. Durante A, Foglia Manzillo G, Burzotta F, et al. Long term follow-up of “full metal jacket” of de novo coronary lesions with new generation zotarolimuseluting stents. Int J Cardiol 2016;221:1008–12. 6. Christopoulos G, Karmpaliotis D, Wyman MR, et al. Percutaneous intervention of circumflex chronic total occlusions is associated with worse

left anterior descending coronary artery diffuse disease: differences in radiation exposure and fluoroscopic/procedural times. Cardiovasc Revasc Med 2017 May 18 [E-pub ahead of print]. 8. Gasparini GL, Rossi ML, Presbitero P. Follow-up improvement of distal vessel diameter after successful chronic total coronary occlusion recanalization. J Am Coll Cardiol Intv 2014;7:e31–3.

KEY WORDS chronic total occlusion, coronary artery disease, coronary stenting