Bioresorbable Scaffold Thrombosis

Bioresorbable Scaffold Thrombosis

JACC VOL. 68, NO. 5, 2016 Letters AUGUST 2, 2016:569–75 In the symptomatic population, the standardized both is the cause of the increased risk of...

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JACC VOL. 68, NO. 5, 2016


AUGUST 2, 2016:569–75

In the symptomatic population, the standardized

both is the cause of the increased risk of IE. Instead,

3-month risk of IE per 10,000 was 7.1 (95% confidence

we identified a clinical profile of individuals at higher

interval [CI]: 5.6 to 8.3) in the colonoscopy arm and

risk of IE following a colonoscopy.

3.7 (95% CI: 3.6 to 3.9) in the no colonoscopy arm; risk difference of 3.3 (95% CI: 1.9 to 4.5). In the surveillance population, the risk was 0.5 (95% CI: 0.1 to 0.8) in the colonoscopy arm and 0.5 (95% CI: 0.5 to 0.6) in the no colonoscopy arm; risk difference of 0 (95% CI: -0.4 to 0.4). In the prevention population, the risk was 0.6 (95% CI: 0.2 to 0.9) in the colonoscopy arm and 0.5 (95% CI: 0.4 to 0.5) in the no colonoscopy arm; risk difference of 0.1 (95% CI: -0.3 to 0.4). Results were similar before and after 2007, when a change in prophylaxis guidelines occurred (1). In the symptomatic population, the risk difference

*Xabier García-Albéniz, MD, PhD John Hsu, MD, MBA Marc Lipsitch, DPhil Michael Bretthauer, MD, PhD Roger W. Logan, PhD Sonia Hernández-Díaz, MD, DrPH Miguel A. Hernán, MD, DrPH *Department of Epidemiology Harvard T.H. Chan School of Public Health 677 Huntington Avenue Boston, Massachusetts 02115

was >0 only in individuals with preexisting risk fac-

E-mail: [email protected]

tors for IE (52%), and greatest among those in whom a

polyp was removed or a biopsy was performed

Please note: This work was funded by National Institutes of Health grants P01-CA134294, R01-CA164023, and R01-HS023128 and the Raymond P. Lavietes Foundation. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

(Table 1). Our findings suggest that individuals without risk factors for IE and those without gastrointestinal symptoms did not have an elevated IE risk after


colonoscopy, which is reassuring given that millions

1. Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee. Circulation 2007;116:1736–54.

of people receive a colonoscopy each year for these purposes. On the other hand, we estimated a modestly increased risk among individuals with risk factors for IE who undergo a polypectomy or a biopsy

2. Banerjee S, Shen B, Baron TH, et al. Antibiotic prophylaxis for GI endoscopy. Gastrointest Endosc 2008;67:791–8.

during a colonoscopy following recent symptoms.

3. Gagne JJ, Glynn RJ, Avorn J, et al. A combined comorbidity score predicted

Our analyses cannot disentangle whether the colonoscopy, the preexisting lesion, or a combination of

mortality in elderly patients better than existing scores. J Clin Epidemiol 2011; 64:749–59. 4. Hernán MA, Robins JM. Using big data to emulate a target trial when a randomized trial is not available. Am J Epidemiol 2016;183:758–64.

T A B L E 1 Adjusted 3-Month Risk of Infective Endocarditis

(95% CI) by Type of Colonoscopy and by the Presence of Risk for Infective Endocarditis in the Symptomatic Population, Cases per 10,000 Risk

Excess Risk

Bioresorbable Scaffold Thrombosis Why BRS Size Matters

All Colonoscopy with polypectomy or biopsy

7.9 (6.1 to 9.9)

4.2 (2.3 to 6.1)

Colonoscopy without polypectomy or biopsy

5.6 (3.5 to 7.5)

1.8 (-2.2 to 3.8)

No colonoscopy

3.7 (3.6 to 3.9)


In a recent paper, Puricel et al. (1) presented an interesting analysis of the mechanisms and predictors of bioresorbable scaffold thrombosis in a large registry of >1300 patients. Their analysis pointed to scaf-

High risk Colonoscopy with polypectomy or biopsy

13.5 (10.2 to 17.0) 7.3 (4.0 to 10.8)

Colonoscopy without polypectomy or biopsy

8.6 (5.7 to 12.2)

2.3 (-0.7 to 5.9)

No colonoscopy

6.3 (6.0 to 6.5)


Colonoscopy with polypectomy or biopsy

1.7 (0.5 to 3.0)

0.7 (-0.4 to 2.0)

Colonoscopy without polypectomy or biopsy

2.0 (0.4 to 4.0)

1.1 (-0.5 to 3.1)

No colonoscopy

1.0 (0.9 to 1.1)


fold underexpansion and a final minimal scaffold diameter of <2.4 mm as predicator of scaffold thrombosis, with the smallest postprocedural mini-

Low risk

mal lumen diameter of <2.1 mm strongly associated with a risk of event. The overall results of the ABSORB (ABSORB Bioresorbable Scaffold vs. Xience Metallic Stent for Prevention of Restenosis in Patients at High Risk of

CI ¼ confidence interval; Ref. ¼ reference.

Restenosis) trial series have been overall reassuring and showed no difference in target lesion failure and clinical outcomes at 1 year. However, patients treated



JACC VOL. 68, NO. 5, 2016


AUGUST 2, 2016:569–75

T A B L E 1 SAR: Comparison of BVS and a Thin Strut Metallic DES

(Xience) Depending on Reference Vessel Diameter

Please note: Dr. Mattesini has received consulting fees from Abbott. Dr. Di Mario has received a research grant from Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

SAR (%) Reference Vessel Diameter (mm)

BVS 3.0

Xience 3.0






1. Puricel S, Cuculi F, Weissner M, et al. Bioresorbable coronary scaffold







thrombosis: multicenter comprehensive analysis of clinical presentation, mechanisms, and predictors. J Am Coll Cardiol 2016;67:921–31.


BVS ¼ bioresorbable vascular scaffold; DES ¼ drug-eluting stent; SAR ¼ strutto-artery ratio.

with biodegradable scaffold had nevertheless a twice higher risk of definite or probable stent thrombosis at 1 year compared with those treated with regular drugeluting stents (DES) (odds ratio: 1.99; p ¼ 0.05) (2).


2. Cassese S, Byrne RA, Ndrepepa G, et al. Everolimus-eluting bioresorbable vascular scaffolds versus everolimus-eluting metallic stents: a meta-analysis of randomised controlled trials. Lancet 2016;387:537–44. 3. Ellis SG, Kereiakes DJ, Metzger DC, et al. Everolimus-eluting bioresorbable scaffolds for coronary artery disease. N Engl J Med 2015;373: 1905–15.

REPLY: Bioresorbable Scaffold Thrombosis Why BRS Size Matters

Subgroup analysis in the largest randomized study conducted so far (ABSORB III) has shown that bio-

We thank Dr. Foin and colleagues for their letter

resorbable vascular scaffolds (ABSORB BVS [Abbott

and fully share their comments. As they state, the

Vascular, Abbott Park, Illinois]) implanted in smaller

results of our study are in line with the evidence from

vessel diameter (<2.63 mm) had a higher 1-year rate

the ABSORB III study that the scaffold footprint

of device thrombosis compared with Xience (Abbott

(or strut/artery ratio [SAR]) is a strong predictor of

Vascular) (2.3% vs. 0.9%; relative risk ratio: 2.65).

patient prognosis (1). This concept has led to a

However, BVS implanted in vessels >2.63 mm had no

warning against the use of scaffolds in vessels

difference in device thrombosis at 1 year compared

<2.5 mm, which was reinforced strongly at the recent

with metallic DES (0.8% vs. 0.6%; relative risk ratio:

Food and Drug Administration panel, and with which

1.28) (3).

we fully agree.

So why does vessel reference size matter so much

There are other implications of this concept. First,

for bioresorbable technologies? The ABSORB BVS 2.5

sizing is particularly important, especially in the

and 3.0 sizes are actually the same device, mounted

2.5 mm range. Quantitative coronary angiography

on different delivery systems, with important impli-

might be, in the authors’ opinion, an insufficiently

cations on the stent to artery ratio, which increases

accurate tool. In our practice, we rather meticulously

from 27% in a 3.0-mm vessel to 33% in a 2.5-mm

follow the “1:1:1 rule”: the nominal diameter of the

vessel. In case the BVS is implanted in a very small

predilation balloon must be the same as the target

vessel or remains underexpanded, the stent-to-artery

vessel size and the scaffold intended to be implan-

ratio can increase to >40% at 2.0 mm, a large differ-

ted. Sizing can be made by comparing, in 2 different

ence compared with a thin strut metallic stent like

planes, the diameter of the balloon with that of the

Xience, which has a stent-to-artery ratio of 13% at


3.0 mm and 20% when deployed in a 2.0-mm vessel,

Second, full expansion of the balloon in 2

respectively (Table 1). This emphasizes the impor-


tance of using BVS in the appropriate reference vessel

10% indentation in a 2.5-mm balloon leads to a








size until dedicated BVS design for smallest vessel

minimum lumen diameter below the threshold

sizes become available.

of danger. Imaging in two different angiographic planes again provides important information and

*Nicolas Foin, MSc, PhD Alessio Mattesini, MD Philip Wong, MD Carlo Di Mario, MD, PhD


*National Heart Research Institute Singapore

stantially, with a much larger footprint/SAR for the

5 Hospital Drive

3.5-mm device. Accordingly, when treating vessels of

Singapore 169609

a diameter intermediate between 3.0 and 3.5 mm, the

E-mail: [email protected]

operator should be aware of the fact that the under-

deployment of a 3.5-mm scaffold also leads to a

Third, as reported in our paper (Figure 4) (2), the curves






scaffolds versus 2.5-/3.0-mm scaffolds differ sub-