Prognostic implications of plaque characteristics and stenosis severity in patients with coronary artery disease

Selected in Journal of the American College of Cardiology by E. Asher , S. Brugaletta

References

Authors

Lee JM, Choi KH, Koo BK, Park J, Kim J, Hwang D, Rhee TM, Kim HY, Jung HW, Kim KJ, Yoshiaki K, Shin ES, Doh JH, Chang HJ, Cho YK, Yoon HJ, Nam CW, Hur SH, Wang J, Chen S, Kuramitsu S, Tanaka N, Matsuo H, Akasaka T.

Reference

J Am Coll Cardiol. 2019 May 21;73(19):2413-2424

Published

May 2019

Link

Read the abstract

Reviewers

Elad Asher

@AsherElad

Interventional cardiologist / Cardiologist

Shaarey Zedek Medical Center - Jerusalem, Israel

Salvatore Brugaletta

@sbrugaletta

Interventional cardiologist / Cardiologist

Barcelona, Spain

Our Comment

This joint review is part of the PCRonline GLOBAL Journal Club Initiative by selected members of the EAPCI/PCR Journal Club and PCR NextGen, and is based on the underlying idea of “Bringing peers together, exchanging ideas, towards a common standard of care”.

Why this study – the rationale/objective?

Although the presence of ischemia is a key prognostic factor in patients with coronary artery disease (CAD), there is a discrepancy between angiographic stenosis severity and the presence of myocardial ischemia. The presence of high-risk plaque characteristics (HRPC) is also associated with increased risk of cardiovascular events. The clinical outcomes of fractional flow reserve (FFR) -guided percutaneous coronary intervention (PCI) are better than those of angiography-guided PCI or medical treatment. However, clinical events still occur in patients with FFR >0.80.

The aim of the study was to evaluate the:

association between physiological stenosis severity and coronary computed tomography angiography (CTA)-defined HRPC;
prognostic implications of coronary CTA-defined HRPC according to the severity of physiological stenosis in patients with coronary artery disease.

How was it executed – the methodology?

The study was performed in 12 centers in 3 countries (Korea, China, and Japan) between November 2011 and March 2014. It was a post hoc analysis from the 3V FFR FRIENDS study (Clinical implications of 3V FFR). A total of 772 vessels (299 patients) evaluated by both coronary CTA and FFR were analyzed. The presence and number of HRPC (minimum lumen area <4 mm2, plaque burden ≥70%, low attenuating plaque, positive remodeling, napkin-ring sign, or spotty calcification) were assessed using coronary CTA images. The risk of vessel-oriented composite outcome (VOCO) (a composite of vessel-related ischemia-driven revascularization, vessel-related myocardial infarction, or cardiac death) at 5 years was compared according to the number of HRPC and FFR categories.

What is the main result?

The proportions of lesions with ≥3 HRPC were 58.6%, 46.5%, 36.8%, 15.7%, and 3.5% in FFR ≤0.60, 0.61 to ≤0.70, 0.71 to ≤0.80, 0.81 to ≤0.90, and >0.90 categories, respectively.

Both FFR and number of HRPC showed significant association with the cumulative incidence of VOCO at 5 years among deferred vessels (p values 0.008 and 0.023 for FFR and number ofHRPC, respectively).
By maximally selected log-rank statistics, the presence of 3 or more HRPC showed the best discrimination ability for the occurrence of VOCO at 5 years.
In the deferred lesions (FFR>0.8), lesions with ≥3 HRPC showed a significantly higher risk of VOCO compared with those with <3 HRPC (15.0% vs. 4.3%; HR: 3.964; 95% CI: 1.451 to10.828; p = 0.007).
There was no significant difference in the risk of VOCO between ≥3 HRPC versus <3 HRPC in the FFR ≤0.80 group (17.2% vs. 17.0%; HR: 1.257; 95% CI: 0.300 to 5.270; p = 0.754).
The cumulative incidence of VOCO at 5 years was 4.3%, 15.0%, and 10.7% among the deferred vessels with FFR >0.80 and <3 HRPC, deferred vessels with FFR >0.80 and ≥3 HRPC, and stented vessels with FFR ≤0.80, respectively.
A multivariable marginal Cox model revealed that FFR, ≥3 HRPC, and diabetes mellitus were independently associated with the occurrence of VOCO.

Critical reading and relevance for clinical practice

In this study, there was a significant difference in the number of HRPC among the different ranges of FFR. The number of HRPC increased with a decrease in FFR, and vice versa.

Moreover, both FFR and number of HRPC showed a significant association with the cumulative incidence of VOCO at 5 years and both were independent predictors of VOCO in the deferred vessels. Although the authors concluded that physiological stenosis severity and number of HRPC were closely related, and both components had significant association with the risk of clinical events, the prognostic implication of HRPC was different according to FFR.

In future, several ongoing studies will try to provide a better answer to whether revascularization for lesions with FFR >0.80 but with vulnerable plaque characteristics would reduce the risk of clinical events [i.e. PROSPECT II, PREVENT (Preventive Coronary Intervention on Stenosis With Functionally Insignificant Vulnerable Plaque), and FLAVOUR (Fractional Flow Reserve And IVUS for Clinical OUtcomes in Patients With InteRmediate
Stenosis)].

However, the strategy of preventive revascularization based on plaque characteristics assessed by invasive imaging modalities should be considered in the context of procedure-related risk in daily clinical practice. Integration of both the severity of physiological stenosis and plaque vulnerability would probably provide better prognostic stratification than individual component alone. Nevertheless, the study has several limitations: it is a post hoc analysis, intravascular ultrasound or optical coherence tomography was not systematically performed and the difference in terms of VOCO was mainly driven by ischemia driven revascularization.