05 Aug 2020

Left main and multivessel disease

Safety of Revascularization Deferral of Left Main Stenosis Based on Instantaneous Wave-Free Ratio Evaluation

Selected in JACC Cardiovascular Interventions by D. Milasinovic

The main message appears to be that iFR-based deferral of LM revascularization is not linked to an excessive risk of MACE during 30-month median follow-up. Given the historical predominance of angiography-based decision making, this study provides further evidence in support of thinking and acting beyond angiography in patients with left main disease.

References

Authors

Takayuki Warisawa, Christopher M. Cook, Christopher Rajkumar, James P. Howard, Henry Seligman, Yousif Ahmad, Stephanie El Hajj, Shunichi Doi, Akihiro Nakajima, Masafumi Nakayama, Sonoka Goto, Rafael Vera-Urquiza, Takao Sato, Yuetsu Kikuta, Yoshiaki Kawase, Hidetaka Nishina, Ricardo Petraco, Rasha Al-Lamee, Sukhjinder Nijjer, Sayan Sen, Sunao Nakamura, Amir Lerman, Hitoshi Matsuo, Darrel P. Francis, Yoshihiro J. Akashi, Javier Escaned and Justin E. Davies

Reference

J Am Coll Cardiol Intv. 2020 Jul, 13 (14) 1655-1664.

Published

July 2020

Link

Read the abstract

Reviewer

Dejan Milasinovic

@MilasinD18

Interventional cardiologist / Cardiologist

Belgrade, Serbia

Latest contributions

EuroPCR 2025: innovation, clinical trials and education Calcified un-dilatable lesions in ACS: what should I do? PCI for complex calcific coronary artery disease - LIVE Case

My Comment

Why this study? – the rationale/objective

This study sought to evaluate long-term outcomes following iFR-based deferral or treatment of left main (LM) coronary artery disease.

How was it executed? – the methodology

Study population:

314 patients with an intermediate LM stenosis were included, of which 151 underwent revascularization (85 PCI and 66 CABG) and 163 were deferred based on iFR cutoff value of 0.89.

Methodology:

iFR was measured at the distal point of the LM segment either in the LAD or in the CX (beyond ostial stenosis if it existed).
When angiographic downstream disease was detected, pressure wire was placed either in the non-diseased segment or just proximal to the first stenosis.
Primary endpoint was MACE (death, myocardial infarction (MI) and ischemia driven target lesion revascularization (TLR)).
Median follow-up was 30 months, with all patients having at least 6 months of follow-up.

What is the main result?

MACE rate was 14.6% in the revascularized group vs. 9.2% in the deferred group (HR: 1.45; 95% CI: 0.75 to 2.81; p=0.26). None of the individual MACE components were significantly different between the groups.

The observed numerical difference in the rate of MACE was mainly due to increased repeat revascularization in distal coronary artery tree segments, i.e. non-LM revascularization in patients with PCI or CABG as compared with deferred patients.

Critical reading and the relevance for clinical practice:

In terms of a wider applicability, at least the following 3 issues may be of further relevance.

First, the iFR measurement technique. Since a LM stenosis may be associated with a diffuse form of atherosclerotic disease, an iFR pullback of epicardial arteries may perhaps be interesting in potentially estimating the relative importance of different angiographically apparent stenoses, including the left main. This could be relevant since the occurrence of non-LM revascularization was not infrequent (3.7% vs. 12.6% in deffered vs. revascularized group, respectively).
Second, it appears that a considerable proportion of patients with an iFR>0.89 (roughly one-fifth judging from Figure 3) had an angiographic stenosis of >50%, thus perhaps cautioning against a premature decision to revascularize based solely on angiography.
Third, at the same time there was a high MACE rate (close to 30%) in patients in whom revascularization was not performed despite an iFR≤0.89 (and which were, due to violating the iFR-based deferral protocol, not part of the final study cohort).

Therefore, the second and the third point combined reveal the delicacy of deciding on LM revascularization, with the results of the present study being supportive of adding iFR to the clinical decision-making algorithm in individual patients with LM disease.