Recent randomised studies have shown that, when deploying the most commonly used stent, the outcome of percutaneous coronary intervention (PCI) of the left main coronary artery (LMCA) is similar to the outcomes resulting from coronary artery bypass in patients with a broad range of SYNTAX scores.1
The devices usually implanted are all balloon-expandable regardless of their composition, meaning they may reach the final diameter of their own balloon or the one used for post-dilatation. Stentys® (Stentys, Paris, France) is a self-expandable nitinol (an alloy of nickel and titanium) device. It has a feature that enables its dimensions to be increased until it reaches the vessel wall; this feature, along with its cylindrical shape, makes it particularly appealing for the treatment of tapered vessels, such as the distal LMCA.2 Since data regarding the clinical outcome of this device in this particular setting are scarce, we designed the MATISSE study, a retrospective, spontaneous, multicentre registry that enrolled all patients treated with the self-expandable sirolimus-eluting Stentys for the treatment of LMCA disease at 10 international PCI-expert centres.3
The co-primary study endpoints were procedural success, defined as angiographic success without the occurrence of adverse events during hospitalisation, and device-orientated adverse cardiac events (DOCE), a composite endpoint of cardiac death, target lesion revascularisation, and target-vessel myocardial infarction, at a minimum of 6 months clinical follow-up. Angiographic success was defined as final thrombolysis in myocardial infarction (TIMI) 3 flow in both branches, and final stenosis <20% in the main branch and <50% in the secondary branch. Secondary endpoints were the single components of DOCE and stent thrombosis.
Between January 2014 and September 2016, a total of 151 patients (16%) were enrolled in the MATISSE study. Lesions were located in the distal LMCA bifurcation in 84% of patients. Procedural success, the primary endpoint, was achieved in 150 patients. At an average follow-up of 239±161 days, DOCE occurred in 13 patients (8.6%), with 2 (1.3%) cardiac deaths. Target lesion revascularisation occurred in 7 patients (4.6%). There were two cases of definite stent thrombosis: one was acute and one was very late.
With our study, we showed that the mid-term outcome of a real-world population treated with this device is comparable to best-in-class balloon-expandable stents;1 the results of the MATISSE registry are, indeed, in line with the EXCEL study in terms of acute procedural success and clinical outcome.
Since percutaneous treatment of the LMCA is challenging from a technical point of view, we argue that a self-expandable stent may share some potential advantages, in particular:
- Often, LMCA lesions involve a bifurcation with a relevant branch, and the characteristics of this device, not requiring a final kissing balloon inflation, make bifurcation management easier.
- In distal LMCA lesions, wherein the stent is required to protrude in the left anterior descending or circumflex artery, the discrepancy between the proximal and distal segments of the vessel makes a self-apposing, tapered stent particularly appealing.
- There is a reduced risk of stent under-expansion and malapposition.4-6
In conclusion, our study showed that PCI of the LMCA in a complex patient population is feasible and associated with good clinical outcome with a dedicated device at mid-term follow-up.