2.1

Study design and population

Left Main AngioplasTy wIth a Self-apposing StEnt-MATISSE is a retrospective, multicenter registry which enrolled consecutive patients treated with the self-apposing sirolimus-eluting Stentys for the treatment of LM disease at 17 international centers. Inclusion criteria were broad and included stable or unstable angina pectoris and acute coronary syndromes. Angiographic criteria for entering the registry were LM disease with stenosis diameter ≥ 50% at visual estimation. Before opting for the percutaneous treatment, all patients were adequately informed about the risks and benefits of both the percutaneous and surgical options. In case of high Syntax score (>32) all patients were discussed with the referral cardiac surgeon unless the patient refused the CABG option.

Exclusion criteria were cardiogenic shock at admission and the impossibility to undergo prolonged (≥6 months) dual anti-platelet therapy (DAPT).

2.2

Study device

The Stentys coronary stent is a self-apposing, nitinol, sirolimus-eluting stent (1.4 μg/mm ² of drug per surface) with a nominal strut width of 102–133 μm incorporated in a proprietary coating ProTeqtor® (Hemoteq AG, Würselen, Germany), a durable polymer matrix of polysulphone and a soluble polymer (polyvinylpyrrolidone) that acts as an excipient. The stent is compatible with a 6 Fr guiding catheter and the current monorail delivery system makes it deployable by withdrawal of a retractable sheath. It is available in three lengths (17, 22 and 27 mm) and three sizes: 2.5–3.0 mm (small), 3.0–3.5 mm (medium), and 3.5–4.5 mm (large). The theoretical maximum diameter reached with the “medium” sized device is 5 mm, and 6.5 mm with the “large” one.

2.3

Study procedure

The procedure was performed according to international guidelines and local protocols. Lesion preparation, either with semi-compliant, non-compliant or scoring balloons, or rotational atherectomy, was left to the operator’s choice, but highly recommended. In case of distal LM involvement, either a provisional or a two-stent strategy could be adopted, according to the operator experience and the characteristics of the lesion. Stent post-dilatation was encouraged as the use of intracoronary imaging, either with intravascular ultra-sound or optical coherence tomography. After the procedure, patients were treated according to local practice receiving 100 mg of aspirin daily and a P2Y12 inhibitor (Clopidogrel, Ticagrelor or Prasugrel) for a minimum of 6 months.

2.4

Clinical endpoints and follow-up

Primary study endpoint was the occurrence of major adverse cardiovascular events (MACE), a composite endpoint of cardiac death, target lesion revascularization (TLR) and target-vessel myocardial infarction, after 9 months of clinical follow-up. Angiographic success was defined as final TIMI 3 flow in both branches and final stenosis <20% in the main branch and < 50% in the secondary branch. Procedural success was defined as angiographic success without the occurrence of adverse events during hospitalization. Secondary endpoints were the single components of MACE and stent thrombosis (ST). Follow-up was performed through clinical assessment; a minimum follow-up of 6 months was required to enter the study. All angiographic analyses were performed by the official center investigator.

Angiographic follow up was not required by study protocol, thus the TLR rate was clinically-driven only.

2.5

Statistical analysis

Continuous variables are reported as mean (standard deviation) or median (interquartile range) and compared by Student’s t or Mann-Whitney tests, when appropriate. Categorical variables are reported as raw numbers (%) and compared by Pearson chi-square or Fisher exact tests, when appropriate.. Proportional hazards assumption was not violated in statistical analysis. Due to the limited number of events, only the following covariates were considered in the statistical plan: diabetes mellitus, postdilation rate, 2-stent strategy, final kissing balloon inflation. A two-sided P value <0.05 was considered statistically significant; all analyses were performed with SPSS 21.0 (IBM, Armonk, USA).

2.1

Study design and population

Left Main AngioplasTy wIth a Self-apposing StEnt-MATISSE is a retrospective, multicenter registry which enrolled consecutive patients treated with the self-apposing sirolimus-eluting Stentys for the treatment of LM disease at 17 international centers. Inclusion criteria were broad and included stable or unstable angina pectoris and acute coronary syndromes. Angiographic criteria for entering the registry were LM disease with stenosis diameter ≥ 50% at visual estimation. Before opting for the percutaneous treatment, all patients were adequately informed about the risks and benefits of both the percutaneous and surgical options. In case of high Syntax score (>32) all patients were discussed with the referral cardiac surgeon unless the patient refused the CABG option.

Exclusion criteria were cardiogenic shock at admission and the impossibility to undergo prolonged (≥6 months) dual anti-platelet therapy (DAPT).

2.2

Study device

The Stentys coronary stent is a self-apposing, nitinol, sirolimus-eluting stent (1.4 μg/mm ² of drug per surface) with a nominal strut width of 102–133 μm incorporated in a proprietary coating ProTeqtor® (Hemoteq AG, Würselen, Germany), a durable polymer matrix of polysulphone and a soluble polymer (polyvinylpyrrolidone) that acts as an excipient. The stent is compatible with a 6 Fr guiding catheter and the current monorail delivery system makes it deployable by withdrawal of a retractable sheath. It is available in three lengths (17, 22 and 27 mm) and three sizes: 2.5–3.0 mm (small), 3.0–3.5 mm (medium), and 3.5–4.5 mm (large). The theoretical maximum diameter reached with the “medium” sized device is 5 mm, and 6.5 mm with the “large” one.

2.3

Study procedure

The procedure was performed according to international guidelines and local protocols. Lesion preparation, either with semi-compliant, non-compliant or scoring balloons, or rotational atherectomy, was left to the operator’s choice, but highly recommended. In case of distal LM involvement, either a provisional or a two-stent strategy could be adopted, according to the operator experience and the characteristics of the lesion. Stent post-dilatation was encouraged as the use of intracoronary imaging, either with intravascular ultra-sound or optical coherence tomography. After the procedure, patients were treated according to local practice receiving 100 mg of aspirin daily and a P2Y12 inhibitor (Clopidogrel, Ticagrelor or Prasugrel) for a minimum of 6 months.

2.4

Clinical endpoints and follow-up

Primary study endpoint was the occurrence of major adverse cardiovascular events (MACE), a composite endpoint of cardiac death, target lesion revascularization (TLR) and target-vessel myocardial infarction, after 9 months of clinical follow-up. Angiographic success was defined as final TIMI 3 flow in both branches and final stenosis <20% in the main branch and < 50% in the secondary branch. Procedural success was defined as angiographic success without the occurrence of adverse events during hospitalization. Secondary endpoints were the single components of MACE and stent thrombosis (ST). Follow-up was performed through clinical assessment; a minimum follow-up of 6 months was required to enter the study. All angiographic analyses were performed by the official center investigator.

Angiographic follow up was not required by study protocol, thus the TLR rate was clinically-driven only.

2.5

Statistical analysis

Continuous variables are reported as mean (standard deviation) or median (interquartile range) and compared by Student’s t or Mann-Whitney tests, when appropriate. Categorical variables are reported as raw numbers (%) and compared by Pearson chi-square or Fisher exact tests, when appropriate.. Proportional hazards assumption was not violated in statistical analysis. Due to the limited number of events, only the following covariates were considered in the statistical plan: diabetes mellitus, postdilation rate, 2-stent strategy, final kissing balloon inflation. A two-sided P value <0.05 was considered statistically significant; all analyses were performed with SPSS 21.0 (IBM, Armonk, USA).