Antiplatelet therapy in patients with conservatively managed spontaneous coronary artery dissection from the multicentre DISCO registry

Selected in European Heart Journal by A. Zengin , A. N. Calik

The aims of this study were to assess the use of antiplatelet drugs in medically treated spontaneous coronary artery dissection (SCAD) patients and to investigate the relationship between single (SAPT) and dual (DAPT) antiplatelet regimens and 1-year patient outcomes.

Reviewers

Ahmet Zengin

Interventional cardiologist / Cardiologist

Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Center - Istanbul, Türkiye

Ali Nazmi Calik

@ANazmiCalik

Interventional cardiologist / Cardiologist

Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Center - Istanbul, Türkiye

Our Comment

Why this study? – the rationale/objective

Spontaneous coronary artery dissection (SCAD) has now been recognized as an important cause of acute coronary syndrome (ACS) in young to middle-aged individuals, especially women. Understanding the pathophysiology with the improvements in intravascular imaging has increased our knowledge about the disease.

There is robust evidence that most patients may be stabilized by conservative therapy rather than an invasive approach. However, the optimal duration and the type of antiplatelet therapy has yet to be determined in conservatively managed patients due to the critical differences with atherosclerotic coronary artery disease.

The current analysis from the international DISCO SCAD registry aimed to highlight this gap by comparing the efficacy and safety of different antiplatelet regimens.

How was it executed? – the methodology

The DISCO is a multicenter, observational, retrospective registry including SCAD patients from 23 centres in Italy and Spain. In the present analysis, conservatively managed SCAD patients who had data availability on prescribed antiplatelet therapy (APT) were included. 

According to the APT received at hospital discharge, the study population was divided into two groups (SAPT; aspirin or P2Y12 inhibitor or DAPT; aspirin plus P2Y12 inhibitor). The primary objective was to evaluate the incidence of 1-year MACE (all-cause death, non-fatal MI, unplanned revascularization) between those groups. 

What is the main result?

A total of 314 SCAD patients were recruited, and 199 patients who were managed conservatively included in the analysis. One-third of patients (33.7%) were treated with SAPT, whereas 132 were prescribed DAPT (66.3%). The mean age of the study population was 52.3± 9.3 years, and 88.9% were female. Non-ST-elevation ACS (NSTE-ACS) was the most frequent admission diagnosis (n= 109; 54.8%), followed by STEMI (n= 74; 37.2%).

At 11.8±1.3 month mean follow-up duration, 14.6% of patients experienced MACE, where more than half of those occurred during the index hospitalization. MACE rates were significantly higher in the DAPT group when compared with patients treated with SAPT (18.9% vs 6.0%; HR 2.62, 95% CI 1.22–5.61, p= 0.013), mainly driven by the increased rates of re-infarction and need for repeated revascularization.

Also, DAPT treatment (HR 4.54; 95% CI1.31–14.28; P = 0.016) and type 2a SCAD (HR 3.69;95% CI 1.41–9.61; P = 0.007) were found to be independent predictors of MACE in cox regression analysis.

 

Source: European Heart Journal - International DISCO SCAD Registry

Source: European Heart Journal - International DISCO SCAD Registry

Critical reading and the relevance for clinical practice

The DISCO trial showed that DAPT therapy in medically managed SCAD patients is associated with increased adverse event rates in the long-term follow-up compared to SAPT.

Some degree of platelet inhibition seems reasonable in SCAD patients when balancing the risk of intramural hematoma progression and the possible risk of increased thrombogenicity of the disrupted subendothelial layer. Particularly in patients with contained intramural hematoma (Type 2) without a depressurizing tear, potent platelet inhibition may worsen intramural bleeding with further propagation and compression of the true lumen.

On the other hand, in type 1 SCAD patients with an initial intimal tear between the true and false lumen or in type 2 SCAD patients with a reverse, depressurizing tear secondary to growing IMH in the false lumen have the risk of thrombus occurrence at the tear site. Taken together with the results of the current analysis addressing the Type 2 SCAD and DAPT as the independent predictors of MACE, it may be reasonable to refrain from DAPT, particularly in type 2 SCAD patients not having a decompressing tear between the true and false lumen.

Despite its non-randomized and retrospective nature, the current analysis of the DISCO SCAD registry sheds light on the issue, which no study has focused on to date and has provided interesting results which may guide cardiologists in their decision-making process