A drug-eluting coronary stent made of absorbable material performed similarly to the gold-standard metal one in a non-inferiority trial among patients with the more serious type of heart attack known as ST-segment elevation myocardial infarction (STEMI), according to results of the ABSORB STEMI TROFI II trial.
â€œThis is the first randomised controlled trial to compare the stent coverage between these two types of stents in the STEMI setting,â€ said senior investigator Patrick W Serruys, MD, PhD, who presented the findings at ESC Congress 2015, with simultaneous publication in The Lancet (to be confirmed).
Unlike metallic stents which remain permanently in place, absorbable stents also known as â€œbioresorbable vascular scaffoldsâ€ (BVS) eventually biodegrade restoring the natural physiology of coronary vessels â€“ â€œa factor which may be more important in STEMI patients, who tend to have delayed arterial healing as compared to patients with stable coronary artery disease,â€ explained Professor Serruys, from the International Centre for Circulatory Health, Imperial College, London, UK.
The study included 191 STEMI patients (mean age 58.6 years) undergoing primary percutaneous coronary intervention at 8 medical centres.
Patients were randomised to receive either a BVS (n=95) or metallic stent (n=96), both types being â€œdrug-elutingâ€, meaning coated in everolimus, a drug to reduce the risk of vessel reblockage.
The primary endpoint of the study was a 6-month score assessing stent coverage and restenosis of the vessel using coronary optical coherence tomography (OCT) imaging.
Given the chosen criteria for non-inferiority, the score was similar (1.74 in the BVS arm and 2.80 in the metallic stent arm), indicating almost complete arterial healing in both groups and meeting the criteria for non-inferiority (P 0.001).
Clinical events measured as aÂ composite of cardiac death, target vessel myocardial infarction (MI), or clinically-driven target lesion revascularisation, were 1.1% in the BVS arm compared to 0.0% in the metallic stent arm (P=ns), with one case of definite subacute thrombosis in the BVS arm.
â€œThis trial provides the basis for further exploration in clinical outcomes trials,â€ noted Dr. Serruys.
Imperial College London