Distal embolus protection during primary percutaneous coronary intervention: Lessons learned from the clinical trials

A commentary on the manuscript by Celik entitled “Distal embolus protection during primary percutaneous coronary intervention: Lessons learned from the clinical trials”

“…As they pointed out, [1] the Enhanced Myocardial Efficacy and removal by Aspiration of Liberalized Debris (EMERALD) trial, [3] the randomized controlled Protection Devices in PCI Treatment of Myocardial Infarction for Salvage of Endangered Myocardium (PROMISE) study [4] and the Protection of distal Embolization in High-Risk Patients with Acute Myocardial Infarction (PREMIAR) study [5] failed to demonstrate a clear benefit of the routine use of a distal protection (DP) during primary percutaneous coronary intervention (PCI) as compared with conventional PCI strategy, whereas the analyses of several single-center trials have shown that primary PCI using DP device may result in improved surrogate markers of effective reperfusion such as corrected TIMI frame count, myocardial blush grade and STsegment resolution, left ventricular function, and clinical outcomes in comparison with either historical or concurrent controls [6][7][8][9][10][11].The major reason for the different outcomes between these single-center trials and 3 randomized trials could be ascribed to differences in populations. The EMERALD, PROMISE and PREMIAR trials, however, might have included patients at a lower risk for these thrombotic complications, which could lead to a negation of the efficacy of the DP, since the incidences of distal embolization and no-reflow (defined as TIMI grade ≤ 1 flow) were markedly lower in the control arm in the EMERALD trial (5.8% and 2.5%, respectively), the PROMISE trial (8% and 0%, respectively) and the PREMIAR study (11% and 3%, respectively) compared with controls in other trials in which the benefit of the DP had been proven (9.9% to 19.8% and 6.2% to 38.1%, respectively) [6][7][8][9][10][11].…”

“…We thank Dr. Celik and colleagues for their interesting comments [1] on our manuscript [2]. As they pointed out, [1] the Enhanced Myocardial Efficacy and removal by Aspiration of Liberalized Debris (EMERALD) trial, [3] the randomized controlled Protection Devices in PCI Treatment of Myocardial Infarction for Salvage of Endangered Myocardium (PROMISE) study [4] and the Protection of distal Embolization in High-Risk Patients with Acute Myocardial Infarction (PREMIAR) study [5] failed to demonstrate a clear benefit of the routine use of a distal protection (DP) during primary percutaneous coronary intervention (PCI) as compared with conventional PCI strategy, whereas the analyses of several single-center trials have shown that primary PCI using DP device may result in improved surrogate markers of effective reperfusion such as corrected TIMI frame count, myocardial blush grade and STsegment resolution, left ventricular function, and clinical outcomes in comparison with either historical or concurrent controls [6][7][8][9][10][11].The major reason for the different outcomes between these single-center trials and 3 randomized trials could be ascribed to differences in populations.…”

“…However, the benefit of a DP device was not shown in other clinical or angiographic variables, such as gender, age, diabetes, hypercholesterolemia, prior infarction, preinfarction angina, pain onset to PCI time, left ventricular ejection fraction, left anterior descending artery, multivessel coronary disease, preprocedural TIMI flow grade, calcification, bifurcation, stent length or maximal inflation pressure [2]. As Dr. Celik and colleagues suggested, [1] therefore, the beneficial effects of a DP in patients with ST-segment elevation acute myocardial infarction might be limited to specific population, and it should be used in this high-risk population subset.…”

“…We have read with great interest the article of Koch and colleagues [1] describing association of apolipoprotein (apo) E polymorphism with myocardial infarction (MI) and healthy subjects, in southern German population. We would like to add some comments and observations concerning the other populations that may be of interest.…”