The latest news from the ongoing meeting of the American College of Cardiology in Chicago is that using the Export® Aspiration Catheter from Medtronic before stenting, in patients with ongoing acute myocardial infarction (AMI), can “significantly improve blood flow and survival rates compared to conventional treatment with percutaneous coronary intervention (PCI) alone.” The study, led by Felix Zijlstra, MD, PhD from University Medical Center Groningen, Netherlands, recruited 1,071 patients who were randomly assigned to PCI supported by the Export aspiration catheter (535 pts) or to PCI using conventional techniques (536 pts).
From the joint statement by the Society for Cardiovascular Angiography and Interventions and the American College of Cardiology:
To assess the quality of myocardial perfusion, the researchers documented myocardial blush grade. A myocardial blush grade of 0 or 1 indicates that little or no x-ray dye has reached from the surface artery into the heart muscle, a sign that the microcirculation is blocked. A myocardial blush grade of 3 indicates that x-ray dye has reached deep into the heart muscle, a sign of good blood flow through the microcirculation. A myocardial blush grade of 2 falls in between. Analysis of the elevated ST-segment on the electrocardiogram — specifically, its return to a normal baseline — was also used to gauge the quality of blood flow to the heart muscle.
During angiography, researchers observed a blush grade of 0 or 1 in 17 percent of patients treated with the aid of the aspiration catheter and in 26 percent of patients treated with conventional PCI (p less than 0.001). At 30 days, clinical outcomes were strongly related to the degree of myocardial reperfusion. The rate of death in patients with a myocardial blush grade of 0/1, 2 and 3 was 5.2 percent, 2.9 percent and 1.0 percent, respectively (p equals 0.003). The combined rates of repeat heart attack, repeat procedure in the target artery and death in patients with a myocardial blush grade of 0/1, 2 and 3 were 14.1 percent, 8.8 percent and 4.2 percent, respectively (p less than 0.001).
At one-year follow-up, mortality was significantly lower in patients treated with the aspiration catheter (p equals 0.04), as was a combination of death and heart attack. A similar, highly significant relationship was observed between myocardial blush grade and death, or a combination of death and repeat heart attack (p equals 0.001).
The study team concluded that the degree of blood perfusion into the heart muscle helps to predict the patient’s clinical condition, and that aspiration of debris from the treated artery during PCI can reduce the risk of death and repeat heart attack, even one year later.
Device That Clears Debris From Artery Aids Blood Flow in PCI… (.pdf)
Product page: Export® XT Aspiration Catheter…
Medtronic press release: Heart Attack Patients Benefit from Thrombus Aspiration Prior to Stenting, Study Shows…