Intraluminal Thrombus in Facilitated Versus Primary Percutaneous Coronary Intervention: An Angiographic Substudy of the ASSENT-4 PCI (Assessment of the Safety and Efficacy of a New Treatment Strategy With Percutaneous Coronary Intervention) Trial

Study Questions:

What is the effect of facilitated percutaneous coronary intervention (PCI) on presence and consequence of intraluminal thrombus?

Methods:

The authors reported data from the angiographic substudy of the ASSENT-4 trial. Angiographic findings, including residual Thrombolysis In Myocardial Infarction (TIMI) thrombus grade 2 and/or distal embolization and/or slow flow deemed to reflect thrombus burden following PCI, were correlated with ST-segment resolution, epicardial blood flow, and clinical outcome. The clinical composite endpoint was death, congestive heart failure, or shock.

Results:

Patients in the facilitated PCI group were more likely to have TIMI flow grade 2/3 in the infarct-related artery at the first angiogram (73.7% vs. 33.4%, p < 0.001) compared with patients undergoing primary PCI. However, they also had a higher thrombus burden following PCI (19.7% vs. 13.4%, p = 0.002) compared with patients in the primary PCI group. There was no difference in the post-PCI TIMI flow between the two groups. Post-PCI TIMI thrombus grade was significantly associated with ST-segment resolution (p < 0.001) and TIMI frame count (p < 0.0001) in both groups. Facilitation with tenecteplase (p = 0.005) and thrombus burden (odds ratio, 2.43; 95% confidence interval, 1.30-4.51; p = 0.0052) were independent predictors of 90-day mortality in addition to age, Killip class, and anterior wall infarction.

Conclusions:

The use of facilitated PCI was associated with better initial patency of the infarct-related artery, but higher residual thrombus burden and worse clinical outcomes.

Perspective:

The study provides some mechanistic insights underlying the worse outcomes associated with facilitated PCI. The results of the ASSENT-4 and FINESSE trials (N Engl J Med 2008;358:2205-17) clearly demonstrate that clinical outcomes with facilitated PCI are worse than those with primary PCI, and thus, facilitated PCI has all but been abandoned in clinical practice.

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Acute Heart Failure

Keywords: Myocardial Infarction, Thrombosis, Heart Failure, Percutaneous Coronary Intervention


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