Is it possible to predict which patients need distal protection during primary angioplasty?

Background: Although the benefit of distal protection (DP) during primary percutaneous coronary intervention (PCI) remains questionable, there appears to be efficacy in some clinical situations. We sought to identify in patients with ST-segment elevation acute myocardial infarction (STEMI) which clinical and angiographic characteristics might indicate the patient who will benefit from the use of a DP device. Methods: A series of 103 consecutive patients with STEMI undergoing primary PCI using DP were compared with 98 consecutive patients treated by primary PCI alone. Results: The overall rates of thromboembolic complications and achievement of optimal reperfusion (myocardial blush grade ≥ 2 and ST-segment resolution ≥ 70%), and infarct size, were similar between the 2 groups. However, DP use was associated with higher rates of optimal reperfusion in patients with right coronary artery (RCA) lesions (OR 2.45; 95% CI, 1.07 to 5.59; P = 0.034), thrombus score ≥ 4 (OR 2.64; 95% CI, 1.07 to 6.50; P = 0.034) or infarct-related artery (IRA) of ≥ 3.5 mm in diameter (OR 4.09; 95% CI, 1.02 to 16.40; P = 0.047). In this population (RCA location, thrombus score ≥ 4, or IRA ≥ 3.5 mm), DP use reduced the risk of thromboembolic complications (64%, P = 0.012, 45%, P = 0.035 and 54%, P = 0.050, respectively), resulting in a smaller infarct size (8.0 ± 5.1 vs. 11.7 ± 7.5, P = 0.028, 13.1 ± 8.8 vs. 17.4 ± 10.0, P = 0.026 and 15.5 ± 10.8 vs. 22.1 ± 10.1, P = 0.042, respectively). Conclusions: The use of a DP during primary PCI may lead to a reduction of thromboembolic complications, subsequent higher rates of optimal reperfusion and reduced infarct size in patients with RCA culprit lesions, a large thrombus, or large IRA.