Effect of Distal Protection Device on the Microvascular Integrity during Primary Stenting in Acute Myocardial Infarction: Distal Protection Device in Acute Myocardial Infarction

Abstract

Background and Objectives：Phasic coronary flow velocity patterns and microvascular integrities are known to be prognostic factors in acute myocardial infarction (AMI). The use of a distal protection device during primary percutaneous coronary intervention (PCI) may preserve the microvascular integrity of the myocardium by preventing distal embolization of thrombotic materials. This study assessed the effects of such a device on microvascular integrity preservation through Doppler studies of the coronary flow velocities in AMI patients treated with primary PCI.

Subjects and Methods：A total of fifty-eight consecutive patients (mean age 54±15, 46 males) with ST segment-elevated AMI, who had undergone primary PCI within 24 hours after onset, were enrolled in the study. The subjects were divided into two groups: 30 patients with the PurcuSurge GuardWire Temporary Occlusion and Aspiration System and 28 without. The TIMI flows and TMP grades (TIMI myocardial perfusion grade) were evaluated. The coronary flow velocities were measured after PCI with a Doppler wire at the baseline, and also after intracoronary adenosine (24-48 μg) induced hyperemia. The coronary flow velocity reserve (CFR), diastolic deceleration time (DDT) and microvascular resistance index (MVRI) were calculated.

Results：Between the two groups, no significant differences were found in the angiographic characteristics and CFR. In patients with a distal protection device, however, the post-PCI TMP grades were more favorable (TMP 0/1: 13.3%, TMP 2: 23.3%, TMP 3: 63.4% vs. TMP 0/1: 35.7%, TMP 2: 35.7%, TMP 3: 28.6%, p=0.023), with TMP grade 3 being most common (63.4% vs. 28.6%, p=0.010). These patients also exhibited lower bMVRI and hMVRI levels (4.33±2.22 vs. 5.55±2.36 mmHg · m-1·sec (p=0.047) and 2.39±1.40 vs. 3.14±1.36 mmHg·cm-1 · sec (p=0.045), respectively), and longer bDDT and hDDT (679±273 vs. 519±289 msec (p=0.035) and 761±256 vs. 618±272 msec (p=0.044), respectively).

Conclusions：Distal protection with the PurcuSurge GuardWire system may effectively preserve the microvascular integrity of the myocardium during primary PCI in AMI patients.