Single Catheter Primary Percutaneous Coronary Intervention Method in Patients With ST Elevation Myocardial Infarction

<<Background>>

Acute ST-segment elevation myocardial infarction is a disease of high acute-phase mortality rate, but the life can be saved by implementing emergency percutaneous coronary intervention (PCI). Its efficacy is higher than that of thrombolytic therapy. Moreover, shortening of total ischemia time reduces the mortality rate and can promote recovery of cardiac function. The total ischemia time can be classified into the time from onset to arrival at hospital and the time from arrival at hospital to recanalization of coronary artery (Door-to-balloon time), and shortening of time in all steps is recommended. Various methods, including the part of transportation to hospital and from arrival at hospital to treatment room, are proposed, but there is no effective method for shortening of procedure time for PCI.

Since the right and left dual-purpose universal guiding catheter can be inserted into both the left and right coronary arteries, the time for replacement of catheter can be shortened. Since IKARI Curve catheter is considered to be the most excellent catheter as the universal guiding catheter, it is considered useful for shortening of reperfusion time in myocardial infarction.

<<Objectives.>>

There are a lot of reports that decreased mortality and improvement of cardiac function are observed by shortening of the time from onset of acute myocardial infarction to recanalization. However, shortening of catheterization time, a part of the time, has not been examined. In 60 patients in a single-center retrospective study performed in Tokai University, the time from arterial puncture to reperfusion was shortened, and the time from arrival at hospital to reperfusion was also shortened. In 1275 patients in a multi-center retrospective study, moreover, the time from arterial puncture to reperfusion was significantly shortened by 4 minutes, and a significant decrease was also observed in the time from arrival at hospital to reperfusion. The Door-to-balloon time at this time was 68±46 minutes in the SC-PCI group and 76±51 minutes by the conventional method. Moreover, the time from insertion of sheath to balloon was 19±14 minutes in the SC-PCI group and 23±14 minutes by the conventional method. In addition, shortening of fluoroscopy time was also observed.

Based on this result, the information shall be collected from prospective multi-center randomized study and analyzed to verify that the right and left dual-purpose guiding catheter is useful for shortening of reperfusion time in myocardial infarction.

<<Methods.>>

Multi-center cooperative prospective interventional study, 2-group comparative study, and randomization <Conventional method> If the patients are allocated to this group, the procedure shall be started with an angiographic catheter.

An angiographic catheter is a catheter classified into a special treatment material, "Angiographic Catheter (General Model) Request Code 738180000," and approved for insurance coverage. The catheters adopted by each institution shall be used.

Coronary angiography shall be performed using an angiographic catheter, and PCI shall be performed by replacing to a guiding catheter. There are methods in which a catheter for angiography on right and left sides is performed, a dual-purpose contrast catheter is used, and one contrast catheter and guiding catheter are used, but any method is acceptable if the procedure is started from an angiographic catheter.

<SC-PCI method> When allocated to this group, the procedure shall be started with a guiding catheter of Ikari L Curve. As the Ikari L Curves approved for insurance coverage in Japan, 52 types exist by catalogue according to the difference in diameter and form, of 6 shafts of 5 companies (attached documents). Any of them shall be used. Thereafter, the right and left coronary angiography shall be performed with one right and left dual-purpose guiding catheter, and then PCI shall be performed.

Even if allocated to any group, Synergy stent shall be used when a stent is placed in coronary artery dilation.

A prospective randomization study shall be performed to reduce the bias. For the Sheath-to-First device activation time, a primary endpoint, a test of superiority shall be performed. For the Door-to-balloon time, a secondary endpoint, a test of non-inferiority shall be performed, and if the non-inferiority is demonstrated, a test of superiority shall also be performed.

The primary endpoint shall be analyzed by Intention-to-treat. The operators who can participate in this study shall take charge of any group, and who are the PCI operators who have used the Ikari L Curve guiding catheter on the right coronary artery in at least 5 patients and left coronary artery in at least 5 patients.

<<Number of Target Patients and Rationales for Setting>>

<Number of target patients> 400 patients in total (200 patients for SC-PCI method, 200 patients for conventional method) <Rationale for setting> In a multicenter retrospective study, the time from insertion of sheath to balloon (S2B) was 19±14 minutes in the SC-PCI group and 23±14 minutes for the conventional method. When testing at the level of significance of 0.05 and the power of 0.8 based on this value, the number of patients will become 388. Considering 3% dropout cases, registration of a total of 400 patients is planned.

A secondary endpoint, the D2B time was 68±46 minutes in the SC-PCI group and 76±51 minutes for the conventional method as a result of retrospective study. When testing at the level of significance of 0.05 and the power of 0.8 based on this value, the number of patients will become 1160. Therefore, the power is insufficient to show significance in the analysis of D2B time, and a non-inferiority test shall be performed. The margin of noninferiority is set at 1.3. If the D2B time by the conventional method is 76 minutes, the 1.3 times longer time is 98.8 minutes, and the difference is 22.8 minutes. In the treatment of myocardial infarction, the difference of 23 minutes or more is considered to be inferior from the standpoint of expert, and therefore it was set. Non-inferiority test shall be performed based on the 95% confidence interval (test of two-sided 5% or one-sided 2.5%) of the difference from mean value. If non-inferiority is shown, the test of superiority shall also be performed.