Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Background: In patients with cardiogenic shock (CS), acute myocardial infarction (AMI) is the most common cause, and a percutaneous microaxial ventricular assist device (Impella, Abiomed, Danvers, MA) is a choice for temporary mechanical circulatory support. However, data are limited on complications and outcomes of Impella treatment in patients with CS with and without AMI. Methods and Results: Using nationwide prospective registry data in Japan, we included a total of 2047 patients with CS in whom the Impella devices were successfully placed between February 2020 and December 2021. Patients were divided into 2 groups according to the primary indication for the Impella use: AMI versus non‐AMI. The primary end point was a composite of in‐hospital all‐cause death and major complications. Of the 2047 patients, the Impella was indicated for AMI in 1337 (65.3%). In the group without AMI, myocarditis was the leading cause of CS. Patients with AMI‐CS were older and more likely to have cardiovascular risk factors than those with non‐AMI‐CS. The rates of in‐hospital mortality (46.0% versus 43.9%, P =0.38) and major complications (35.2% versus 34.7%, P =0.85) were similar between the 2 groups. Overall, multivariable analysis identified older age, higher body mass index, previous transient ischemic attack or stroke, out‐of‐hospital cardiac arrest, and the Impella 5.0 as factors significantly associated with the primary end point. Conclusions: The use of Impella in patients with and without AMI was related to similar clinical outcomes with high mortality and complication rates. Further studies are needed to identify patients who may benefit from the Impella devices in CS. Registration: URL: https://www.umin.ac.jp/english . Identifier: UMIN000033603.

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.