Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention in unprotected left main coronary artery disease: A systematic review

The left main coronary artery feeds most of the heart, so a stent there is among the highest-stakes procedures in cardiology. This systematic review asks whether ultrasound guidance makes it safer than the angiogram alone.

Pooling randomized and non-randomized studies of unprotected left main PCI, the authors find IVUS guidance associated with significantly lower rates of major adverse events, all-cause and cardiac death, heart attack, and stent thrombosis. The rationale mirrors IVUS in general — seeing true vessel size and stent expansion from inside — but the stakes are higher here, where a poorly deployed stent can be catastrophic.

The practical takeaway is to favor IVUS guidance for left-main PCI specifically, where the margin for error is smallest. The resistance is infrastructural — operators and centers without IVUS capability or habituated to angiography alone.

We rate the evidence moderate-to-solid: a PRISMA-guided synthesis, but built mostly on non-randomized studies (only two RCTs among twelve), with some author industry ties. Its clinical significance is high — left-main intervention is high-risk and common enough that a guidance technique cutting mortality and major events matters a great deal for a critical population.