# Deferred Versus Immediate Stenting in Late-Presenting ST-Segment Elevation Myocardial Infarction (STEMI) Patients With a High Thrombus Burden: A Retrospective Analysis

## TL;DR

This study found that waiting to place a stent improved heart blood flow and reduced risks in heart attack patients with high blood clot burden.

## Contribution

The study provides evidence that deferred stenting improves outcomes in late-presenting STEMI patients with high thrombus burden.

## Key findings

- Deferred stenting reduced no reflow and distal embolization in high thrombus burden STEMI patients.
- Deferred stenting improved post-procedure blood flow and myocardial blush grade.
- Deferred stenting lowered major adverse cardiovascular events at one year.

## Abstract

Background: Late-presenting patients with ST-segment elevation myocardial infarction (STEMI), defined as those presenting ≥12 hours after symptom onset, represent a high-risk and often underrepresented population. Despite evidence supporting primary percutaneous coronary intervention (PCI) in these patients, those with a high thrombus burden (HTB) face an increased risk of no reflow and adverse outcomes, particularly with immediate stenting. The optimal stent timing in this subgroup remains unclear.

Methods: This retrospective study included 200 patients with late-presenting STEMI and angiographically confirmed HTB. Patients were assigned to either the deferred stenting (DS; n=100) group or the immediate stenting (IS; n=100) group. Clinical and procedural outcomes, including myocardial blush grade (MBG), thrombolysis in myocardial infarction (TIMI) flow, and major adverse cardiovascular events (MACE) at one year, were compared.

Results: The DS group was associated with significantly lower no reflow (11 (11%) vs. 26 (26%), p=0.01), less distal embolization (6 (6%) vs. 16 (16%), p=0.04), and higher post-PCI TIMI grade 3 flow (73 (73%) vs. 57 (57%), p=0.03) and MBG 3 (58 (58%) vs. 36 (36%), p=0.01). One-year MACE was significantly reduced in the DS group (7 (7%) vs. 20 (20%), p=0.01). The DS group was independently associated with improved myocardial perfusion and lower MACE.

Conclusion: In late-presenting STEMI patients with HTB, deferred stenting yielded superior perfusion and clinical outcomes compared to immediate stenting. These findings underscore the importance of individualized stent timing strategies in this high-risk, often overlooked subgroup.