Correlation between intracoronary thrombus components and coronary blood flow after percutaneous coronary intervention for acute myocardial infarction at different onset time

Postdilatation after stent deployment during primary percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

The utilization of postdilatation in primary percutaneous coronary intervention (PCI) is feared to induce suboptimal coronary blood flow and compromise the outcome of the patients. This meta-analysis sought to verify whether postdilatation during primary PCI is associated with worse angiographic or long-term clinical outcomes.

METHODS

Systematic literature searches were conducted on PubMed, The Cochrane Library, ClinicalTrials.gov, EBSCO, and Europe PMC on 10 March 2024. Eligible studies reporting the outcomes of postdilatation among ST-segment elevation myocardial infarction patients were included. The primary outcome was no-reflow condition during primary PCI based on angiographic finding. The secondary clinical outcome was major adverse cardiovascular events (MACEs) comprising all-cause death, myocardial infarction, target vessel revascularization (TVR), and stent thrombosis.

RESULTS

Ten studies were finally included in this meta-analysis encompassing 3280 patients, which was predominantly male (76.6%). Postdilatation was performed in 40.7% cases. Postdilatation was associated with increased risk of no-reflow during primary PCI [Odd Ratio (OR) = 1.33, 95% Confidence Interval (CI): 1.12-1.58; P = .001)]. Conversely, postdilatation had a tendency to reduce MACE (OR = 0.70, 95% CI: 0.51-0.97; P = .03) specifically in terms of TVR (OR = 0.41, 95% CI: 0.22-0.74; P = .003). No significant differences between both groups in relation to mortality (OR = 0.58, 95% CI: 0.32-1.05; P = .07) and myocardial infarction (OR = 1.5, 95% CI: 0.78-2.89; P = .22).

CONCLUSIONS

Postdilatation after stent deployment during primary PCI appears to be associated with an increased risk of no-reflow phenomenon after the procedure. Nevertheless, postdilatation strategy has demonstrated a significant reduction in MACE over the course of long-term follow-up. Specifically, postdilatation significantly decreased the occurrence of TVR. Key messages: What is already known on this topic?  Optimizing stent deployment by performing postdilatation during percutaneous coronary intervention (PCI) is essential for long-term clinical outcomes. However, its application during primary PCI is controversial due to the fact that it may provoke distal embolization and worsen coronary blood flow. What this study adds?  In this systematic review and meta-analysis of 10 studies, we confirm that postdilatation during primary PCI is associated with worse coronary blood flow immediately following the procedure. On the contrary, this intervention proves advantageous in improving long-term clinical outcomes, particularly in reducing target vessel revascularization. How this study might affect research, practice, or policy?  Given the mixed impact of postdilatation during primary PCI, this strategy should only be applied selectively. Future research should focus on identifying patients who may benefit from such strategy.

Long-term outcomes of the modest stent expansion strategy for the culprit lesion of acute myocardial infarction

Slow flow during primary percutaneous coronary intervention (PCI) is a common complication. Our group showed that the stent (or post-balloon) diameter-to-vessel diameter ratio was inversely associated with slow flow phenomenon. We advocated the utility of modest stent expansion strategy, which was defined as the stent (or post-balloon) diameter-to-culprit vessel diameter ratio < 0.71, for prevention of slow flow phenomenon. This study aimed to compare the long-term outcomes in patients with acute myocardial infarction (AMI) between the modest stent expansion strategy and the aggressive stent expansion strategy (the stent diameter-to-culprit vessel diameter ratio ≥ 0.71). We included 584 AMI patients, which were divided 177 patients in the modest stent expansion group and 146 patients in the aggressive stent expansion group. The primary endpoint was major adverse cardiac events (MACE), which was defined as a composite of cardiac death, ischemia driven target vessel revascularization, and stent thrombosis. The slow flow after stent deployment was more frequently observed in the aggressive stent expansion group (24.0%) than in the modest stent expansion group (4.0%) (P < 0.001). The Kaplan-Meier curves revealed that MACE was comparable between the two groups (P = 0.64). The multivariate COX hazard model showed the non-significant association between the modest stent expansion strategy and MACE (vs. aggressive stent expansion: hazard ratio 1.005, 95% confidence interval 0.619-3.242, P = 0.41). In conclusion, the modest stent expansion strategy was not associated with long-term MACE. Therefore, the modest stent expansion strategy may be a good choice for the culprit lesion of AMI.