Nonculprit Stenosis Evaluation Using Instantaneous Wave-Free Ratio in Patients With ST-Segment Elevation Myocardial
Troels Thim1, Matthias Götberg2, Ole Fröbert3
1Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.
Insights
Acute instantaneous wave-free ratio (iFR) measurements in ST-segment elevation myocardial infarction (STEMI) patients are valid for assessing nonculprit stenoses. However, agreement with follow-up iFR decreases with longer intervals post-STEMI.
Area of Science:
- Cardiology
- Interventional Cardiology
- Physiology
Background:
- Management of nonculprit stenoses in ST-segment elevation myocardial infarction (STEMI) is complex and often guided by angiography.
- Acute functional assessment of these stenoses may offer valuable insights.
- The instantaneous wave-free ratio (iFR) is a physiological index used to assess stenosis severity.
Purpose of the Study:
- To evaluate the agreement between acute and follow-up instantaneous wave-free ratio (iFR) measurements in nonculprit stenoses of STEMI patients.
- To determine the validity of acute iFR for ruling out hemodynamically significant stenoses.
- To investigate the impact of the time interval between acute and follow-up assessments on iFR agreement.
Main Methods:
- Patients with STEMI undergoing primary percutaneous coronary intervention had nonculprit stenoses assessed by iFR immediately after intervention.
- Follow-up iFR measurements were performed at a later stage.
- iFR < 0.90 was defined as hemodynamically significant.
Main Results:
- A total of 120 patients with 157 nonculprit lesions were analyzed.
- Median acute iFR was 0.89, and median follow-up iFR was 0.91.
- Overall classification agreement between acute and follow-up iFR was 78%, with a negative predictive value of acute iFR at 89%.
Conclusions:
- Acute iFR assessment is a valid method for excluding significant nonculprit stenoses in STEMI patients post-PCI.
- The time delay between acute and follow-up iFR significantly impacts classification agreement.
- Physiological changes during STEMI may contribute to discrepancies in iFR classification over time.
Objectives:
The aim of this study was to examine the level of agreement between acute instantaneous wave-free ratio (iFR) measured across nonculprit stenoses in patients with ST-segment elevation myocardial infarction (STEMI) and iFR measured at a staged follow-up procedure.
Background:
Acute full revascularization of nonculprit stenoses in STEMI is debated and currently guided by angiography. Acute functional assessment of nonculprit stenoses may be considered.
Methods:
Immediately after successful primary culprit intervention for STEMI, nonculprit coronary stenoses were evaluated with iFR and left untreated. Follow-up evaluation with iFR was performed at a later stage. iFR <0.90 was considered hemodynamically significant.
Results:
One hundred twenty patients with 157 nonculprit lesions were included. Median acute iFR was 0.89 (interquartile range [IQR]: 0.82 to 0.94; n = 156), and median follow-up iFR was 0.91 (interquartile range: 0.86 to 0.96; n = 147). Classification agreement was 78% between acute and follow-up iFR. The negative predictive value of acute iFR was 89%. Median time from acute to follow-up evaluation was 16 days (IQR: 5 to 32 days). With follow-up within 5 days after STEMI, no difference was observed between acute and follow-up iFR, and classification agreement was 89%. With follow-up ≥16 days after STEMI, acute iFR was lower than follow-up iFR, and classification agreement was 70%.
Conclusions:
Acute iFR evaluation appeared valid for ruling out significant nonculprit stenoses in patients with STEMI undergoing primary percutaneous coronary intervention. The time interval from acute to follow-up iFR influenced classification agreement, suggesting that inherent physiological disarrangements during STEMI may contribute to classification disagreement.
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