Author + information
- Troels Thim1,
- Matthias Götberg2,
- Ole Frobert3,
- Robin Nijveldt4,
- Niels van Royen5,
- Sergio Baptista6,
- Sasha Koul7,
- Thomas Kellerth8,
- Hans Erik Botker1,
- Evald Christiansen1,
- Lars Jakobsen1,
- Steen Dalby Kristensen1 and
- Michael Maeng1
- 1Aarhus University Hospital, Aarhus, Denmark
- 2Department of Cardiology, Lund University, Skane University Hospital, Lund, Sweden
- 3Universitetssjukhuset Orebro, Orebro, Sweden
- 4Radboudumc, Nijmegen, Netherlands
- 5Radboud University, Nijmegen, Netherlands
- 6Hospital Fernando Fonseca, Amadora, Portugal
- 7Department of Cardiology, Lund University, Skåne University Hospital Lund, Lund, Sweden
- 8Orebro University Hospital, Orebro, Sweden
Classification agreement between instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) is approximately 80% in stable patients. It was recently shown that FFR guidance, as compared to iFR guidance, was associated with a higher risk of subsequent revascularization among patients with non- ST-segment elevation myocardial infarction. The classification agreement, and the impact of time interval, between iFR and FFR in the assessment of non-culprit lesions after recent ST-segment elevation myocardial infarction (STEMI) has not been described.
The iSTEMI study assessed agreement between iFR across non-culprit stenoses at the index procedure in patients with STEMI versus iFR and FFR at a follow-up angiography. The interval between STEMI and follow-up evaluation was at the discretion of the treating physicians. In this substudy, classification agreement between follow-up iFR and follow-up FFR was evaluated within groups defined according to follow-up time point after STEMI, i.e., <5 days, 5-15 days, and ≥16 days. iFR < 0.90 and FFR ≤ 0.80 were considered hemodynamically significant.
Among 120 patients with 157 non-culprit stenoses, follow-up iFR and FFR was available in 112 patients with 146 non-culprit stenoses. Median follow-up interval was 16 days (IQR 5-32 days). The overall classification agreement was 84%. With follow-up <5 days after STEMI, there was classification agreement between iFR and FFR was in 27 of 35 (77%) non-culprit stenoses. With follow-up 5-15 after STEMI, there was classification agreement in 33 of 38 (86%) non-culprit stenoses. With follow-up ≥16 days after STEMI, there was classification agreement in 63 of 73 (86%) non-culprit stenoses. The observed differences in these proportions over time after STEMI were not statistically significant (<5 versus ≥5 days, p=0.19).
Overall, classification agreement between iFR and FFR in the assessment of non-culprit lesions after STEMI was comparable to that observed in stable patients. Time interval between STEMI and follow-up evaluation may impact agreement between follow-up iFR and follow-up FFR, although the observed differences were not statistically significant.
CORONARY: Acute Myocardial Infarction