The Multi-center Evaluation of the Accuracy of the Contrast MEdium INduced Pd/Pa RaTiO in Predicting FFR (MEMENTO-FFR) Study.

AIMS: Adenosine administration is needed for the achievement of maximal hyperaemia fractional flow reserve (FFR) assessment. The objective was to test the accuracy of Pd/Pa ratio registered during submaximal hyperaemia induced by non-ionic contrast medium (contrast FFR [cFFR]) in predicting FFR and comparing it to the performance of resting Pd/Pa in a collaborative registry of 926 patients enrolled in 10 hospitals from four European countries (Italy, Spain, France and Portugal). METHODS AND RESULTS: Resting Pd/Pa, cFFR and FFR were measured in 1,026 coronary stenoses functionally evaluated using commercially available pressure wires. cFFR was obtained after intracoronary injection of contrast medium, while FFR was measured after administration of adenosine. Resting Pd/Pa and cFFR were significantly higher than FFR (0.93±0.05 vs. 0.87±0.08 vs. 0.84±0.08, p<0.001). A strong correlation and a close agreement at Bland-Altman analysis between cFFR and FFR were observed (r=0.90, p<0.001 and 95% CI of disagreement: from -0.042 to 0.11). ROC curve analysis showed an excellent accuracy (89%) of the cFFR cut-off of ≤0.85 in predicting an FFR value ≤0.80 (AUC 0.95 [95% CI: 0.94-0.96]), significantly better than that observed using resting Pd/Pa (AUC: 0.90, 95% CI: 0.88-0.91; p<0.001). A cFFR/FFR hybrid approach showed a significantly lower number of lesions requiring adenosine than a resting Pd/Pa/FFR hybrid approach (22% vs. 44%, p<0.0001). CONCLUSIONS: cFFR is accurate in predicting the functional significance of coronary stenosis. This could allow limiting the use of adenosine to obtain FFR to a minority of stenoses with considerable savings of time and costs.

Percutaneous coronary intervention in the Occluded Artery Trial: procedural success, hazard, and outcomes over 5 years.

BACKGROUND: The Occluded Artery Trial (OAT) was a 2,201-patient randomized clinical trial comparing routine stent-based percutaneous coronary intervention (PCI) versus optimal medical therapy alone in stable myocardial infarction (MI) survivors with persistent infarct-related artery occlusion identified day 3 to 28 post MI. Intent-to-treat analysis showed no difference between strategies with respect to the incidence of new class IV congestive heart failure, MI, or death. The influence of PCI failure, procedural hazard, and crossover on trial results has not been reported. METHODS: Study angiograms were analyzed and adjudicated centrally. Factors associated with PCI failure were examined. Time-to-event analysis using the OAT primary outcome was performed by PCI success status. Landmark analysis (up to and beyond 30 days) partitioned early hazard versus late outcome according to treatment received. RESULTS: Percutaneous coronary intervention was adjudicated successful in >87%. Percutaneous coronary intervention failure rates were similar in US and non-US sites, and did not significantly influence outcome at 60 months (hazard ratio for success vs fail 0.79, 99% CI 0.45-1.40, P = .29). Partitioning of early procedural hazard revealed no late benefit for PCI (hazard ratio for PCI success vs medical therapy alone 1.06, 99% CI 0.75-1.50, P = .66). CONCLUSIONS: Percutaneous coronary intervention failure and complication rates in the OAT were low. Neither PCI failure nor early procedural hazard substantively influenced the primary trial results.