Clinical Pearls & Morning Reports
Published July 21, 2021
It is unclear whether a fractional flow reserve (FFR)-guided approach results in better clinical outcomes than an angiography-guided approach for complete revascularization in patients with ST-elevation myocardial infarction (STEMI) and multivessel disease. Puymirat et al. conducted a trial that compared the two strategies for the management of nonculprit lesions in patients with STEMI and multivessel disease. Read the NEJM Original Article here.
Q: How did the FFR-guided strategy compare with the angiography-guided strategy for complete revascularization in the trial by Puymirat et al.?
A: Among patients with STEMI and multivessel disease who had undergone successful PCI of the infarct-related artery, an FFR-guided strategy for complete revascularization was not superior to an angiography-guided strategy for reducing the risk of the composite primary outcome (death from any cause, nonfatal myocardial infarction, or unplanned hospitalization leading to urgent revascularization at 1 year). At 1 year, the primary outcome had occurred in 32 of 586 patients (5.5%) in the FFR-guided group and in 24 of 577 (4.2%) in the angiography-guided group (hazard ratio, 1.32; 95% confidence interval [CI], 0.78 to 2.23; P=0.31).
Q: Was a benefit of FFR identified with respect to any outcome of the trial?
A: The lack of benefit of FFR with respect to the primary outcome was consistent across the prespecified subgroups. The individual components of the primary outcome, as well as all other clinical outcomes, did not differ significantly between the two groups. Death from any cause occurred in 9 patients in the FFR-guided group and in 10 patients in the angiography-directed group (hazard ratio, 0.89; 95% CI, 0.36 to 2.20).
A: For the treatment of nonculprit lesions, the authors encouraged investigators to perform complete revascularization during the index procedure. In practice, however, this was rarely done, since only 4% of the patients had an immediate nonculprit-lesion intervention, which suggests that FFR measurement that is performed at the same time as PCI of the infarct-related artery may be unrealistic under routine clinical conditions. The trial results should therefore be interpreted as pertaining to patients who are undergoing staged multivessel procedures.
A: Staged procedures expose the patient to a second procedure with its associated risks, and in some instances the second procedure proves unnecessary since no intervention will be performed. The performance of FFR during the initial procedure, which would result in fewer additional procedures, could save exposure to radiation and contrast materials. However, there is concern that prolonging the index procedure could lead to a higher risk during a period of acute vulnerability (active prothrombotic state, acute inflammation, and risks of hemodynamic instability and arrhythmia) than repeating the procedure 48 hours later when the patient’s condition is more stable. Also, assessment of nonculprit lesions may be uncertain during the acute event, when vasospasm may lead to an overestimate of stenosis severity. Finally, the validity of FFR in patients with acute myocardial infarction, and particularly anterior myocardial infarction, is debated. Only a randomized trial comparing immediate with staged PCI will resolve the question of the most effective timing of multivessel procedures in patients with STEMI.