Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI
Matthias Götberg, Evald H Christiansen, Ingibjörg J Gudmundsdottir, Lennart Sandhall, Mikael Danielewicz, Lars Jakobsen, Sven-Erik Olsson, Patrik Öhagen, Hans Olsson, Elmir Omerovic, Fredrik Calais, Pontus Lindroos, Michael Maeng, Tim Tödt, Dimitrios Venetsanos, Stefan K James, Amra Kåregren, Margareta Nilsson, Jörg Carlsson, Dario Hauer, Jens Jensen, Ann-Charlotte Karlsson, Georgios Panayi, David Erlinge, Ole Fröbert, iFR-SWEDEHEART Investigators, Jens Aarøe, Hans Erik Bøtker, Steen Dalby Kristensen, Christian Juhl Terkelsen, Anne Kaltoft, Lars Romer Krusell, Peter Hårdhammar, Anna Myredal, Johan Pontén, Martin Adielsson, Henrik Wagner, Anja Fagerström, Michael Lindstaedt, Mats Allared, Tage Nilsson, Per Stalby, Aydin Toksöz, Waldemar Czekierda, Christos Pagonis, Leszek Zagozdzon, Thorarinn Gudnason, Thorbjorn Gudjonsson, Berglind Libungan, Sigurpáll Scheving, Axel Sigurdsson, Oskar Angerås, Truls Råmunddal, Sebastian Völz, Pallonji Bhiladvala, Mats Birgander, Per Bondesson, Sasha Koul, Anders Lundin, Thomas Molund, Fredrik Scherstén, Henrik Enhörning, Bo Jonsson, Mattias Törnerud, Bo Lindvall, Daniel Wadell, Bo Lagerqvist, Bertil Larsson, Christoph Varenhorst, Erik Diderholm, Per Grimfjärd, Usama Dhaha, Thomas Kellerth, Kristian Wachtell, Eva Jacobsson, Ulf Bohman, Elisabet Ärnström, Camilla Hartman, Martina Tillberg, Claes Held, Theresa Hallberg, Camilla Svanberg, Mikael Nygård, Thomas Engstrøm, Matthias Götberg, Evald H Christiansen, Ingibjörg J Gudmundsdottir, Lennart Sandhall, Mikael Danielewicz, Lars Jakobsen, Sven-Erik Olsson, Patrik Öhagen, Hans Olsson, Elmir Omerovic, Fredrik Calais, Pontus Lindroos, Michael Maeng, Tim Tödt, Dimitrios Venetsanos, Stefan K James, Amra Kåregren, Margareta Nilsson, Jörg Carlsson, Dario Hauer, Jens Jensen, Ann-Charlotte Karlsson, Georgios Panayi, David Erlinge, Ole Fröbert, iFR-SWEDEHEART Investigators, Jens Aarøe, Hans Erik Bøtker, Steen Dalby Kristensen, Christian Juhl Terkelsen, Anne Kaltoft, Lars Romer Krusell, Peter Hårdhammar, Anna Myredal, Johan Pontén, Martin Adielsson, Henrik Wagner, Anja Fagerström, Michael Lindstaedt, Mats Allared, Tage Nilsson, Per Stalby, Aydin Toksöz, Waldemar Czekierda, Christos Pagonis, Leszek Zagozdzon, Thorarinn Gudnason, Thorbjorn Gudjonsson, Berglind Libungan, Sigurpáll Scheving, Axel Sigurdsson, Oskar Angerås, Truls Råmunddal, Sebastian Völz, Pallonji Bhiladvala, Mats Birgander, Per Bondesson, Sasha Koul, Anders Lundin, Thomas Molund, Fredrik Scherstén, Henrik Enhörning, Bo Jonsson, Mattias Törnerud, Bo Lindvall, Daniel Wadell, Bo Lagerqvist, Bertil Larsson, Christoph Varenhorst, Erik Diderholm, Per Grimfjärd, Usama Dhaha, Thomas Kellerth, Kristian Wachtell, Eva Jacobsson, Ulf Bohman, Elisabet Ärnström, Camilla Hartman, Martina Tillberg, Claes Held, Theresa Hallberg, Camilla Svanberg, Mikael Nygård, Thomas Engstrøm
Abstract
Background: The instantaneous wave-free ratio (iFR) is an index used to assess the severity of coronary-artery stenosis. The index has been tested against fractional flow reserve (FFR) in small trials, and the two measures have been found to have similar diagnostic accuracy. However, studies of clinical outcomes associated with the use of iFR are lacking. We aimed to evaluate whether iFR is noninferior to FFR with respect to the rate of subsequent major adverse cardiac events.
Methods: We conducted a multicenter, randomized, controlled, open-label clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2037 participants with stable angina or an acute coronary syndrome who had an indication for physiologically guided assessment of coronary-artery stenosis were randomly assigned to undergo revascularization guided by either iFR or FFR. The primary end point was the rate of a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization within 12 months after the procedure.
Results: A primary end-point event occurred in 68 of 1012 patients (6.7%) in the iFR group and in 61 of 1007 (6.1%) in the FFR group (difference in event rates, 0.7 percentage points; 95% confidence interval [CI], -1.5 to 2.8; P=0.007 for noninferiority; hazard ratio, 1.12; 95% CI, 0.79 to 1.58; P=0.53); the upper limit of the 95% confidence interval for the difference in event rates fell within the prespecified noninferiority margin of 3.2 percentage points. The results were similar among major subgroups. The rates of myocardial infarction, target-lesion revascularization, restenosis, and stent thrombosis did not differ significantly between the two groups. A significantly higher proportion of patients in the FFR group than in the iFR group reported chest discomfort during the procedure.
Conclusions: Among patients with stable angina or an acute coronary syndrome, an iFR-guided revascularization strategy was noninferior to an FFR-guided revascularization strategy with respect to the rate of major adverse cardiac events at 12 months. (Funded by Philips Volcano; iFR SWEDEHEART ClinicalTrials.gov number, NCT02166736 .).
Source: PubMed