Clinical trial NCT05592535: Outcomes With Fractional Flow Reserve in Chronic Coronary Syndrome
Official title: Prognostic Impact of Fractional Flow Reserve in Chronic Coronary Syndrome: Quasi-Experimental Findings Using a Regression Discontinuity Design
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Chronic Coronary Syndrome
Keywords: Percutaneous Coronary Intervention
Fractional Flow Reserve
Lead sponsor: Uppsala University
Sponsor class: OTHER
First posted: 2022-10-24
Enrollment: 5000
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients with chronic coronary syndrome undergoing coronary angiography and FFR measurement in Sweden.

Brief summary: The use of fractional flow reserve (FFR) to assess the functional relevance of coronary stenoses has been demonstrated to reduce the risk urgent revascularization in chronic coronary syndrome patients.\[1\] The goal of this study is to assess whether the utility of using FFR during percutaneous coronary intervention (PCI) in chronic coronary syndrome patients is confirmed in a real-life scenario. This study will implement a regression discontinuity design (RDD). RDD is a quasi-experimental study design able to provide robust findings on causality using observational data.

Detailed description: All patients in this study were included in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR), a sub-registry of SWEDEHEART. \[2\] Data regarding FFR assessments are documented in SCAAR in terms of FFR values and coronary segments investigated with FFR. The use of FFR during PCI is left at the discretion of the operator. Since a nondeterministic assignment to revascularization is expected at the cut-off, a fuzzy RDD design will be used in the analyses. Moreover, FFR values equal to 0.80 (at the cut-off) will be excluded from the analysis since treatment assignment exactly at the cut-off may substantially vary across operators and this may create distortions in the treatment discontinuity. Local linear regression estimates with Kernel triangulation and asymmetric bandwidth selection will be used in the analysis. Bandwidth selection will be based on a fully data-driven approach that minimizes the bias-variance trade-off.\[3\] Estimates from RDD will be presented as risk differences \[RD\] complemented by 95% robust confidence intervals.\[4\]

Eligibility criteria: Inclusion Criteria:

* Chronic coronary syndrome undergoing coronary angiography and FFR measurement
* Swedish personal identification number

Exclusion Criteria:

* previous coronary artery bypass grafting
* left main disease or undergoing FFR/PCI of left main
* IVUS/OCT use
* diffuse disease (≥ 2 segments treated in a same vessel investigated with FFR, ≥ 2 segments investigated with FFR in a same vessel)
* PCI in a distal segment with respect to FFR measurements

Primary outcomes:
measure: Risk difference (%) for the composite of all-cause death and FFR-oriented target vessel revascularization by PCI
timeFrame: Up to one year following index FFR measurement
Secondary outcomes:
measure: Risk difference (%) for the composite of all-cause death, FFR-oriented target vessel revascularization by PCI and hospitalization for acute myocardial infarction
timeFrame: Up to one year following index FFR measurement
measure: Risk difference (%) for the composite of all-cause death and new hospitalization for acute myocardial infarction
timeFrame: Up to one year following index FFR measurement
measure: Risk differences (%) for the individual components of the composite outcome measures
timeFrame: Up to one year following index FFR measurement
Other outcomes:
Locations:
Study officials:
References:
citation: De Bruyne B, Pijls NH, Kalesan B, Barbato E, Tonino PA, Piroth Z, Jagic N, Mobius-Winkler S, Rioufol G, Witt N, Kala P, MacCarthy P, Engstrom T, Oldroyd KG, Mavromatis K, Manoharan G, Verlee P, Frobert O, Curzen N, Johnson JB, Juni P, Fearon WF; FAME 2 Trial Investigators. Fractional flow reserve-guided PCI versus medical therapy in stable coronary disease. N Engl J Med. 2012 Sep 13;367(11):991-1001. doi: 10.1056/NEJMoa1205361. Epub 2012 Aug 27.
citation: Jernberg T, Attebring MF, Hambraeus K, Ivert T, James S, Jeppsson A, Lagerqvist B, Lindahl B, Stenestrand U, Wallentin L. The Swedish Web-system for enhancement and development of evidence-based care in heart disease evaluated according to recommended therapies (SWEDEHEART). Heart. 2010 Oct;96(20):1617-21. doi: 10.1136/hrt.2010.198804. Epub 2010 Aug 27.
citation: Calonico S, Cattaneo MD, Farrell MH. Optimal bandwidth choice for robust bias corrected inference in regression discontinuity designs. Econom J. 2020;23(2):192-210.
citation: Calonico S, Cattaneo MD, Titiunik R. Robust nonparametric confidence intervals for regression-discontinuity designs. Econometrica. 2014;82(6):2295-2326.