Pressure-derived estimations of coronary flow reserve are inferior to flow-derived coronary flow reserve as diagnostic and risk stratification tools. (15th March 2019)

• Record Type: Journal Article
• Authors: Wijntjens, Gilbert W.M.; van Lavieren, Martijn A.; van de Hoef, Tim P.; Echavarría-Pinto, Mauro; Meuwissen, Martijn; Stegehuis, Valérie E.; Murai, Tadashi; Escaned, Javier; Piek, Jan J.
• Is Part Of: International journal of cardiology. Volume 279(2019)
• Page Start: 6
• Page End: 11
• Publication Date: 2019-03-15
• Subjects: Pressure-derived coronary flow reserve -- Pressure-bounded coronary flow reserve -- Coronary flow reserve -- Long-term clinical outcome; Cardiology -- Periodicals; Electronic journals; 616.12
• DOI: 10.1016/j.ijcard.2018.11.013
• Languages: English
• ISSNs: 0167-5273

Abstract

Abstract: Background: Pressure-derived coronary flow reserve (CFRpres ) and pressure-bounded CFR (CFRpb ) enable simple estimation of CFR from routine pressure measurements, but have been inadequately validated. We sought to compare CFRpres and CFRpb against flow-derived CFR (CFRflow ) in terms of diagnostic accuracy, as well as regarding their comparative prognostic relevance. Methods: We evaluated 453 intermediate coronary lesions with intracoronary pressure and flow measurements. CFR was defined as hyperemic flow/baseline flow. The lower bound (CFRpres ) and upper bound of CFRpb were defined as √[(ΔPhyperemia ) / (ΔPrest )] and [(ΔPhyperemia ) / (ΔPrest )], respectively. Long-term follow-up (median: 11.8-years) was performed in 153 lesions deferred from treatment to document the occurrence of major adverse cardiac events (MACE) defined as a composite of cardiac death, myocardial infarction and target vessel revascularization. CFR < 2.0 was considered abnormal. Results: CFRpb was normal or abnormal in 56.7% of stenoses, and indeterminate in 43.3% of stenoses. There was a poor diagnostic agreement between CFRpres and CFRpb with CFRflow (overall agreement: 45.5% and 71.6% of vessels, respectively). There was equivalent risk for long-term MACE for lesions with abnormal versus normal CFRpres (Breslow p = 0.562), whereas vessels with abnormal CFRflow were significantly associated with increased long-term MACE (Breslow p < 0.001). For vessels where CFRpb was abnormal or normal, there was equivalent risk for long-term MACE for vessels with abnormal versus normal CFRpb (Breslow p = 0.194), whereas vessels with abnormal CFRflow were associated with increased MACE rates over time (Breslow p < 0.001). Conclusions: Pressure-derived estimations of CFR poorly agree with flow-derived measurements of CFR, which may explain the inferior association with long-term MACE as compared to flow-derived CFR. Highlights: Pressure-derived coronary flow reserve systematically underestimates flow-derived coronary flow reserve. Pressure-bounded coronary flow reserve is determinable in 56.7% of cases. Flow-derived coronary flow reserve is only within the extreme pressure-bounded coronary flow in less than half of measurements. Pressure-derived estimations of coronary flow reserve have inferior prognostic value compared to flow-derived CFR.