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Observational Study
. 2023 Jun 5;19(2):e123-e133.
doi: 10.4244/EIJ-D-22-00694.

Changes in absolute flow, myocardial resistance and FFR after chronic total occlusion percutaneous coronary intervention

Sarosh A Khan  1   2 , Osama Alsanjari  1   2 , Daniëlle C J Keulards  3 , Pieter-Jan Vlaar  3 , Jufen Zhang  2 , Klio Konstantinou  1   2 , Samer Fawaz  1   2 , Rupert Simpson  1   2 , Gerald Clesham  1   2 , Paul A Kelly  2 , Kare H Tang  2 , Christopher M Cook  1   2 , James Cockburn  4 , Nico H J Pijls  3 , David Hildick-Smith  4 , Koen Teeuwen  3 , Thomas R Keeble  1   2 , Grigoris V Karamasis  1   2   5 , John R Davies  1   2
Affiliations
Observational Study

Changes in absolute flow, myocardial resistance and FFR after chronic total occlusion percutaneous coronary intervention

Sarosh A Khan et al. EuroIntervention. .

Abstract

Background: Randomised studies of percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) have shown inconsistent outcomes, suggesting incomplete understanding of this cohort and their coronary physiology. To address this shortcoming, we designed a prospective observational study to measure the recovery of absolute coronary blood flow following successful CTO PCI Aims: We sought to identify patient and procedural characteristics associated with a favourable physiological outcome after CTO PCI.

Methods: Consecutive patients with a CTO subtending viable myocardium underwent PCI utilising contemporary techniques and the hybrid algorithm. Immediately after PCI, and at 3-month follow-up, physiological measurements were performed utilising continuous thermodilution.

Results: A total of 81 patients were included with a mean age of 63.6±8.9 years, and 66 (81.5%) were male. Physiological measurements of absolute coronary blood flow in the CTO vessel increased by 30% (p<0.001) and microvascular resistance reduced by 16% (p<0.001) from immediately post-CTO PCI to follow-up assessment. Fractional flow reserve increased by 0.02 (p=0.015) in the same period. Prior coronary artery bypass graft (CABG) and a higher estimated glomerular filtration rate (eGFR) were associated with a larger change in absolute flow. An extraplaque strategy was associated with a smaller change in absolute flow.

Conclusions: Post-CTO PCI, there is a continued augmentation in absolute coronary blood flow and reduction in microvascular resistance from baseline to follow-up at 3 months. Prior CABG and a higher baseline eGFR were predictors of a larger change in absolute coronary flow, whilst an extraplaque final wire path strategy predicted a smaller change. Lastly, the patient characteristics and comorbidities had a larger influence than procedural factors on the observed change in absolute flow.

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Conflict of interest statement

C. Cook is a consultant for Philips, Boston Scientific, and Viz.ai; has received an institutional grant from Edwards Lifesciences; and has equity in Cerebria. N. Pijls has received institutional grants from Abbott and Hexacath; is a consultant for Abbott and GE Healthcare; and has minor equities in Philips, ASML, and HeartFlow. T. Keeble has received research grants from Boston Scientific, Volcano, Terumo, and Abbott Vascular. G. Karamasis has received honoraria from Abbott Vascular; and has received a research grant from Abbott Vascular. J. Davies has received a research grant from Medtronic. The other authors have no conflicts of interest to declare.

Figures

Figure 1
Figure 1. Absolute coronary blood flow at index and follow-up per vessel.
Absolute coronary blood flow at index and follow-up by CTO vessel. Bars: interquartile range (IQR). Dots: median value. CTO: chronic total occlusion; LAD: left anterior descending artery (n=20); LCx: left circumflex artery (n=8); RCA: right coronary artery (n=53)
Central illustration
Central illustration. Absolute coronary flow after successful CTO PCI and clinical predictors of change in flow.
Patients underwent CTO-vessel PCI (A) followed by immediate measurements of absolute flow in the culprit vessel. These measurements were repeated at follow-up (B). Absolute coronary flow increased from index to follow-up by 30% (C). Predictors of change in absolute flow (ΔQ) (D); an extraplaque final wire path predicted a smaller change in absolute flow, whereas prior CABG and a higher eGFR predicted a larger change in absolute flow. CABG: coronary artery bypass graft; CTO: chronic total occlusion; eGFR: estimated glomerular filtration rate; PCI: percutaneous coronary intervention
See this image and copyright information in PMC

References

    1. Nijjer SS, Petraco R, van de, Sen S, van Lavieren, Foale RA, Meuwissen M, Broyd C, Echavarria-Pinto M, Al-Lamee R, Foin N, Sethi A, Malik IS, Mikhail GW, Hughes AD, Mayet J, Francis DP, Di Mario, Escaned J, Piek JJ, Davies JE. Change in coronary blood flow after percutaneous coronary intervention in relation to baseline lesion physiology: results of the JUSTIFY-PCI study. Circ Cardiovasc Interv. 2015;8:e001715. - PMC - PubMed
    1. Cosgrove C, Mahadevan K, Spratt JC, McEntegart M. The Impact of Calcium on Chronic Total Occlusion Management. Interv Cardiol. 2021;16:e30. - PMC - PubMed
    1. Guo Y, Peng H, Zhao Y, Liu J. Predictors and complications of side branch occlusion after recanalization of chronic total occlusions complicated with bifurcation lesions. Sci Rep. 2021;11:4460. - PMC - PubMed
    1. Werner GS. The role of coronary collaterals in chronic total occlusions. Curr Cardiol Rev. 2014;10:57–64. - PMC - PubMed
    1. Werner GS, Martin-Yuste V, Hildick-Smith D, Boudou N, Sianos G, Gelev V, Rumoroso JR, Erglis A, Christiansen EH, Escaned J, di Mario, Hovasse T, Teruel L, Bufe A, Lauer B, Bogaerts K, Goicolea J, Spratt JC, Gershlick AH, Galassi AR, Louvard Y EUROCTO trial investigators. A randomized multicentre trial to compare revascularization with optimal medical therapy for the treatment of chronic total coronary occlusions. Eur Heart J. 2018;39:2484–93. - PubMed

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