14 Dec 20. Featured Paper

Coronary 18F-fluoride uptake & progression of coronary artery calcification.

Link to paper on Circulation: Cardiovascular Imaging

Authors

Mhairi K. Doris, Mohammed N. Meah, Alastair J. Moss, Jack P.M. Andrews, Rong Bing, Rebecca Gillen, Nick Weir, Maaz Syed, Marwa Daghem, Anoop Shah, Michelle C. Williams, Edwin J.R. van Beek, Laura Forsyth, Damini Dey, Piotr J. Slomka, Marc R. Dweck, David E. Newby, Philip D. Adamson

Abstract

Background: Positron emission tomography (PET) using ¹⁸F-sodium fluoride (¹⁸F-fluoride) to detect microcalcification may provide insight into disease activity in coronary atherosclerosis.

This study aimed to investigate the relationship between ¹⁸F-fluoride uptake & progression of coronary calcification in patients with clinically stable coronary artery disease.

Methods: Patients with established multivessel coronary atherosclerosis underwent ¹⁸F-fluoride PET-computed tomography angiography & computed tomography calcium scoring, with repeat computed tomography angiography & calcium scoring at one year.

Coronary PET uptake was analyzed qualitatively & semiquantitatively in diseased vessels by measuring maximum tissue-to-background ratio.

Coronary calcification was quantified by measuring calcium score, mass, & volume.

Results: In a total of 183 participants (median age 66 years, 80% male), 116 (63%) patients had increased ¹⁸F-fluoride uptake in at least one vessel.

Individuals with increased ¹⁸F-fluoride uptake demonstrated more rapid progression of calcification compared with those without uptake (change in calcium score, 97 [39–166] versus 35 [7–93] AU; P<0.0001).

Indeed, the calcium score only increased in coronary segments with ¹⁸F-fluoride uptake (from 95 [30–209] to 148 [61–289] AU; P<0.001) & remained unchanged in segments without ¹⁸F-fluoride uptake (from 46 [16–113] to 49 [20–115] AU; P=0.329).

Baseline coronary ¹⁸F-fluoride maximum tissue-to-background ratio correlated with 1-year change in calcium score, calcium volume, & calcium mass (Spearman ρ=0.37, 0.38, & 0.46, respectively; P<0.0001 for all).

At the segmental level, baseline ¹⁸F-fluoride activity was an independent predictor of calcium score at 12 months (P<0.001).

However, at the patient level, this was not independent of age, sex, & baseline calcium score (P=0.50).

Conclusions: Coronary ¹⁸F-fluoride uptake identifies both patients & individual coronary segments with more rapid progression of coronary calcification, providing important insights into disease activity within the coronary circulation.

At the individual patient level, total calcium score remains an important marker of disease burden & progression.

Keywords

• Atherosclerosis

• Calcium

• Coronary angiography

• Positron emission tomography

• Risk factors