Factors Predicting 150 and 200 Microgram Adenosine Requirement during Four Increasing Doses of Intracoronary Adenosine Bolus Fractional Flow Reserve Assessment

Abstract

Direct intracoronary adenosine bolus is an excellent alternative to intravenous adenosine fractional flow reserve (FFR) measurement. This study, during four increasing adenosine boluses (50, 100, 150, and 200 mcg), aimed to explore clinical and angiographic predictors of coronary stenotic lesions for which the significant ischemic FFR (FFR ≤ 0.8) occurred at 150 and 200 mcg adenosine doses. Data from 1055 coronary lesions that underwent FFR measurement at the Central Chest Institute of Thailand from August 2011 to July 2021 were included. Baseline clinical and angiographic characteristics were analyzed. The FFR ≤ 0.8 occurred at adenosine 150 and 200 mcg boluses in 47 coronary lesions, while the FFR ≤ 0.8 occurred at adenosine 50 and 100 mcg boluses in 186 coronary lesions. After univariable and multivariable logistic regression analyses, four characteristics, including male sex, younger age, non-smoking status, and FFR procedure of RCA, were predictors of the occurrence of FFR ≤ 0.8 at adenosine 150 and 200 mcg doses. Combining all four predictors as a predictive model resulted in an AuROC of 0.72 (95% CI: 0.68-0.76), an 86% negative predictive value. Comparing these four predictors, the FFR procedure of RCA gave the most predictive power, with the AuROC of 0.60 (95% CI: 0.56-0.63).

Keywords: fractional flow reserve; intracoronary adenosine; percutaneous coronary intervention.

Figure 1

Study flow chart. FFR—fractional flow reserve; IV—intravenous; mcg—microgram; IC—intracoronary; Pd/Pa—ratio of pressure distal to coronary lesion divided by pressure of aorta; BMI—body mass index; DM—diabetes mellitus; HT—hypertension; HLP—hyperlipidemia; LCA—left coronary artery; RCA—right coronary artery; TVD—triple vessels coronary artery disease.

Figure 2

Donut chart summary: in which dose of intracoronary adenosine did the FFR occur? mcg—microgram.

Figure 3

Three categories of changes in Pd/Pa value during FFR measurement: FFR > 0.8 (822 lesions), FFR ≤ 0.8 occurring at adenosine 150, 200 mcg (47 lesions), and FFR ≤ 0.8 occurring at adenosine 50, 100 mcg (186 lesions). FFR—fractional flow reserve; Pd/Pa—ratio of pressure distal to coronary lesion divided by pressure of aorta; mcg—microgram.

Figure 4

Comparison of area under receiver operating characteristic curve (AuROC) between all 12 predictors, final 4 predictors, and only single predictor (FFR procedure of RCA) in predicting the occurrence of FFR ≤ 0.8 at adenosine 150, 200 mcg. FFR—fractional flow reserve; RCA—right coronary artery.