Feasibility and Improved Diagnostic Yield of Intracoronary Adenosine to Assess Microvascular Dysfunction With Bolus Thermodilution

Figure 1. Study flow chart. CAD indicates coronary artery disease; FFR, fractional flow reserve; INOCA, myocardial ischemia with not obstructive coronary artery disease; LCA, left coronary artery; mcg, micrograms; and RCA, right coronary artery.

Figure 2. Classification agreement between intracoronary and intravenous adenosine for CFR and IMR. Scatterplots comparing the distribution of CFR and IMR values between LDIC, HDIC, and intravenous adenosine (n=102 patients). The dashed black lines indicate the cutoff for both indices (CFR <2.0; IMR ≥25) and the resulting 4 quadrants provide the classification agreement between adenosine modalities. CFR indicates coronary flow reserve; HDIC, high‐dose intracoronary adenosine; IMR, index of microcirculatory resistance; and LDIC, low‐dose intracoronary adenosine.

Figure 3. Comparison of the components of CFR and IMR indices by adenosine administration method. Dot and line diagram with overlapped box‐and‐whisker plots displaying the individual and overall changes in baseline Tmn, hyperemic Tmn, and hyperemic Pd with HDIC and intravenous adenosine. The P value compares each metric between HDIC and IV adenosine. CFR indicates coronary flow reserve; HDIC, high‐dose intracoronary adenosine; Pd, intracoronary distal pressure; and Tmn, mean transit time.

Figure 4. Comparison of procedural time by dose and route of adenosine administration. Dot and line diagram depicts changes in procedural time within each patient for each dose and route of adenosine administration during microcirculatory assessment with bolus thermodilution. Box‐and‐whisker plots summarizing overall distribution of procedural time for each adenosine modality are shown at the top. *Compares LDIC vs HDIC, **LDIC vs intravenous, ***HDIC vs intravenous. HDIC indicates high‐dose intracoronary adenosine; and LDIC, low‐dose intracoronary adenosine.

Figure 5. Comparison of chest pain intensity by visual analog scale according to the dose and route of adenosine administration. Visual analog scale: 1–10, 0 = no pain, 10 = most severe pain possible. *Compares LDIC vs HDIC, **LDIC vs intravenous, ***HDIC vs IV. HDIC indicates high‐dose intracoronary adenosine; and LDIC, low‐dose intracoronary adenosine.