Fractional flow reserve extracts a 3D model of the coronary arteries which is used to perform computational fluid dynamic calculations. It defines the coronary artery boundaries.
A cross- sectional study was conducted in Seventy-three patients between the age group of 42-65 (mean= 56). About 63% of the patient population were males. The range between 8-16 (mean= 11) years after the heart transplantation were included in the study.
Depending on the type of data, Mann–Whitney-U, Kruskal–Wallis, chi-square, or Fisher’s analyses were performed. Patients were divided into 3 groups depending on the time of analysis: up to 10 years, 10 - 15 years, and 15 or more years after Focal hemodynamically. Fifteen (21%) patients were on mammalian target of rapamycin receptor inhibitor (mTORi), sixty patients (82%) were on statins and/or ezetimibe. Beta-blockers were administered before CT scan in 51 (70%) patients. The median heart rate of the patients included in the study was 74 (66–84) beats per minute. Significant stenosis (stenosis > 30% with CT-derived fractional flow reserve ≤ 0.8) was found in Eighteen (25%) patients. The remaining fifty five patients were without a hemodynamically significant focal CT-derived fractional flow reserve stenosis (CT-derived fractional flow reserve > 0.80).?
In 74% of the patients CT-derived fractional flow reserve for the distal left anterior descending artery was < 0.90 in 74%. 10 (18%) patients with a distal CT-derived fractional flow reserve ≤ 0.8, including 1 with a distal CT-derived fractional flow reserve ≤ 0.8 in all coronaries had ≥ 1 coronary artery.
In patients without focal stenosis, the overall distal CT-derived fractional flow reserve was 0.88 (0.86-0.91), 0.87 (0.86-0.90), and 0.88 (0.86-0.91) (median with 25th-75th percentile) at 5-9, 10-14, or ≥ 15 years after transplantation, respectively (p = 0.93).
?The authors conclude that CCTA scan derived CT-derived fractional flow reserve values performed in heart transplant patients showed that about 25% of patients had focal coronary stenosis with fractional flow reserve ≤ 0.8 and also fractional flow reserve values are often abnormal in heart transplant patients even without a focal stenosis.