Coronary CT angiography a new promising tool in Heart transplanted patients: from clinical and economical benefits to coronary inflammation detection

Abstract

Abstract Background Heart transplanted patients are usually monitored with invasive diagnostic techniques for detecting cardiac allograft vasculopathy (CAV). However coronary CT angiography (CCTA) is a new promising tool in the initial stages of CAV bringing clinical and economical benefits. Purpose 1) assess the non-inferiority of CCTA in comparison to coronary angiography (CA), in terms of radiation and contrast dose, costs, hospitalization hours, complications and diagnostic accuracy; 2) analyse the different role of immunological and non-immunological risk factors predicting CAV in patients undergoing CCTA; 3) Investigate the rule of coronary inflammation through the pericoronary-fat-attenuation-index (pFAI) at CCTA in the progression of CAV. Methods 179 heart transplanted patients were retrospectively analysed: 78 performed a CCTA and 101 performed a CA between March 2021 and May 2022. Results CCTA and CA showed similar radiation doses (8.47 [1.46-30] versus 8.15 [1.38-87.34]; p=0.796) and rate of complications (0 (0%) vs 3 (3%); p=0,258). CCTA in comparison with CA required less hours of hospitalization (0.5 hours versus 23.7 12.31 hours; p<0.001), lower costs (120 euros versus 2800 euros; p<0.001) and less contrast agent (60.4 8.7 ml versus 95.68 47.6ml; p<0.001). Diagnostic accuracy was similar between CCTA and CA (95% vs 100%; p=0,169). Among the non immunological risk factors for CAV, only smoking showed a statistically significance in predicting CAV (p=0.015). Among immunological risk factors, TNF was the only independent predictor in the progression of CAV (HR 8.23; IC 95% 1.47-45.81; p=0.019). There were no statistically correlation between pFAI at CCTA either as a continuous variable or as a categorical variable (>-70.1HU) and the progression of CAV (p=NS). Conclusions CCTA is similar to CA in terms of radiation dose and rate of complications and is superior in terms of hospitalization hours, costs and contrast agent injected. Diagnostic accurancy was equivalent between CCTA and CA. TNF was the only independent predictor in the progression of CAV. Pericoronary inflammation assessed by pFAI at CCTA was not associated with the progression of CAV.