Per-vessel myocardial blood flow improvement after coronary artery bypass graft surgery quantified by CT myocardial perfusion imaging.
Source: PubMed, NCBI / U.S. National Library of Medicine
While coronary artery bypass grafting (CABG) aims for complete angiographic revascularization, data on vessel-specific physiological recovery remains limited. We aimed to quantitatively assess region-specific changes in myocardial blood flow (MBF) before and after CABG using dynamic CT myocardial perfusion imaging (CT-MPI). Twenty-six patients underwent coronary CT angiography (CCTA) and stress dynamic CT-MPI before and after CABG. Vessel-specific territories were segmented using a patient-specific minimum cost path algorithm. Myocardial territories were categorized by CABG status and baseline perfusion. Among 70 grafted territories, baseline perfusion was reduced by >30%, 20-30%, and 10-20% in 20, 20, and 21 territories, respectively. Only territories with baseline hypoperfusion >30% reduction showed significant MBF increases post-CABG (n ​= ​20, p ​< ​0.001), with improvement strongly dependent on the baseline deficit. In territories with severest baseline hypoperfusion, the volume of myocardium with MBF<0.7 markedly decreased (mean bias -30.36 ​± ​18.16%, p ​< ​0.00001), and the same for MBF>0.9 markedly increased (mean bias 29.23 ​± ​18.61%, p ​< ​0.00001) post-CABG. Perfusion improvement did not differ significantly across graft types. Our analyses suggest that postoperative perfusion improvement varies substantially between vessel territories and is primarily driven by the seve
Abstract
While coronary artery bypass grafting (CABG) aims for complete angiographic revascularization, data on vessel-specific physiological recovery remains limited. We aimed to quantitatively assess region-specific changes in myocardial blood flow (MBF) before and after CABG using dynamic CT myocardial perfusion imaging (CT-MPI). Twenty-six patients underwent coronary CT angiography (CCTA) and stress dynamic CT-MPI before and after CABG. Vessel-specific territories were segmented using a patient-specific minimum cost path algorithm. Myocardial territories were categorized by CABG status and baseline perfusion. Among 70 grafted territories, baseline perfusion was reduced by >30%, 20-30%, and 10-20% in 20, 20, and 21 territories, respectively. Only territories with baseline hypoperfusion >30% reduction showed significant MBF increases post-CABG (n ​= ​20, p ​< ​0.001), with improvement strongly dependent on the baseline deficit. In territories with severest baseline hypoperfusion, the volume of myocardium with MBF<0.7 markedly decreased (mean bias -30.36 ​± ​18.16%, p ​< ​0.00001), and the same for MBF>0.9 markedly increased (mean bias 29.23 ​± ​18.61%, p ​< ​0.00001) post-CABG. Perfusion improvement did not differ significantly across graft types. Our analyses suggest that postoperative perfusion improvement varies substantially between vessel territories and is primarily driven by the severity of baseline ischemia. Minimal improvement in territories without pre-existing hypoperfusion underscores the importance of per-vessel functional assessment to guide more effective revascularization strategies.