1Universitätsklinikum Frankfurt Med. Klinik III - Kardiologie, Angiologie Frankfurt am Main, Deutschland; 2Charité - Universitätsmedizin Berlin CC 11: Med. Klinik für Kardiologie Berlin, Deutschland; 3Klinikum Ernst von Bergmann gGmbH Zentrum für Notfall und Intensivmedizin Potsdam, Deutschland; 4UniversitätsSpital Zürich Universitäres Herzzentrum Zürich, Schweiz
Background: Several studies have demonstrated the prognostic benefit of a physiology-guided complete revascularization in patients with acute coronary syndrome (ACS) and multivessel disease. Concerns regarding the feasibility and diagnostic reliability in setting of ACS due to microvascular dysfunction in a highly prothrombotic and inflammatory setting could be eliminated for fractional flow reserve (FFR), the current gold standard in invasive hemodynamic assessment. Quantitative flow ratio (QFR) represents an angiography-based tool for fast functional evaluation based on three-dimensional quantitative coronary angiography and computational algorithms. A good diagnostic performance and first prognostically beneficial implications could be shown for QFR. Patients with diabetes mellitus are at increased cardiovascular risk and often exhibit diffuse coronary artery disease, especially in setting of ACS. Whether presence of diabetes mellitus has an impact on the diagnostic performance of QFR in setting of ACS is unknown. This study sought to investigate the diagnostic reliability of QFR assessment in non-culprit lesions in patients with acute coronary syndrome and diabetes mellitus.
Methods: A total of 421 patients with ACS and multivessel disease who underwent primary PCI of the ACS-causing culprit lesion and were planned for staged PCI of at least one non-culprit lesion (>70% diameter stenosis by visual estimation) were enrolled in the analysis. Post-hoc serial QFR analyses of 513 non-culprit vessels were performed by certified investigators blinded to clinical characteristics. Measurements at time of staged PCI were used as reference for the results of analysis at time of ACS.
Results: The total study cohort of 421 patients with ACS (50.5% STE-ACS and 49.5% NSTE-ACS) consisted of 67 diabetic and 254 non-diabetic patients. The majority of 72.9% had male gender and median age was 66 [58-76] years. The median time interval between ACS and staged coronary angiography was 49 [42-58] days. Non-culprit lesion characteristics did not demonstrate significant differences between both groups. QFR in non-culprit vessels did not change between time of ACS and time of staged procedure in patients with diabetes (0.84 vs. 0.85, p=0.57) as well as without diabetes (0.86 vs. 0.89, p=0.14). A strong correlation (Spearmans correlation coefficient: r=0.92, p<0.001 in diabetic; and r=0.90, p<0.001 in non-diabetic patients) and good agreement (Bland Altman analysis: mean difference 0.01, 95%CI -0.05-0.07 in diabetic; and 0.01, 95%CI -0.04-0.05 in non-diabetic patients) between serial QFR assessment could be seen in both groups. Importantly, QFR as assessed at time of ACS showed high diagnostic performance with high sensitivity (93.48% and 95.48%), specificity (90.62% and 94.35%) and diagnostic accuracy (91.82% and 94.79%) in prediction of QFR ≤0.80 at the time of staged procedure irrespective of the presence of diabetes mellitus.
Conclusions: The present study confirmed the feasibility and diagnostic reliability of QFR assessment in the evaluation of non-culprit lesions at time of ACS irrespective of the presence of diabetes mellitus. These results support angiography based QFR as valuable tool in patients with ACS to detect hemodynamic relevant stenoses and provide a functional tool for further risk stratification and optimization of revascularization strategy in diabetic patients with ACS and multivessel disease.