Background: In a previous analysis we could demonstrate that quantitative flow ratio based on acute angiograms (aQFR) effectively assesses hemodynamic relevance of non-culprit lesion in patients with myocardial infarction. However, it is still unclear whether the effectiveness of this method is influenced by comorbidities or relevant patient characteristics, which may alter local hemodynamics and therefore limit the applicability of aQFR. Therefore, aim of this analysis was assess the role of potential confounders in aQFR.

Methods: We retrospectively assessed the diagnostic efficiency of aQFR in 280 vessels from 220 patients, comparing it with staged ischemia testing. Diagnostic efficiency in the presence of risk factors for altered coronary flow (age, sex, diabetes, obesity, nicotine use, hypertension, diastolic dysfunction, left ventricular ejection fraction (LVEF)) was assessed. 

Results: Comparing diagnostic efficiency of aQFR in the evaluation of non-culprit lesions, adiposity (AUC 0.918 for BMI<30 vs. 0.730 for BMI≥30, p=0.044) and hypertension (AUC 0.951 vs. 0.853, p=0.039) numerically influenced effectivity of aQFR. On the contrary, sex, age, diabetes mellitus , smoking, diastolic dysfunction or reduced LVEF did not influence the diagnostic efficiency of aQFR. Please refer to Table 1 for further details. In summary, aQFR yielded a very good diagnostic efficiency (defined as AUC≥0.80) in all subgroups, with exception for adipose patients.

Conclusion: Assessment of hemodynamic relevance of non culprit lesions with aQFR may be hampered by obesity, probably due to microvascular dysfunction. Otherwise, this method is effective independently from patient characteristics