Relationship Between Coronary Collateral Circulation and The Presence of Bendopnea in Patients with Ischemic Low Ejection Fraction Heart Failure

Background: Coronary collateral circulation(CCC) is a physiological protective mechanism that deve-lops as a result of critical coronary artery stenosis and ischemia. Bendopnea, shortness of breath upon bending forward, is linked to poor cardiac index, increased pulmonary capillary wedge pressure, and coronary artery disease. This study aims to investigate the relationship between coronary collateral circulation and the presence of bendopnea in patients with ischemic low ejection fraction heart failure. Materials and Methods: The cross-sectional study screened 1024 patients diagnosed with heart failure with low ejection fraction after coronary angiography between January 2023 and January 2024, and 259 met the inclusion criteria. Inclusion criteria for the study were defined as having stable coronary artery disease and low ejection fraction heart failure (LVEF<40%) Patients were categorized into ben-dopnea+ and bendopnea- groups. Rentrop classification was used as a basis for the evaluation of CCC Results: There were 158 patients (mean age: 74.1±12.9 years, % 66.4 male) in the bendopnea+ group, while there were 101 patients (mean age: 67.2±14.2 years, %70.2 male) in the bendopnea- group. Bendopnea+ patients were older and had a higher number of NYHA class 3-4 individuals(p<0.001). NT-proBNP(p=0.001) and uric acid levels(p=0.001) were significantly higher in the bendopnea+ group. The Gensini score(p=0.001) and poor collateral circulation(p=0.001) were significantly higher in the bendopnea+ group. Systolic pulmonary artery pressure (sPAP) was notably higher in the bendopnea+ group (p=0.001). Regression analyses identified age(OR: 1.355 %95 CI:1.212-1.517 p=0.001), NT-proBNP(OR: 1.252 %95 CI:1.195-1.412 p=0.001), NYHA class 3-4(OR: 1.245 %95 CI:1.195-1.412 p=0.001),, Gensini score(OR: 1.328 %95 CI:1.213-1.515 p=0.001), and poor collateral circulation(OR: 1.318 %95 CI:1.162-1.441 p=0.001) as independent risk factors for bendopnea. Conclusions: The study concludes that insufficient coronary collateral circulation is an independent risk factor for bendopnea in ischemic heart failure patients.