Effect Of DCB-Only Strategy In Side Branch Protection For True Coronary Bifurcation Lesions

Background:The provisional stenting(PS)strategy is currently the standard management for most coronary bifurcation lesions(CBL),but the main vessel(MV)placement of stents influences the local anatomical structure,which may lead to the carina and plate displacement,resulting in stenosis or occlusion of side branch(SB).How to fully protect SB from serious stenosis or occlusion of SB is one of the core issues of interventional therapy for CBL at present.Objectives:Subjects were chosen from patients who had real non-left main CBL with MV residual stenosis<30%and SB residual stenosis<50%after sufficient predilatation.The primary observation indicators were the degree of stenosis,the major cardiovascular adverse events after a 6-month follow-up,and the minimum lumen diameter and area of MV and SB assessed by coronary angiography and optical coherence tomography.To evaluate and compare the PS strategy’s ability to protect SB in patients with true coronary bifurcation lesion(TCBL)and the drug-coated balloon(DCB)only strategy’s ability to do so.Methods:Patients with TCBL of the coronary arteries judged to be non-left main stem by inpatient parallel coronary angiography at the Department of Cardiology,China-Japan union Hospital of Jilin University from January 2020 to June 2022,and with MV residual stenosis<30%,SB residual stenosis<50%after adequate predilatation,MV and SB were both below type C stenosis and TIMI≧III grade as the study subjects,and the patients were divided into experimental group(n=26)and control group(n=27),and the patients in the experimental group were treated with DCB-only strategy and the patients in the control group were treated with PS strategy.Baseline data such as age,gender,body mass index(BMI),past history,blood biochemistry,myocardial markers,and left ventricular ejection fraction(LVEF)were compared between the two groups.Medina staging and vessel distribution of true bifurcation stenosis lesions were clarified by coronary angiography before surgery,and MV and SB vessels were measured by coronary angiography and OCT examination before and immediately after the intervention,respectively.Reference diameter and area,minimum lumen diameter and area,and assessment of the degree of stenosis were observed for intraoperative and immediate postoperative procedure-related complications(clamping above C,coronary rupture,pericardial effusion,in-stent thrombosis,no recurrent flow,stent offload,PCI-related myocardial infarction).Patients were followed up by telephone at 6 months after the procedure to compare the incidence of MACEs in patients with the DCB-only strategy and the PS strategy.Results:There were no statistically significant differences in age,gender,body mass index,smoking history,alcohol consumption,hypertension,or diabetes mellitus between the DCB-only and PS strategy groups(P>0.05);there were no statistically significant differences in LDL-C,creatinine,glycated hemoglobin,homocysteine,NT-pro BNP,and LVEF between the two groups(P>0.05).There was no statistically significant difference between the DCB-only strategy and PS strategy groups(P>0.05);there was no significant difference in Medina staging and vessel distribution of CBLs on preoperative coronary angiography(P>0.05);the MV reference diameter and area,MV minimum diameter and area,MV stenosis,SB reference diameter and area,SB minimum diameter and area,and LVEF measured on preoperative OCT in both groups.There were no statistically significant differences in the MV reference diameter and area,MV minimum diameter and area,MV stenosis,SB reference diameter and area,SB minimum diameter and area,and SB stenosis measured by preoperative OCT in the two groups(P>0.05).There was no statistically significant difference in the minimum diameter and area of MV,residual stenosis of MV between the two groups measured by immediate postoperative OCT(P>0.05);the minimum diameter of SB in patients in the DCB-only group measured by immediate postoperative OCT was significantly greater than that in the PS strategy group[2.03(1.96-2.11)mm vs.1.98(1.92-2.03)mm,P=0.031],the minimum SB lumen area was significantly larger than in the PS strategy group[3.62(3.17-3.82)mm2 vs.3.42(3.25-3.52)mm~2,P=0.012],the percentage of SB residual stenosis was significantly smaller than in the PS strategy group[5.98(5.17-7.56)vs.7.56(5.51-9.47)P=0.024],and the differences between the two groups were statistically significant.at 6-month follow-up,there was no statistically significant difference in the incidence of MACEs events between patients in the DCB-only and PS strategy groups(P>0.05).Conclusion:1.Patients with non-left main coronary true bifurcation lesions(Medina1,1,1,Medina1,0,1 and Medina0,1,1)and with MV residual stenosis<30%and SB residual stenosis<50%after adequate pretreatment,the immediate results of the DCB-only strategy for MV vessels were comparable to the PS strategy.2.In patients with non-left main coronary artery true bifurcation lesions(Medina1,1,1,Medina1,0,1 and Medina0,1,1)and with MV residual stenosis<30%and SB residual stenosis<50%after adequate pretreatment,the immediate results of the DCB-only strategy for SB vessels were superior to the PS strategy.3.At 6-month postoperative follow-up,there was no significant difference in the incidence of MACEs between patients with the DCB-only strategy and those with the PS strategy.