Clinical Significance Of Delayed Contrast Angiography After Acute Stenting In Patients With Acute ST Segment Elevation Myocardial Infarction

Objectives:Clinical studies on the hazards of contrast agents mostly focus on contrast nephropathy,and there are few clinical studies on the effect of contrast agents on microcirculation in patients undergoing percutaneous coronary intervention(PCI).The unique physicochemical properties of contrast agent may promote the development of no-reflow.Therefore,this study focused on the effect of contrast agents on microcirculatory disturbance in patients with acute ST segment elevation myocardial infarction(STEMI).Methods:The patients with STEMI undergoing emergency PCI who were admitted to the Department of Cardiology at the Third Hospital of Hebei Medical University were selected as study population from February 2016 to December 2017.The study included 78 patients finally.They were divided into the conventional angiography group and the delayed angiography group according to the computer-generated random sequence.After completing preoperative preparation,emergency PCI was performed.The radial artery approach was used for selective coronary angiography and the contrast agent used non-ionic iohexol.Conventional angiography group:according to the routine emergency PCI;delayed angiography group:after stenting,observing the situation of stents with as little contrast agent as possible,and performing contrast angiography after 5 minutes.Baseline data and post-PCI postoperative iohexol consumption were recorded in both groups.Outcome measures were:thrombolysis in myocardial infarction(TIMI)blood flow classification,TIMI myocardial perfusion grading(TMPG),and corrected TIMI frame count(CTFC).ST-segment resolution(STR)compliance rate(STR≥70%indicates compliance),left ventricular ejection fraction(LVEF),major adverse cardiac events(MACEs).Statistical software SPSS 22.0 was used for data processing.P≤0.05 indicates a statistical difference.Results:There was no significant difference in baseline data and contrast agent consumption between the two groups(P>0.05).There was no significant difference in TIMI grade 3 blood flow between the delayed angiography group and the conventional angiography group(χ~2=0.020,P=0.887).Delayed angiography significantly improved TMPG blood flow(χ~2=4.640,P=0.031)and CTFC(t=2.034,P=0.045),the difference was statistically significant.The90-minute STR compliance rate was higher in the delayed contrast group(χ~2=4.165,P=0.041).Delayed angiography significantly improved postoperative LVEF at 3 months(t’=2.262,P=0.027).Although there was no statistically significant difference in the incidence of MACEs between the two groups at 3 months,delayed angiography showed a better trend in improving the prognosis of patients(χ~2=1.800,P=0.180).Conclusions:Delayed angiography can improve myocardial perfusion in patients with STEMI after emergency stenting and prevent the occurrence of no reflow.The strategy can also improve cardiac function,reduce the tendency of patients with MACEs and improve the prognosis.