Preserved Myocardial Viability In Patients With Chronic Total Occlusion Of A Single Coronary Artery

Preserved myocardial viability in patients with chronic total occlusion of a single coronary arteryObjective.To assess the benefits of coronary collateral circulation on myocardial perfusion,viability and function in patients with total occlusion of a single coronary artery using the 99mTc-sestamibi SPECT and 18F-fluorodeoxyglucose PET.Methods.164 consecutive patients were included who underwent coronary angiography results exhibited total occlusion of a single coronary artery and received 99mTc-MIBI SPECT and 18F-FDG PET within 90 days of angiography.Myocardial perfusion and viability in patients with collateral circulation and those without collateral circulation were compared.Long-term following-up was performed through a review of patient clinical records.Results.Collateral circulation was present in 56 patients(34%)and absent in 108 patients(66%).The total perfusion defect size(TPD)in patients with collateral circulation decreased when compared to those without(30%±13%to 35%±14%,P<0.05).The myocardial viability was 22%±12%in patients with collateral circulation,and 12%±9%in those without(P<0.001).The left ventricular ejection fraction(LVEF)was higher,and the end-diastolic(EDV)and end-systolic(ESV)left ventricular volumes were lower in patients with collateral circulation(39%±11%,138±66,89±57)compared to patients without collateral circulation(31%±9%,177±55,125±48,all P<0.001,respectively).Multi-factor logistic regression identified that concerning the variables of sex,age,hypertension,diabetes,smoking,hyperlipidemia,family history,TPD,Scar,Mismatch,EDV,ESV,LVEF,collateral circulation,treatment type and others,only LVEF(OR:1.1,95%CI:1.0-1.3,P<0.01)and treatment type(OR:3.9,95%CI:1.9-7.8,P<0.001)were significantly associated with therapeutic effects.Conclusion.Collateral circulation can preserve resting myocardial blood perfusion and myocardial viability,and help maintain the function of the left ventricular myocardium.The LVEF and appropriate treatment strategy will have a substantial impact on the therapeutic outcome.Rescue Scheme to improve myocardial 18F-FDG uptake in PET/CT myocardial metabolic imagingObjective.To assess the feasibility of the rescue scheme of the second injection low dose 18F-FDG with simultaneous 1-2U insulin injection and oral administration about 10g glucose to improve the image quality of 18F-fluorodeoxyglucose PET myocardium metabolic imaging.Methods.Fifty-one consecutive patients whose 18F-FDG PET/CT myocardial metabolic image quality was poor to uninterpretable received a rescue scheme after the first imaging.Image quality of the initial and rescue images was compared.The qualitative visual estimation of image quality was graded as Grade 0,homogeneously minimal;Grade 1,mostly minimal or mild uptake;Grade 2,moderate uptake;Grade 3,good uptake.The myocardial 18F-FDG maximum standardized uptake value(SUVmax),blood-pool mean standardized uptake value(SUVmean)and the myocardium-to-blood-pool activity ratio(M/B)were measured to quantitatively assess the image quality.Results.Grade of 0,1,2 and 3 were observed in 24(47%),24(47%),3(6%)and 0(0%)patients at the initial imaging;and grade 0,1,2 and 3 were observed in 0(0%),3(5.9%),4(7.8%)and 44(86.3%)patients at the rescue imaging,P<0.001.The median of rescue image quality score(3,range 1-3)was significantly higher than that of the initial image(1,range 0-1),P<0.001.The rescue M/B was higher than the initial M/B significantly(3.4±1.4 versus 1.6±0.6;P<0.001).Conclusion.The rescue scheme is effective and practical for improvement of myocardial 18F-FDG uptake and the image quality of metabolic imaging without significant increase of radiation dose.