Cintilografia com MIBI-dipiridamol negativa em doença coronariana grave no pré-operatório de correção de aneurisma de aorta abdominal

Abstract

coronary artery. Both lesions were successfully treated with angioplasty and stent implantation. The patient received antiplatelet therapy for 30 days. Forty-five days after angioplasty, with another normal sestamibi-dipyridamole perfusion imaging, and without any symptoms, the abdominal aortic aneurysm was corrected through retroperitoneal access while the patient was anesthetized with lumbar peridural anesthesia with a catheter combined with general anesthesia. Clamping of the infra-renal aorta lasted 49 minutes, and the surgery lasted 2 hours and 25 minutes. The patient received 3500 mL of crystalloids, 500 mL of hydroxyethyl amide, 150 mL of 20% albumin, and 445 mL of blood retrieved from intraoperative auto-transfusion. The diuresis during surgery was 1000 mL, 800 being in the period after reperfusion. At the beginning of surgery, hemoglobin was 14.3g/dL, and, after surgery, it was 11.4g/dL. The patient was extubated at the end of surgery and remained in the ICU for 20 hours. The postoperative period was uneventful, and the patient was discharged from the hospital 4 days after surgery. Two years after surgery, the patient is in excellent condition, with no cardiovascular symptoms. DiscussionThe incidence of coronary artery disease is significantly greater in patients undergoing vascular surgery than in the general surgical population 1,2 . Myocardial perfusion imaging with sestamibi and dipyridamole has a sensitivity of 96%, when stenoses > 70% are considered, and specificity for detecting disease in the anterior descending coronary artery and in the right coronary artery of 97% and 89%, respectively 3 . The limitations of perfusion imaging are found in patients with hypertension, ventricular hypertrophy and left bundlebranch block. Stress echocardiography is preferred for that subgroup 4 . In addition, other factors, such as caffeine ingestion before the test (inadequate preparation), presence of 3-vessel lesions, and the use of beta-blockers may reduce the sensitivity of myocardial perfusion imaging. Patients who will undergo perfusion imaging with drugs, such as adenosine or dipyridamole, should refrain from having caffeine and medications derived from the xanthines at least in the 24 hours preceding the test. Caffeine and the xanthines block the adenosine receptors, reducing the effect of vasodilation and heart rate elevation. These alterations reduce the sensitivity of the test and increase the chance of false-negative results 5,6 . Patients with 3-vessel lesions or a lesion in the left main coronary artery have a worse prognosis. Nevertheless, in the presence of 3-vessel lesions, perfusion imaging may detect a "balanced" pattern of perfu- In high-risk noncardiac surgeries, such as vascular surgeries, that cause greater cardiac demand, patients with significant coronary artery disease (CAD) should be adequately identified and undergo pharmacological optimization or surgical revascularization. Some studies have tried to define strategies to identify patients at risk for perioperative cardiac events; how...