ABC | Volume 114, Nº2, February 2020

Update Update of the Brazilian Guideline on Nuclear Cardiology – 2020 Arq Bras Cardiol. 2020; 114(2):325-429 Table 2 – Indication criteria for myocardial perfusion scintigraphy in symptomatic patients Assessment of patients with non-acute chest pain or ischemic equivalent Score Low pretest probability of CAD, with interpretable resting ECG and ability to exercise 3 Low pretest probability of CAD, with uninterpretable resting ECG or inability to exercise 7 Intermediate pretest probability of CAD, with interpretable resting ECG and ability to exercise 7 Intermediate pretest probability of CAD, with uninterpretable resting ECG or inability to exercise 9 High pretest probability of CAD, regardless of interpretable resting ECG and ability to exercise 8 ACS: acute coronary syndrome; CAD: coronary artery disease; ECG: 12-lead electrocardiogram. Table 3 – Indication criteria for myocardial perfusion scintigraphy in asymptomatic patients and/or patients with prior exams Asymptomatic patients – detection of CAD/risk stratification Score Low risk (ATP III criteria) 1 Intermediate risk (ATP III criteria) – interpretable ECG 3 Intermediate risk (ATP III criteria) – uninterpretable ECG 5 High risk (ATP III criteria) 7 High risk and calcium score (Agatston) between 100 and 400 7 Calcium score (Agatston) > 400 7 Low-risk Duke score (> +5) 2 Intermediate-risk Duke score (between −11 and + 5) 7 High-risk Duke score (< −11) 8 Agatston: score that defines the presence and quantity of calcium in coronary arteries, characterizing atherosclerosis; ATP III: Adult Treatment Panel, from the program for detection, evaluation, and treatment of high cholesterol in adults; CAD: coronary artery disease. with the use of prognostic scores, such as the Duke score, may also benefit from complementary investigation via MPS, especially if their risk scores are intermediate or high (Table 3). Diverse examples of clinical situations cited in Table 3 may also be found in the section on integration of diagnostic modalities . When patients have established ischemic heart disease and are asymptomatic, early myocardial perfusion studies with radiopharmaceuticals should be avoided following percutaneous coronary intervention and/or myocardial revascularization surgery procedures. In the event of percutaneous coronary intervention and myocardial revascularization surgery, the application of MPS has been observed to have a favorable cost-benefit ratio for follow up after more than 2 and 5 years, respectively, even in asymptomatic patients. Symptomatic patients with specific clinical conditions (or equivalent manifestations) may benefit from the exam before this period (Table 4). For patients with previous exams who manifest new symptoms or who require assessment of the repercussion of diagnosed intermediate lesions and characterization of arteries with obstructive lesions “responsible” for a larger myocardial area at risk, as well as patients with multivascular diseases, the indication for MPS is classified as appropriate or possibly appropriate. In patients with established coronary disease and worsening symptoms, MPS may aid in quantifying ischemic burden (extent and intensity of defects) and in determining medical management. In clinically stable patients with previous exams performed more than 2 years prior, MPS may be appropriate (Table 5). In patients who present acute chest pain, with clinical suspicion of acute coronary syndrome (ACS), normal or uninterpretable ECG (old left bundle branch block or pacemaker) and normal biomarkers, resting myocardial scintigraphy may exclude acute cardiovascular events with a high degree of safety (high negative predictive value [NPV]), allowing patients to be discharged from the emergency room. If the exam is normal, investigation may continue with outpatient tests involving physical or pharmacological stress, whether associated or non-associated with non-invasive imaging, and even anatomical assessment via coronary angio-CT, in specific conditions. For patients with ACS who are clinically stable, with neither recurring chest pain nor HF, and who have not undergone any invasive exam, MPS is useful for detecting presence and extent of myocardial ischemia (Table 6). Indications for MPS to assess pre-operative risk of non- cardiac surgeries and vascular surgeries have also been recently revised. 16 Patients who will undergo low-risk surgeries do not need to undergo MPS. If the surgery is not low-risk, functional capacity is the factor that determines Table 4 – Indication criteria for myocardial perfusion scintigraphy in patients who have undergone revascularization procedures (CABG or PCI) Previous percutaneous revascularization or surgical procedures Score Symptomatic 8 Asymptomatic, CABG less than 5 years prior 5 Asymptomatic, CABG 5 or more years prior 7 Asymptomatic, percutaneous revascularization less than 2 years prior 3 Asymptomatic, percutaneous revascularization 2 or more years prior 6 CABG: myocardial revascularization surgery; PCI percutaneous coronary intervention. 333