ABC | Volume 111, Nº6, December 2018

Original Article Andrade et al Prognostic Value of Myocardial Scintigraphy Arq Bras Cardiol. 2018; 111(6):784-793 There were 19 nonfatal AMI and this outcome was also more prevalent among those with abnormal MPS without ischemia compared to the other participants, but without statistical relevance. A total of 139 revascularizations was documented, 10 patients underwent coronary artery graft bypass surgery, 126 underwent PCI, and 3 underwent both. Among the groups, revascularization was more frequent among patients with ischemia, with an annual rate of 10.3%, and less expressive among patients with normal and abnormal perfusion without ischemia, with an annual rate of 3.7% and 3%, respectively. Data on the occurrence of outcomes according to the perfusion groups are shown in Table 3. In the univariate analysis, including clinical and scintigraphic characteristics, age above 70 years, AH, DM, use of pharmacological stress protocol, indication of preoperative MPS, and total perfusion defect higher than 6% were considered predictors. After multivariate adjustment, with the exception of AH, the other variables emerged as independent predictors of death (Table 4). The Kaplan-Meier survival curve stratified by ranges of total perfusion defect in Figure 2 shows the direct relationship between the extent of the defect and mortality, especially when it reaches values greater than 6%. The independent predictors of revascularization were incomplete revascularization as an indication for MPS, the interval between PCI and MPS of less than 2 years, and the ischemic defect greater than 3%, as shown in Table 5. The Kaplan-Meier curve that was stratified by ischemic defect ranges demonstrates the strong association between the extent of ischemia and the occurrence of the endpoint (Figure 2). The only factor independently associated with cardiovascular mortality was the total perfusion defect greater than 6%, and with non-fatal AMI was the presence of DM. When analyzing the group of patients with ischemia at MPS (n = 189), there was a greater presence of males (73% × 63%, p = 0.031), a higher frequency of incomplete revascularization as an indication of the MPS (39% × 14%, p = 0.02) and a higher prevalence of the interval prior PCI-CPM less than 2 years (54% × 30%, p = 0.001) among those submitted to revascularization (36%), compared to the group that did not undergo intervention (64%). The extent of ischemic defect was greater among revascularized patients (7% × 6%, p = 0.162), but different from expected, with no statistical significance. Similarly, mortality was lower among revascularized patients (9% × 12%, p = 0.453), however, with no statistical value. When comparing the populations that underwent MPS in the interval of less than or more than 2 years after PCI, no significant clinical or scintigraphic differences were observed between them. Mortality in the follow-up period was also similar, as shown in Figure 3. Discussion The use of MPS in the follow-up of asymptomatic patients after PCI has been studied in the last decades. The first studies evaluated the use of MPS in the first 6 months after the procedure; 9-12 then, some authors tried to establish the use of this functional test later in this subgroup. 13,14 Most of the publications included patients who underwent MPS after fixed intervals following PCI, ranging from 4 months 12 to 60 months. 14 In the current study, this interval varied from days to years, allowing assessment of the prognostic value of MPS when performed at varying intervals after percutaneous revascularization. Table 3 – Outcomes according to perfusion Endpoints Normal Abnormal with ischemia Abnormal without ischemia p value Patients, n 304 193 150 Death (61) 19 (6,3%) 21 (10,9%) 21 (14%) 0,021 Cardiovascular death (27) 7 (2,3%) 9 (4,7%) 11 (7,3%) 0,064 Patients, n 295 289 245 Non-fatal AMI (19) 10 (3,4%) 3 (1,5%) 6 (4,1%) 0,855 Revascularization (139) 52 (17,6%) 68 (36%) 19 (13,1%) < 0,001 AMI: acute myocardial infarction. Table 4 – Predictors of mortality Characteristics Univariate analysis HR (95% CI) p value Multivariate analysis OR (95% CI) p value Age > 70 years 4.27 (2.40 to 7.60) < 0,001 3.40 (1.85 to 6.24) < 0,001 Arterial Hypertension 2.26 (1.20 to 4.28) 0,010 1.48 (0.73 to 3.00) 0,276 Diabetes Mellitus 3.50 (2,04 to 5.99) < 0,001 2.37 (1.30 to 4.31) 0,004 Preoperative MPS, indication 3.85 (1.88 to 7.90) < 0,001 2.25 (1.02 to 4.98) 0,044 Pharmacological stress 4.67 (2.56 to 8.50) < 0,001 2.51 (1.35 to 4.67) 0,003 TPD > 6% 2.40 (1.40 to 4.08) 0,001 2.33 (1.31 to 4.12) 0,004 MPS: myocardial perfusion scintigraphy; TPD: total perfusion defect. 787