ABC | Volume 112, Nº1, January 2019

Original Article Dotta et al Regional QT dispersion as predictor of reperfusion Arq Bras Cardiol. 2019; 112(1):20-29 Figure 1 – Distribution of patients by the presence of ST-segment resolution (classical electrocardiographic criteria for reperfusion) and angiographic profile of TIMI flow (1a) or perfusion pattern (TIMI flow and Bulsh grade); in the culprit artery; T3B3 (+): patients with TIMI 3 and Blush grade 3 in the culprit artery; T3B3 (-): patients with TIMI 3 and Blush grade < 3 in the culprit artery (1b). 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Percentage (a) (b) With ST-segment resolution Without ST-segment resolution With ST-segment resolution Without ST-segment resolution TIMI flow 0 1 TIMI flow & Blush grade T3B3 (–) T3B3 (+) 2 3 50 45 35 25 15 5 0 30 20 10 40 Number Table 4 – Clinical characteristics in the groups of patients with or without angiographic criteria for adequate reperfusion according to TIMI flow and Blush grades Characteristics T3B3 (+) T3B3 (-) p-value n =53 n =51 Age (years), md (IQR) 54 (47-63) 56 (52-62) 0.51 Male, n (%) 28 (52.8) 38 (74.5) 0.02 Type 2 DM, n (%) 8 (15.1) 13 (25.5) 0.19 Hypertension, n (%) 27 (50.9) 33 (64.7) 0.16 Dyslipidemia, n (%) 15 (28.3) 21 (41.2) 0.17 Smokers, n (%) 24 (45.3) 27 (53) 0.43 Time for TNK administration, (min): md –IQR 185 (137-257) 138 (110-240) 0.18 Time < 180, (min): n (%) 32 (60) 22 (43) 0.12 Ejection fraction, (%): m ± DP 52.6 ± 9.8 47.8 ± 8.5 0.009 Anterior AMI, n (%) 18 (34) 24 (47) 0.17 Non-anterior, n (%) 35 (66) 27 (53) 0.17 Data expressed as mean and standard deviation (m ± SD), median and interquartile range (md, IQR), number and percentage, n (%); T3B3 (+): patients with TIMI 3 and Blush grade 3 in the culprit artery; T3B3 (-): patients with TIMI 3 and Blush grade < 3 in the culprit artery; DM: diabetes mellitus; AMI: acute myocardial infarction; TNK: tenecteplase. Categorical variables were compared by Pearson’s chi-square test or Fisher’s exact test, and continuous numerical variables were compared by the Student’s t test for independent sample or Mann-Whitney test, as appropriate. heterogeneity. 19 Many studies have shown that patients with increased QTcD (approximately > 60 ms) had 2-3.4 increased risk of cardiovascular mortality. Multivariate analysis of these studies showed a 34% increased cardiovascular risk for each increment of 17ms in QTbD or QTcD > 60 ms in patients with diabetes mellitus without previous AMI. 20-22 There is a QTcD variation during the first days of AMI; it increases in the first hours and decreases some days thereafter, especially following fibrinolytic therapy 23-25 or revascularization procedure. 26,27 A reduction in QTcD in the days following fibrinolysis shows the efficacy of the therapy. 28 Based on the speculation that changes in QTcD could predict reperfusion assessed 90 minutes after fibrinolysis, in a small study with 47 patients, the authors analyzed QTcD only in precordial leads and found a higher QTcD in the group that met the electrocardiographic criterion for reperfusion. However, the parameter was not predictive of angiographic reperfusion. 29 One limitation of this study was the small number of patients 24