ABC | Volume 110, Nº4, April 2018

Original Article Muñoz et al Atrial fibrillation ablation in valve disease Arq Bras Cardiol. 2018; 110(4):312-320 not included in further analyses to avoid collinearity in the multivariate analysis. No association was found between deformation parameters and AF recurrence. As can be seen in Figure 4, employing the univariate log rank test, AF recurrence seems to be associated with: larger LA volume (p = 0.030), older age (p = 0.027), and inversely, with mitral valve intervention (p = 0.006). A Cox proportional hazard model was built to explore potential sources of confusion and interactions. After SA of AF, LA volume was the only parameter associated with sustained SR (p = 0.028). Mitral surgery (p = 0.056) and age (p = 0.412) were not significantly associated with SR maintenance in the multivariate analyses. Discussion AF is the most common arrhythmia in general population and is even more common in VHD patients. This arrhythmia is cause of symptoms, hospital admissions, adverse events (systemic embolisms, side effects of antiarrhythmic drugs, etc.) and therefore, has a high impact in survival and quality of life. In addition, the presence of AF determines the necessity for antithrombotic therapy, and even the selection of the type of prosthesis. 1,2 This study was conducted in patients who would otherwise have been chosen to heart rate control. Due to the scarcity of data about this treatment in “pure” VHD series, the current study may provide novel insights in this clinical Figure 2 – Intraclass correlation coefficient calculated (ICC) and Bland Altman difference plot combined with calculation of 95% limits of agreement (CI) of the intra-rater (A,C) and inter-rater (B,D) agreement of LA strain (LA S) and LA strain rate (LA SR) 25 20 15 10 5 0 –5 –10 –15 –20 20 15 10 5 0 –5 –10 –15 –20 –25 0 20 40 60 80 0 20 40 60 80 100 +1.96 SD 12.6 Mean 0.6 –1.96 SD –11.4 +1.96 SD 0.93 Mean 0.07 –1.96 SD –0.79 +1.96 SD 0.52 Mean –0.05 –1.96 SD –0.62 +1.96 SD 11.7 Mean –1.0 –1.96 SD –13.6 1.5 1.0 0.5 0.0 –0.5 –1.0 –1.5 1.0 0.8 0.6 0.4 0.2 0.0 –0.8 –0.6 –0.4 –0.2 –1.0 –3.0 –3.0 –2.5 –2.5 –1.5 –1.5 –0.5 –0.5 0.5 0.5 0.0 0.0 –2.0 –2.0 –1.0 –1.0 ICC 0.94 CI 0.94-0.96 ICC 0.93 CI 0.88-0.95 ICC 0.82 CI 0.70-0.88 ICC 0.93 CI 0.84-0.96 A B C D INTRA-RATER INTER-RATER LA S LA SR Table 2 – Strain and strain rate parameters in the post-surgery group versus healthy individuals (Median and Interquatile Range were used because non-normal distribution of variables). P values were calculated with Mann-Whitney test LASs Median (P 25 -P 75 ) LASa Median (P 25 -P 75 ) LASRe Median (P 25 -P 75 ) LASRa Median (P 25 -P 75 ) Post-surgery group 16.9 (14.1-20.6) 5.9 (4.5-7) -0.55 (-0.45- -0.67) -0.41 (-0.56- -0.25) Control group 42.5 (36.3-48.8) 13.1 (11.6-16.2) -1.83 (-1.4- -2) -1.6 (-1.8- -1.4) p < 0.001 < 0.001 < 0.001 < 0.001 LASe: LA systolic strain; LASa: LA diastolic strain; LASRe: LA early strain rate; LASRa: LA late strain rate 315