RESUMEN
Objective This study aimed to evaluate the reliability of Tslew in survelliance of allograft rejection after heart transplantations in rats. Methods Forty rats underwent modified Ono's heterotopic heart transplantation. The autonomous IMEG and VER were recorded with epicardiac pacing leads fixed at right ventricular outflow tracts, left ventricular apex and free wall. Tslews were detected daily in these 10 syngeneic and 30 allogeneic transplants. Syngeneic transplants were sacrificed on 7th postoperative day and allogeneic transplants were sacrificed on 3rd, 5th and 7th postoperative days, respectively.Histopathologic studies were performed at the same time. Results On the 3rd ,5th and 7th postoperative days Tslews depressed gradually in the allogeneic group. The depressions between 3rd and 5th, 3rd and 7th were obvious( P ＜0.05 ). No significant differences were observed in the syngeneic group. Tslews differed between the two groups at 5th and 7th postoperative days ( P ＜0.05 ). The Depression correlated with histopathologic results. Area under ROC( receiver operating characteristic) curve (AUC) of Tslew was 0.9474 and the 95% confidence interval(CI) was (0. 8753 -1. 0000 ). At the cutoff point of 92% ( ≤92% considered positive), Tslew had a sensitivity (Se) 100%, specificity (Sp) 63.64%, positive predictive value (PV + )82.61%, negative predictive value (PV-) 100%, respectively. At the cutoff point 85%, Sp 90.91%, Se 78.95%, PV +93.75 %, PV- 71. 43%. At the best cutoff point 90%, Tslew had a Se 94.74%, Sp 81. 82%, PV + 82.61%, PV- 90%.Whereas QRS had a Se 68.42%, Sp 90.91%, PV + 92.86%, PV- 62.50% at the best cutoff point of 72.3%. Conclusion Tslew of VER are reliable indexs to monitor acute allograft rejection after heart transplantations in rats. Having great diagnostic value, Tslew may be used as a replacement for EMB at the best cutoff point when EMB can' t be performed. At cutoff point of 92%, Tslew may be used as a screening index.
RESUMEN
Objective To investigate the reliability of intramyocardial electrogram (IMEG) in monitoring acute rejection after human heart transplantation. Methods From June 2004 to March 2009, 32 patients underwent orthotopic heart transplantations. During the operation telemetric pacemakers were placed under the skin of the body with connected bipolar electrodes implanted into epimyocardium. Postoperative IMEGs, including the autonomous IMEG and ventricular evoked response (VER) were recorded routinely. The endomyocardium biopsy (EMB) was taken routinely and performed once again when positive IMEG results or other positive signs were observed. Results Totally 523 IMEGs has been produced, 41 of VERs were recorded together with autonomous IMEGs and EMBs, in which 17 EMB specimens were confirmed positive and 24 negative. AUC of QRS was 0.7537, Se was 88.24%, Sp was 62. 50%; AUC of Tslew was 0. 9081, Se was 94. 12%, Sp was 87. 50%. QRS and Tslew had significant difference in AUC of ROC, with x2 = 4. 22, P＜0. 05; AUC of combined diagnostic index (positive when either QRS or Tslew is positive and negative when both values are negative) was 0. 7917, Se was 100.00%, Sp was 58. 33%. Conclusion QRS amplitude of the autonomous IMEGs, Tslew of VERs and combined diagnostic index are reliable indexes for monitoring acute allograft rejection after human heart transplantation. Furthermore, Tslew has a better prognostic value than QRS.