Impact of high titre of antiphospholipid antibodies on postoperative outcome following pulmonary endarterectomy.

OBJECTIVES: Antiphospholipid (a-PL) antibodies, especially IgG isotype, have been associated with a variety of neurological manifestations related to thrombotic mechanism and reactivity against nervous tissues. Furthermore, high titre of a-PL antibodies has been also correlated to chronic thromboembolic pulmonary hypertension (CTEPH) and, therefore, is frequently reported in patients undergoing pulmonary endarterectomy (PEA). The impact of a-PL antibodies in postoperative outcome following PEA, however, has not been clearly evaluated yet. In this paper, we investigated the impact of a high a-PL IgG titre (HAPT) on postoperative outcome following PEA. METHODS: From April 1994 to October 2008, out of 204 patients undergoing PEA at our centre, 184 were prospectively screened for a-PL antibodies. According to the preoperative IgG titre, patients were divided into two groups: Group A (high a-PL antibodies titre - HAPT) with a-PL IgG titre >10 U/ml and Group B (low a-PL antibodies titre - LAPT) with a-PL IgG titre

Artificial neural networks versus multiple logistic regression to predict 30-day mortality after operations for type a ascending aortic dissection.

BACKGROUND: There are few comparative reports on the overall accuracy of neural networks (NN), assessed only versus multiple logistic regression (LR), to predict events in cardiovascular surgery studies and none has been performed among acute aortic dissection (AAD) Type A patients. OBJECTIVES: We aimed at investigating the predictive potential of 30-day mortality by a large series of risk factors in AAD Type A patients comparing the overall performance of NN versus LR. METHODS: We investigated 121 plus 87 AAD Type A patients consecutively operated during 7 years in two Centres. Forced and stepwise NN and LR solutions were obtained and compared, using receiver operating characteristic area under the curve (AUC) and their 95% confidence intervals (CI) and Gini's coefficients. Both NN and LR models were re-applied to data from the second Centre to adhere to a methodological imperative with NN. RESULTS: Forced LR solutions provided AUC 87.9±4.1% (CI: 80.7 to 93.2%) and 85.7±5.2% (CI: 78.5 to 91.1%) in the first and second Centre, respectively. Stepwise NN solution of the first Centre had AUC 90.5±3.7% (CI: 83.8 to 95.1%). The Gini's coefficients for LR and NN stepwise solutions of the first Centre were 0.712 and 0.816, respectively. When the LR and NN stepwise solutions were re-applied to the second Centre data, Gini's coefficients were, respectively, 0.761 and 0.850. Few predictors were selected in common by LR and NN models: the presence of pre-operative shock, intubation and neurological symptoms, immediate post-operative presence of dialysis in continuous and the quantity of post-operative bleeding in the first 24 h. The length of extracorporeal circulation, post-operative chronic renal failure and the year of surgery were specifically detected by NN. CONCLUSIONS: Different from the International Registry of AAD, operative and immediate post-operative factors were seen as potential predictors of short-term mortality. We report a higher overall predictive accuracy with NN than with LR. However, the list of potential risk factors to predict 30-day mortality after AAD Type A by NN model is not enlarged significantly.

Procalcitonin is useful whereas C-reactive protein is not, to predict complications following coronary artery bypass surgery.

BACKGROUND: The respective value of procalcitonin (PCT) and C-reactive protein (CRP) as markers of postoperative complications after coronary bypass surgery is unclear. Therefore, complications during one week after surgery were studied to evaluate the predictive role of PCT and CRP changes during the immediate postoperative period. METHODS: Thirty-two patients, in whom an uneventful immediate postoperative course was anticipated, were prospectively enrolled and followed-up to the 7th postoperative day. At the end of the follow-up, patients were divided into two groups. Group A were patients with an uncomplicated postoperative course and Group B were patients with a complicated postoperative course. RESULTS: Serum samples were drawn for PCT and CRP determination after induction of anesthesia (baseline), at the end of surgery and daily until postoperative day 2. Baseline serum PCT concentrations were 0.11 +/- 0.09 and 0.20 +/- 0.21 ng/mL in Groups A and B, respectively (NS). Serum PCT concentration increased compared with baseline in both groups during the first two days after surgery. The increase in serum PCT concentration was significantly greater in Group B than A patients (p < 0.0002). Considering a perioperative abnormal cut-off value of >0.5 ng/mL, there were none in Group A versus 57% in Group B (p < 0.0001). Baseline serum CRP concentrations were 1.44 +/- 1.30 and 1.58 +/- 1.35 ng/mL in Groups A and B, respectively (NS). After surgery, CRP increased significantly compared with baseline in both groups. When changes in time-varying variables were included in a logistic model, complications were predicted by changes (between baseline and end of surgery values) of PCT (coefficient = 9.410; t = 2.18) and heart rate (coefficient = 0.075; t = 1.57), whereas changes of CRP, white blood cells, mean blood and central venous pressures did not contribute statistically. The model constant was -4.827 (t = -2.43) and the ROC curve area was 0.8971. Thus, absolute PCT changes of 0.20, 0.40 and 0.60 ng/mL carry an approximate risk of 5, 26 and 69%, respectively, of postoperative complications in the time frame of this study. CONCLUSIONS: A postoperative serum PCT concentration of >0.5 ng/mL is highly suggestive of a postoperative complication. CRP changes do not contribute to predictive information.