Table 4.
Forced (All Covariates Entered) Logistic Regression Model to Predict 30-Day Post-Operative Status after Type A Acute Aortic Dissection among 87 Patients Operated, Between 2002 and Early 2008, at Sant’Anna Hospital, Cardiac Surgical Department
| Covariates | Mean ±SD | Coeff | SE | t | p= | OR | ±95%CI |
|---|---|---|---|---|---|---|---|
| Demographic | |||||||
| Year of surgery | 2005±2 | 0.1559 | 0.3548 | 0.44 | 0.6603 | 1.17 | 0.58-2.34 |
| Age (years) | 63±12 | -0.0183 | 0.0582 | -0.31 | 0.7534 | 0.98 | 0.88-1.10 |
| Sex (0=female; 1=male) | 0.60 | 0.0997 | 1.0592 | 0.09 | 0.9250 | 1.10 | 0.14-8.81 |
| Pre-operative | |||||||
| High blood pressure | 0.90 | -2.7545 | 1.7825 | -1.54 | 0.1223 | 0.07 | 0.00-2.09 |
| Marfan syndrome | 0.13 | -0.4687 | 1.7302 | -0.27 | 0.7865 | 0.63 | 0.02-18.59 |
| Shock | 0.33 | 3.5944 | 1.3587 | 2.64 | 0.0082 | 36.39 | 2.54-521.87 |
| Intubated | 0.06 | 79.9123 | 5007.2077 | 0.02 | 0.9873 | 0.00 | 0.00-0.00 |
| Neurological symptoms | 0.03 | -63.1073 | 4023.8080 | -0.02 | 0.9875 | 0.00 | 0.00-0.00 |
| Previous cardiac surgery | 0.07 | 17.2228 | 1389.1579 | 0.02 | 0.9901 | 0.00 | 0.00-0.00 |
| Operative | |||||||
| Extracorporeal circulation (min) | 216±76 | 0.0109 | 0.0071 | 1.54 | 0.1225 | 1.01 | 1.00-1.03 |
| Circulatory arrest (min) | 25±23 | -0.0278 | 0.0308 | -0.90 | 0.3667 | 0.97 | 0.92-1.03 |
| Brain protection (coded)a | 1.70±0.59 | -0.4011 | 0.8997 | -0.45 | 0.6557 | 0.67 | 0.11-3.90 |
| Bicuspid aortic valve | 0.01 | -16.4768 | 10209.3636 | -0.00 | 0.9987 | 0.00 | 0.00-0.00 |
| Hemopericardium | 0.68 | 1.5558 | 1.3749 | 1.13 | 0.2578 | 4.74 | 0.32-70.14 |
| Type of surgery (coded)b | 4.93±2.60 | 0.2358 | 0.2563 | 0.92 | 0.3576 | 1.027 | 0.77-2.09 |
| Immediate Post-operative | |||||||
| Bleeding in the first 24 hours (ml) | 768±638 | -0.0019 | 0.0012 | -1.58 | 0.1304 | 1.00 | 0.99-1.00 |
| Limb ischemia | 0.02 | -14.2374 | 7265.5683 | -0.02 | 0.9994 | 0.00 | 0.00-0.00 |
| Renal complications | 0.18 | -30.2771 | 2059.4766 | -0.01 | 0.9883 | 0.00 | 0.00-0.00 |
| Dialysis in continuous | 0.07 | 46.3386 | 3549.8350 | 0.01 | 0.9896 | 0.00 | 0.00-0.00 |
| Chronic renal failure | 0.05 | 49.2799 | 3570.6862 | 0.01 | 0.9890 | 0.00 | 0.00-0.00 |
| Enterological complications | 0.03 | -28.2509 | 11745.4953 | -0.00 | 0.9981 | 0.00 | 0.00-0.00 |
| Neurological deficits | 0.08 | 47.9856 | 2880.9335 | 0.02 | 0.9867 | 0.00 | 0.00-0.00 |
| Constant | -314.7065 | ||||||
Table 4. There were 87 patients with data complete for all 22 covariates considered and 20 were 30-day deaths (22.9%). The forced logistic model classified correctly 80% of patients who died and 100% of survivors (94.05% of overall cases were thus correctly classified) with a global chi-square equal to 70.23 (p<0.0001). Other specifications as in Table 3.