Utility of the Penn Classification in Predicting Outcomes of Surgery for Acute Type A Aortic Dissection Naoyuki Kimura, MD, PhDa,*, Tetsu Ohnuma, MDb, Satoshi Itoh, MD, PhDa, Yusuke Sasabuchi, MDb, Kayo Asaka, MDb, Junji Shiotsuka, MDb, Koichi Adachi, MDa, Koich Yuri, MDa, Harunobu Matsumoto, MD, PhDa, Atsushi Yamaguchi, MD, PhDa, Masamitsu Sanui, MD, PhDb, and Hideo Adachi, MD, PhDa The Penn classification, a risk assessment system for acute type A aortic dissection (AAAD), is based on preoperative ischemic conditions. We investigated whether Penn classes predict outcomes after surgery for AAAD. Three hundred fifty-one patients with DeBakey type I AAAD treated surgically, January 1997 to January 2011, were divided into 4 groups per Penn class: Aa (no ischemia, n [ 187), Ab (localized ischemia with branch malperfusion, n [ 67), Ac (generalized ischemia with circulatory collapse, n [ 46), and Abc (localized and generalized ischemia, n [ 51). Early and late outcomes were compared between groups. In-hospital mortality was 3% (6 of 187) for Penn Aa, 6% (4 of 67) for Penn Ab, 17% (8 of 46) for Penn Ac, and 22% (11 of 51) for Penn Abc. Multivariate logistic regression analysis showed Penn classes Ac and Abc, operation time >6 hours, and entry in the descending thoracic aorta to be risk factors for in-hospital mortality. Incidences of neurologic, respiratory, and hepatic complications differed between groups. Five-year cumulative survival was 85% in the Penn Aa group, 74% in the Penn Ab group (p [ 0.027 vs Penn Aa), 78% in the Penn Ac group, and 67% in the Penn Abc group (p 48 hours. Renal failure was defined as a newly developed need for renal replacement therapy. Liver dysfunction was defined as hepatocellular jaundice with a bilirubin level of at least 3 times the upper limit of normal (total bilirubin > 3.0 mg/dl), transaminase elevation to at least 5 times the upper limit of normal (alanine aminotransaminase [ALT] > 225 U/L and aspartate aminotransaminase [AST] > 200 U/L), or both.3 In addition, we assessed the time course of perioperative serum bilirubin and transaminase levels per Penn class, after excluding patients who died. Two patients whose postoperative laboratory data were missing were excluded from liver dysfunction study. In-hospital data were obtained by a review of hospital records. Serum bilirubin, ALT, and AST levels had been recorded preoperatively and daily or every other day until 7 days after surgery. Preoperative hematologic data (hematocrit level, platelet count) had also been recorded. Follow-up data (median, 50.3 months) included general health condition, aortic rupture or reoperation, survival time, and cause of death, which were ascertained through our outpatient clinic, through written or telephone contact with the patient or a relative or through the local cardiologist. Aortic events were defined as aortic rupture, redissection, reoperation, endovascular stenting, or sudden death. Followup data were obtained for 99% (347 of 351) of the study patients. Data are presented as mean
SD, median (interquartile range) values, or percentages, as appropriate; p 30 kg/m2), Marfan syndrome, bicuspid aortic valve, hypertension, diabetes, smoking, chronic obstructive pulmonary disease, hemodialysis, previous coronary disease, previous cerebral vascular disease, peripheral artery disease, chronic kidney disease, cirrhosis, liver dysfunction, previous cardiac surgery, severe aortic insufficiency, Penn classes (Penn Aa, Ab, Ac, and Abc), coma, hemopericardium, location of the entry tear, arterial cannulation site, hemiarch replacement, aortic arch replacement, aortic root replacement, aortic valve replacement, coronary artery bypass grafting, prolonged CPB time (>180 minutes), prolonged myocardial ischemia time (>120 minutes), prolonged operation time (>360 minutes), resection of the primary entry tear, and the amount of blood transfused. Cumulative 5-year survival per Penn class was plotted by the Kaplan-Meier method and analyzed by logrank test. All statistical analyses were performed with SPSS 17.0 for Windows software (SPSS, Inc., Chicago, IL).

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The American Journal of Cardiology (www.ajconline.org)

Table 2 Preoperative characteristics of the study patients overall and per Penn class Total (n ¼ 351)

Variable Age (yr), mean (SD) Men Marfan syndrome Bicuspid aortic valve Hypertension Diabetes mellitus Current smoker Previous coronary disease Previous cerebrovascular disease Hemodialysis Previous surgery for valvular disease Previous surgery for thoracic aortic disease Severe aortic insufficiency Organ ischemia Brain Spinal cord Coronary Visceral Kidney Extremity Preoperative laboratory values Hematocrit (%), mean (SD) Platelet (103/ml), mean (SD) Bilirubin (mg/dl), mean (SD) Alanine aminotransaminase (U/L), median (IQR) AST (U/L), median (IQR)

Class Aa (n ¼ 187)

Class Ab (n ¼ 67)

Class Ac (n ¼ 46)

Class Abc (n ¼ 51)

63
12 193 (55%) 10 (3%) 3 (1%) 251 (72%) 26 (7%) 118 (34%) 17 (5%) 27 (8%) 7 (2%) 4 (1%) 1 (0.3%)

62
12 96 (51%) 7 (4%) 2 (1%) 132 (71%) 16 (9%) 68 (37%) 11 (6%) 19 (10%) 2 (1%) 4 (2%) 1 (0.5%)

60
13 47 (70%) 2 (3%) 0 46 (69%) 2 (3%) 27 (40%) 1 (2%) 4 (6%) 2 (3%) 0 0

65
10 22 (48%) 0 0 35 (76%) 4 (9%) 10 (22%) 2 (4%) 1 (2%) 2 (4%) 0 0

64
12 28 (55%) 1 (2%) 1 (2%) 38 (75%) 4 (8%) 13 (26%) 3 (6%) 3 (6%) 1 (2%) 0 0

34 (10%)

18 (10%)

5 (8%)

7 (15%)

4 (8%)

0 0 0 0 0 0

22 (33%) 0 0 13 (19%) 15 (22%) 40 (59%)

0 0 11 (23%) 0 0 0

28 1 11 4 5 14

50 1 22 17 20 54

(14%) (0.3%) (6%) (5%) (6%) (15%)

(55%) (2%) (22%) (8%) (10%) (28%)

36
6 19
7 0.9
0.5 22 (15e39)

37
6 20
8 0.9
0.5 21 (14e31)

36
5 18
7 0.9
0.6 19 (14e32)

36
7 19
7 0.9
0.5 27 (16e67)

36
6 18
7 0.7
0.4 42 (15e120)

27 (20e52)

24 (19e35)

25 (20e42)

45 (26e99)

65 (24e214)

Number of patients is shown unless otherwise indicated. IQR ¼ interquartile range.

Table 3 Operative variables overall and per Penn class Variable

Total (n ¼ 351)

Class Aa (n ¼ 187)

Aortic arch replacement Hemiarch replacement Aortic root replacement Aortic valve replacement Coronary bypass Entry resection Arterial cannulation site Subclavian Femoral Subclavian þ femoral Apex Operation time (min), median (IQR)† CPB time (min), median (IQR)† Aorta clamp time (min), median (IQR)† Blood transfusion (ml), median (IQR)†

57 84 14 4 27 259

(16%) (24%) (4%) (1%) (8%) (74%)

27(14%) 39 (21%) 10 (5%) 2 (1%) 2 (1%) 132 (71%)

148 110 82 11 355

(42%) (31%) (23%) (3%) (290e450)

90 48 46 3 350

(48%) (26%) (25%) (2%) (285e425)

Class Ab (n ¼ 67)

Class Ac (n ¼ 46)

13 21 1 1

(19%) (31%) (2%) (1%) 0 53 (79%)

30 10 23 4 350

5 (11%) 9 (20%) 2 (4%) 0 13 (28%) 32 (70%)

(45%) (15%) (34%) (6%) (296e450)

14 23 7 2 368

(30%) (50%) (15%) (4%) (290e486)

Class Abc (n ¼ 51) 12 15 1 1 12 42 14 29 6 2 420

(24%) (29%) (2%) (2%) (24%) (82%)

0.27 0.23 0.47 0.82