Validity of the Hardman Index to PredictOutcome in Ruptured Abdominal AorticAneurysm

M.A. Sharif, FRCS,1 N. Arya, FRCS,1 C.V. Soong, MD,1 L.L. Lau, MD,1

M.E. O’Donnell, MRCS,2 P.H. Blair, MD,2 and A.G. McKinley, MD,2

Belfast, Northern, Ireland, United Kingdom

This study assessed the validity of the Hardman index in predicting outcome following open re-pair of ruptured abdominal aortic aneurysm and whether this scoring system can be used reliablyto select patients for surgical repair. Patients undergoing open repair of ruptured abdominal aor-tic aneurysm in two university teaching hospitals over a 5-year period were identified from a com-puterized hospital database. Thirty-day mortality was the main outcome measure. Five Hardmanindex factors were calculated and related to outcome retrospectively. There were 178 patientswith a mean age of 73.9 years (range 51e94) and a male to female ratio of 5.4:1. The overallin-hospital mortality was 57.3% (102/178). Univariate analysis of risk factors showed that age>76 years (P ¼ 0.007, odds ratio [OR] 2.34, 95% confidence interval [CI] 1.26-4.37) and electro-cardiograghic evidence of ischemia on admission (P ¼ 0.002, OR 3.75, 95% CI 1.57-8.93) wereassociated with high mortality. However, loss of consciousness (P ¼ 0.155, OR 1.56, 95% CI0.85-2.86), hemoglobin <9 g/dL (P ¼ 0.118, OR 1.89, 95% CI 0.85-4.22), and serum creatinine>0.19 mmol/L (P ¼ 0.691, OR 1.25, 95% CI 0.42-3.70) were not significant predictors of mortal-ity. Using a multivariate analysis, age >76 years (P ¼ 0.043, OR 2.29, 95% CI 1.03-5.11) andmyocardial ischemia (P ¼ 0.029, OR 2.93, 95% CI 1.12-7.67) were again found to be the signif-icant predictors of mortality. The operative mortality was 44%, 46%, 68%, 79%, and 100% forHardman scores of 0, 1, 2, 3, and 4, respectively. No patient had a score of 5. The Hardman in-dex is not a reliable predictor of outcome following repair of ruptured abdominal aortic aneurysm.High-risk patients may still survive and should not be denied surgical repair based on the scoringsystem alone. Further evaluation of the risk factors is required to reliably and justifiably excludethose patients in whom the intervention is inappropriate.

INTRODUCTION

The prevalence of abdominal aortic aneurysm

(AAA) is high, and despite recent advances in surgi-

cal, anesthetic, and intensive care techniques, the

1Department of Vascular and Endovascular Surgery, Belfast CityHospital, Belfast, Northern Ireland, United Kingdom.

2Vascular Surgery Unit, Royal Victoria Hospital, Belfast, NorthernIreland, United Kingdom.

Presented to a meeting of the Australian and New Zealand Society forVascular Surgery, Vascular 2005, Sydney, Australia, September 9-14,2005.

Correspondence to: M.A. Sharif, FRCS, Department of Vascular andEndovascular Surgery, Belfast City Hospital, Lisburn Road, Belfast, BT97AB, Northern Ireland, United Kingdom, E-mail: aneessharif@yahoo.co.uk

Ann Vasc Surg 2007; 21: 34-38DOI: 10.1016/j.avsg.2006.08.002� Annals of Vascular Surgery Inc.Published online: January 12, 2007

34

mortality for open repair remains high. A nation-

based prospective study of ruptured AAA (rAAA)

from Canada reported an early mortality of

51.4%.1 The community mortality from rAAA is

67-88%.2-4 In-hospital operative mortality differs

from center to center depending on selection crite-

ria. However, most centers report an operative mor-

tality of 40-45%.5,6 This figure combined with

community mortality accounts for an overall mor-

tality of >90%.

It has been suggested that operative mortality

could be improved by selecting those patients for

surgery who have a reasonable chance of survival.

This would allow better use of limited hospital re-

sources. Although some preoperative variables indi-

cate increased mortality, an absolute risk is difficult

to work out.7,8 Various preoperative scoring systems

have been proposed to help in this selection process,

Vol. 21, No. 1, 2007 Validity of the Hardman index to predict rAAA outcome 35

including POSSUM (Physiological and Operative

Severity Score for the Enumeration of Mortality

and Morbidity),9 the Glasgow Aneurysm Score,10

and the Hardman index.11 However, none of them

is robust or validated to predict outcome, and hence,

the decision to operate is often subjective.

A successful scoring system would accurately

identify the subgroup of patients with 100% mortal-

ity, hence avoiding unnecessary surgery and the

suffering of grieving relatives. Hardman’s index

has been popularized because of its simplicity and

possible accuracy. This study aimed, firstly, to assess

whether the Hardman index accurately predicts

mortality in patients with rAAA and, secondly, to

see whether this scoring system could be used reli-

ably to select patients for surgery in our practice.

PATIENTS AND METHODS

All patients undergoing open repair of rAAA over

a 5-year period, from November 1999 to October

2004, in two university teaching hospitals in Belfast

were included. These tertiary referral centers in vas-

cular surgery provide services to Northern Ireland

with a population of 1.7 million.12 Data were re-

trieved from medical case records and analyzed in

a retrospective fashion.

The decision to operate was made by one of the

seven consultant vascular surgeons based on indi-

vidual cases. No patient was turned down for surgery

on the basis of specific selection criteria. However,

patients with advanced malignancy, dementia,

debilitating cardiac or pulmonary conditions, and

disabling stroke were not offered surgical repair.

The operation was performed either by or under

the supervision of a consultant vascular surgeon.

rAAA was defined as the presence of retroperitoneal

or intraperitoneal blood from an AAA at laparo-

tomy. Mortality was defined as death within 30

days of operation. Patients undergoing urgent repair

of inflammatory or symptomatic AAA without

evidence of rupture were excluded.

The Hardman index was calculated for all pa-

tients based on five risk factors recorded at presen-

tation prior to any resuscitation. These include

age>76 years, history of loss of consciousness, elec-

trocardiographic (ECG) evidence of ischemia on ad-

mission (>1 mm ST segment depression or T-wave

changes), hemoglobin <9 g/dL, and serum creati-

nine >0.19 mmol/L. A patient could score from

0 to 5 depending on the number of positive Hard-

man criteria on admission.

Statistical Analysis

Data were analyzed using SPSS 12.0.1 for Windows

(SPSS, Chicago, IL). The univariate association of

the five index factors was assessed by chi-squared

or logistic regression analysis. A variable was ex-

cluded from analysis if its value was not recorded

at the time of admission, and P < 0.05 was consid-

ered statistically significant. Multivariate analysis

of risk factors was carried out by logistic regression,

with variables selected by backward elimination

using a significance level of 10%.

RESULTS

Out of a total of 209 consecutive patients presenting

with rAAA, 180 underwent open repair in the two

hospitals during the 5-year study period. Twenty-

nine patients (22 males, 7 females) declined surgical

repair for the reasons stated in Table I. Case notes

were missing for two patients undergoing surgical

repair, and hence they were excluded from further

analysis. The mean age was 73.9 years (range

51-94), with a male preponderance of 5.4 to 1. The

mean age for men and women was 72.7 ± 7 and

79.9 ± 7.4 years, respectively. Overall in-hospital

operative mortality was 57.3% (102/178). There

was a slightly lower mortality for women (43%)

compared to men (60%) (odds ratio [OR] 2.00,

95% confidence interval [CI] 0.88-4.53, P ¼0.092), even though this did not reach statistical

significance.

Loss of consciousness, hemoglobin, creatinine,

and ECG on admission were recorded in 97.8%

(174/178), 82.6% (147/178), 81.5% (145/178),

and 78.7% (140/178) of cases, respectively. All

five indices were recorded in 65% (115/178) at

the time of admission. A univariate analysis was per-

formed to assess the significance of each of the five

Hardman index factors to predict operative mortal-

ity. Only age >76 years (P ¼ 0.007) and myocardial

Table I. Reasons for not operating on patients

with ruptured aneurysm (n ¼ 29)

Reason Number of patients

Patient refused surgery 11

Poor cardiac risk 6

Hospital death before surgery 5

Senile dementia 3

Carcinoma colon 2

Severe COAD 1

Disabling stroke 1

COAD, Chronic Obstructive Airway Disease.

36 Sharif et al. Annals of Vascular Surgery

ischemia on admission (P ¼ 0.002) were predictive

of mortality. However, loss of consciousness (P ¼0.155), hemoglobin <9 g/dL (P ¼ 0.118), and creat-

inine >0.19 mmol/L (P ¼ 0.691) were not signifi-

cant predictors of mortality (Table II). The

Hardman variables were categorized into three

groups, and the mortality for each group is shown

in Table III. Age >76 years and evidence of myocar-

dial ischemia on admission were associated with in-

creased mortality compared to those who were not

in these categories. Using the multivariate logistic

regression analysis, age >76 years (P ¼ 0.043) and

myocardial ischemia (P ¼ 0.029) were again found

to be significant prognosticators of mortality (Table

IV). Operative mortality increased with rising score:

44% (12/27), 46% (18/39), 68% (21/31), 79% (11/

14) and 100% (4/4) for scores 0, 1, 2, 3, and 4, re-

spectively (Fig. 1). No patient had a score of 5.

Table II. Univariate association with mortality

on logistic regression for the five risk factors

VariableNumberanalyzed OR 95% CI P

Age >76 years 178 2.34 1.26e4.37 0.007

Loss of consciousness 174 1.56 0.85e2.86 0.155

Hemoglobin <9 g/dL 147 1.89 0.85e4.22 0.118

Creatinine >0.19

mmol/L

145 1.25 0.42e3.70 0.691

ECG ischemia 140 3.75 1.57e8.93 0.002

Table III. Mortality by subgroups of the five

variables

Variable Number of patients Death Mortality (%)

Age (years)

>76 77 53 68.8*

�76 101 49 48.5

History of LOC

Present 78 49 62.8

Absent 96 50 52.1

Unknown 4 3 75

Hemoglobin

<9 g/dL 35 24 68.6

�9 g/dL 112 60 53.6

Unknown 31 18 58.1

Creatinine

>0.19 mmol/L 15 9 60

�0.19 mmol/L 130 71 54.6

Unknown 33 22 66.7

ECG ischemia

Present 38 30 78.9*

Absent 102 51 50

Unknown 38 21 55.3

LOC, loss of consciousness.

*Increased mortality (P < 0.050) compared with other variables.

DISCUSSION

A selective approach for the repair of rAAA should

be based on a reliable scoring system, which is sim-

ple and able to accurately predict operative mortal-

ity. This system should be able to differentiate

those patients who have no chance of survival

from those who are likely to benefit from surgery

in view of ethical and resource issues.

With mounting pressures on limited resources,

most surgeons in the United Kingdom are beginning

to favor a more selective approach for the repair of

rAAA.13 However, such a selective policy must be

based on a scoring system that is reliable and robust

in its application. Until recently, Hardman’s scoring

system was regarded as a reliable tool to select pa-

tients for surgery in rAAA. The popularity of this

system was based on its simplicity and theoretical

accuracy. It has been verified by four independent

series,14-17 involving a total of 469 patients from

five centers (Table V). Nevertheless, a recent study

from Edinburgh18 has cast doubts on the validity

of this selection scoring system and has reported

a mortality of only 33% with a score of �3, in con-

trast to 100% mortality originally reported in the

Hardman et al. study.11 Moreover, the study shows

a relatively higher mortality (55%) with a score of 1.

This study shows that out of the five index factors

only two (age >76 years and myocardial ischemia

on admission) are significantly related to mortality.

Table IV. Multivariate analysis of risk factors

by logistic regression using a significance level

of 10% (n ¼ 121)

Variable OR 95% CI P

Age >76 years 2.29 1.03e5.11 0.043

Hemoglobin <9 g/dL 2.27 0.88e5.86 0.089

ECG ischemia 2.93 1.12e7.67 0.029

Fig. 1. Operative mortality by number of positive Hard-

man factors.

Vol. 21, No. 1, 2007 Validity of the Hardman index to predict rAAA outcome 37

Table V. Percentage operative mortality by number of positive criteria in different studies

Study group, year Total number Score 0 Score 1 Score 2 Score 3 Score 4

Sydney, 199611 (154) 16 37 72 100 100

Plymouth, 199914 (69) 18 28 48 100 100

Gloucester, 200315 (188) 35 55 74 90 100

S’ampton/Adelaide, 200316 (75) 8 24 55 100 100

Manchester, 200417 (137) 40 46 77 92 100

Edinburgh, 200518 (82) 15 55 38 33*

Belfast (current) (178) 44 46 68 79 100

*Mortality figures for a score �3.

Although overall mortality increased with rising

scores, in contrast to the original study by Hardman

et al.,11 the current study shows that patients with

a score of 3 had 79%, rather than 100%, mortality.

If a decision not to operate was made in this group,

three out of 14 patients would have been denied

a life-saving operation. However, as there were

only 18 patients with a score �3, the results of this

study should be interpreted cautiously. Nonethe-

less, even in Hardman’s study, only eight patients

had scores �3.11

These results suggest that the Hardman scoring

system is unreliable in predicting operative mortal-

ity and, hence, repair should not be denied based

on this scoring system alone. A randomized study

would be ideal for precise prediction of mortality,

but obviously this may not be ethical in the setting

of rAAA. However, a more elaborative evaluation

of the risk factors is required before patients with

rAAA can justifiably be excluded from surgery. Until

such time, the decision to operate should be made

on clinical grounds by the operating surgeon at the

time of presentation.

A consistent apprehension with the validity of

any scoring system used to decide whether surgery

should be offered to patients with rAAA has been

the availability of data at the time of patient presen-

tation. In an emergency situation, a full set of the

five Hardman variables may not always be available

at the time of making a decision to operate. In this

study, all five factors were recorded in only two-

thirds of the patients. A similar finding was observed

by Hardman et al.,11 with loss of consciousness, he-

moglobin, creatinine, and ECG trace being available

in, respectively, 98.1%, 86.4%, 83.8%, and 72.1%

of patients only. Although, there is no mention of

the total number of patients for whom all five factors

were available, it could be speculated that this will

be no more than 72.1%. Unfortunately, despite

ECG evidence of myocardial ischemia being the

most predictive indicator of mortality, it was avail-

able in the least number of patients in both series.

CONCLUSIONS

The findings of this study show that the Hardman

index is not a reliable prognosticator of outcome

following repair of rAAA. High-risk patients may

still survive surgical repair, and the scoring system

could not be recommended for routine use in clini-

cal decision making. Further prospective evaluation

of the risk factors is required to reliably exclude

those patients in whom surgical intervention is

inappropriate.

The authors thank Dr. Chris Patterson (Department of Medical

Statistics, Queen’s University Belfast) for help with the

statistical analyses and all the consultant vascular surgeons at

Belfast City Hospital and Royal Victoria Hospital for

contributing cases which led to the successful completion of this

project.

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