Research Article Volume 2 Issue 1
Hospital and Heart Research Institute and disease studies, Bangladesh
Correspondence: Tanvir Rahman, Hospital and Heart Research Institute and disease studies, House6, Rad32/A, Sector7, Uttara Dhaka1230, Bangladesh, Tel 8801755578936
Received: November 15, 2014  Published: January 28, 2015
Citation: Rahman T, Mamunul AH, Alam S (2015) Proposed Cardiac Risk Assessment System by HHRIDSHospital and Heart Research Institute and Disease Studies for Cardiac and Non Cardiac Surgery. J Cardiol Curr Res 2(1): 00048. DOI: 10.15406/jccr.2015.02.00048
Pre and post operative risk and mortality assessment is an utmost for any surgery. So an improved risk assessment system can save life from over enthusiastic surgery and can modify some variable risk factors which ultimately scores down the expected risk and most of the time can warn surgeon about pre and post operative complications and helps to take necessary precautions pre operatively and most importantly patient can get the information of relative risk in the proposed operation and can think twice before giving consent. Taking all these factors under consideration HHRIDS has proposed a risk assessment system (CRASH) [1,2]. Including 20 factors which are easily obtainable most of which are obtained from simple history taking physical examination and doing some very simple investigations. Among them 3 factors are non modifiable and 17 others are well modifiable where just taking some simple measures those can be modified and total risk is down scored. Lowest score is 02and highest possible score is 80. Where it is assumed that risk score of 80 has 100% chance of pre and post operative complications including chance of mortality so for each score post operative complication is assumed as 1.25%. Estimated scores of included cases who are having some sort of pre and post operative complications including 30 days mortality are distributed and divided in 3 groups (<10% lying below 1st decile,1040%lying between 1st  4th decile and > 41100% range of data lying above 4th decile) and patients are categorized as mild, moderate and high risk groups respectively. Here CRASH score < 8(27), 832 and >32 (to be exact >32.8) are now being considered as low, moderate and high risk groups respectively. With total calculated score no of major scores (score 4) to be mentioned Eg. CRASH score 43 (with 4 majors).
Keywords: CRASH; HHRIDS; HHRIDS score; Risk assessment system; Cardiac risk assessment
Total 20 risk factors are selected for the risk scoring system. Among them 3 are non modifiable and 17 are modifiable where appropriate management of those risk factors can down regulate the risk score as well as can decrease the post operative complications and postoperative 30days mortality. Vast retrospective and prospective study will go on for validation of the scoring system. But now it has been established on long time experiences and evidence based practice.
20 variables found to be independent predictors of pre and post operative complication including 30days mortality. These variables are subsequently incorporated into the proposed risk scoring system (CRASH). The number per and post operative complications including 30 days mortality observed and the number predicted by the scoring system, indicated good concordance ( $${\chi}^{2}$$ test, P=..). The area (se) under the receiver operating characteristic curve was which demonstrated a reasonable predictive value for the score. Validation of scoring system $$Sensitivity\left(SEN\right)=\frac{a}{a+c}\times 100$$ (proportion of disease positive who are test positive/increase SEN less FN so 100% SEN means all disease positives are true positive no FN/highly sensitive test is helpful when test result is negative/important to rule out or exclude disease) $$\left(SPE\right)=\frac{d}{\left(b+d\right)}\times 100$$ (proportion of disease negative who are test negative/increase SPE less FP so 100% SPE means all disease negatives are true negative, no FP/highly specific test is helpful when test result is positive/helpful to include/confirm disease) $$Positive\text{}predictive\text{}value\left(PPV\right)=\frac{a}{\left(a+b\right)}\times 100$$ (proportion of test positive who are disease positive/probability of having disease when person is test positive increase PPV decreases chance of false positive) $$Negative\text{}predictive\text{}value\left(NPV\right)=\frac{d}{\left(c+d\right)}\times 100$$ (proportion of test negative who are disease negative/probability of not having disease when person is test negative/increase NPV decreases chance of false negative) $$Positive\text{}likelihood\text{}ratio\left(LR+\right)=\frac{\left[\frac{a}{\left(a+c\right)}\right]}{\left[\frac{b}{\left(b+d\right)}\right]}=\frac{SEN}{\left(1SPE\right)}$$ (probability of positive test result when the person is diseased LR+=no diagnostic value,>1=diagnostic value,>10=high diagnostic value) $$Negative\text{}likelihood\text{}ratio\left(LR\right)=\frac{\left[\frac{c}{\left(a+c\right)}\right]}{\left[\frac{d}{\left(b+d\right)}\right]}=\frac{\left(1SEN\right)}{SPE}$$ (probability of negative test result when the person is not diseased LR0=no diagnostic value, <1=diagnostic value, <.1=high diagnostic value) comparison with other systems will be calculated by $${\chi}^{2}$$ test for each risk groups(low moderate and high risk group) (Table 13).
No. 
Risk factors 
score 
1. 
AGE 


<40years 
0 

4049years 
1 

5059years 
2 

6069years 
3 

>70years 
4 
2. 
previous operation 


No operation 
0 

Uneventful operation 
1 

Cardio respiratory operation 
4 
3. 
Pre operative conditions 


Healthy/fit 
0 

ASA1 


ASA2 


ASA3 


ASA4 


ASA5/surgical site infection/moribund/septicaemia/SIRS 
4 
4. 
GCS 


15 
0 

12+ 
1 

712 
2 

46 
3 

<3 
4 
5 
Temparature 


3638.4 
0 

(3040.9) (3039) 
2 

≥41 ≤29◦c 
4 
6. 
History of previous MI 


No history 
0 

>6months 
1 

36 months 


<3 months 

7. 
Stress activity index 


No angina/no limitation of activity 
0 

no limitation of activity except in fast run 
1 

Slight limitation of activity cant climb >2stair can’t walk>2 block at level 
2 

Marked limitation of activity 
3 

Rest anginaDukes grade IV 
4 
8. 
pulse 


80120 
0 

<40 >120 regular 
3 

<40 >120 irregular, drop beat 
4 
9. 
BP 


<120,<80 optimal 


<130, <85 normal 
0 

(140159),(9099)grade I 
1 

(160179),(100109)grade II 
2 

>180,>110 grade III 
3 

Malignant HTN, grade IV, target organ damage, refractory to Rx 
4 
10. 
DM 


No DM 
0 

CATA(F<10,R<14,HbA1c<8%) 
1 

CATB(F<14,R<1417,HbA1c<810%) 
2 

CATC(F>1410,R>17,HbA1c>10%) 
3 

Type 1,GDM,pregnancy,undergoing surgery, uncontrolled, DKA 
4 
11. 
Respiratory rate/function 


No dyspnoea in normal pace 
0 

1420 /dyspnoea/can walk as long as like with taking time 
1 

2030/orthopnoea/block limitation 
2 

3040/PND/dyspnoea on ordinary exercise(room to bath/kitchen) 
3 

>40 or<5/rest dyspnoea 
4 
12. 
Obesity(more than double weight than expected at that age and height of individual 


BMI2025 
0 

BMI 2530(pre obase) 
1 

BMI 3035(mild obase /class I) 
2 

BMI 3540(moderate obase/class II) 
3 

BMI>40 morbid obase(class III) 
4 
13. 
LVEF 


Normal (still there is 12% risk) 
1 

>55(2.2% risk) 
2 

3554(5.4% risk) 
3 

<35(19.5%risk) 
4 

(<50 >70) in cardiac surgery 
4 
14. 
Chol : HDL 


<7 
0 

>7 
4 
15. 
Renal impairment 


Urine output >30ml/hr 
1 

Urine output 2030mi/hr 
2 

Urine output 515ml/hr 
3 

Urine output <5ml/hr, serum creatinine>1.2mg/dl 
4 
16. 
Serum potassium 


3.35.5 
0 

<2.9 >5.9/7mmol/lit 
4 
17. 
Haemoglobin 


>10gm/dl 
0 

<8gm/dl 
1 

68gm/dl 
3 

<6gm/dl 
4 
18. 
ECG 


normal 
0 

STT change 
4 

Pathological Q 
4 

Ectopics >4/min 
4 

Abnormal QRS 
4 
19. 
Proposed operation 


Minor elective single procedure 
1 

Major single procedure elective 
2 

Major more >1 procedure elective 
3 

emergency 
4 
20. 
Smoking 


Non smoker 
0 

Ceased 10years back 
1 

Ceased up 5years back 
2 

Ceased up <3months back 
3 

Current smoker 
4 
Table 1: Proposed cardiac risk assessment system by HHRIDS (CRASH).
Test(scoring system) 
Gold standard 
Total 

CRASH positive 
a(TP) 
b(FP) 
a+b 
CRASH negative 
c(FN) 
d(TN) 
c+d 
total 
a+c 
b+d 
N=a+b+c+d 
Table 2:
Test(scoring system) 
Gold standard (clinically observed) 
Total 

CRASH positive 
a(TP) 
b(FP) 
a+b 
CRASH negative 
c(FN) 
d(TN) 
c+d 
total 
a+c 
b+d 
N=a+b+c+d 
Table 2: Testing of scoring system.
Test 
Outcome +ve 
Outcome –ve 
Total 
New(Crash ) 
a 
b 
a +b 
Old/conventional 
c 
d 
c+d 
total 
a+c 
b+d 
GT=a+b+c+d 
Table 3: Comparison with other systems by χ^{2} test for each risk groups(low moderate and high risk group).
©2015 Rahman, et al. This is an open access article distributed under the terms of the, which permits unrestricted use, distribution, and build upon your work noncommercially.