Prognosis

Watch out for ^b  

• arrhythmias
• mitral regurgitation
• ventricular septal rupture
• signs of heart failure
• post-infarct angina  

Arrhythmias

The risk of ventricular fibrillation is increased with ^b  

• young age 
• admission bradycardia 
• hypotension 
• current smoking 
• an inferioposterior infarct 
• widespread ST elevation 
• hypokalaemia   

See chapters on bradyarrhythmia and tachyarrhythmias for more details 

Heart failure and cardiogenic shock

• a dilated heart ^b  
• a reduced ejection fraction ^b  

Rank your patient's severity using the Killip classification

• old age (> 65 ) 
• reduced left ventricular ejection fraction (< 35% ) 
• elevated CK-MB (> 160 IU ) 
• diabetes mellitus 
• previous myocardial infarction 

^a

There is no clear benefit from intra-aortic balloon counterpulsation for cardiogenic shock. ^d  

Pericarditis and pericardial effusions

Give NSAIDs if there is evidence of pericarditis ^c

Ventricular rupture

• cardiac tamponade
• pulseless electrical activity
• a large pericardial effusion (> 5 mm diameter on echocardiography)
• haemopericardium on pericardiocentesis  

Reinfarction

The risk of reinfarction is increased with

• hypertension ^b  
• elevated total cholesterol or triglycerides ^b  
• angina before MI ^a  
• a non-Q wave MI ^b  
• worsening angiographic findings ^a  
• ST-segment depression on exercise test ^a  

Angina

Refer all patients with symptomatic angina pectoris presenting spontaneously >36 hours after admission for arteriography, followed by PTCA or CABG as required ^a  

See unstable angina chapter for more details on therapy

Left ventricular aneurysms

Start anticoagulation if patients have an aneurysm. ^a  

Mitral regurgitation

Death

The risk of dying is increased with:

• increasing age ^{a  b}  
• female sex ^{a  b}  (women over 65) ^b
• hospitals that admit few cases of MI ^a  
  
• previous cardiovascular disease
  • previous myocardial infarction ^a or subsequent recurrent infarction ^{a  b} 
  • previous angina  ^{a  b}  or early post-infarction angina ^a  
  • a previous stroke  ^b 
  • an increasing number of stenosed coronary vessels ^b  or previous CABG ^b  
    
• cardiovascular risk factors
  • hypertension  ^b  
  • smoking ^b  
  • diabetes mellitus ^{a  b}  
    
• an anterior myocardial infarction ^{a  b} 
• a Q wave infarct ^b  
  
• an abnormal admission ECG (the more abnormalities present, the greater the risk of dying) ^a  
  • abnormal QRS complexes ^a  
  • ST elevation, ^b  particularly if present in many leads ^b  
  • bundle-branch block ^b  
  • specifically for an inferior MI 
    • precordial ST depression ^b  
    • evidence of right ventricular infarction (ST elevation 0.1 mV or more in lead V _4R ) ^a  
      
• complications
  • evidence of heart failure ^{a b} particularly cardiogenic shock  ^a  
    • worsening Killip class ^{a b} 
    • reduced ejection fraction ^{a b}  
    • reduced LV end diastolic pressure ^a  
  • increased heart rate  ^b  
  • hypotension  ^b  
  • mitral regurgitation ^b particularly if early ^a
    
• arrhythmias
  • 10 or more premature ventricular contractions per hour  ^{a b}
  • ventricular fibrillation (particularly after 48 hours) ^{a b}  
  • 2nd ^b or 3rd degree heart block  ^{a b} after 24 hours
  • cardiac arrest ^{a  b}  
    
• psychosocial factors
  • depression ^a  
  • lack of social support ^a  e.g. living alone ^b
  • failure to take medication ^b  
  • education for < 12 years ^b  

Use the following clinical prediction rule to rank your patient's risk of dying within 30 days:  ^a

Sum the following points:

Clinical feature a b	Score
aged 75 or more	3
aged 65-74	2
history of diabetes, hypertension or angina	1
systolic bp < 100 mmHg	3
heart rate > 100 beats/min	2
Killip class II-IV (evidence of heart failure)	2
weight < 67 kg	1
anterior ST elevation or left bundle-branch block	1
time to reperfusion therapy > 4 hours	1

Risk of death at 30 days following a myocardial infarction

Score a b	Death at 30 days following reperfusion	Death at 30 days following no reperfusion
9+	35%	29%
8	23%	25%
7	18%	24%
6	15%	22%
5	10%	19%
4	6%	14%
3	4%	10%
2	2%	7%
1	0.9%	3%
0	0.7%	2%