View source for Chronic stable angina risk assessment in patients with an intermediate or high probability of coronary artery disease

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{{Chronic stable angina}}

{{CMG}}; '''Associate Editor-in-Chief:''' [[Lakshmi Gopalakrishnan|Lakshmi Gopalakrishnan, M.B.B.S.]]

'''For more information on T Wave Alternans for Risk Stratification during Exercise Stress Testin, click [[Exercise stress testing#T Wave Alternans for Risk Stratification during Exercise Stress Testing|here]].'''

==Overview==
Based on the ACC/AHA guidelines,<ref name="pmid10351980">Gibbons RJ, Chatterjee K, Daley J, Douglas JS, Fihn SD, Gardin JM et al. (1999) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=10351980 ACC/AHA/ACP-ASIM guidelines for the management of patients with chronic stable angina: executive summary and recommendations. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Chronic Stable Angina).] ''Circulation'' 99 (21):2829-48. [http://circ.ahajournals.org/content/99/21/2829.full.pdf] PMID: [http://pubmed.gov/10351980 10351980]</ref> the [[Chronic stable angina assessing the pretest probability of coronary artery disease|pretest probability]] of underlying [[coronary artery disease]] (CAD) can be classified into low (less than 10%-20%), intermediate (between 20%-80%) and high probability (more than 80%-90%). All patients with intermediate to high probability of [[CAD]] need to undergo exercise stress testing<ref name="pmid1875969">Mark DB, Shaw L, Harrell FE, Hlatky MA, Lee KL, Bengtson JR et al. (1991) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1875969 Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease.] ''N Engl J Med'' 325 (12):849-53. [http://dx.doi.org/10.1056/NEJM199109193251204 DOI:10.1056/NEJM199109193251204] PMID: [http://pubmed.gov/1875969 1875969]</ref><ref name="pmid3579066">Mark DB, Hlatky MA, Harrell FE, Lee KL, Califf RM, Pryor DB (1987) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=3579066 Exercise treadmill score for predicting prognosis in coronary artery disease.] ''Ann Intern Med'' 106 (6):793-800. PMID: [http://pubmed.gov/3579066 3579066]</ref> to stratify the risk of subsequent coronary events and hence determine the appropriate diagnostic and therapeutic interventions. Bruce protocol and DUKE score are widely adopted methods for exercise stress testing. The exercise capacity, clinical, hemodynamic and electrocardiographic responses must be considered while interpreting the results of exercise treadmill test.

==Exercise Treadmill Test Interpretation==
*[[Angina]]: If occurred during or after exercise, particularly if it forces to stop the test.
*[[ST segment]] changes if occurred during or after exercise. Factors that indicate high probability of underlying [[CAD]] include:
:*Positive [[J point]]
:*Horizontal [[ST segment depression]] of less than or equal to 2mm
:*Downsloping of [[ST segment depression]]
:*Early positive response within 6-minutes
:*Persistence of [[ST segment depression]] for more than 6-minutes into recovery
:*[[ST segment depression]] in five or more leads
:*Exertional [[hypotension]]
*Hemodynamic responses like changes in [[heart rate]] or [[blood pressure]] with exercise
*Workload in metabolic equivalents (METs)
:*In a 40-year old man weighing 70kg, 1 MET refers to the resting volume oxygen consumption per minute (VO2).
:*1 MET = 3.5 mL/min/kg of body weight

==Methods to Assess Exercise Treadmill Test==
Bruce protocol:
*Bruce protocol is most widely used and has seven stages, with a complete 21-minute exercise and each  stage lasting for 2-minutes.
*The result is satisfactory when a patient completes of 9-12minutes of exercise or 85% of the maximum predicted changes in [[heart rate]].

{| border="1" align="center" style="background:lightskyblue"
|-
| bgcolor="CornFlowerBlue" |'''Stage 1'''
| 0-3 min
| 1.7 mph
| 10% grade
| 5.0 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 2'''
| 3-6 min
| 2.5 mph
| 12% grade
| 6.8 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 3'''
| 6-9 min
| 3.4 mph
| 14% grade
| 9.4 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 4'''
| 9-12 min
| 4.2 mph
| 16% grade
| 13.3 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 5'''
| 12-15 min
| 5.0 mph
| 18% grade
| 16.6 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 6'''
| 15-18 min
| 5.5 mph
| 20% grade
| 19.5 METS
|-
| bgcolor="CornFlowerBlue" |'''Stage 7'''
| 18-21 min
| 6.0 mph
| 22% grade
| 22.7 METS
|}

DUKE treadmill score = [(exercise duration in minutes) - (5 x [[ST segment deviation]], during or after exercise, in millimeters) - (4 if angina occurs or 8 if angina is the reason to stop the test)]<ref name="pmid19384658">Johnson GG, Decker WW, Lobl JK, Laudon DA, Hess JJ, Lohse CM et al. (2008) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=19384658 Risk stratification of patients in an emergency department chest pain unit: prognostic value of exercise treadmill testing using the Duke score.] ''Int J Emerg Med'' 1 (2):91-5. [http://dx.doi.org/10.1007/s12245-008-0031-5 DOI:10.1007/s12245-008-0031-5] PMID: [http://pubmed.gov/19384658 19384658]</ref>
{| border="1" align="center" style="background:lightskyblue"
|-
| bgcolor="CornFlowerBlue" |'''CAD risk probability (DTS)'''
| bgcolor="CornFlowerBlue" |'''4-year survival'''
| bgcolor="CornFlowerBlue" |'''Annual mortality'''
|-
| Low probability (more than 5 DTS)
| 99%
| 0.25%
|-
| Moderate probability (-10 to 4 DTS)
| 95%
| 1.25%
|-
| High probability (less than -10 DTS)
| 79%
| 5%
|}

==ACC/AHA Guidelines- Risk Assessment and Prognosis in Patients With an Intermediate or High Probability of CAD (DO NOT EDIT)<ref name="pmid10351980">Gibbons RJ, Chatterjee K, Daley J, Douglas JS, Fihn SD, Gardin JM et al. (1999) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=10351980 ACC/AHA/ACP-ASIM guidelines for the management of patients with chronic stable angina: executive summary and recommendations. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Chronic Stable Angina).] ''Circulation'' 99 (21):2829-48. [http://circ.ahajournals.org/content/99/21/2829.full.pdf] PMID: [http://pubmed.gov/10351980 10351980]</ref>==

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightGreen"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class I]]

|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''1.''' Patients undergoing initial evaluation. (Exceptions are listed below in [[ACC AHA Guidelines Classification Scheme#Classification of Recommendations|classes IIb]] and [[ACC AHA Guidelines Classification Scheme#Classification of Recommendations|III]]) ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''2.''' Patients after a significant change in cardiac symptoms. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|}

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightCoral"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class III]]

|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''1.''' Patients with severe [[comorbidity]] likely to limit life expectancy or prevent [[revascularization]]. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|}

{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIb]]

|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' Patients with the following [[Chronic stable angina risk stratification electrocardiogram/chest x-ray|ECG]] abnormalities:
|-
| bgcolor="LemonChiffon"|'''a.''' Preexcitation ([[Wolff-Parkinson-White syndrome]]). ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: B]])''
|-
| bgcolor="LemonChiffon"|'''b.''' Electronically paced ventricular rhythm. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: B]])''
|-
| bgcolor="LemonChiffon"|'''c.''' More than 1 mm of rest [[ST segment depression]]. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: B]])''
|-
| bgcolor="LemonChiffon"|'''d.''' Complete [[left bundle-branch block]]. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' Patients who have undergone [[cardiac catheterization]] to identify [[ischemia]] in the distribution of a coronary lesion of borderline severity. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' [[Revascularization|Post-revascularization]] patients who have a significant change in anginal pattern suggesting [[ischemia]]. ''([[ACC AHA Guidelines Classification Scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|}

==References==
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