Diagnostic Tools

Diagnosis of coronary artery disease (CAD) is typically based on medical and family history, risk factors, and results from physical examinations, diagnostic tests and procedures.

Two broad screening strategies have been proposed for CAD in people living with HIV (PLWHIV):1

  • define the pre-test risk of disease from predisposing risk factors such as hypertension, elevated serum cholesterol, cigarette smoking and physical inactivity
  • detect established coronary heart disease (CHD), even in the earliest stages

There is no single test to diagnose CAD; instead there are a number of tests that can be performed including:2–4

  • electrocardiograph (ECG): certain electrical patterns of the ECG can suggest the likelihood of CAD
  • stress testing or exercise ECG: in which the heart is made to work hard and beat faster (e.g. through exercise or medication used to speed up the heart rate). Some stress tests use a radioactive dye, sound waves of positron emission tomography (PET) or magnetic resonance imaging (MRI). A stress test can elicit signs of CAD such as:
    • abnormal changes in heart rate or blood pressure
    • shortness of breath or chest pain
    • changes in heart rhythm or heart electrical activity.
       
  • chest x-rays: which can reveal signs of heart failure, as well as lung disorders and other signs/symptoms not due to CAD2

The role of risk assessment

Referral for further diagnostic testing may depend on the10-year risk of coronary heart disease (CHD):5

  • patients with a low pre-test probability and a low global CHD risk score (e.g. <10%) should not be referred for further testing
  • patients at intermediate risk are most suitable for non-invasive testing
  • patients with a high pre-test probability (>20%) should be considered for invasive arteriography
  • these conclusions, however, are derived from non-HIV-infected populations and recommendations for PLWHIV are lacking

For more information see Recommendations for the Non-Invasive Diagnosis of Stable Angina. 



A number of tools exist to assess cardiovascular (CV) risk; these include:

Whether existing risk stratification equations, such as the Framingham equation, are valid in HIV-infected patients remains unclear.5 For more information refer to a recent article on risk prediction models in PLWHIV:6

  • a comparison of the Framingham, PROCAM and SCORE risk assessments in HIV-infected patients showed differences in the identification of high-risk individuals7
  • a CV risk model has been developed using data from HIV-infected patients, including routinely collected CV risk parameters and exposure to individual antiretroviral (ARV) drugs8
    • however, this algorithm has not been formally validated, and the relative contribution of ARVs is based on the analysis of only one cohort

Computerized clinical decision support systems have been advocated to improve management of patients at risk for CHD. However, the use of systemic computerized routine provision of CHD risk profiles, in addition to guidelines, did not improve risk factors for CHD in patients on highly active ARV therapy (HAART).9



Acute coronary syndromes (ACS)

Identifying patients with an acute coronary syndrome within the large number with suspected cardiac pain is a diagnostic challenge, especially in those lacking clear symptoms or electrocardiographic features.10 ACS is a life-threatening state of atherothrombotic disease10 and may be considered a medical emergency:

  • the main diagnostic categories of ACS, unstable angina and myocardial infarction (MI), are defined by serum concentrations of cardiac enzymes and markers11
  • during the process of ACS diagnostic assessment and exclusion of differential diagnoses, the patient’s risk level is repeatedly assessed and serves as a guide for therapeutic management (see Figure 1)10
  • refer to the ESC guidelines10,12 for more details

Figure 1. Overview of diagnosis and treatment for ACS10

ECG = electrocardiograph; NSTEMI = non-ST-elevation myocardial infarction; STEMI = ST-elevation myocardial infarction.

Reproduced with permission from the European Society of Cardiology  



References

  1. Hsue PY, Squires K, Bolger AF, et al. Screening and assessment of coronary heart disease in HIV-infected patients. Circulation. 2008;118:e41–47.
  2. National Heart Lung and Blood Institute website. Accessed 28 February 2011. 
  3. MedlinePlus: Stable angina. Accessed 28 February 2011.
  4. Guidelines on the Management of Stable Angina Pectoris. The Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology, 2007. Accessed 18 April 2011.
  5. Grinspoon SK, Grunfeld C, Kotler DP, et al. State of the science conference: Initiative to decrease cardiovascular risk and increase quality of care for patients living with HIV/AIDS: executive summary. Circulation. 2008;118:198–210.  
  6. Schambelan M, Wilson PW, Yarasheski KE, et al. Development of appropriate coronary heart disease risk prediction models in HIV-infected patients. Circulation. 2008;118:e48-53.  
  7. Moreira Guimarães MM, Bartolomeu Greco D, Ingles Garces AH, et al. Coronary heart disease risk assessment in HIV-infected patients: a comparison of Framingham, PROCAM and SCORE risk assessment functions. Int J Clin Pract. 2010;64:739–745.  
  8. Friis-Møller N, Thiébaut R, Reiss P, et al. Predicting the risk of cardiovascular disease in HIV-infected patients: the data collection on adverse effects of anti-HIV drugs study. Eur J Cardiovasc Prev Rehabil. 2010;17:491–501. 
  9. Bucher HC, Rickenbach M, Young J, et al. Randomized trial of a computerized coronary heart disease risk assessment tool in HIV-infected patients receiving combination antiretroviral therapy. Antivir Ther. 2010;15:31–40.  
  10. European Society of Cardiology Full Guidelines and Pocket Guidelines on Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation (2007). Accessed 3 May 2011
  11. Scottish Intercollegiate Guidelines Network. Guideline 93: Acute coronary syndromes
  12. European Society of Cardiology Full Guidelines and Pocket Guidelines on Management of Acute Myocardial Infarction in Patients Presenting with ST-Segment Elevation (2008).  Accessed 3 May 2011.