How do I differentiate between Hypertensive Arteriosclerotic Vascular Disease (HASVD), Ischemic Heart Disease (IHD), and Coronary Artery Disease (CAD)?

Differentiating Between HASVD, IHD, and CAD

Coronary Artery Disease (CAD) refers specifically to the atherosclerotic narrowing of coronary arteries, while Ischemic Heart Disease (IHD) is the broader clinical syndrome resulting from myocardial oxygen supply-demand imbalance, and Hypertensive Arteriosclerotic Vascular Disease (HASVD) refers to vascular damage from chronic hypertension that can lead to ischemia even without significant coronary stenosis. 1, 2

Definitions and Relationships

• CAD is defined as impedance or blockage in one or more of the arteries supplying the heart, usually due to atherosclerosis 1
• IHD is defined as an imbalance between myocardial oxygen supply and demand, representing the broader clinical spectrum that includes both symptomatic and asymptomatic conditions 1, 3
• HASVD refers to vascular damage resulting from chronic hypertension, which can cause myocardial ischemia through mechanisms other than obstructive coronary disease 4, 5

Key Diagnostic Differences

Clinical Presentation

• In CAD, chest pain is typically related to exertion and relieved by rest or nitroglycerin (classic angina) 1, 2
• In IHD without significant CAD, symptoms may be present despite normal coronary arteries due to microvascular dysfunction 5, 6
• In HASVD, patients may have hypertension-mediated organ damage including left ventricular hypertrophy (LVH) with or without typical anginal symptoms 4, 7

Risk Factor Profile

• CAD is strongly associated with traditional risk factors: smoking, dyslipidemia, diabetes, family history 1, 2
• HASVD is primarily driven by long-standing hypertension, often with evidence of end-organ damage in multiple vascular beds 4, 6
• IHD encompasses both CAD and non-CAD causes of ischemia, including HASVD, microvascular dysfunction, and increased oxygen demand states 1, 3

Diagnostic Approach

History and Physical Examination

• Assess chest pain characteristics using Diamond-Forrester criteria: typical angina, atypical angina, or non-anginal chest pain 1
• Evaluate for hypertension history, including duration, control, and evidence of end-organ damage 4, 7
• Look for signs of LVH (displaced PMI, S4 gallop) which may suggest HASVD 5, 7

Initial Testing

• 12-lead ECG: Look for ST-T wave changes, Q waves, or LVH pattern 1, 2
• Basic laboratory tests: Lipid profile, glucose, renal function 1, 2
• Calculate pretest probability of CAD using validated tools (Duke Clinical Score performs better than Diamond-Forrester) 1

Advanced Diagnostic Testing

• For suspected CAD: Exercise stress testing, stress imaging (echo or nuclear), or coronary CT angiography based on pretest probability 1, 2
• For suspected HASVD: Echocardiography to assess for LVH and diastolic dysfunction 4, 5
• For differentiating causes of IHD: Consider coronary flow reserve assessment or invasive coronary angiography with fractional flow reserve (FFR) 1, 5

Diagnostic Algorithm

1. Assess clinical presentation and risk factors:

   • Typical angina + multiple CAD risk factors → High probability of CAD 1
   • Atypical symptoms + hypertension + LVH → Consider HASVD 4, 5

2. Initial non-invasive testing:

   • High CAD probability: Consider direct coronary angiography 1
   • Intermediate CAD probability: Stress testing with imaging 1
   • Low CAD probability with hypertension: Echocardiography to assess for LVH 5, 7

3. Interpretation of results:

   • Obstructive coronary disease on angiography → CAD diagnosis 1, 2
   • Normal coronaries with LVH and hypertension → HASVD diagnosis 4, 5
   • Evidence of ischemia with or without obstructive CAD → IHD diagnosis 1, 3

Common Pitfalls and Caveats

• Not all chest pain in hypertensive patients is due to HASVD; significant CAD may coexist 4, 6
• Stress ECG has lower specificity in patients with LVH or HASVD; consider stress imaging instead 5, 7
• The presence of LVH significantly increases cardiovascular risk and mortality even in patients with non-obstructive CAD 3, 4
• Women and elderly patients more commonly have non-obstructive CAD or HASVD as causes of IHD 1, 2
• Microvascular dysfunction can cause ischemia in patients with HASVD even with angiographically normal coronary arteries 5, 6

Treatment Implications

• CAD management focuses on antiplatelet therapy, statins, and revascularization when appropriate 2, 8
• HASVD management emphasizes aggressive blood pressure control to prevent further vascular damage 4, 7
• In patients with both conditions, blood pressure targets should be below 140/90 mmHg, with caution if diastolic BP falls below 60 mmHg 4, 7