Ischemic Heart Disease – CCS 2014 Guideline

A focused Hx and PE be obtained to elucidate

1. symptoms,
2. cardiac risk factors,
3. medical history
4. signs of CV disease or other aetiologies of symptoms

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 Chest Pain Criteria

1. Substernal chest discomfort with characteristic quality and duration
   • Dull retrosternal discomfort/ache/heaviness that might or might not radiate to the jaw, neck, shoulders or arms
2. Provoked by exertion or emotional stress
3. Relieved promptly (within 5min) by rest or nitroglycerin (can be misleading)

NonClassic symptoms are common in DM

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Cardiac Risk Factors

Nonmodifiable

1. Age, Sex, ethnic origin
2. Family Hx of premature established CV disease

Modifiable

1. Smoking
2. Dyslipidemia, DM, HTN, CKD
3. Depression
4. Physical inactivity, diet
5. Obesity or metabolic syndrome

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PMH: document

• CV comorbidities of heart failure, valvular heart disease,
• Cerebrovascular and peripheral vascular disease,
• Renal disease

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Ix: Initial assessment – outine testing that includes:

1. Hgb, full cholesterol panel, fasting glucose, A1c
2. renal function tests, liver function tests, thyroid function tests
3. 12-lead ECG

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Non-invasive testing for dx and prognostic purposes:

1. ≥30yo with 2 or 3 anginal criteria,
2. Men ≥ 40 & women ≥60 with 1 anginal features
3. Men< 40 & women < 60 with 1 anginal feature with features indicative of CV risk
   • abn baseline ECG, DM, smoking, hyperlipidemia, HTN, CKD – esp in women

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Initial noninvasive test

• Exercise Test, if nterpretable rest ECG and able to exercise, is preferred because it is relevant to pt’s activities & provides assessment of functional capacity
• Exercise myocardial perfusion imaging or exercise echo for pt able to exercise but a rest ECG that precludes ST segment interpretation
• MIBI – cannot exercise but no LBBB or paced rhythm
• MIBI / CCTA – LBBB or paced rhythm
• rest LV function assessed in all pt with suspected SIHD
• Complementary, noninvasive modality if initially equivocal or nondx test results or a strong discrepancy between clinical and test results
• CCTA not be used (min radiation exposure) if pt likely need invasive angiography due to high risk symptom pattern, high pretest probability of CAD, severe risk factors
• Invasive angiography if pt with SIHD who have a high pretest % of CAD, high-risk features on previous noninvasive testing, survived sudden cardiac arrest, life-threatening arrhythmias

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DDx

• CV: Aortic dissection, CHF, pericarditis, syndrome X (microvascular dz)
• Pulm: PE, pneumothorax, pleuritis, primary pulmonary HTN
• GI: Esophagitis, esophageal spasm, biliary colic: colecystitis, choledocholithiasis, cholangitis, PUD, pancreatitis
• Chest Wall: costochondritis, fibrositis, fibromyalgia, Rib #, sternoclavicular arthritis
• Neuro: Cervical dz, herpes zoster
• Psych: anxiety, hyperventiliation, panic disorder, affective disorder (depression), somatiform disorder, thought disorder (delusions)

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Conditions exacerbate ischemia

↑ O2 demand

• Noncardiac:
  • hyper/hypothermia, hyperthyroidism, sympathomimetic toxicity (cocaine),
  • HTN, anxiety, high cardiac output states (AV fistulae)
• Cardiac: LVH, AS, HCM, dilated cardiomyopathy, tachycardia

↓O2 supply

• Noncardia:
  • Anemia, hypoxemia/high altitude, sickle cell
  • pneumonia, Asthma, COPD, pulm HTN, Interstitial pulm fibrosis, OSA
  • sympathomimetic toxicity (cocaine, pheochromocytoma)
  • Hyperviscosity – polycythemia, leukemia, thrombocytosis, hypergammaglobulinemia
• Cardiac: AS, HCM, CAD, microvascular dz, coronary spasm

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High Risk Features of noninvasive test results (>3% death / MI)

Exercise treadmill

≥ 2 mm of ST-segment depression at low (< 5 metabolic equivalents) workload or persisting into recover Exercise-induced ST segment elevation, VT, or VF Failure to increase systolic blood pressure to > 120 mm Hg or sustained decrease > 10 mm Hg during exercise

Myocardial perfusion imaging

Severe resting LV dysfunction (LVEF ≤ 35%) not readily explained by noncoronary causes Severe stress-induced LV dysfunction (peak exercise LVEF < 45% or decrease in LVEF with stress ≥ 10%) or Stress-induced LV dilation Resting perfusion abnormalities ≥ 10% of the myocardium in patients without previous history or evidence of MI Stress-induced perfusion abnormalities encumbering ≥ 10% myocardium or stress segmental scores indicating multiple vascular territories with abnormalities Increased lung uptake

Stress echocardiography

Inducible wall motion abnormality involving > 2 segments / coronary beds Wall motion abnormality developing at low dose of dobutamine (≤ 10 μg/kg/min) or at a low heart rate (< 120 beats per minute)

Coronary computed tomographic angiography

Multivessel obstructive CAD or left main stenosis on CCTA

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Chronic Tx for SIHD (stable ischemic heart dz) to improve prognosis

1. ASA 81mg po daily indefinetely
2. ACEi if pt has HTN, DM, LVEF<40%, CKD & reasonable to consider ACEi in all pt with SIHD
   • ARBs if intolerant of ACEi
3. β-blocker therapy if SIHD & LVEF<40% ± heart failure or prev MI- indefinetely
4. Clopidogrel 75mg po daily if ASA intolerant
5. Dual antiplatelet Tx – not be used in routine Rx or  beyond the time period required as a result of stenting
6. Statin in accordance with CCS2012 lipid guidelines

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Chronic Tx of anginal symptoms

1. β-blockers – first-line therapy for chronic stable angina if the patient has had an MI, or has reduced ejection fraction or heart failure, with the dose titrated to reach a target resting heart rate of 55-60 beats per minute
2. β-blockers or long-acting CCB (dihydropyridine) –  for chronic stable angina in uncomplicated patients (no MI, ↓EF, CHF)
3. Add a long-acting nitrate when initial treatment with a β-blocker and/or a long-acting CCB is not tolerated or contraindicated or does not lead to adequate symptom control
4. Avoid nondihydropyridine CCB in combination with β-blockers if there is risk of AV block or excessive bradycardia
5. Chelation therapy, allopurinol, magnesium supplementation, coenzyme Q10, suxiao jiuxin wan or shenshao tablets, and testosterone should NOT be used to attempt to improve angina or exercise tolerance
6. Implementation and optimization of medical therapy should be achieved within 12-16 weeks of an initial evaluation suggesting presence of SIHD without high-risk features during which adequacy of symptom control and quality of life can be assessed before consideration of revascularization therapy

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Revascularization Tx

• Coronary angiography – early in patients with high-risk noninvasive test features
• Medically refractory symptoms or inadequate CV quality of life while using medical therapy should undergo elective coronary angiography in anticipation of possible revascularization procedures

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Clinical F/U

• Follow-up visits should include a focused history, physical examination, and clinically appropriate laboratory testing, with an emphasis on ensuring optimal risk factor control.
  1. Hx: any changes in symptoms of angina or heart failure, adherence to prescribed medications and any side effects, addition of new medications, appropriate nutrition, weight optimization, smoking cessation where appropriate, and onset of any new disease conditions.
  2. OE: resting heart rate and blood pressure, signs of heart failure or arrhythmia, and new or worsening vascular bruits or murmurs, and status of the abdominal aorta.
  3. Ix: metabolic fitness (serum lipids, glucose, complete blood count, renal function) and a resting ECG (asymptomatic for comparison in the future or change in symptoms).
     1. ECG repolarization abnormalities have been shown to predict CV events.
• Refer to a comprehensive cardiac rehabilitation program
  • Asymptomatic patients with SIHD, with the approval of their physician, should accumulate 150 minutes of moderate to vigorous physical activity per week, preferably in bouts of 10 minutes or more, with additional exercise providing additional benefits
• Pt whose symptoms are not controlled with use of optimal medical therapy should be re-evaluated as per the sections on diagnosis and revascularization
• Routine use of exercise stress testing (excluding formal cardiac rehabilitation programs) or exercise/pharmacological stress cardiac imaging in asymptomatic patients with SIHD should be avoided, but consider if
  1. Change in symptoms
     • order the same test for easier comparison
  2. Atypical initial presentation
  3. Revascularization was not performed or is known to be suboptimal / incomplete
  4. Undergoes strenuous tasks at work, during hobbies, or unsupervised exercise programs
  5. Has an unexplained but angina-free deterioration in exercise capacity
  6. High risk occupations (commercial driver)

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Objectives:

1. Given a specific clinical scenario in the office or emergency setting, diagnose presentations of ischemic heart disease (IHD) that are:
– classic.
– atypical (e.g., in women, those with diabetes, the young, those at no risk).
2 In a patient with modifiable risk factors for ischemic heart disease (e.g., smoking, diabetes control, obesity), develop a plan in collaboration with the patient to reduce her or his risk of developing the disease.
3 In a patient presenting with symptoms suggestive of ischemic heart disease but in whom the diagnosis may not be obvious, do not eliminate the diagnosis solely because of tests with limited specificity and sensitivity (e.g., electrocardiography, exercise stress testing, normal enzyme results).
4 In a patient with stable ischemic heart disease manage changes in symptoms with self-initiated adjustment of medication (e.g., nitroglycerin) and appropriate physician contact (e.g., office visits, phone calls, emergency department visits), depending on the nature and severity of symptoms.
5 In the regular follow-up care of patients with established ischemic heart disease, specifically verify the following to detect complications and suboptimal control:
– symptom control.
– medication adherence.
– impact on daily activities.
– lifestyle modification.
– clinical screening (i.e., symptoms and signs of complications).
6 In a person with diagnosed acute coronary syndrome (e.g., cardiogenic shock, arrhythmia, pulmonary edema, acute myocardial infarction, unstable angina), manage the condition in an appropriate and timely manner.

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References:

http://www.onlinecjc.ca/article/S0828-282X%2814%2900356-0/abstract