to hibernation, the artery is now open and there is no persistent ischemia. In the post-MI and post-cardiac surgery cases, temporary support with inotropes or IABP is sometimes needed until the myocardium recovers, provided there is no ongoing ischemia. Unlike hibernation, the artery is open and nuclear uptake is usually normal at rest. Repetitive stunning from a significant stenosis (exertional ischemia) can lead to persistent dysfunction and hibernation.
Recovery of function occurs 1–6 months after revascularization (faster with stunning, days to 1 month). See Chapter 4 for viability evaluation.
In a patient with active chest pain and severe CAD, the myocardial dysfunction is usually an actively ischemic dysfunction, rather than hibernation or stunning.
Ischemic preconditioning is the phenomenon whereby brief exposure to ischemia preconditions the heart and makes it more resilient to a later, prolonged and severe ischemia. In fact, ischemia stimulates protective myocyte receptors, such as adenosine receptors and G-protein receptors (protein kinase C). There are two windows of protection: the first starts within a few minutes of the brief ischemia and lasts a few hours; the second occurs at 24 hours and lasts 96 hours. This is partly why patients with pre-infarct angina suffer from smaller
infarcts and have better outcomes. Also, patients with severe pre-existing disease have already formed mature collaterals, which attenuate the infarct size.
QUESTIONS AND ANSWERS
1 Question 1. A 67-year-old man with a history of HTN and diabetes presents with exertional chest pain CCS III for 3–4 months. Chest pain is relieved with rest and with his wife’s NTG. He has left lower extremity claudication. On exam, distal left lower extremity pulses are not palpable. ECG shows LVH with 0.5 mm ST-segment depression. What is the most appropriate next step?Coronary angiographyExercise stress ECGExercise stress SPECTAdenosine SPECT
2 Question 2. A 67-year-old man with a history of LAD stent placed 2 years ago presents with mild angina on heavy exertion (CCS I). He is on atenolol, amlodipine, aspirin, and atorvastatin. BP 110/65, pulse 58 bpm. Exercise stress test result: 8 min on a Bruce protocol, mild angina occurred, DTS score +4. Nuclear perfusion shows a small area of apical–lateral ischemia, with a summed stress score of +3. Coronary angiography shows 60% proximal LCx stenosis, 30% mid-LAD, 40% mid-RCA. What is the next step?PCI of LCx. No need for FFR since the lesion is angiographically significantPCI of LCx. No need for FFR since the stress test is positiveFFR of LCx. Stent if FFR <0.80Continue medical therapy, no PCI
3 Question 3. A 76-year-old man presents with chest pain on heavy activity. His home medications consist of aspirin and a statin. A nuclear stress test shows mild/moderate anterior ischemia, and coronary angiography shows 80% mid-LAD stenosis. What is the next step?Medical therapy. There is no mortality difference between CABG, PCI, and medical therapy for this lesionPCICABG, since it provides mortality benefit compared to PCI or medical therapy
4 Question 4. Same scenario as Question 3, except the patient has severe anterior ischemia and 80% proximal LAD stenosis.Medical therapy.PCICABG, since it provides mortality benefit compared to PCI or medical therapy
5 Question 5. A 76-year-old man presents with chest pain on heavy activity (walking >2 blocks). He receives aspirin and a statin. A nuclear stress test shows moderate anterior ischemia, and coronary angiography shows 80% proximal LAD stenosis and 75% mid-RCA and mid- LCx stenoses. What is the next step?Medical therapyPCICABGA or CB or C
6 Question 6. A 47-year-old executive man, asymptomatic, is starting an exercise program at the gym. He is asymptomatic during daily activities. A stress test is ordered by his family physician. He exercises for 5 minutes and develops 1.5 mm ST depression without chest pain. Nuclear images show a large anterior and anterolateral reversible defect, with a normal EF and no TID. What is the next step?Just initiate medical therapyPerform coronary angiography, but only revascularize if left main or three-vessel CAD is presentCTAB or C
7 Question 7. A 56-year-old man presents with angina walking up one flight of stairs or less (= CCS III). He is not receiving any antianginal therapy. His nuclear stress test shows severe inferior ischemia. His angiogram shows CTO of the RCA with features that make it favorable for PCI (non-calcified, ~2 cm long)True or false: PCI is not appropriate, as the patient is not receiving maximal antianginal therapy
8 Question 8. A 50-year-old female, smoker, presents with chest pain that occurs with exertion, but not consistently, and sometimes occurs at rest. Each episode lasts ~45 minutes. BP = 160/95, HR = 78. She undergoes a treadmill nuclear stress testing. She exercises for 5 minutes, does not report any chest pain, and no ST abnormality is seen. Her nuclear images show a large reversible anterior defect with a summed stress score of +10. The patient prefers to try medical therapy first if deemed appropriate by the physician. What is her Duke Treadmill Score? What is the most appropriate next step?Start aspirin, statin, β-blockers and amlodipine. Coronary angiography is indicated, as her risk of cardiac events is >5% per yearStart aspirin, statin, β-blockers and amlodipine. CTA is indicated, as her risk of cardiac events is >5% per yearNo further test is indicated, as her risk of cardiac events is <1% per yearStart amlodipine, since the likely diagnosis is vasospasm
9 Question 9. A 65-year-old diabetic patient is planning to undergo elective cholecystectomy. He has mild dyspnea on exertion (>4 METs) but no angina. He undergoes preoperative testing with a nuclear SPECT, which shows severe inferior ischemia and preserved EF. Coronary angiography shows 80% mid-RCA stenosis. What is the next step?Aggressive medical regimen. Revascularization is not indicated. His surgical risk is intermediate but revascularization will not improve itAggressive medical regimen. Revascularization is not indicated. His surgical risk is low and revascularization will not improve itAggressive medical regimen and PCI of the RCA with BMSAggressive medical regimen and PCI of the RCA with DES
10 Question 10. A 58-year-old woman has exertional chest pain (and some episodes of pain with mental stress). While undergoing treadmill stress ECG, she develops severe chest pain, inferior ST-segment elevation, and multiple runs of non-sustained VT. The pain and ST elevation resolve at 5 minutes of recovery. Coronary angiography is performed and shows a smooth 80% stenosis of the mid-RCA, which improves to a mild, 25% stenosis with NTG. What is the prognosis and what is the treatment?Even in the absence of obstructive CAD, her risk of unstable angina/MI/VT is ~20% at several years of follow-up. She must be placed on amlodipine and statinIn the absence of obstructive CAD, her risk of unstable angina/MI/VT is low (<5%) at several years of follow-up. Provide CCB for symp- tomatic reliefVasospasm frequently occurs on top of obstructive CAD. Perform IVUS to ensure that the residual stenosis is not a more severe stenosis or a ruptured plaque.
11 Question 11. A 55-year-old woman, smoker, presents with exertional chest pain. A nuclear stress test shows a reversible anterior defect. Coronary angiography is performed and does not show any obstructive CAD. Moderate bridging of the mid-LAD (50% obstructive) is seen. What is the diagnosis?Myocardial bridgingCoronary epicardial vasospasmMicrovascular dysfunctionAny of the above
12 Question 12. What diagnostic testing could help establish the diagnosis in the patient of Question 11?Stress echoStress MRIIntracoronary acetylcholine testingIntracoronary or intravenous adenosine testingAdminister NTG during coronary angiography, even if no spasm is seenB, C, D, and EAll of the above
13 Question 13. A 50-year-old man presents with resting chest pain and ST-segment elevation in the inferior leads. His coronary angiography shows a smooth 90% mid-RCA stenosis that is relieved with NTG. Which statement is incorrect?Prinzmetal angina is twice more common in women than menMicrovascular dysfunction is more common than macrovascular spasmWithout CCB therapy, recurrent MI occurs in a substantial proportion of patients with Prinzmetal angina (~20%)The definite diagnosis requires a concomitant
