12. F. Stress MRI and stress PET are the best non-invasive modality for the diagnosis of microvascular dysfunction, followed by stress SPECT (which has the pitfall of a high false-positive rate in women). Stress echo and stress ECG have a lower yield. Invasively, there are two aspects of microvascular dysfunction: (i) microvascular spasm, unveiled by acetylcholine, (ii) inability to vasodilate and increase coronary flow, unveiled by adenosine infusion. Concerning myocardial bridging, NTG administration may worsen it and further suggest it as a culprit.
36 Answer 13. A. Macrovascular spasm is only slightly more common in women than men. Microvascular dysfunction is 4 times more common in women than men.
37 Answer 14. C. In stable CAD, PCI only improves angina control. There is no demonstrated effect on MI or mortality, even if the lesion appears angiographically critical. It may improve unstable angina presentations (FAME 2 trial), but not MI. PCI is appropriate in a patient with severe angina, especially if it persists despite antianginal therapy. In the stable CAD setting, revascularization with CABG improves mortality of patients with left main disease and likely that of patients with three-vessel disease or two-vessel disease with proximal LAD (in multivessel disease without left main involvement, CABG may only reduce MI risk, not mortality, as per BARI 2D trial).
38 Answer 15. C. In stable CAD, PCI has not demonstrated a reduction of mortality or MI in comparison with medical therapy, even when the proximal LAD is treated (COURAGE, ISCHEMIA, MASS, MASS II trials). CABG may reduce mortality in single-vessel proximal LAD according to a meta-analysis of old CABG vs. medical therapy trials, but not according to more recent trials (MASS, BARI 2D, ISCHEMIA). Preoperative revascularization has not demonstrated an improvement of postoperative outcomes, except, possibly, in the case of left main or three-vessel CAD.
39 Answer 16. C. Asymptomatic restenosis is not clearly associated with adverse prognosis. Also, there is no evidence that PCI for recurrent, asymptomatic ischemia improves outcomes, and thus routine testing is not indicated. Concerning choice B, note that, after CABG, ~27% of patients have recurrent events at 5 years, yet each SVG has ~30% risk of occlusion at 5 years (most SVG occlusions are asymptomatic).
40 Answer 17. D. ISCHEMIA trial, wherein revascularization did not prove superior to conservative management in stable, high-risk CAD, excluded patients with PCI or CABG in the last year. COURAGE trial excluded patients with isolated in-stent restenosis. Symptomatic DES restenosis is often treated with repeat PCI: intracoronary imaging is performed to check for stent expansion, as stent underexpansion accounts for at least 50% of DES restenosis and is treated with high-pressure balloon inflation. If restenosis is mainly due to neointimal hyperplasia or if it is diffuse or extending outside the stent, repeated DES stenting is performed (stent inside a stent). CABG is an alternative therapy for LAD in-stent restenosis.
41 Answer 18. A. The stress test does not reveal high-risk findings and proves a good functional capacity. Thus, medical therapy for low-risk CAD vs. microvascular disease may be initiated. CTA or stress imaging may be performed for further risk stratification, but is not necessary.
42 Answer 19. C. Half of women with typical angina have no significant CAD. The most likely cause of angina in this case is endothelial dysfunction, with inability of the microvasculature to dilate during stress. Macrovascular spasm is a second possibility, but it is less likely and more commonly presents as rest pain (vs. exertional pain in microvascular dysfunction). The diagnosis is made non-invasively by comparing the rest and post-adenosine myocardial perfusion using PET or MRI. Unlike macrovascular spasm, metoprolol is a first-line treatment for microvascular dysfunction (CorMica trial).
43 Answer 20. A. The patient has mild angina (CCS I) and mild functional limitation. This is a typical ISCHEMIA trial patient, where PCI does not improve survival or MI rates. To qualify for revascularization, his angina needs to be severe and persistent despite two antianginal drugs, or he needs to have left main disease (+/- 3-vessel CAD or 2-vessel with proximal LAD)
44 Answer 21. A.
45 Answer 22. The patient does not clearly have angina, although dyspnea may be an angina equivalent (exertional dyspnea is commonly multifactorial and is not as specific as chest pain for CAD). Revascularization would only be appropriate for severe angina, or clinical HF caused by LV dysfunction. If dyspnea and LV dysfunction persist after medical therapy, PCI of RCA may be justified. If performed immediately, FFR of the LAD may be low but exaggerated as it supplies collaterals to the RCA (for the same lesion: larger territory→> lower FFR). It is best to perform FFR of such a moderate LAD stenosis only after RCA recanalization, when such recanalization becomes indicated.Answer 23.
46 Answer 23. Decision to revascularize is guided by: (1) severity of angina, and (2) presence of left main disease (+/- other high-risk anatomical features, such as 3-vessel CAD or 2-vessel with proximal LAD). ISCHEMIA trial questioned the role of severe ischemia which was previously used to guide revascularization.
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