Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 39

There are two types of patients within this group:

1 About 10% of patients presenting with a picture of type 1 MI have normal coronary arteries or insignificant CAD (<50% obstructive), this prevalence being higher among women and younger patients (15% of women) (MINOCA).17-25 Half of these patients have a completely normal angiographic appearance of the coronary arteries. MINOCA may be due to: (a) overlooked or recanalized plaque rupture (even at an angiographically normal site), (b) vasospasm, (c) myocarditis or (d) takotsubo. In a meta-analysis of all comers with MINOCA, MRI established the diagnosis in most of the patients (three main diagnoses: myocarditis 38%, infarction from plaque rupture or vasospasm 24%, and takotsubo 16%) (see Section I.E).19,26,27 IVUS and provocative coronary testing (for vasospasm) may also be performed.18,20 The long-term prognosis is generally good.

2 ~15% have significant CAD but are not deemed candidates for revascularization. These patients may have limited CAD in a small branch or a distal coronary segment that supplies a small territory, which is therefore not considered an appropriate revascularization target. The majority of these patients, however, have extensive and diffuse CAD, more extensive than patients undergoing PCI, along with more comorbidities (history of CABG, MI, PAD, stroke, CKD, anemia).25,85 These patients are not considered candidates for PCI or CABG because of the diffuseness of the CAD, the small diameter of the involved vessels (< 2 mm), the lack of appropriate distal targets for CABG, or the medical comorbidities. Their mortality is high, 3–4 times higher than the mortality of patients who are candidates for revascularization (~20% at 3–4 years).25,85,86

In patients with insignificant CAD whose angiographic or IVUS appearance suggests stabilized plaque rupture, long-term aggressive medical therapy is indicated (including 1 year of clopidogrel or ticagrelor). This also applies to the patients with significant CAD who do not get revascularized.