Abstract
BackgroundIt is estimated that 5% to 10% of patients with myocardial infarction (MI) present with no obstructive coronary artery lesions. Until now, most studies have focused on acute coronary syndrome, including different clinical entities with a similar presentation encompassed under the term MINOCA (MI with non-obstructive coronary arteries). The aim of this study is to assess the prognosis of patients diagnosed with true infarction, confirmed by cardiovascular magnetic resonance (CMR), in the absence of significant coronary lesions.MethodsProspective multicenter registry study, including 120 consecutive patients with a CMR-confirmed MI without obstructive coronary artery lesions. The primary clinical outcome was major adverse cardiovascular events (MACE: death, non-fatal infarction, stroke, or cardiac readmission), assessed over three years.ResultsSeventy-six patients (63.3%) were admitted with a diagnosis of acute coronary syndrome, and 44 (36.6%) for other causes (mainly heart failure); the definitive diagnosis was established by CMR. Most patients (64.2%) were men, and the mean age was 58.8 ± 13.5 years. Patients presented with small infarcts: 83 (69.1%) showed late gadolinium enhancement (LGE) in one or two myocardial segments, mainly transmural (in 77.5% of patients) and with a preserved left ventricular ejection fraction (median 54.8%, interquartile range 37–62). The most frequent infarct location was inferolateral (n = 38, 31.7%). During follow-up, 43 patients (35.8%) experienced a MACE, including 9 (7.5%) who died. In multivariable analysis, LGE in two versus one myocardial segment doubled the risk of adverse cardiac events (hazard ratio [HR] 2.32, 95% confidence interval [CI] 0.97–5.83, p = 0.058). Involvement of three or more myocardial segments almost tripled the risk (HR 2.71, 95% CI 1.04–7.04, p = 0.040 respectively).ConclusionsPatients with true MI but without significant coronary artery lesions predominantly had small infarcts. Myocardial 3-segment LGE involvement is associated with a significantly higher risk of adverse cardiac events.
Highlights
It is estimated that 5% to 10% of patients with myocardial infarction (MI) present with no obstructive coronary artery lesions
acute coronary syndrome (ACS) is generally associated with obstructive coronary artery disease, in up to 30% of these patients neither plaque nor thrombosis are visible in the coronary angiography [2]
This situation has occurred more frequently in recent years, in large part due to increased access to coronary angiography and the existence of more sensitive and specific troponins for diagnosing myocardial infarction (MI) [3]. These advances have led to the definition of a new entity, MI with non-obstructive coronary arteries (MINOCA), whose diagnosis is established when the coronarography shows the following features: (a) it meets universal criteria for MI; (b) the coronary angiogram shows no obstruction of the coronary arteries, defined as the absence of coronary diameter stenosis > 50% on any artery that is potentially responsible for the MI; and (c) there is no specific or overt clinical cause for acute presentation [4]
Summary
It is estimated that 5% to 10% of patients with myocardial infarction (MI) present with no obstructive coronary artery lesions. ACS is generally associated with obstructive coronary artery disease, in up to 30% of these patients neither plaque nor thrombosis are visible in the coronary angiography [2] This situation has occurred more frequently in recent years, in large part due to increased access to coronary angiography and the existence of more sensitive and specific troponins for diagnosing myocardial infarction (MI) [3]. These advances have led to the definition of a new entity, MI with non-obstructive coronary arteries (MINOCA), whose diagnosis is established when the coronarography shows the following features: (a) it meets universal criteria for MI; (b) the coronary angiogram shows no obstruction of the coronary arteries, defined as the absence of coronary diameter stenosis > 50% on any artery that is potentially responsible for the MI; and (c) there is no specific or overt clinical cause for acute presentation [4]. As their prognostic and therapeutic management are different, it is vital to reach an accurate diagnosis in these patients [5]
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