Coronary Angiography in Critically Ill Patients With Type II Myocardial Infarction

INTRODUCTION Myocardial ischemia is common in critically ill patients. When the cause of myocardial ischemia and subsequent necrosis is a mismatch between the delivery and consumption of oxygen in the myocardium and not acute coronary artery thrombosis, we are talking about type II myocardial infarction (type II MI) (1). The most common cause of such MI is infection - sepsis. The infection increases oxygen consumption in the heart muscle, which can lead to acute ischemia when the coronary reserve is reduced (chronic stable coronary disease). This is manifested by troponin leakage, ischemic changes in the electrocardiogram (ECG), or impaired contraction of the heart muscle. In critically ill patients, acute coronary artery thrombosis may also occur due to hyper coagulability, which cannot be identified without urgent invasive coronary diagnostics.

Due to the lack of data on the efficacy of acute percutaneous revascularization, these patients are generally treated medically. The cause of the increase in oxygen consumption is treated. Usually invasive diagnostics is performed only in case of severe hemodynamic instability, very high levels of troponin, or clear newly formed segmental wall contraction disorders visible on ultrasound. Delays to invasive diagnostics are generally longer than the time frames recommended for invasive diagnostics in the treatment of type I MI without the ST segment elevation in ECG (NSTE-ACS).

HYPOTHESES

1. Obstructive coronary artery disease suitable for percutaneous revascularization is present in most patients with type II MI.
2. Type I MI (acute coronary artery thrombosis) is misdiagnosed in some patients.
3. Echocardiogram and a 12-lead electrocardiogram are not reliable in predicting coronary artery disease.
4. Urgent coronary angiography is safe in patients with type II MI.
5. Percutaneous coronary revascularization (if indicated) reduces the size of myocardial necrosis and may improve survival in the critically ill patients with type II MI.

METHODS A prospective randomized trial in critically ill patients with type II MI will be performed. All patients will undergo coronary angiography in the first 24 hours after the diagnosis. If acute coronary artery thrombosis is found, PCI will be done according to the latest European Society of Cardiology guidelines for NSTE-ACS (2). In the case of non-obstructive coronary artery disease or a normal coronary angiogram, standard treatment of the underlying disease (pneumonia, sepsis, chronic obstructive pulmonary disease, etc.) will be continued. Patients with stable obstructive coronary artery disease will be randomized into two groups - interventional and control group. The first group of patients will undergo immediate percutaneous coronary intervention (PCI) (of all obstructive lesions or until 300 mL of contrast is reached), the second group will receive only medical treatment and a delayed PCI if needed before hospital discharge.