The outcome of patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) and impaired kidney function: a 3-year observational study

BACKGROUND: Myocardial infarction with nonobstructive coronary arteries (MINOCA) constitutes about 10% of the cases of acute coronary syndromes (ACS). It is a working diagnosis and requires further diagnostics to determine the cause of ACS. METHODS: In this study, 178 patients were initially diagnosed with MINOCA over a period of 3 years at the Department of Invasive Cardiology of the University Clinical Hospital in Białystok. The value of estimated glomerular filtration rate (eGFR) was calculated for all patients. The patients were divided into 2 groups depending on the value of eGFR: group 1—53 patients with impaired kidney function (eGFR < 60 mL/min/1.73 m(2); 29.8%) and group 2—125 patients with normal kidney function (eGFR ≥ 60 mL/min/1.73 m(2); 70.2%). RESULTS: In group 1, the mean age of patients was significantly higher than that of group 2 patients (77.40 vs 59.27; p < 0.0001). Group had more women than group 2 (73.58% vs 49.60%; p = 0.003). Group 1 patients had higher incidence rate of arterial hypertension (92.45% vs 60.80%; p < 0.0001) and diabetes (32.08% vs 9.60%; p = 0.0002) and smoked cigarettes (22.64% vs 40.80%; p = 0.020). Group 1 patients had higher incidence rate of pulmonary edema, cardiogenic shock, sudden cardiac arrest (13.21% vs 4.00%; p = 0.025), and pneumonia (22.64% vs 6.40%; p = 0.001). After the 37-month observation, the mortality rate of the patients with MINOCA was 16.85%. Among group two patients, more of them became deceased during hospitalization (7.55% vs 0.80%; p = 0.012), followed by after 1 year (26.42% vs 7.20%; p = 0.0004) and after 3 years (33.96% vs 9.6%; p < 0.0001). Multivariate analysis revealed that the factors increasing the risk of death in MINOCA are as follows: older age, low eGFR, higher creatinine concentration, low left ventricular ejection fraction, and ST elevation in ECG. CONCLUSION: Impaired kidney function is diagnosed in every third patient with MINOCA. Early and late prognosis of patents with MINOCA and renal dysfunction is poor, and their 3-year mortality is comparable to patients with myocardial infarction with significant stenosis of the coronary arteries and impaired kidney function.