Phenotypes of the no-reflow phenomenon during percutaneous coronary interventions in myocardial infarction

Aim. Using the cluster analysis, to determine and describe clinical and pathogenetic phenotypes of the coronary microvascular obstruction phenomenon (CMVO) that occurs during percutaneous coronary interventions (PCI) in patients with myocardial infarction (MI). Materials and methods. The study included 190 patients with CMVO that occurred during PCI for type 1 MI: 137 (72%) men, 53 (28%) women, the median age was 64 [56; 70] years. The study was conducted in 2013-2020. CMVO criteria: blood flow < 3 points in the infarct-related artery (IRA) according to the TIMI flow grade (TFG); perfusion < 2 points according to the Myocardial Blush Grade; ST segment resolution < 70%. ST-elevation MI (STEMI) was found in 170 patients (89%). Primary PCI was noted in 127 (67%) cases. Nine patients (4.7%) died. Phenotyping was performed using the expectation - maximization (EM) algorithm. Results. Three phenotypes were identified in a ratio of 56% (n = 106) / 27% (n = 52) / 17% (n = 32). The values of the parameters are the following, respectively: age 62 [54; 67] / 73 [67; 79] / 59 [50; 65] years; women 8 (8%) / 39 (77%) / 6 (19%); STEMI 102 (96%) / 43 (83%) / 25 (78%); thrombolysis 46 (43%) / 6 (12%) / 11 (34%); class 1 [1; 2] / 2 [1; 4] / 2 [2; 2] acute heart failure; platelet-to-lymphocyte ratio 110 [78; 153] / 106 [85; 132] / 132 [100; 182]; glucose at admission 8.0 [6.9; 9.6] / 11.1 [8.8; 15.2] / 7.5 [6.1; 8.1] mmol / l; total cholesterol 4.7 [4.2; 5.4] / 5.3 [3.7; 6.2] / 5.1 [4.5; 6.2] mmol / l; glomerular filtration rate according to CKD-EPI 77 [64; 88] / 58 [46; 74] / 81 [64; 88] ml /min / 1.73m(2); Syntax Score 15 [10; 21] / 20 [14; 26] / 8 [5; 10]; Syntax Score in the IRA 9 [8; 15] / 12 [7; 16] / 6 [3; 7]; coronary collaterals according to Rentrop: grade 0 [0; 1] / 0 [0; 1] / 0 [0; 0]; thrombosis of the IRA according to the TIMI thrombus grade 5 [5; 5] / 5 [3; 5] / 1 [0; 2]; TFG 0 [0; 0] / 0 [0; 1] / 2 [2; 3]; aspiration thrombectomy 30 (28%) / 7 (13%) / 4 (13%); IRA diameter 3.5 [3.0; 3.5] / 3.0 [2.8; 3.5] / 3.5 [3.0; 3.5] mm; balloon angioplasty 99 (93%) / 45 (87%) / 16 (50%); PCI of 2 or more arteries 0 (0%) / 4 (8%) / 3 (9%). Deaths - 2 (1.9%), 7 (13.5%), and 0 (0%) patients, respectively (p = 0.002,chi 2 Pearson). Conclusion. Three phenotypes were identified. Phenotype 1: severe IRA thrombosis, mostly men, moderate atherosclerotic lesions. Phenotype 2: mostly elderly women, high hyperglycemia, severe atherosclerotic lesions, severe AHF, impaired renal function, IRA thrombosis. Phenotype 3: mostly men, minor changes in the coronary arteries, absence of significant thrombosis and preserved blood flow in the IRA before PCI, elevated levels of inflammatory markers and total cholesterol.