Slow Flow and No-reflow Phenomenon in the Intervention of Coronary Arteries at the Vietnam National Heart Institute: Bach Mai Hospital

Background: Slow or no-reflow (NR) can occur in both acute coronary syndrome (ACS) and chronic coronary syndrome (CCS), with an incidence rate of up to 32% in patients with ACS. NR is associated with increased rates of rehospitalization, ventricular remodeling, malignant arrhythmias, and heart failure and is an independent predictor of myocardial infarction and mortality. Although various treatments and medications, such as adenosine, nitroglycerin, nicardipine, and adrenaline, have shown effectiveness in improving flow when this phenomenon occurs, not all cases respond to these flow-improving drugs. In addition, the use of these drugs may be unsuitable due to adverse developments that contraindicate their use. Objective: A descriptive of the clinical and paraclinical characteristics and slow or NR phenomenon during coronary artery interventions at the Vietnam National Heart Institute, Bach Mai Hospital. Methods: This is an observational study describing the clinical and paraclinical characteristics and management methods for slow or NR in 40 patients undergoing coronary artery interventions at the Vietnam National Heart Institute, Bach Mai Hospital. Results: Among the 40 observed patients, 80% were admitted with a diagnosis of ST-elevation myocardial infarction (STEMI). Males accounted for 57.5%, averaging 71.43 ± 10.97 years. All patients had mildly reduced left ventricular systolic function (LVEF) with an LVEF of 45.75 ± 10.43%. Slow flow primarily occurred in the culprit branch, with the left anterior descending artery (LAD) accounting for 50% and the right coronary artery for 32%. There were 14 anemic patients, accounting for 35%, with the lowest hemoglobin level being 80 g/L. Blood potassium levels <3.5 mmol/L accounted for 22.5%, with the lowest being 2.9 mmol/L. Adenosine was used to manage slow flow in 33 patients, with 32 (97%) patients showing improved flow after administration. Six patients were treated with nitroglycerin, which improved thrombolysis in myocardial infarction (TIMI) flow in four patients. Two patients did not respond to nitroglycerin but responded to adenosine. Two patients with TIMI flow 0–1 did not respond to adenosine and were subsequently treated with adrenaline; however, TIMI flow did not improve, leading to short-term complications during hospitalization. Conclusion: Slow or NR is commonly observed in patients with ACS, predominantly in elderly males. These cases are often seen in patients with heart failure and mildly to moderately reduced LVEF. The LAD is the most frequently affected coronary artery branch compared to the other two branches. Adenosine is the first-line drug and is more effective in managing slow or NR.