Predictive role of intracoronary electrocardiography for procedural success in coronary no-reflow

The no-reflow phenomenon (NRP) is associated with increased mortality and morbidity in patients with ST-segment elevation myocardial infarction (STEMI). Despite the lack of a definitive treatment for NRP, predicting procedural success remains a challenge. This study aims to evaluate the potential of intracoronary electrocardiography (ic-ECG) in predicting the success of the primary percutaneous coronary intervention (pPCI) in STEMI patients who develop NRP.

Patients with acute anterior STEMI who underwent pPCI between November 2021 and May 2022 were included in this prospective study. Patients were categorized into two groups based on the thrombolysis in myocardial infarction (TIMI) flow grade, with those having a grade less than 3 defined as NRP. The NRP group was further analyzed to explore the relationship between the percentage of ST-segment resolution (STR) in ic-ECG records taken during pPCI and the recovery of left ventricular ejection fraction (LVEF).

Seventy-one patients with acute anterior STEMI were included in the study, 26 of whom (36.6%) developed the NRP. Baseline characteristics such as peak troponin levels (6267.8±2488.4 vs. 3244.6±3183 ng/mL, P=0.013), low-density lipoprotein cholesterol (LDL-C) levels (104.5±40 vs. 138.8±29.9 mg/dL, P=0.021), and total cholesterol levels (167.5±44.5 vs. 222.7±69.2 mg/dL, P=0.024) were significantly different between patients with and without LVEF recovery in the NRP group. Importantly, the change in ic-ECG STR was significantly higher in the recovery group (65.5±17% vs. 21±22.3%, P<0.001). Multivariate regression analysis confirmed that the percentage change in ic-ECG STR was an independent predictor of LVEF recovery (P=0.035). A cut-off ic-ECG STR change greater than 42% was identified through ROC analysis as a predictor of LVEF recovery with a sensitivity of 100% and specificity of 84.6% (AUC=0.938, P<0.001).

The percentage change in ST-segment resolution measured by ic-ECG is an independent predictor of LVEF recovery in STEMI patients who develop NRP. A greater than 42% change in ic-ECG STR during the procedure is independently associated with improved LVEF, highlighting its value in guiding clinical decision-making and improving patient outcomes.