Collateral Circulation Not Correlated With Reciprocal ST-Segment Depression in STEMI

The presence of collateral vessels was not found to correlate with reciprocal ST-segment depression in opposite leads in patients who underwent primary percutaneous coronary intervention (PPCI) for first time acute ST-segment elevation myocardial infarction (STEMI), according to study results published in the Journal of Electrocardiology.

The role of collateral circulation in the promotion of reciprocal electrocardiogram (ECG) changes observed in patients with acute STEMI is unclear.

In this single-center, cross-sectional study conducted between November 2018 and May 2019, 112 patients with acute STEMI (age range, 41-69 years; 75.9% men) who were treated with PPCI were enrolled. Participants underwent a clinical evaluation consisting of a complete history and physical exam, 12-lead ECG, laboratory investigations, transthoracic echocardiography, and coronary angiography with culprit artery PPCI.

The cohort was divided according to the presence (n=66; 59%; mean age, 54.0±12.9 years; 27.3% women) or absence (n=46; mean age, 58.1±10.9 years; 19.6% women) of reciprocal changes on ECG.

The group with vs without reciprocal ECG changes had inferior infarctions (P <.001) and multivessel disease (P =.02) occurring more frequently, shorter time to door (P <.001), higher levels of creatine kinase-MB (P <.001), lower left ventricular (LV) ejection fraction (P =.004), higher LV end systolic and diastolic dimensions (P <.001 for both), and a higher incidence of the right coronary artery (RCA) being the culprit vessel (P < .001). Incidences of occlusion in the proximal left anterior descending artery, distal left circumflex artery and distal RCA were also higher in patients exhibiting reciprocal change vs no change.

Percentage changes after PPCI were 61.2±12.35% and 50.5±10.87% for ST-segment elevation and reciprocal ST-segment depression, respectively (P =.0023).

No correlation was established between collateral circulation and reciprocal changes on ECG (r =0.026; P =.8). Inferior infarction (P =.024), multi-vessel disease (P =.022), low ejection fraction (P =.007), and RCA as the culprit vessel (P =.034) were all found to be independent predictors of reciprocal ST-segment depression.

Study limitations include its single-center setup, observational design, lack of randomization, underpowering for subgroup analysis, and lack of information on the prognostic value of reciprocal changes.

“There is no correlation between concomitant reciprocal ST-segment changes and presence of collateral vessels in [patients with] acute STEMI. So the pathogenesis of reciprocal ST-segment changes result from an interplay of ischemia at distance due to multi-vessel [coronary artery disease] and benign mirror electrical changes not caused by collateral circulation diverting blood to ischemic area from non-diseased artery,” noted the authors.

Reference

Radwan HI, Ahmed AAE, Ammar AS, Roshdy HS. Relation of collateral circulation with reciprocal changes in patients with acute ST-elevation myocardial infarction. J Electrocardiol. 2020;60:36-43. doi:10.1016/j.jelectrocard.2020.03.011