Recovery of right ventricular function and strain in patients with ST-segment elevation myocardial infarction and concurrent chronic total occlusion

Abstract

The right ventricle (RV) is frequently involved in ST-segment elevation myocardial infarction (STEMI) when the culprit or concurrent chronic total occlusion (CTO) is located in the right coronary artery (RCA). We investigated RV function recovery in STEMI-patients with concurrent CTO. In EXPLORE, STEMI-patients with concurrent CTO were randomized to CTO percutaneous coronary intervention (PCI) or no CTO-PCI. We analyzed 174 EXPLORE patients with serial cardiovascular magnetic resonance imaging RV data (baseline and 4-month follow-up), divided into three groups: CTO-RCA (CTO in RCA, culprit in non-RCA; n = 89), IRA-RCA (infarct related artery [IRA] in RCA, CTO in non-RCA; n = 56), and no-RCA (culprit and CTO not in RCA; n = 29). Tricuspid annular plane systolic excursion (TAPSE), RV ejection fraction (RVEF), RV global longitudinal strain (GLS) and free wall longitudinal strain (FWLS) were measured. We found that RV strain and TAPSE improved in IRA-RCA and CTO-RCA (irrespective of CTO-PCI) at follow-up, but not in no-RCA. Only RV FWLS was different among groups at baseline, which was lower in IRA-RCA than no-RCA (- 26.0 ± 8.3% versus - 31.0 ± 6.4%, p = 0.006). Baseline RVEF, RV end-diastolic volume and TAPSE were associated with RVEF at 4 months. RV function parameters were not predictive of 4 year mortality, although RV GLS showed additional predictive value for New York Heart Association Classification > 1 at 4 months. In conclusion, RV parameters significantly improved in patients with acute or chronic RCA occlusion, but not in no-RCA patients. RV FWLS was the only RV parameter able to discriminate between acute ischemic and non-ischemic myocardium. Moreover, RV GLS was independently predictive for functional status.

Keywords: Cardiovascular magnetic resonance; Chronic total occlusion; Right ventricle; ST-segment elevation myocardial infarction; Strain analysis.

Fig. 1

Flowchart of patient selection. CMR cardiovascular magnetic resonance; CTO chronic total occlusion; IRA infarct-related artery; PCI percutaneous coronary intervention; RCA right coronary artery; RV right ventricle

Fig. 2

Measurement of right ventricular function parameters. A and B End-diastolic length (A) and end-systolic length (B) measurement for the calculation of the tricuspid annular plane systolic excursion; C Right ventricular strain measurement using feature tracking, with the green line indicating tracking of the free wall and white line indicating the septum tracking; D Strain curves, with the upper curve indicating the general RV strain curve and the lower curve indicating the RV strain curves divided into septum (white), average (white) and free wall (green). eS indicates end-systolic and eD indicates end-diastolic; E, F Right ventricular contours in the short-axis end-diastole (E) and end-systole (F) for RV volume measurements

Fig. 3

Recovery of different right ventricular function parameters. A RVEF recovery; B TAPSE recovery; C RV global longitudinal strain recovery; D RV free wall longitudinal strain recovery. CTO chronic total occlusion; FWLS free wall longitudinal strain; IRA infarct-related artery; PCI percutaneous coronary intervention; RCA right coronary artery; RV right ventricle; RVEF right ventricular ejection fraction; TAPSE tricuspid annular plane systolic excursion