Correlation of Non-Invasive Transthoracic Doppler Echocardiography with Invasive Doppler Wire-Derived Coronary Flow Reserve and Their Impact on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention

Abstract

Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. Methods: We included 36 patients with invasive Doppler wire assessment on days 3-7 after STEMI treated with primary percutaneous coronary intervention (PCI), of which TTDE-derived CFR was measured in 47 vessels (29 patients) within 6 h of the invasive Doppler. Infarct size was assessed by cardiac magnetic resonance at a median of 8 months. Results: The correlation between invasive and non-invasive CFR was modest in the overall cohort (rho 0.400, p = 0.005). It improved when only measurements in the LAD artery were considered (rho 0.554, p = 0.002), with no significant correlation in the RCA artery (rho -0.190, p = 0.435). Both invasive (AUC 0.888) and non-invasive (AUC 0.868) CFR, measured in the recanalized culprit artery, showed a good ability to predict infarct sizes ≥18% of the left ventricular mass, with the optimal cut off values of 1.85 and 1.80, respectively. Conclusions: In patients with STEMI, TTDE- and Doppler wire-derived CFR exhibit significant correlation, when measured in the LAD artery, and both have a similarly strong association with the final infarct size.

Keywords: STEMI; coronary flow reserve; coronary microcirculation; infarct size; primary PCI.

Figure 1

Correlation between invasive, Doppler wire-derived and non-invasive, transthoracic Doppler echocardiography-derived coronary flow reserve in patients with ST-segment elevation acute myocardial infarction. (A) Overall population including measurements in both LAD (red dots) and RCA (green dots) arteries. (B) Significant correlation between invasive and non-invasive coronary flow reserve in the LAD artery. (C) Lack of significant correlation between invasive and non-invasive coronary flow reserve in the RCA artery.

Figure 2

Bland–Altman graph showing similar pattern of agreement over a range of CFR values in the LAD (red dots) and RCA (green dots) arteries.

Figure 3

Correlation of invasive, Doppler wire-based (A) and non-invasive, echocardiography-derived coronary flow reserve (B), measured in the culprit vessel on days 3–7 after primary PCI, with final infarct size on cardiac magnetic resonance imaging.

Figure 4

ROC analysis showing good capacity of both Doppler-wire-based (A) and echocardiography-derived (B) coronary flow reserve to predict infarct sizes ≥18% of the left ventricle.

Figure 5

ROC analysis showed good capacity of both Doppler-wire-based (A) and echocardiography-derived (B) coronary flow reserve to predict left ventricular ejection fractions <40%.

Figure 6

Representative images showing the recanalized LAD artery (A) with invasive Doppler wire-based assessment of coronary flow velocity at rest (B1) and in hyperemia (B2), and the corresponding echocardiography-derived measurements of coronary flow velocity at rest (C1) and during hyperemia (C2), which correlate with the degree of myocardial fibrosis from the mid anterior wall to the apex of the left ventricle on cardiac magnetic resonance imaging (D1–D4).