Functional Assessment of the Collateral-Dependent Circulation in Chronic Total Coronary Occlusion Using Transthoracic Doppler Ultrasound and Venous Adenosine Infusion

Abstract

The measurement of collateral flow reserve (CFR; the hyperemic/baseline collateral flow velocity ratio) in patients with chronic total coronary occlusion requires invasive and expensive techniques. Noninvasive transthoracic coronary Doppler echocardiography may be an alternative option. Fifty-one patients with chronic total coronary occlusion were evaluated by transthoracic coronary Doppler echocardiography and venous adenosine infusion to measure CFR in occluded coronary arteries (the left anterior descending artery in 44 patients and the artery supplying the posterior descending artery in 7 patients). CFR data were plotted against 3 angiographic parameters: (1) grade of the epicardial filling of the occluded artery (1 ‫؍‬ absent, 2 ‫؍‬ partial, 3 ‫؍‬ complete), (2) stenosis of the donor artery, and ( Recently, transthoracic coronary Doppler echocardiography (TDE) has been introduced and validated for the noninvasive prediction of coronary artery disease, 1-4 the assessment of coronary recanalization in acute myocardial infarction, 5 and the evaluation of therapeutic coronary interventions. 6 -8 TDE can also predict left anterior descending (LAD) coronary occlusion on the basis of reversed flow in the epicardial artery 9 and in its perforating branches. 10 We undertook this study to (1) assess the feasibility of TDE to noninvasively measure coronary flow reserve of the collateral-dependent circulation distal to the occluding lesion and (2) determine the relation of collateral flow reserve (CFR) to the angiographic collateral anatomy and flow. MethodsStudy population: We enrolled 56 consecutive patients (46 men, 10 women, mean age 59 Ϯ 9 years, range 43 to 75) with chronic total occlusion of the LAD (44 patients) and of the artery supplying the posterior descending coronary artery (PD; 12 patients). Inclusion criteria were (1) Thrombolysis In Myocardial Infarction anterograde coronary flow grade 0, (2) normal global and regional left ventricular function at rest (wall motion score index ϭ 1), and (3) the absence of Q-wave myocardial infarction. Patients with contraindications to adenosine administration were excluded. All patients were in sinus rhythm and fasting state and provided written informed consent. All coronary active medications were withdrawn the day before the Doppler study. Figure 1 shows the clinical model that we used: occluded coronary artery (either the LAD or the artery supplying the PD), visible collaterals toward the occluded artery, and good left ventricular function.TDE: TDE was performed as previously described in a modified 2-chamber view, 4,6 using Sequoia C256 and C512 ultrasound systems (Siemens-Acuson, Mountain View, California). The LAD was scanned by a dedicated 7-MHz transducer (3.5 MHz in color Doppler ultrasound) along the anterior interventricular groove, 6 and the PD was scanned using a standard 3.5-MHz transducer (2 MHz in color Doppler ultrasound). 4 The best long-axis view in color Doppler imaging was obtained to optimize the angle be-

Transthoracic Echocardiography in the Assessment of Coronary Arteries

“…CFVR is always depressed in the collateral dependent vascular area, and the value<2.0 is registered in the LAD or PDA distal to the occlusion in all cases (Takeuchi et al, 2005, Pizzuto et al, 2006. But TTE is able to reveal patients with CFVR <1.0 reflecting coronary steal effect which www.intechopen.com…”

“…Coronary steal effect occurs when collateral circulation is poor and the donor artery is significant stenotic (Pizzuto et al, 2006;Braden, 2006).…”

“…Coronary Angiography -Advances in Noninvasive Imaging Approach for Evaluation of Coronary Artery Disease 46 develops in 33% to 47% of occluded vessel territories (Takeuchi et al, 2005, Pizzuto et al, 2006. Coronary steal effect occurs when collateral circulation is poor and the donor artery is significant stenotic (Pizzuto et al, 2006;Braden, 2006).…”

“…It has been established that retrograde flow in distal LAD is a good marker of LAD occlusion with 88% sensitivity and 100% specificity and retrograde flow in the PDA is a good marker of RCA occlusion with 67% sensitivity and 100% specificity (Otsuka et al, 2005). But Pizzuto et al, 2006, doubted such a high sensitivity of TTE in the detection of LAD occlusion having revealed a retrograde flow in distal LAD in only 43% of patients with CTO and normal anterograde flow in more than half patients (55%). Angiography data demonstrate that in LAD and RCA occlusions, besides collateral flow distal to the occluded region through the connections on the epicardial surface, 63-86% of patients have intramyocardial collateral channels lying usually in the interventricular septum.…”

The meaning of retrograde coronary flow after primary PCI

“…Coronary flow in collaterals may be visualized by angiography to certain extent, but may be also functionally evaluated non-invasively by transthoracic Doppler echocardiography by the means of coronary flow and coronary flow reserve, which is in the presence of occluded artery retrograde 2 . This case demonstrates unusual presentation of stress echocardiography (secho) and coronary flow reserve (CFR) in the patient after primary percutaneous coronary intervention (pPCI).…”