Left Coronary Artery Obstruction Research Articles

Detection of left coronary ostial obstruction during transcatheter aortic valve replacement by coronary flow velocity measurement in the left main trunk by intraoperative transesophageal echocardiography

BackgroundCoronary obstruction is a rare but catastrophic complication of transcatheter aortic valve replacement (TAVR) and occurs mostly at the left coronary artery (LCA) ostium. However, some patients do not show any clinical findings, and thus, its detection is sometimes difficult. The peak diastolic flow velocity in left main coronary artery (LM) was reportedly increased in significant stenosis lesions. We evaluated the effectiveness of measuring blood flow velocities in LM by transesophageal echocardiography (TEE) for the detection of LCA ostial obstruction during a TAVR procedure. MethodsA total of 1105 consecutive patients who underwent TAVR in Sendai Kousei Hospital between September 2014 and December 2020 were enrolled. The LM blood flow velocity was measured at pre- and post-valve implantation. ResultsAmong the 1105 patients, 9 had LCA ostial obstruction. The peak LM blood flow velocity at post-TAVR [0.90 (0.39–1.15) vs. 0.37 (0.28–0.50) m/s; p = 0.0046) was significantly higher in 9 patients who had LCA ostial obstruction, compared with the remaining 1096 patients who had not (controls), although no significant difference was observed before the TAVR procedures between the two groups. The post- to pre-TAVR LM flow velocity ratio [2.26 (1.31–3.42) vs. 1.06 (0.82–1.36); p = 0.0030] was also significantly higher in patients with LCA obstruction, compared to the controls. Furthermore, the post- to pre-TAVR LM blood flow velocity ratio was >2.0 in all six hemodynamically stable patients with LCA obstruction, whereas <2.0 in all three patients with LCA obstruction who showed hemodynamic collapse at post-TAVR procedure. ConclusionCoronary blood flow velocity in LM significantly increased in hemodynamically stable LCA obstruction patients. The intraprocedural TEE measurement of the LM flow velocities would be potentially useful to detect asymptomatic and hemodynamically stable LCA ostial obstruction.

A case of anomalous left coronary artery obstruction caused by lotus valve implantation

Trans-catheter aortic valve implantation (TAVI) in patients with high surgical risk is an alternative therapeutic option for severe aortic stenosis. Although second generation TAVI devices are available now, this therapy still cannot overcome all serious complications. Among them, coronary obstruction is a life threatening complication, however, there is no report concerning the complication in patients with anomalous coronary arteries. Here we present a case with coronary obstruction of an anomalous left main coronary that occurred after implantation of the mechanical expanding Lotus valve (Boston Scientific Inc.). © 2016 Wiley Periodicals, Inc.

0459: MRI evaluation of coronary anatomy and myocardial perfusion after arterial switch for transposition of great arteries

Coronary arteries obstruction is the main cause of mortality and morbidity in patients who underwent arterial switch for transposition of great arteries. Long-term outcome of coronary transfer and its consequences on myocardial perfusion is scarcely known. Objective: To evaluate feasibility of cardiac MRI to describe coronary anatomy, myocardial perfusion and fibrosis after arterial switch operation. 110 patients (mean age 13.5 y) were included. Twenty-five/110 had had previously documented coronary artery obstruction. cMRI procotol included cine SSFP in short axis, two-chamber, three and four chamber view, and perfusion analysis before and after dipyridamole infusion. Anatomy was evaluated by 3D heart sequence in 78 patients. Finally, late enhancement was evaluated ten minutes after injection of contrast agent in 71 patients. Perfusion could be evaluated in all patients. One perfusion defect was identified. All patients with prior negative myocardial ischemia test had normal perfusion on MRI even those with mild to moderate coronary stenosis. Anatomical evaluation of proximal coronary arteries was possible in 71/78 patients. Finally, we found limited myocardial fibrosis in only two/78 patients who had left coronary artery obstruction that had been repaired. cMRI is feasible and gives comprehensive information on coronary artery anatomy and physiology after the arterial switch operation. Use of cMRI as a screening tool for late coronary artery obstruction should be evaluated in larger series of patients to estimate its sensitivity and specificity.

MRI evaluation of coronary anatomy and myocardial perfusion after arterial switch for transposition of great arteries

Coronary arteries obstruction is the main cause of mortality and morbidity in patients who underwent arterial switch for transposition of great arteries. Long-term outcome of coronary transfer and its consequences on myocardial perfusion is scarcely known. To evaluate feasibility of cardiac MRI to describe coronary anatomy, myocardial perfusion and fibrosis after arterial switch operation. 110 patients (mean age 13.5 y) were included. Twenty-five/110 had had previously documented coronary artery obstruction. cMRI protocol included cine SSFP in short axis, two-chamber, three and four chamber view, and perfusion analysis before and after dipyridamole infusion. Anatomy was evaluated by 3D heart sequence in 78 patients. Finally, late enhancement was evaluated ten minutes after injection of contrast agent in 71 patients. Perfusion could be evaluated in all patients. One perfusion defect was identified. All patients with prior negative myocardial ischemia test had normal perfusion on MRI even those with mild to moderate coronary stenosis. Anatomical evaluation of proximal coronary arteries was possible in 71/78 patients. Finally, we found limited myocardial fibrosis in only two/78 patients who had left coronary artery obstruction that had been repaired. cMRI is feasible and gives comprehensive information on coronary artery anatomy and physiology after the arterial switch operation. Use of cMRI as a screening tool for late coronary artery obstruction should be evaluated in larger series of patients to estimate its sensitivity and specificity.

Left Coronary Artery Occlusion After Percutaneous Pulmonary Valve Implantation

Percutaneous pulmonary valve implantation (PPVI) is an attractive option for patients with pulmonary valve insufficiency or stenotic right ventricular outflow tracts. We present the case of a 26-year-old patient in which PPVI was used to treat d-transposition of the great arteries, uncommon coronary artery anatomy, and conduit stenosis that resulted from multiple operations on the right outflow. Days after discharge to home, she experienced acute chest discomfort correlating with ischemia noted on an electrocardiogram and elevated troponin levels. Coronary angiography confirmed mechanical compression of the left anterior descending coronary artery. The valve was removed in an emergency operation and replaced with a biological conduit.

Late coronary complications after arterial switch operation and their treatment

To report the late coronary complications and their treatment after arterial switch operation (ASO). Asymptomatic patients after ASO may have coronary ostial stenosis or obstruction. Since 1980, 279 patients were operated with ASO. At the time of preparing this article, selective follow-up coronary angiograms were done on 81 patients. Coronary stenosis was found in six patients. A 6-year-old patient with left coronary artery (LCA) ostial stenosis and a 9-year-old patient with conus branch occlusion had good collaterals without a need for further treatment. One patient with LCA obstruction, myocardial infarction, and left ventricular failure was operated with osteoplasty at age of 16 years. In three essentially asymptomatic patients, stenting of LCA ostium stenosis was done: in two of them with drug-eluting stents at 9 and 10 years of age and in one with bare-metal stent at 18 years of age. One of these patients was earlier treated with balloon dilatation at 5 years of age which caused intimal dissection. Asymptomatic patients with an uneventful course after ASO may have coronary obstruction. This necessitates follow-up coronary evaluation in all patients. Stenting of the coronary arteries is an option for treatment.

Mild Supravalvular Aortic Stenosis With Left Coronary Obstruction in a Neonate

A premature infant with a large patent ductus arteriosus and mild supravalvular aortic stenosis had evidence of severe myocardial ischemia after ductus ligation. Urgent reoperation was required to relieve severe obstruction of the left coronary orifice and the supravalvular stenosis was repaired. This unusual presentation early in infancy emphasizes that left coronary artery obstruction should be suspected even in the presence of mild supravalvular stenosis.

Complete Left Coronary Artery Obstruction

A case of angiographically documented complete left cornary artery (LCA) obstruction is presented. Complete occlusion of the main LCA is associated with a poor prognosis, and patients with this lesion should be considered for immediate emergency coronary bypass graft surgery.