Ambarish Gopal

Epidemiology, Traditional and Novel Risk Factors in Coronary Artery Disease

Coronary artery disease (CAD) mortality has been declining in the United States and in regions where health care systems are relatively advanced. Still, CAD remains the number one cause of death in both men and women in the United States, and coronary events have increased in women. Many traditional risk factors for CAD are related to lifestyle, and preventative treatment can be tailored to modifying specific factors. Novel risk factors also may contribute to CAD. Finally, as the risk for CAD is largely understood to be inherited, further genetic testing should play a role in preventative treatment of the disease.

Evaluating paravalvular leak after TAVR

Aortic regurgitation (AR) after transcatheter aortic valve replacement (TAVR) has been associated with significant adverse outcomes;1–4 therefore, its assessment is clinically important. The most common cause of AR post-TAVR is paravalvular leak (PVL), which occurs if the valve is undersized; annulus geometry is markedly elliptical or the prosthetic valve does not seat properly against the native valve tissue due to excessive calcium or malpositioning. The second Valve Academic Research Consortium-2 (VARC-2) gives recommendations for grading the severity of PVL5 but these are based on expert consensus and not empirically-derived data. Two papers attempt to address the difficult and clinically vexing problem of how to grade the severity of PVL after TAVR.6 ,7 Both studies compare transthoracic echocardiography (TTE) with cardiac MRI (CMR) for grading severity of PVL. Both pertain to balloon-expandable valves (Sapien, Sapien XT, Sapien 3, Edwards Lifesciences, Irvine, California, USA) using both transfemoral and transapical approaches. Both used a similar methodology for CMR quantitation of regurgitant fraction (RF) and regurgitant volume (RV) by phase contrast imaging. Orwat et al 6 compared TTE grading with quantitative flow measurement by CMR with calculation of RF for the assessment of AR. CMR was completed in 59 of 65 consecutive patients a median of 69 days post-TAVR, with both TTE and CMR being done on the same day. TTE grading of PVL as none, mild, moderate or severe was done subjectively by incorporating circumferential extent of the AR jet origin in a short-axis view, jet width in a long-axis …

Implantation of Transcatheter Aortic Prosthesis in 3 Patients With Mitral Annular Calcification

Mitral annular calcification (MAC) is a chronic degenerative process at the fibrous base of the mitral valve. It is a feared diagnosis in the context of mitral valve operations because of the risk of severe adverse events such as atrioventricular disruption, injury to the circumflex artery during debridement, and difficult placement of annular sutures. We report a series of 3 consecutive female patients with severe circular MAC who underwent successful mitral valve replacement through a lateral minithoracotomy with use of an inverted transcatheter aortic valve.

Clinical Leaflet Thrombosis in Transcatheter and Surgical Bioprosthetic Aortic Valves by 4DCT

BACKGROUND The incidence of leaflet thrombosis after transcatheter aortic valve replacement (TAVR) with active surveillance by four-dimensional computed tomography (4DCT) ranges from 7% to 14%. The incidence of leaflet thrombosis when 4DCT is performed for clinical and echocardiographic indications is unknown. METHODS All patients with prior TAVR or surgical aortic valve replacement (SAVR) who underwent evaluation between October 2015 and January 2017 at our institution and had clinical or echocardiographic indications of leaflet thrombosis were evaluated by 4DCT. Indications for 4DCT by echocardiography included (1) interval increase in mean gradient of 10 mm Hg or more, (2) interval decrease in ejection fraction of 10% or more, (3) thrombus seen on transthoracic echocardiography, (4) persistent or increasing paravalvular leak, or (5) valve dehiscence or thickened leaflets seen on transthoracic echocardiography. Clinical indicators were (1) stroke, (2) transient ischemic attack, or (3) new or worsening heart failure. RESULTS During the study period, 612 patients underwent TAVR, and 101 patients (55 TAVR; 46 SAVR) met the criteria for 4DCT imaging. Leaflet thrombosis was seen in 17 of 55 TAVR patients (30.9%) and 15 of 46 SAVR patients (32.6%). Follow-up imaging with 4DCT after treatment with anticoagulation showed improvement or resolution in thrombus burden and leaflet excursion in all TAVR patients and in two-thirds of SAVR patients. CONCLUSIONS One-third of patients with clinical or echocardiographic indications suggestive of leaflet thrombosis were found to have evidence of leaflet thrombosis using 4DCT. This allowed tailored anticoagulation therapy with resolution of the thrombus in most patients and avoiding unnecessary anticoagulation in the remaining two-thirds of patients.

Anomalous Coronary Arteries in TAVR Patients: Anatomic Considerations for Pre-Procedural Planning

Anomalous coronary arteries are reported to occur in 0.2– 2.3% of patients undergoing imaging or pathology studies The condition is usually benign and mostly encountered incidentally during coronary angiography, computed tomography or autopsy. Transcatheter aortic valve replacement (TAVR) is now routinely used in patients with aortic stenosis. Most patients undergoing TAVR have 3-dimensional reconstructed computed tomograms (3D CT) as part of pre-procedural planning and anomalous coronary artery anatomy is encountered not infrequently (Figures 1–6). Coronary artery obstruction during and after TAVR procedure can occur in 0.5–1% of individuals. One cause of coronary compromise during TAVR can be compression of an anomalous coronary

Validation of a low-dose contrast 64-slice cardiac computed tomography angiography protocol for aortic valve annulus sizing

Abstract Cardiac computed tomography angiography (CCTA) is the gold standard for accurately sizing the aortic valve annulus prior to aortic valve replacement. A reduction of contrast volume administered for CCTA, without sacrificing image quality, is desirable. Signal-to-noise ratio represents final CCTA image quality. Consecutive patients referred to CCTA for aortic valve annulus sizing were retrospectively analyzed. Patients were grouped into a low-dose contrast (LDCT) group and traditional dose contrast (TDCT) group. In the LDCT group, contrast dose was <50% of the maximal allowable dose (3.7 × estimated glomerular filtration rate). Guided by a time-density curve, the contrast was administered in a two-stage infusion, and retrospectively gated images were acquired with a 64-multidetector computed tomography scanner. Out of 123 patients (age 80 ± 9 years; 46% female), 65 (52.9%) underwent LDCT and 58 (47.2%) underwent TDCT. Contrast volume was significantly lower in the LDCT group (LDCT 41.2 ± 9.8 vs TDCT 76.2 ± 14.2 mL; P < 0.001). The signal-to-noise ratio of the aortic root was 10.4 ± 4.1 for the LDCT group and 8.4 ± 3.3 for the TDCT group (P = 0.004). Aortic root dimensions could be measured in both LDCT and TDCT groups. In conclusion, LDCT with 64-slice CCTA can effectively size the aortic valve annulus to direct aortic valve replacement while offering reduced contrast exposure.

INCIDENCE OF VALVE LEAFLET THROMBOSIS IN TRANSCATHETER AND SURGICAL BIOPROSTHETIC AORTIC VALVES BY 4D CT IMAGING

Background: The incidence of valve thrombosis after transcatheter aortic valve replacement (TAVR) and surgical AVR (SAVR) when referred for clinical and echocardiographic indications, as well as response to anticoagulation is unknown. Methods: Between 11/2015 and 10/2016, all patients with clinical

Pathologic confirmation of valve thrombosis detected by four-dimensional computed tomography following valve-in-valve transcatheter aortic valve replacement

A major concern regarding transcatheter aortic valve replacement (TAVR) is leaflet thrombosis. Four-dimensional computed tomography (4D-CT) is the preferred imaging modality to evaluate patients with suspected valve thrombosis. To date, the abnormal findings visualized by 4D-CT suggestive of leaflet thrombosis have lacked pathologic confirmation from a surgically explanted valve in a surviving patient. Herein, we provide pathologic confirmation of thrombus formation following surgical explantation of a thrombosed TAVR prosthesis that was initially identified by 4D-CT.