An 84-year-old male patient presented with the following medical history: ischemic cardiomyopathy with a left ventricular ejection fraction of 35% on recent echocardiogram, automatic implanted cardioverter-defibrillator, chronic kidney disease (stage II), World Health Organization category II pulmonary hypertension, and prior coronary artery bypass graft surgery, and bioprosthetic surgical aortic valve replacement (for aortic stenosis). In the past several weeks, the patient has had progressive shortness of breath, lower extremity edema, and decreased exercise tolerance. After seeing his primary cardiologist, he was sent to the emergency department where he was found to have elevated B-type natriuretic peptide levels, and creatinine of 4.0 mg/dL. After an initial trial of diuretics, dobutamine-assisted diuresis was initiated. Transthoracic echocardiography showed severe bioprosthetic aortic regurgitation and a left ventricular ejection fraction of 20%. The patient was evaluated by the cardiothoracic surgery team and deemed to be high risk for re-operative valve replacement with a Society of Thoracic Surgeons score of 12%.
Based on the echocardiographic images, what should be the next best step in managing this patient?
The correct answer is: C. Valve-in-valve transcatheter aortic valve replacement
Assessing the etiology of regurgitation in surgical bioprosthetic aortic valves is challenging. Acoustic shadowing and the eccentric nature of the regurgitant jets often mask the true origin (i.e., intravalvular vs. paravalvular regurgitation). As such, perceived erroneous origin may lead to inaccurate diagnosis. Video 1 shows significant bioprosthetic aortic valve regurgitation without a clear origin of the jet. Video 2 reveals an anterior regurgitant jet that appears to be paravalvular in origin; however, the exact point of origin is not well seen. If one takes a closer look, a hint of a central regurgitant jet can be seen at the level of the aortic valve leaflet tips. Further, an acoustic shadow can be appreciated that divides the anteriorly directed eccentric central jet into two parts. Videos 3 and 4 show further imaging from an apical 5-chamber view, which confirms the suspicion that there is degenerative leaflet disease producing central regurgitation. Indeed, after a valve-in-valve transcatheter aortic valve replacement, the central regurgitation is completely eliminated (Video 5). Given the different transcatheter treatment approaches to intravalvular vs. paravalvular regurgitation, the exact origin of the jet must be reviewed carefully, keeping in mind that the perceived origin might not accurately elucidate the etiology (in this case, eccentric intravalvular regurgitation masquerading as paravalvular regurgitation). Given the high Society of Thoracic Surgeons score and low ejection fraction, the preferable approach would likely be transcatheter rather than surgical. Although perhaps not needed in every case, there should be a very low threshold to obtain a pre-procedure transesophageal echocardiogram if there is any question regarding the presence of paravalvular leak around the surgical prosthesis because this will not be fixed with a valve-in-valve procedure.