Transcatheter Aortic Valve Replacement for Aortic Bioprosthetic Valve Failure With Cardiogenic Shock

Abstract: Acutely failing bioprosthetic valves represent a clinical emergency and are exceedingly challenging given the paucity of therapeutic options. Oftentimes, these patients are not re-operative candidates due to clinical instability. We present 2 cases of acute degenerative aortic bioprosthetic valve failure with cardiogenic shock treated with transcatheter aortic valve replacement (TAVR). These cases were characterized by hemodynamic instability with vasopressor dependence and (multiple) organ failure. These 2 cases demonstrate that TAVR should be considered as a treatment option for unstable patients with bioprosthetic failure. 

J INVASIVE CARDIOL 2013;25(11):625–626

Key words: TAVR, cardiogenic shock

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Transcatheter aortic valve replacement (TAVR) is an established alternative to surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis in patients at high surgical risk, and is considered superior to medical management in patients who are deemed inoperable.¹ Since the introduction of TAVR, several reports have suggested that off-label use of TAVR for failed surgically-inserted bioprosthetic valves (valve-in-valve) is feasible and effective.² However, to our knowledge, there have not been any reports of valve-in-valve TAVR for hemodynamically unstable patients due to acute bioprosthetic valve failure. We present a case series of 2 patients with acute degenerative bioprosthetic aortic valve insufficiency leading to cardiogenic shock with multiple organ failure, who were treated successfully with TAVR. 

Case Reports

Patient 1. A 57-year-old man with past medical history of bicuspid aortic valve s/p bioprosthetic aortic valve replacement in 2001, repair of coarctation of the aorta as a teenager, and hypertension presented to an outside hospital with 1-week history of acutely worsening shortness of breath, as well as nausea and vomiting. He was found to be in acute heart failure with evidence of liver and renal dysfunction and was transferred for higher level of care. Two months prior to admission, a transthoracic echocardiogram (TTE) revealed moderate aortic insufficiency (AI), with preserved left ventricular function (ejection fraction, 60%). A repeat TTE on admission revealed severe AI, decreased ejection fraction to 40%-50% with left ventricular dilation (6 cm), RVSP of ~75 mm Hg suggesting acute on chronic AI. In the 24 hours following admission, the patient’s condition deteriorated with development of cardiogenic shock requiring inotropic support, acute renal failure requiring continuous renal replacement therapy (CRRT), and progressive liver failure. 

He was deemed to be a high-risk candidate for any surgical intervention due to his critical state (logistic EuroSCORE of 56%, EuroSCORE II of 41.1%), re-do sternotomy, and extensive chest wall collaterals from prior coarctation. After careful review by a multidisciplinary team, the patient was considered for valve-in-valve TAVR. He underwent expedited TAVR evaluation with peripheral and coronary angiography immediately prior to valve replacement. Using transesophageal echocardiogram (TEE; Figure 1A) and aortic root angiography, a 26 mm Edwards Sapien was chosen and successfully deployed via transfemoral approach. The pulmonary artery systolic pressure (PAPs) dropped from 75 to 40 mm Hg following intervention. The procedure was complicated by high-grade atrioventricular block requiring permanent pacemaker placement. Follow-up imaging demonstrated no significant residual transvalvular or perivalvular AI (Figure 1B). He was discharged 14 days after the procedure. At 4-month follow-up exam, the patient’s condition was much improved, with minimal heart failure symptoms and restored renal and liver function. 

Patient 2. An 81-year-old man with a history of coronary artery disease and aortic stenosis s/p bioprosthetic aortic valve replacement and 5-vessel coronary artery bypass in 1999 presented to an outside hospital with acute onset of chest pain and shortness of breath. He was diagnosed with an acute non-ST elevation myocardial infarction. Coronary angiogram demonstrated patent bypass graft and severe aortic regurgitation due to degenerative and failing bioprosthesis. This was confirmed by TEE (Figure 1C). The initial ejection fraction was estimated to be 45%. 

Due to his comorbidities, re-do sternotomy, and frailty, he was considered to have prohibitive risk for surgical aortic valve replacement (logistic EuroSCORE of 82.1%, EuroSCORE II of 52.6%) and was transferred to our institution to be considered for TAVR. Within 12 hours from transfer, the patient’s condition quickly deteriorated with refractory hypotension, high-grade atrioventricular block, and asystole. The patient received 20 minutes of cardiopulmonary resuscitation and emergent temporary transvenous pacemaker. Due to his tenuous status and high surgical risk, he was considered for compassion use of TAVR. He also had expedited TAVR evaluation with peripheral angiography immediately prior to procedure. He underwent successful TAVR with a 23 mm Sapien valve via transfemoral approach. Intraoperative TEE demonstrated no valvular AI and trace paravalvular leak. The PAPs dropped from 76 to 34 mm Hg following intervention. Due to persistent high-grade atrioventricular block, a permanent pacemaker was placed. There was resolution of heart failure symptoms (Figure 1D) and the patient was discharged from the hospital 5 days after the procedure. 

Discussion

TAVR has emerged to become an attractive, less invasive treatment option for patients with symptomatic severe aortic valve stenosis. Several case reports, as well as a registry data analysis, have established the value of TAVR in stable patients with native aortic valve regurgitation or failed bioprosthetic valves.^2-4 Patients with hemodynamic instability requiring inotropic therapy or mechanical support devices were excluded in the first major TAVR trials,¹ with only 1 observational study demonstrating high mortality associated with TAVR in cardiogenic shock.⁵ However, our cases demonstrate that TAVR is effective and feasible in patients with degenerative bioprosthetic valve failure who present with cardiogenic shock due to acute aortic regurgitation and with no other therapeutic options. Due to the acuity of the situation and need for a thoughtful yet urgent decision, a multidisciplinary team approach is critical for these patients. With this approach, the evaluation process can be expedited. Many times, patients are too unstable to have the standard imaging needed to evaluate the peripheral vasculature. In this situation, we prefer evaluating the iliac and common femoral arteries using peripheral angiography under fluoroscopy at the time of the TAVR. The size of the existing bioprosthetic valve provides the dimensions necessary for appropriate valve sizing, obviating the need for additional annulus imaging. 

Acutely failing bioprosthetic valves represent a clinical emergency and are exceedingly challenging given the paucity of therapeutic options. Often, these patients are not re-operative candidates due to clinical instability. These 2 cases demonstrate that TAVR should be considered as a treatment option in carefully selected high-risk patients with no other options. However, we do recognize that due to differences in pathology, etiology, and patient comorbidities, cardiogenic shock in the presence of acute AI might not be predictive of TAVR outcomes for cardiogenic shock in the presence of aortic stenosis. Further studies are needed to further elucidate this point, as well as the long-term outcomes in this patient population. 

References

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