Treatment of Severe Regurgitation of Stentless Aortic Valve Prosthesis with a Self-Expandable Biological Valve

From the Division of Cardiology, Ferrarotto Hospital, University of Catania, Italy. Disclosure: Dr. Gian Paolo Ussia is a proctor for CoreValve Inc. None of the other authors report any conflicts of interest regarding the content herein. Manuscript submitted September 10, 2008, provisional acceptance given October 29, 2008, and final version accepted November 3, 2008. Address for correspondence: Gian Paolo Ussia MD FSCAI, Director of Interventional Structural and Congenital Heart Disease Programme, Invasive Cardiology, Division of Cardiology – Ferrarotto Hospital, University of Catania, Catania, Italy. E-mail: gpussia@hotmail.com

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ABSTRACT: Percutaneous valvular replacement in aortic stenosis is an emerging alternative therapy for high-risk patients. Initial experience suggests that outcomes compare favorably with conventional valve surgery in selected patients with comorbidities such as advanced age. Although the current devices are approved for stenotic native valves, percutaneous approaches to treat degenerated aortic bioprostheses have been reported. Here we describe the case of an 85-year-old female with severe regurgitation of a stentless biological prosthesis treated using the third-generation of CoreValve Revalving System™.

J INVASIVE CARDIOL 2009;21:E51–E54

Key words: aortic regurgitation, percutaneous, bioprosthesis

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Degenerative aortic valve stenosis (AVS) is the most common valvular heart disease in the elderly. Surgical aortic valve replacement (SAVR) is a time-honored technique that has produced excellent results.¹ A recent Survey, which investigated the adherence to the current guidelines on the management of severe AVS, showed that more than 30% of patients directed towards surgical AVR did not undergo intervention because advanced age and/or comorbid conditions.² Since the first-in-man implantation in 2002,3 percutaneous aortic valve replacement (PAVR) is emerging as a safe and effective alternative technique to surgery for severe AVS treatment in patients judged to be poor candidates for surgery because of very high procedural risk.^4–6 The current indications for percutaneous valve implantation were recently described by the European Societies of Cardiology and Cardiosurgery.⁷ Two PAVR systems are currently available in Europe with CE mark approval: the Edwards-Sapien™ steinless steel balloon-expandable bovine valve (Edwards Lifesciences, Irvine, California); and the self-expandable CoreValve™ 18 Fr prosthesis (CoreValve, Inc., Irvine, California). These devices are approved for treatment of severe AVS, but percutaneous valve replacement to treat severe regurgitation of a biological prosthesis has been described.^8–10 Here we report on a case of PAVR using the 18 Fr CoreValve Revalving System. Case Report. An 85-year-old female patient was referred to our center for angina pectoris (Canadian Cardiovascular Society Classification Grade 3) and severe dyspnea and was in New York Heart Association (NYHA) Functional Class IV. She had a history of rheumatic fever in childhood and in 1996 underwent mitral commissurotomy and SAVR for severe AVS with a Biocor 21 stentless biological prosthesis (St. Jude Medical, St. Paul, Minnesota). In the past year she experienced deterioration of her functional capacity with several in-hospital admissions for heart failure and a history of fever 6 months previously. Physical examination revealed a diastolic murmur due to aortic regurgitation, pulmonary rales and high blood pressure (170/90 mmHg). Her creatinine clearance was 48.9 ml/minute and the electrocardiogram showed normal sinus rhythm and subendocardial ischemia in the anterior precordial leads. A chest X-ray showed pulmonary congestion and an enlarged cardiac silhouette. Transthoracic echocardiography (TTE) revealed severe aortic regurgitation with a mean transvalvular gradient of 28 mmHg and an enlarged left ventricle with preserved systolic left ventricular function (left ventricular ejection fraction 56%) (Table 1). Right-heart catheterization showed moderate pulmonary hypertension (pulmonary artery systolic pressure [PAPs]/d/m 75/20/35 mmHg, pulmonary capillary wedge pressure [PWCP] 18 mmHg), with low cardiac output measured with the Fick method (CO 2.6 L/minute). Coronary angiography showed a 70% of the left anterior descending (LAD) artery, confirmed severe aortic regurgitation (Figure 1), and both the iliac and femoral arteries were found to have a diameter of 9 mm and 8 mm, respectively. The patient had a Logistic EuroScore of 44.64% and was considered a high-risk candidate for reoperation. She was therefore proposed for PAVR. The procedure was proposed and approved for compassionate use by the local institutional ethics committee. After informed consent was obtained, the procedure was performed under local anesthesia. Using the left femoral artery, percutaneous coronary angioplasty of the LAD was performed and a tacrolimus-eluting stent was placed. Then the contralateral artery was cannulated with a 9 Fr introducer and vascular sutures were preimplanted with a Prostar® XL 10 Fr device (Abbott Vascular Devices, Redwood City, California). A temporary pacemaker (PM) was placed in the right ventricle via the left femoral vein and a 7 Fr Pigtail catheter was positioned just above the aortic valve. Once the bioprosthesis was crossed with an Amplatz Left 7 Fr catheter, an Amplatz Super Stiff exchange guidewire was positioned in the left ventricle, and the 9 Fr sheath was replaced with the 18 Fr introducer. Using the Pigtail as a marker, a 26 mm CoreValve prosthesis was positioned across the degenerated bioprosthesis valve with the help of repeated aortography (Figure 2). The inflow part of the device was released during right ventricular pacing at 180 bpm to achieve a more stable position of the valve. Once the new bioprosthetic valve was deployed, aortography showed a 3+ paravalvular leak caused by hypoexpansion of the prosthesis just at the level of the stentless valve, therefore, postdilatation with a 25 mm x 40 mm Nucleus Balloon (NuMed, Inc., Hopkinton, New York) was performed to optimize the expansion (Figure 3). The final aortogram showed a 2+ paravalvular leak with no hemodynamic compromise and optimal device placement; moreover, right catheterization showed an increase in cardiac output (CO) (post- implantation CO 4.1 L/minute). The femoral artery access sites were closed using percutaneous arterial closure systems: the right with the preimplanted suture wires, and the left with the Perclose 6 Fr (Abbott Vascular Devices). The procedure and fluoroscopy times were 47 and 13 minutes, respectively. After 24 hours, the temporary PM was removed and TTE confirmed good positioning of the device, the persistence of a 2+ paravalvular leak, mild mitral stenosis and regurgitation (Figure 4) and an echocardiographic PAPs of 45 mmHg. The patient was discharged after 10 days of hospitalization in NYHA Functional Class I on clopidogrel 75 mg daily for 3months and aspirin 100 mg daily indefinitely. Two months after the procedure, the patient was asymptomatic (NYHA Class I) and echocardiography showed a reduction of the paraprosthetic leak with a peak transvalvular gradient of 15 mmHg and preserved functionality of the left ventricle (LVEF 55%). Discussion. The currently available results obtained with PAVR suggest that this technique is feasible and provides hemodynamic and clinical improvement^4–6 in patients with severe symptomatic AVS at high risk for surgery. In a recent paper, Piazza⁶ reported the results of PAVR using the CoreValve prosthesis in 676 patients (mean age 81 ± 6.6 years) at high risk for cardiac surgery with a mean logistic EuroSCORE of 23.1 ± 13.8%. Procedural success was 97%, the mean aortic valve gradient decreased from 49.4 ± 13.9 to 3 ± 2 mmHg, procedural mortality was 1.5% and the 30-day all-cause mortality rate was 8%. The most frequent complication was complete AV block which occurred in 9.3% of cases treated uneventfully with permanent PM implantation. Other cardiovascular events such as stroke, cardiac tamponade, myocardial infarction and coronary artery flow impairment due to prosthesis implantation occurred in less than 2% of all patients. Despite these good results, PAVR is actually recommended only for elderly patients at high risk of surgery,⁷ the reasons are the short follow-up period and lack of information on the long-term performance and durability of the percutaneous valve. Because the devices available are approved only for aortic valve stenosis treatment, there are very few case reports on the treatment of aortic regurgitation secondary to a degenerated aortic bioprosthesis.^8–10 The case presented here involves a patient with severe bioprosthesis dysfunction for subacute endocarditis and the consequent severe aortic regurgitation whose clinical picture was complicated by residual mild mitral stenosis and LAD stenosis. The surgical risk for redo was very elevated due to age, the heart failure, the NYHA Class 3, chronic renal insufficiency and pulmonary hypertension. In terms of the standard technique for CoreValve implantation, we faced several challenges: a) whether to perform balloon valvuloplasty before device implantation; b) the lack of annulus calcification which usually helps to correctly position the valve; c) the necessity to reduce the patient’s left ventricular systolic pressure for a more stable position of the valve in the initial deployment phase. Standard balloon valvuloplasty before the implantation of the device was not performed because the consistency of the biological leaflets was not known poor and the possibility of fragment mobilization was too high. We didn’t have any radiopaque marker for helping us in the positioning of the device. Usually the severe aortic valve calcifications or the radiopaque prosthetic ring¹⁰ are used as useful landmarks. The Biocor stentless prosthesis is completely invisible at fluoroscopy, therefore we used the pig tail tip just above the valve and frequent aortograms. The standard technique of PAVR with CoreValve prosthesis use the right ventricular pacing only during aortic valvuloplasty, In this case it was necessary a 15 seconds burst at 180 bpm, during the valve release for reducing the systolic left ventricle pressure. sufficient for expose the inflow part of the nitinol frame of the prosthesis. After prosthesis implantation, a 3+ paravalvular leak was present, the mechanism was hypoexpansion of the nitinol frame in correspondence of the left coronary cusp. This was predictable because the standard balloon valvuloplasty was not performed, but the leak was managed efficaciously with a post-dilation using a Nucleus 25 x 40 mm balloon (NuMed Inc, Hopkinton, New York) positioned with the waist just in correspondence of the valve. Conclusion. To our knowledge, this is the first case reported of PAVR in an insufficient stentless valve secondary to subacute endocarditis associated with PCI of the LAD in the same session. The procedure described here required a different implantation technique due to the patient’s severe aortic regurgitation. The patient’s hemodynamic and clinical outcomes at 60 days were very satisfactory. The case described here, together with previous reports,¹⁰ show the feasibility and safety of PAVR to treat degenerated bioprostheses using both the CoreValve and the Edwards-Sapien devices. The opportunity to avoid reoperation and anticoagulant therapy and, moreover, to increase the use of surgical bioprostheses rather than mechanical prostheses — even in younger subjects — will be decisive for the clinical development of this approach.

References

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