Coronary Angioplasty After Self-Expandable Transcatheter Aortic Valve Implantation

Abstract: Aortic stenosis and coronary artery disease share comorbidities/risk factors; thus, it is not surprising they occur concomitantly. With increased life expectancy of patients who undergo transcatheter aortic valve implantation (TAVI), the rate of post-TAVI percutaneous coronary intervention (PCI) is expected to rise. In the current report, we present two cases using PCI following CoreValve (Medtronic) implantation. Our cases indicated that the procedure is feasible and safe, but requires careful planning and understanding of the three-dimensional geometry of the prosthetic valve and its relation to the coronary ostia. 

J INVASIVE CARDIOL 2013;25(7):361-363

Key words:nbsp;TAVI, percutaneous coronary intervention

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Aortic stenosis (AS) commonly occurs concomitantly with coronary artery disease (CAD).^1-4nbsp;In surgery, patients with combined severe symptomatic AS and CAD are undergoing aortic valve replacement accompanied by coronary artery bypass grafting (CABG). Due to recent advancements, patients who are at high surgical risk can undergo transcatheter aortic valve implantation (TAVI) procedures.⁵nbsp;Coronary angiography is a prerequisite for evaluating patients who are candidates for TAVI. Nonetheless, the need for pre-TAVI percutaneous coronary intervention (PCI) remains uncertain for preexisting lesions. It seems that there is a higher 30-day and overall mortality rate after TAVI in patients with CAD versus those without CAD.⁶ Aortography and coronary angiography are required both for measurement purposes (potential prosthetic valve position relative to the coronary artery origins) and for demonstrating the coronary anatomy. In the current doctrine, PCI is performed prior to TAVI in most cases, both for distinguishing symptom origin (valve disease versus CAD), and for the reduction of the ischemic risk during and following the procedure. Of note, the metal struts surrounding the valve can potentially alter the access to the source of the coronary arteries. Thus, future PCI could be disturbed and/or become technically challenging, especially after using the self-expandable CoreValve device (Medtronic), which completely covers the aortic root. Sporadic descriptions of PCIs performed following CoreValve implantation have already been reported.^7-10nbsp;We report herein two cases of PCI late following CoreValve TAVI procedures.

Case 1

A 75-year-old male with a history of CAD, who suffered a myocardial infarction and underwent CABG 17 years ago, underwent TAVI and implantation of the 29 mm CoreValve device due to severe symptomatic AS. He was considered at high risk for surgical intervention due tocomorbid diseases and calcified aorta. Two months prior to TAVI, he underwent diagnostic coronary angiography, which revealed patent bypass grafts and native vessels that did not require any further intervention. Ten months after TAVI, the patient complained of effort angina and underwent a stress echocardiography that revealed mild reduction in the systolic function of the left ventricle (LV) with lateral regional wall-motion abnormality. Coronary angiography revealed a 70% diameter ostial stenosis of the first obtuse marginal coronary branch (OM1) (Figure1A). The left main (LM) artery was engaged via the valve struts using a 6 Fr FL 4.0 guiding catheter (Medtronic), introduced via the left femoral approach. A Balance Middle Weight (BMW) 0.014˝ guidewire (Abbott Vascular) was delivered down the OM branch. After predilatation using a 2.5 x 12 mm Maverick balloon (Boston Scientific), a 2.75 x 12 mm Xience Prime drug-eluting stent (Abbott Vascular) was deployed (Figure 1B). A good angiographic result was obtained without complications (Figure 1C). Eight months after the PCI, the patient was symptom free and hada good functional capacity.

Case 2

A 65-year-old male with a history of CABG 10 years ago and multiple comorbidities underwent TAVI using the 29 mm Core-Valve device due to severe symptomatic AS and being considered high risk for open heart surgery. Six months prior to the procedure, he underwent coronary angiography that revealed patent bypass grafts and was treated conservatively. The TAVI procedure was undertaken without complications. Two months after TAVI, he complained of shortness of breath and chest discomfort. Echocardiography demonstrated preserved LV systolic function with minimal gradient over the implanted aortic valve (peak gradient, 9 mm Hg; mean gradient, 5 mm Hg). He underwent a nuclear scan that demonstrated extensive ischemia in the left circumflex (LCX) coronary artery territory. Angiography revealed a new 90% narrowing of the proximal native LCX (that did not receive a graft) that was not identified prior to the TAVI procedure (Figure 2A). A 6 Fr FL 4 guiding catheter was introduced via left radial approach, and was usedfor selective engagement of the LM coronary artery. A Whisper 0.014˝ guidewire (Abbott Vascular) was introduced via the valve struts, down the LCX. The guidewire delivery was used to stabilize the guiding catheter. After predilatation with a 1.5 x 8 mm Maverick balloon (Boston Scientific), a 2.75 x 14 mm Endeavor Resolute drug-eluting stent (Medtronic) was deployed in the proximal section of the artery (Figure 2B). Due to residual narrowing distal to the first stent, a 2.5 x 9 mm ProKinetic stent (Biotronik) was deployed. The final angiographic result was optimal (Figure 2C). Fifteen months later, the patient’s functional status remained markedly improved. 

Discussion

TAVI is a continuously evolving substitution for surgical aortic valve replacement (AVR) in high-risk AS patients. Patients who are candidates for TAVI are either too sick or too old to undergoing surgical AVR. Many of these patients also sustain a significant CAD. The current paradigm is that PCI should be performed prior to TAVI to minimize myocardial ischemia and also to allow for increased coronary flow following the procedure.¹¹ However, with growing TAVI experience, some patients may need PCI following valve implantation. This is especially valid for  patients who undergo valve-in-valve procedures (percutaneous implantation of a prosthesis within a previously implanted, degenerative bioprosthetic valve), a procedure associated with a high rate of coronary obstruction requiring intervention.¹² Notwithstanding, performing PCI after TAVI may be complex and challenging. Some prostheses are designed to be positioned below the coronary ostia, and others, such as the CoreValve device, are designed to extend below and above the coronary ostia. Still, its geometrical design aims to “protect” the coronary ostia. The concavity (“waist”) of the central portion of the frame and its open-cell configuration attempt to avoid the coronary ostia and allow its future intubation, respectively (Figure 3). Nevertheless, since the currently used imaging modality does not provide the spatial and temporal resolutions that reveal the position of the frame struts relative to the coronary ostia, the valve may be deployed in a way that the struts might overlie the ostia, imposing an additional hurdle to the procedure. In those circumstances and according to our experience, the best way to perform a subsequent PCI is to cross the valve-stent struts using a relatively short or even longer tipped catheter, thereafter to selectively channel a way through the coronary ostia via the diamond-shaped cells, in an attempt not to damage the CoreValve nitinol frame and/or the delicate valve leaflets (Figure 3). The alternative approach would be to use a back-up guide (eg, an extra back-up catheter) to engage the coronary completely. Although the procedures highlighted above ended successfully without complications, performing PCI after TAVI is not trivial and requires a high level of expertise and careful planning to assure success. Finally, we think that the access approach for coronary angiography and/or PCI could be via either femoral or radial approaches, with a preference for left over right radial catheterization in order to minimize negotiation within the aortic stent and the valve leaflets.

Conclusion

Post-TAVI PCI is feasible and safe; its frequency is expected to rise. Crossing through a CoreValve bioprostheses is challenging, since it requires comprehension of its three-dimensional geometry and its relation to the coronary ostia, despite the usage of a two-dimensional imaging modality. 

References

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From the Rabin Medical Center, Cardiology, Petach-Tikva, Israel. 

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted November 3, 2012 and final version accepted November 8, 2012.

Address for correspondence: Ran Kornowski, MD, Rabin Medical Center, Cardiology, Jabutinski Street 39, Petah-Tikva, Israel 49100. Email: rkornowski@clalit.org.il