For severe symptomatic aortic stenosis (AS), transcatheter aortic valve replacement (TAVR) is preferred over surgical aortic valve replacement (SAVR) in inoperable patients and is an alternative in high-surgical-risk patients.¹ By the end of 2015, more than 200,000 implants have been performed worldwide, and it is projected that procedural volume will continue to increase.

The prevalence of coronary artery disease (CAD) in TAVR patients ranges from 40 to 75%, and a significant number undergo revascularization before TAVR.² Current guidelines recommend myocardial revascularization for significant CAD (≥70% reduction in luminal diameter in major coronary arteries or ≥50% reduction in luminal diameter in the left main coronary artery) for patients undergoing SAVR or TAVR (percutaneous coronary intervention [PCI] for those undergoing TAVR and coronary artery bypass grafting [CABG] for those undergoing SAVR).¹ However, there are no randomized control trials that support myocardial revascularization in all patients with asymptomatic CAD. The data for combined CABG and valve surgery do not show consistent benefit² and are from an era before the widespread use of fractional flow reserve (FFR) and scores to stratify CAD complexity (for example, the SYNTAX score¹).

The incidence of myocardial infarction with TAVR is generally very low because all the pivotal TAVR trials excluded patients with significant unrevascularized CAD.³ A few small studies have looked at the impact of CAD on TAVR outcomes but have not shown a consistent poor outcome with increased CAD burden.² Most of these studies were limited by small numbers, patients having undergone PCI before TAVR, and an inconsistent definition of CAD. Obviously, there is considerable variability in the definition of "significant CAD," which is a combination of physiologically significant lesions and associated anatomic complexity. This lack of data and variable patient characteristics make it difficult to predict outcomes in this patient population.

Routine revascularization for stable CAD (excluding patients with acute coronary syndromes) is not without controversy.⁴ In general, excluding patients with significant left main or three-vessel CAD, revascularization of stable CAD with PCI provides greater angina relief compared with optimal medical therapy but does not reduce mortality, repeat revascularization, or nonfatal myocardial infarction.⁵ In addition, revascularization with PCI in the presence of ischemia is superior to medical therapy.^6,7 Current guidelines recommend revascularization for left main, three-vessel CAD, or proximal left anterior descending artery disease using a Heart Team approach along with physiologic significance data (using FFR) and anatomic complexity assessment with the SYNTAX score.⁸

Unfortunately, all the trial and guidelines data exclude patients with significant valvular disease needing repair or replacement. Therefore, these recommendations may not be broadly applicable to the TAVR population. Small studies have suggested that selective revascularization in the TAVR population is safe.^9,10 The use of angina symptoms in these patients is problematic because symptomatic AS may be difficult to differentiate from symptomatic CAD. However, with FFR, hemodynamically significant lesions may be selectively treated with PCI. TAVR can cause hemodynamic instability due to procedural factors (rapid pacing, balloon inflation, left ventricular outflow tract obstruction from the delivery catheter, and hypotension from anesthesia), and the presence of physiologically significant CAD with a high ischemic burden, especially with diminished left ventricular function, can adversely affect patient outcomes. In addition, the transcatheter heart valve struts can interfere with access to native coronary arteries and make future PCI difficult.

Given a lack of evidence-based data in the TAVR population currently, we propose PCI for coronary lesions supplying a large myocardial territory, guided by FFR and symptoms (Figure 1). This strategy would exclude patients without ischemia or angina. PCI in patients with severe AS had comparable outcomes to propensity-matched controls, but the mortality was three-fold higher in the highest-risk patients (those with Society of Thoracic Surgeons score >10% and left ventricular ejection fraction <30%).² The optimal timing of PCI is either before or during TAVR, and small studies have shown advantages of both approaches.² The choice of the type of stent used (drug eluting or bare metal) depends on the patient's bleeding risk and TAVR approach (transfemoral or nontransfemoral). When available, data from the ACTIVATION (Percutaneous Coronary Intervention Prior to Transcatheter Aortic Valve Implantation: a Randomised Controlled Trial), SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation), and PARTNER II (Placement of Aortic Transcatheter Valves) trials will provide more guidance for the optimal management of CAD in this complex patient population.

Figure 1

References

1. Nishimura RA, Otto CM, Bonow RO, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63:e57-185.
2. Goel SS, Ige M, Tuzcu EM, et al. Severe aortic stenosis and coronary artery disease--implications for management in the transcatheter aortic valve replacement era: a comprehensive review. J Am Coll Cardiol 2013;62:1-10.
3. Smith CR, Leon MB, Mack MJ, et al. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med 2011;364:2187-98.
4. Sedlis SP, Hartigan PM, Teo KK, et al. Effect of PCI on Long-Term Survival in Patients with Stable Ischemic Heart Disease. N Engl J Med 2015;373:1937-46.
5. Pursnani S, Korley F, Gopaul R, et al. Percutaneous coronary intervention versus optimal medical therapy in stable coronary artery disease: a systematic review and meta-analysis of randomized clinical trials. Circ Cardiovasc Interv 2012;5:476-90.
6. De Bruyne B, Pijls NH, Kalesan B, et al. Fractional flow reserve-guided PCI versus medical therapy in stable coronary disease. N Engl J Med 2012;367:991-1001.
7. De Bruyne B, Fearon WF, Pijls NH, et al. Fractional flow reserve-guided PCI for stable coronary artery disease. N Engl J Med 2014;371:1208-17.
8. Levine GN, Bates ER, Blankenship JC, et al. 2011 ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Society for Cardiovascular Angiography and Interventions. Circulation 2011;124:e574-651.
9. Gasparetto V, Fraccaro C, Tarantini C, et al. Safety and effectiveness of a selective strategy for coronary artery revascularization before transcatheter aortic valve implantation. Catheter Cardiovasc Interv 2013;81:376-83.
10. Van Mieghem NM, van der Boon RM, Faqiri E, et al. Complete revascularization is not a prerequisite for success in current transcatheter aortic valve implantation practice. JACC Cardiovasc Interv 2013;6:867-75.

Keywords: Acute Coronary Syndrome, Anesthesia, Angina Pectoris, Aortic Valve, Aortic Valve Stenosis, Coronary Artery Bypass, Coronary Artery Disease, Hypotension, Myocardial Infarction, Myocardial Revascularization, Percutaneous Coronary Intervention, Prevalence, Stents, Stroke Volume, Surgeons, Transcatheter Aortic Valve Replacement, Ventricular Function, Left, Angina, Stable

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