June 3rd, 2013
How Do Patients with CAD Fare After TAVR?
Sachin Goel discusses his research group’s literature review, published in JACC, focusing on patients with coronary artery disease (CAD) who are evaluated for — and those who undergo — transcatheter aortic valve replacement (TAVR). CardioExchange’s Erica Spatz conducted the interview.
Goel and his research team report that 40% to 75% of patients who undergo TAVR have CAD. They note that the only randomized trial of TAVR (the PARTNER study) excluded patients with untreated, clinically significant CAD requiring revascularization, yet their literature review reveals that 11% to 23% of patients who undergo TAVR have previously undergone percutaneous coronary intervention (PCI). The article identifies patients for whom revascularization should be considered; summarizes the various management options for patients with severe CAD and severe aortic stenosis (AS) who are potential candidates for TAVR; and describes a multidisciplinary team approach to decision making about TAVR.
THE AUTHOR RESPONDS
Spatz: What did you learn in the process of doing this literature review?
Goel: We learned that the effect of CAD on outcomes after TAVR is not well studied. Surgeons have traditionally bypassed all coronary lesions >50% at the time of valve replacement surgery. Among the 11% to 23% of patients who are revascularized percutaneously before undergoing TAVR, outcomes (procedural, short-term, and long-term) are generally good.
Spatz: Revascularization before surgery, including vascular surgery, has never been shown to improve outcomes, yet it seems to be an accepted practice before TAVR. What explains this?
Goel: One of the main concerns while performing TAVR in the presence of unrevascularized, severe proximal coronary stenosis subtending a large area of myocardium is the risk for ischemia and hemodynamic instability during rapid pacing and balloon inflation, both integral parts of the TAVR procedure. Patients with severe AS have reduced myocardial reserve, which is further reduced in the presence of severe CAD, particularly involving proximal epicardial coronary vessels subtending a large area of myocardium. Results from ongoing studies such as PARTNER II, SURTAVI and ACTIVATION will shed more light on which patients with severe CAD need to be revascularized before TAVR.
Spatz: At your institution, how is CAD evaluated in patients being considered for TAVR? How are decisions made regarding revascularization?
Goel: While making decisions about PCI for patients with severe AS and severe CAD who are being evaluated for TAVR, we consider the clinical presentation to be the most important factor. When the clinical presentation is largely secondary to CAD (acute coronary syndrome), then PCI is performed. In terms of process, we use a “heart team” decision-making approach, whereby all patients referred for TAVR are evaluated in a weekly multidisciplinary meeting involving cardiac surgeons, interventional cardiologists, imaging cardiologists, clinical cardiologists, and nurse practitioners. The team reviews each patient’s clinical history, imaging studies such as coronary angiogram, and echocardiography to determine candidacy for surgical AVR versus TAVR. The team also decides whether — and when — to revascularize patients with severe CAD.
Spatz: Your review points to conflicting data about how best to manage CAD in patients undergoing TAVR. How do we make sense of current knowledge for patients who are considering different strategies?
Goel: The conflicting data are partly due to lack of systematic evaluation of the risks and benefits of coronary revascularization in patients undergoing TAVR. The PARTNER trial excluded patients with unrevascularized severe CAD. Ongoing studies should help elucidate the role of revascularization in these patients. Notably, not all patients with severe CAD and AS need to be revascularized before TAVR. Again, the clinical presentation is critical: If a patient presents with symptoms that are largely secondary to CAD, then PCI should be undertaken before TAVR. Otherwise, in cases of stable CAD, we perform PCI only for the small subset of patients who have severe proximal stenoses subtending a large territory of myocardium. CAD that cannot be revascularized is rarely a contraindication for TAVR.
Spatz: What is the most important thing you want readers to take away from your study?
Goel: The most important takeaway is that CAD often coexists with severe AS but that not all severe coronary stenoses need to be treated. The clinical presentation matters most in determining whether patients with severe AS and severe CAD should undergo TAVR. If the clinical presentation is largely related to CAD, revascularization should be considered. In other cases, PCI should be considered only on proximal coronary lesions subtending large areas of myocardium at risk prior to TAVR, pending results from ongoing studies. The multidisciplinary team approach is critical in decision making and achieving good outcomes.
How does your institution handle decision making about TAVR for patients with CAD? Will this new literature review affect how you approach this clinical issue?