Transcatheter Aortic Valve Replacement Without On-Site Cardiac Surgery: A Disappointing Step Backward!^∗Free Access

Introduction

Transcatheter aortic valve replacement (TAVR) is clearly a disruptive therapy that has resulted in the treatment of >100,000 patients with aortic stenosis (AS) worldwide over the past 12 years. The method of introduction of TAVR by the heart team approach into the clinical arena where an excellent therapeutic option, surgical aortic valve replacement (SAVR), already existed was also disruptive. There are many reasons why the adoption of TAVR by the clinical community has been so successful including innovative devices and delivery systems, advanced training of clinicians and clinical sites, a robust evidence base documenting benefit and the cooperative approach between medical specialists by the formation of multidisciplinary heart teams (MDHTs). This heart team approach to care that includes shared decision making with patients and their families has provided a balanced approach to care delivery in which all treatment options are discussed and embraced. The heart team approach has now become the standard of care and is a Class I recommendation in both American and European guidelines (2,3). The engagement of the MDHT has largely mitigated the “turf battles” between interventional cardiologists and cardiac surgeons in the treatment of coronary artery disease (CAD) that existed in the 1990s and 2000s, and created “siloes” of care.

The heart team approach was especially important in the early years of TAVR when treating inoperable and high surgical risk patients. Now that the TAVR has become the preferred approach in these patient population as well as the intermediate surgical risk population, the role of the heart team in the minds of many has seemingly become less important. There are those who question the ongoing need for the heart team approach and want to regress to the way the treatment of CAD was rendered. To their point, in the majority of patients who present with AS, clinical decision making has become fairly straightforward. However, even in situations in which TAVR may be the preferred approach, there are multiple local anatomic issues that may make SAVR the better option. MDHT discussions of these patients often leads to better informed decision making. Furthermore, with the impending outcomes of randomized trials in younger, lower-risk patients, it is reasonable to assume that the role of the heart team will once again become more critical.

This background is important when analyzing the study by Eggers et al. (4) published in this issue of JACC: Cardiovascular Interventions from the Austrian TAVI Registry. There are 10 centers in Austria performing transfemoral TAVR. The data from 1 center was not included in the report due to “missing or invalid data.” Six of the centers have on-site surgery, and 3 centers do not. In this study, the authors analyzed the outcomes of 1,842 patients receiving transfemoral TAVR from January 2011 through November 2016. Of these, 290 patients (15.9%) underwent TAVR at centers without on-site cardiac surgery during that period (an average of 16 cases/center/year) and the remaining 1,532 patients (84.1%) were treated at centers with on-site cardiac surgery. The patient risk profile was higher at nonsurgery centers (logistic EuroSCORE 20.9% vs. 14.2%) with those patients being judged for the most part to not be surgical candidates.

The procedural mortality, defined by the authors as death in the first 72 h post-procedure, was 3.1% (n = 9) in the centers without on-site surgery, over twice as high as the 1.4% in centers with surgery (p = 0.034). In addition, the 30-day mortality was also significantly higher without surgery (6.9% vs. 4.0%; p = 0.039). The 1-year survival was also significantly lower in those centers (80.9% vs. 86.1%; p = 0.017). Because there were significant differences in the patients treated at centers with and without on-site surgery, as well as different devices used, the authors performed propensity score matching to adjust for confounders and found these differences largely disappeared with equivalent outcomes between the 2 types of centers.

There are number of concerns raised by this study from the methodology, analysis, and outcomes standpoint, and more importantly, from the overall concept of standalone TAVR centers. Regarding the study itself, there are a number of significant shortcomings. First, this is a voluntary, site-reported, unaudited registry with all the inherent problems associated with data accuracy and missingness (8.7% of patients had missing values). Second, standardized VARC 2 (Valve Academic Research Consortium 2) reporting definitions were not used, making context comparison difficult. Third, the study is underpowered with only 290 patients treated over 6 years in the centers without surgery on-site. Fourth, there are significant differences in the types of devices used at the different centers. Fifth, because of possible patients case-mix differences between centers with or without on-site surgery, the authors attempted to account for this by using a propensity score matching–approach. However, it is not clear that the right confounders were used in the propensity matching and site variation was not considered. Moreover, the authors tested multiple outcomes independently, but they did not account for this in the analysis, that is, they did not account for multiple comparisons. This is important because after accounting for multiple comparisons, none of the outcomes’ differences highlighted in the paper would be significant, given the relatively low number of events.

It is also not clear that patient outcomes actually were equivalent between the 2 types of centers as the authors have concluded. Procedural, 30-day, and 1-year observed mortality were all significantly higher at centers without on-site surgery. Although 30-day and 1-year outcomes may be due to the higher-risk cohort of patients treated, higher procedural mortality is unlikely to be. The authors were unable to determine whether any of the 9 procedural deaths could possibly have been avoided if on-site surgical rescue was available. Other complications were also more frequent, including procedural complication-free survival being significantly lower and major bleeding, pneumonia, and prolonged hospital stay significantly higher at centers without on-site surgery. At these centers, there were also more patients treated with general anesthesia, with planned surgical access and use of transesophageal echocardiography perhaps possibly explaining some of the higher complication rates.

The most important concern, however, is that it is difficult to understand what the rationale and justification is for these 3 additional centers without on-site surgery. In a country with a population of 8.7 million without long travel distances, it is hard to believe that access to care could be a justification for the creation of these centers. The authors do not provide the rationale despite being asked. These are all low-volume centers with the number of patients treated averaging 16 TAVR procedures/center/year (range 6 to 23/center/year) belying a clear raison d’etre.

It is also difficult to understand what the differences are in the level of surgical support between centers with and without on-site surgery. The authors state that “all cath labs without institutional on-site surgery were equipped with all necessary infrastructural (devices for emergency cardiac surgery such as sternotomy, use of heart lung machine, and so on) and personnel requirements (cardiac and vascular surgeon with surgical assistance personnel present at the cath lab during all TAVR procedures) to perform bailout cardiac surgery. In addition to cardiovascular anesthesiologist, cardiothoracic and vascular surgeons were present during each procedure to allow for bailout surgery if indicated.” (4). With all that equipment and personnel in place, it is hard to understand how this is not “on-site cardiac surgery.” Nonetheless, the authors use as a justification for not needing on-site surgery a reference documenting the high mortality of TAVR patients converted to surgery (5). Yet reviewing this reference, almost two-thirds of patients converted from TAVR to emergent surgery actually do survive, rendering that justification by the authors moot. It does not appear that this is a persuasive argument to forgo surgical availability.

It also appears that the patients are discussed at a conference but that the patients are not routinely seen by a cardiac surgeon. Although the authors state that “all patients were evaluated by local heart teams formed by cardiologists, cardiac surgeons, anesthesiologists, radiologists, vascular and cardiothoracic surgeons, and neurologists,” this seems more virtual than real.

The biggest concern, however, is regarding patients having access to all therapeutic options. These concerns regarding patients having equal and balanced access to all therapies for AS have recently been raised in the United States (6). They are based on the fact that only approximately one-half of the 1,150 centers performing SAVR have the ability to offer TAVR at those sites. Although the challenges of addressing this issue are great, the principle of equal access is irrefutable. It therefore seems to us that opening centers that offer only TAVR and not SAVR appears to be the opposite side of the same coin. This seems to be a disappointing step in the wrong direction in the multidisciplinary team-based approach to care without clear rationale.

In summary, the authors have shown that TAVR can be done in centers without off-site surgery, but the question remains, at what price and to what end? The introduction of TAVR into clinical practice has fostered and catalyzed the heart team. MDHTs are now also commonplace in many areas of cardiovascular care, including mitral and tricuspid valve disease, left atrial appendage occlusion, heart failure, and CAD. The rationale for abandoning this approach and retreating to the times of siloed care does not seem to us to be a movement toward better patient care. We feel that it is critically important for all patients to have equal access to all aspects of care. A recent multisociety expert consensus document in the United States has made updated recommendations for optimal performance of a TAVR center to reflect current best practices (Table 1) (7).

TAVR has clearly been a monumental advance in the treatment of patients with AS. As a byproduct, there has been an equally significant change in our approach to the delivery of cardiac care. It is our hope that we continue to move forward with a multidisciplinary team-based approach to care and not abandon it when the reasons for doing so appear to be lacking. TAVR is more than just a procedure. It is part of a comprehensive treatment program that embraces team-based care by experienced clinicians with shared decision making and access to all treatment options. Let’s look backward to move forward.

Footnotes