Commentary: Ready or not, here it comes: Surgery after transcatheter aortic valve replacement.

Danny Ramzy, MD, PhD

Surgical bailout during TAVR occurs infrequently; however, mortality is high. A TAVR-first strategy may not be ideal, and this must be discussed by heart teams and with patients when considering TAVR.

See Article page 54.

Recently, amidst all the focus on coronavirus disease 2019, a landmark has been quietly passed: For the first time in the United States, annual transcatheter aortic valve replacement (TAVR) has surpassed isolated surgical aortic valve replacement volumes, with 72,991 TAVRs performed during 2019. Circumstances due to the coronavirus disease 2019 pandemic may actually favor TAVR. Limited hospital resources, strict visitation policies, shorter lengths of stay, and fewer intensive care resources have further amplified this shift in 2020. Burke, Oyetunji, and Aldea, from the University of Washington, provide a concise overview of key considerations for surgery following TAVR. The authors point to the timeliness of this important topic, which will be encountered with greater frequency as increased procedure volumes generate a larger at-risk cohort. Increase in the size of the pathology pool will be driven by changes in demographic characteristics of the potential TAVR population. This will include longer life expectancy and earlier structural valve deterioration inherent to using bioprosthetic valves in a younger patient population. Appropriately, the authors highlight the different considerations and outcomes for surgical bailout during TAVR, versus surgical explant, when the valve begins to fail.

Surgical bailout during TAVR occurs at an estimated frequency of about 1%, and has 30-day or index hospitalization mortality of about 50%., Risk factors for needing surgical bailout include female sex, increasing hemoglobin level, increasing left ventricular ejection fraction, nonelective cases, and nonfemoral access. Low volume (<50 TAVRs annually) and high volume centers perform similarly in the frequency of surgical bailout and surgical bailout mortality. In addition to a surgeon's readiness to intervene surgically, the ability to function well as a team is tantamount—as it is with high-level sports. Important anesthesia considerations must not be overlooked. These include readiness to safely and rapidly intubate and convert to general anesthesia, to provide massive transfusion if suddenly required, and to provide a safe time to pause the operation so anesthesia can catch up. Applying the team dynamics concepts from advanced cardiovascular life support, or advanced trauma life support may also be valuable.

While expanding on the author's mention of surgical bailout resulting from aortic dissection during TAVR, it is worth noting that both type A and type B aortic dissection are encountered. In patients who are poor surgical candidates, treatment considerations may include expectant management or endovascular devices, including investigational ascending aortic endovascular aortic repair.

The authors correctly comment on the paucity of long-term data on TAVR to predict valve durability, although some of the TAVR valves are beginning to show their age. In a recent analysis of TAVRs from 2012 to 2017, only 0.2% underwent surgical explant at a median of 212 days post-TAVR. And of this 0.2%, 30-day mortality associated with surgical explant was 13%—nearly double the mortality after reoperative surgical aortic valve replacement. In an analysis of surgical explants after TAVR from the Society of Thoracic Surgeons database, operative mortality was 17% and was worse than expected for redo aortic valve replacement when the initial valve was surgically replaced.

Whereas it may be reassuring that the rates of surgical bailout and surgical explant for TAVR appear low to-date, mortality rates are alarmingly high. In addition to team readiness to perform these more challenging surgical procedures, it is equally important for cardiothoracic surgeons to first identify strategies to reduce mortality rates. Finally, we may have come to a time that a TAVR-first strategy may not be ideal for all patients, and we must include this important consideration in heart team discussions and patient counseling when considering TAVR in the first place.