The value of competition: a patient-tailored approach to aortic valve replacement

Competition is one of the most powerful drives for excellence. The question is, should we appreciate transcatheter aortic valve replacement (TAVR) as a competing or a complementary approach to surgical aortic valve replacement (SAVR). While seeking the best therapeutic options for our patients, we often seek a ‘one solution fits all’ rather than an ‘individualized’ approach that takes into account their comorbidities, medical history, operative risk, physiological reserves, anatomical considerations and finally their preferences. The ‘one solution fits all’ approach is often driven by the desire to improve quality by standardizing procedures rather than having a multitude of approaches that are difficult to evaluate in terms of their relative merits. An individualized solution, however, is more cumbersome and often requires a team approach that involves different specialties, representing not only different treatment modalities but possibly also different evaluations of the patient’s condition. Putting this situation in the context of Aortic valve replacment (AVR), the relative merits of SAVR versus TAVR are further complicated by the fact that the 2 procedures do not share a similar risk profile for postoperative complications [1–4], namely, a higher risk for transfusions and new onset atrial fibrillation versus a higher incidence of vascular complications, pacemaker dependence and paravalvular leakage. It is extremely difficult to find a preference for one of these complications over the other. In the end, it comes down to their relevance for long-term survival and quality of life.

In the current study, Malvindi et al. [5] demonstrated that SAVR not only provided excellent long-term survival (90%, 66% and 31% at 1, 5 and 10 years) but also survival that was similar to the survival of an age- and sex-matched population. Keeping in mind the fact that the control group represents the highest benchmark for comparison, these results are remarkable. Similar long-term survival data were also reported by Nader et al. [6] in a comparable patient population (70% and 28% at 5 and 10 years). Furthermore, Nader et al. [6] showed that their patients had a good quality of life that fell within the expected range of the general population.

Malvindi et al. [5] also pointed out that perioperative complications were the main limiting factor for long-term survival, with a deviation from an uncomplicated postoperative course being associated with a significant reduction in survival (71% vs 92% at 1 year, 46% vs 68% at 5 years and 18% vs 33% at 10 years; log-rank test P = 0.002). A further finding was an improvement in the risk profile of their patients over the period of the study. This result was demonstrated by a reduction in the logistic EuroSCORE from the 2000 to 2004 period to the 2015 to 2019 period from 15.0 ± 9.8% to 12.4 ± 6.9%. In the same periods, the percentage of patients with a left ventricular ejection fraction below 30% dropped from 9% to 5%; the incidence of patients in New York Heart Association functional class III–IV, from 63% to 31%; and those with renal dysfunction, from 7% to 1%. Further, this finding was associated with a drop in postoperative complications from 15.3% to 5.8% and in-hospital mortality from 6% to 1.5% for patients with concomitant procedures and 5.2% to 1.4% for patients with isolated AVR. At the same time, the incidence of permanent cerebral stroke remained almost constant at 0.7% vs 0.8%.

This improvement could be attributed to better patient selection for SAVR while sicker patients were referred to TAVR, a point that could have additionally been analysed in this study but probably was too difficult to accomplish. Nevertheless, regardless of whether this hypothesis was true or false, the study shows that with proper patient selection SAVR can be performed with good early results even when concomitant procedures such as coronary artery bypass grafting or mitral valve surgery are performed. Additionally, it is an excellent result for long-term survival with a valve that will probably outlive the patient. In this context, it is worth mentioning that in most prospective randomized trials comparing TAVR to SAVR [1–4], once they were randomized to the SAVR arm, the patients received additional surgical procedures that they would not have received in the TAVR arm. Because concomitant procedures will, however, extend cardiopulmonary bypass times and add additional risks to in-hospital results, we can either presume that these will have a positive effect on long-term outcome or that we have subjected the patient to an additional risk that would be difficult to account for in the comparison to the TAVR group.

As we eagerly await the long-term results of TAVR regarding survival and valve durability, TAVR has already been approved for use in low-risk patients [7], presumably with the hope that the cumulative risk of TAVR and a second valve-in-valve procedure will still compare favourably to those of SAVR with a valve that will outlive the patient. It has to be pointed out that available data have not shown any concerns regarding early structural valve degeneration in TAVR at up to 6 years of follow-up in older patients [8–10].

Our utmost efforts should therefore target an individualized patient approach to identify the predisposing factors for different perioperative complications of both therapeutic options, to make the best of both. As such, reducing stroke rates, possibly through routine computed tomographic scans of the chest prior to SAVR, patient blood management, improving extracorporeal circulation and perioperative prophylaxis against atrial fibrillation as well as improvement in anaesthesia management comprise the efforts that have to be undertaken for SAVR.

The reasonable approach is, therefore, to distance ourselves from standardized approaches in which we suppose that 1 treatment fits all and is superior in all conditions (even if solely stratified by operative risk) towards an individualized solution that offers the treatment best suited to a particular patient. This goal can only be achieved via a real team approach where the TAVR procedure is not only discussed but actually performed by the team. The added value of the experiences of the individual members in different settings, including prompt emergency management of complications, can help in reducing the toll of these complications on patient outcomes.

REFERENCES