Conclusion
In conclusion, it is noteworthy that in the recent report published in The Journal of the American Medical Association (JAMA)12 of the first 7,710 patients in the TVT/NCDR registry the STS score was a mean of 7 (for the approval of the device for inoperable patients in the PARTNER B trial it was 11 and also for high-risk patients in PARTNER A it was also 11, and this is the population the device should be commercially used in). Thus, there are already moderate-risk patients (for PARTNER 2A moderate-risk study the Cleveland Clinic mean was STS 7) being done commercially. Furthermore, based on the data shown in their Figure 1, institutions doing small volumes of TAVR, particularly <60 TAVR case volume, were also doing more low-risk STS score patients. If two surgeons in these low volume institutions are approving these cases, then it is likely they feel less confident to tackle higher risk patients, like reoperations, despite the fact these patients do paradoxically better with open AVR. Indeed, between January 1999 and mid-2013, at the Cleveland Clinic, we did 329 reoperations of all types for AVR surgery and the mortality rate was 2.4 % and stroke 1.8 %. Furthermore, for our low-risk patients (n=771) with a STS <4 % risk the mortality rate was 0.3 % between 2011 and 2013, and for 74 % intermediate or high-risk there were no deaths (0 %) for a total of 0.2 % death (n=956 patients). The unanswered questions are the long-term durability of TAVR in younger intermediate-risk patients, the stroke risks, and the effect of perivalvular leaks long-term. PARTNER 2A will likely add information but will show mixed results. It is unlikely that further successful prospective randomised trials will be done in the intermediate-risk patients to clarify selection of patients. At least for high-risk and inoperable patients the results are encouraging in our experience.13
The future use of TAVR for moderate-risk will be determined by your answers to the above questions; and in the US, risk creep, the future decisions of congress, CBO recommendations and CMS reimbursement.