Background—: Coronary artery disease (CAD) is highly prevalent in patients undergoing transcatheter aortic valve replacement. In the overall CAD population, complete revascularization or reasonable incomplete revascularization (ICR) is associated with improved outcomes; whether the same applies for the transcatheter aortic valve replacement population is still a matter of debate. Methods and Results—: We conducted a systematic review and meta-analysis of studies that examined the prognostic effect of revascularization completeness in patients undergoing transcatheter aortic valve replacement using the residual SYNTAX score (Synergy Between PCI With Taxus and Cardiac Surgery) to separate between reasonable ICR and ICR (using the individual threshold used by each study). Six studies with a total of 3107 patients were included. The duration of follow-up ranged from 0.7 to 3 years. Overall, ICR was associated with an increased risk for mortality. This was true when comparing ICR patients to those with no CAD (odds ratio, 1.85; 95% confidence interval, 1.42–2.40; P <0.01), to those with reasonable ICR (odds ratio, 1.69; 95% confidence interval, 1.26–2.28; P <0.001), or to both groups combined (odds ratio, 1.71; 95% confidence interval, 1.36–2.16; P <0.001). On the contrary, patients in the reasonable ICR category did not show an increased risk for mortality when compared with those with no CAD (odds ratio, 1.11; 95% confidence interval, 0.89–1.39; P =0.33). Conclusions—: Our results suggest that for patients with CAD undergoing transcatheter aortic valve replacement, a residual SYNTAX score–guided revascularization strategy may carry significant benefits in terms of mortality. Adequate revascularization may offer a unique and valuable opportunity to improve the prognosis of these patients.

Transcatheter aortic valve replacement (TAVR) is now established as the preferred treatment for older adults with severe aortic stenosis (AS) who are at intermediate or higher surgical risk (when femoral access is feasible).¹ The population of patients with TAVR is characterized by a high prevalence of moderate or worse chronic kidney disease (CKD),² which is associated with increased mortality after TAVR.^2,3 The effect of TAVR on kidney function is complicated: on one hand, multiple aspects related to the procedure (eg, exposure to contrast, atheroembolic disease, hypotensive episodes, bleeding) can result in acute kidney injury (AKI) in up to 50% of TAVR cases.⁴ Patients with baseline kidney dysfunction are at the highest risk for AKI, which is associated with a significant increase in the risk for short- and intermediate-term mortality.⁴ On the other hand, it can be hypothesized that the hemodynamic benefits of successfully treating AS, such as improved cardiac output, reduced vascular tone, better kidney perfusion, and reduced venous pressure, have the potential to improve kidney function, similar to the effect of improvement in cardiac function in patients with type 2 cardiorenal syndrome (CRS).⁵ We previously reported that for patients with moderate or worse CKD who suffer from AS, TAVR is associated with a stabilization of kidney function, whereas conservative treatment is associated with deterioration in kidney function.⁶ Data from the Placement of Aortic Transcatheter Valves 1 (PARTNER 1) trial and registry of patients with high or inoperable AS undergoing TAVR reported that for such patients (baseline estimated glomerular filtration rate [eGFR] ≤60 mL/min/1.73 m²), TAVR using a balloon-expandable valve was associated with 10% or greater improvement in eGFR 30 days postprocedure in 42% of treated patients and a deterioration of 10% or greater in 24% of patients. Those with kidney function deterioration had a 50% higher risk for 1-year mortality.⁷ Combined data from the PARTNER 1 and PARTNER 2 trials and registry recently reported that in patients at intermediate or high surgical risk who undergo TAVR with a balloon-expandable valve, CKD stage remained stable or improved in 89% of patients 7 days after TAVR, and the risk for progression to stage 5 CKD was negligible (0.035%).⁸ Whether the same association is true for the overall patient population not enrolled in clinical trials, patients at lower risk (who represent the majority of patients undergoing TAVR in current clinical practice⁹), and those undergoing TAVR with self-expandable valves has not been examined. Because a substantial fraction of TAVR-related AKI cases are reversible and given the results of the PARTNER 1 trial and registry mentioned previously (which indicate that many patients may experience an improvement in kidney function after TAVR), it is likely the steady state kidney function after TAVR, rather than baseline or periprocedural kidney function, that has the more prognostic association with mortality. Our goal in this study was to examine the association of TAVR with kidney function (both periprocedural and steady state) and the association between kidney function change after TAVR and 2-year mortality in a large, single-center cohort.