Letter to Editor on “Associations between blood cell-based inflammatory indices and their changes and mortality in patients undergoing transcatheter aortic valve replacement: a retrospective investigation with prospective multicenter cohort validation study”

To the Editor, Li et al report an ambispective analysis evaluating whether readily available inflammatory indices – neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and neutrophil percentage-to-albumin ratio (NPAR) – and, importantly, their post-transcatheter aortic valve replacement (TAVR) changes are associated with long-term all-cause mortality after TAVR[1]. The paired design (retrospective development with prospective multicenter validation) strengthens confidence that the observed signal is not purely a single-cohort artifact. This commentary follows the TITAN 2025 Guidelines to support transparent and accountable reporting[2]. A key contribution is the explicit shift from “baseline inflammation” to “persistent or rising post-procedural inflammation.” While higher pre-TAVR NLR/PLR/NPAR were associated with worse survival, Li et al showed that post-TAVR values and upward trajectories from baseline convey stronger prognostic information[1]. This framing aligns with mechanistic and clinical observations in structural interventions: early systemic inflammatory responses after TAVR have been linked to adverse outcomes, and inflammation-related phenotypes can stratify longer-term risk. In particular, post-TAVR systemic inflammatory response syndrome has been shown to predict mortality, reinforcing the concept that procedure-triggered inflammatory burden matters, not only pre-existing risk[3]. NPAR appears especially compelling because it integrates neutrophil predominance with albumin, a marker reflecting both inflammation and physiologic reserve. The albumin component is clinically meaningful in this elderly, frailty-prone population: meta-analytic evidence indicates hypoalbuminemia is consistently associated with poorer prognosis after TAVR[4]. Likewise, large registry analyses demonstrate that elevated baseline NLR and its subsequent changes are prognostic after aortic valve replacement, supporting the broader premise that simple leukocyte-derived indices capture clinically relevant vulnerability[5]. Several cautions are important for translation. First, the definition of “post-TAVR” differs across cohorts (averaged 1–6 months vs a fixed 1-month measurement), which may affect threshold portability and could partly explain performance differences[1]. Second, residual confounding is likely: intercurrent infection, bleeding, vascular complications, renal dysfunction, and frailty can shift both blood counts and albumin, potentially making “trajectory” a composite of multiple postoperative states rather than a single pathway. Third, actionability remains uncertain – whether NPAR/NLR-guided strategies (nutrition optimization, surveillance intensity, complication screening) improve outcomes requires prospective implementation studies. Overall, Li et al advance postoperative risk stratification by demonstrating that dynamic, low-cost inflammatory phenotypes – especially NPAR trajectories – carry meaningful prognostic information after TAVR[1]. The next step is harmonized timepoint collection across centers and trials that test whether intervening on modifiable contributors to persistent inflammation/low albumin can translate risk prediction into improved survival.