Impact of Valvulo-Arterial Impedance on Long-Term Quality of Life and Exercise Performance After Transcatheter Aortic Valve Replacement

Abstract

BACKGROUND:In aortic stenosis, valvulo-arterial impedance (Zva) estimates the overall left ventricular afterload (valve and arterial component). We investigated the association of Zva (≥5 versus <5 mm Hg mL −1 m −2 ) on quality of life (QOL) and exercise performance (EP) ≥1 year after transcatheter aortic valve replacement (TAVR). METHODS:The study population consists of 250 TAVR patients in whom baseline Zva and follow-up QOL was prospectively assessed using EuroQOL-5-dimensions instruments; EP was assessed in 192 patients who survived ≥1 year after TAVR using questionnaires related to daily activities. In 124 patients, Zva at 1-year was also available and was used to study the change in Zva (baseline to 1 year) on QOL/EP. RESULTS: Elevated baseline Zva was present in 125 patients (50%). At a median of 28 (IQR, 17-40) months, patients with elevated baseline Zva were more limited in mobility (88% versus 71%; P=0.004), self-care (40% versus 25%; P=0.019), and independent daily activities (taking a shower: 53% versus 38%, P=0.030; walking 100 meter: 76% versus 54%, P=0.001; and walking stairs: 74% versus 54%, P=0.011). By multivariable analysis, elevated Zva predicted unfavorable QOL (lower EuroQOL-5-dimensions-Utility Index, odds ratio, 1.98; CI, 1.15-3.41) and unfavorable EP (any limitation in ≥3 daily activities, odds ratio, 2.55; CI, 1.41-4.62). After TAVR, the proportion of patients with elevated Zva fell from 50% to 21% and remained 21% at 1 year and was found to be associated with more limitations in mobility, self-care, and daily activities compared with patients with Zva <5 mm Hg mL −1 m −2 . CONCLUSIONS: Elevated Zva was seen in half of patients and predicted unfavorable long-term QOL and EP. At 1 year after TAVR, the prevalence of elevated Zva was 21% but remained associated with poor QOL/EP.

Arterial biomarkers in the evaluation, management and prognosis of aortic stenosis

“…The use of arterial biomarkers and indices that encompass and take into account the effect of as many pathophysiological aspects can prove crucial in the assessment of true hemodynamic severity of AVS in cases that traditional indices seem to be insufficient. For example, in patients with paradoxical low-flow, lowgradient severe AVS, the estimation of Zva (which is a surrogate measure of global LV afterload that incorporates both the valvular and the vascular component) might be useful, especially when Zva is > 5 mmHg/mL/m 2 , for the clinician to unmask the pseudonormalization of gradient and blood pressure [40,57]. Moreover, increased aortic stiffness could identify patients that are prone to develop paradoxical low-flow, low-gradient subtypes during the progression of AVS independently of echocardiographic severity indices.…”

A novel echo-parameter supersedes the Society of Thoracic Surgeons risk score in predicting post transcatheter aortic valve replacement mortality

“…Back in 2009, the concept of valvulo-arterial impedance was introduced by Hachicha et al, and this parameter was shown to be independently associated with mortality in aortic stenosis patients who underwent either surgical aortic valve replacement or medical therapy (28). After that, valvulo-arterial impedance was evaluated in multiple studies as a post-TAVR outcome predictor (10,(14)(15)(16)29,30). A cohort study containing 202 TAVR patients reported that patients who died within 6 months had higher baseline Zva and less improvement in post-TAVR Zva.…”

“…Given the underlying comorbidities, the clinical outcomes after TAVR procedure have gained significant attention that involves both conventional and machine learning research approaches (5)(6)(7)(8)(9)(10)(11)(12). There are newer studies focused on the relationship of blood pressure and valvuloarterial impedance (Zva), which estimates the overall left ventricular afterload, and its effect on TAVR prognosis (8)(9)(10)13). Elevated Zva has been reported to be associated with worse quality of life and exercise performance at one year (10), while there are inconsistent results in predicting long-term mortality (14)(15)(16).…”

“…There are newer studies focused on the relationship of blood pressure and valvuloarterial impedance (Zva), which estimates the overall left ventricular afterload, and its effect on TAVR prognosis (8)(9)(10)13). Elevated Zva has been reported to be associated with worse quality of life and exercise performance at one year (10), while there are inconsistent results in predicting long-term mortality (14)(15)(16). Our group previously reported that cardiac power index and gradient-adjusted cardiac power index are good predictors of 1-year mortality after TAVR (6,7).…”

Challenges and opportunities in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve replacement

“…It was demonstrated that the LV global afterload (Zva) was a main predictor of lower stress-corrected mid wall shortening, independent from LV geometry, hypertrophy, and hypertension, despite of mean LVEF all at 60% [82]. In TAVI patients, Nuis et al [83] reported an elevated Z-va occurred in half of the patients at base line and reduced to 21% at 1 year after TAVI, but the patients who had remained to have elevated Z-va were associated with poor quality of life and exercise performance.…”