Coronary microvascular dysfunction is associated with reduced cardiac performance in low flow low gradient aortic stenosis

Abstract Background Little is known about coronary microvascular function of patients with low-flow low-gradient aortic stenosis (LFLGAS). We hypothesized that LFLGAS associated more severe dysfunction (CMD) compared normal-flow high-gradient (NFHGAS) and CMD related to reduced cardiac efficiency. Purpose To perform a prospective invasive assessment in undergoing TAVI compare it NFHGAS. Moreover, we aimed assess the possible acute impact on interactions between performance at speckle tracking echocardiography (STE). Methods Invasive thermodilution-based was systematically performed 41 consecutive isolated AS angiographic unobstructed arteries TAVI. The index microcirculatory resistance (IMR), resistive reserve ratio (RRR) flow (CFR) were derived before after Advanced echocardiographic imaging, including STE, function. Results IMR significantly higher NFHGAS (24.1 [14.6–39.1] vs 12.8 [8.6–19.2] p=0.002). Similarly, RRR lower (1.4 [1.1–2.1] 2.6 [1.5–3.3] p=0.020). No significant differences observed CFR two groups. High low stroke volume (rho=−0.427, p=0.005), output (rho=−0.517, p=0.001), peak atrial longitudinal strain (PALS) (rho=−0.610, p≤0.001) presence fibrillation (54.6% 21.1%, p=0.036). Conversely, only modestly mean pressure valve gradient (rho=−0.304, p=0.054). Notably, group (rho=0.632, p=0.003) but not (rho=−0.222, p=0.333). high AVA (rho=−0.50, p=0.025) (rho=0.157, p=0.497). Paradoxical emerged as phenotype CMD, poor left ventricular systolic dysfunction. determined no variation (IMR: 16.0 [10.4–26.1] 16.6 [10.2–25.6], p=0.403) PALS (15.9 [9.9–26.5] 20.1 [12.3–26.7], p=0.222). global increased overall (−13.2 [8.4–16.6] −15.1 [9.4–17.8], p=0.047). Conclusions impaired Combined advanced non-invasive imaging contributed define different phenotypes. state, efficiency AS. Funding Acknowledgement Type funding sources: Private company. Main source(s): Abbott Vascular