PT - JOURNAL ARTICLE AU - Paolisso, Pasquale AU - Gallinoro, Emanuele AU - Vanderheyden, Marc AU - Esposito, Giuseppe AU - Bertolone, Dario Tino AU - Belmonte, Marta AU - Mileva, Niya AU - Bermpeis, Konstantinos AU - De Colle, Cristina AU - Fabbricatore, Davide AU - Candreva, Alessandro AU - Munhoz, Daniel AU - Degrieck, Ivan AU - Casselman, Filip AU - Penicka, Martin AU - Collet, Carlos AU - Sonck, Jeroen AU - Mangiacapra, Fabio AU - de Bruyne, Bernard AU - Barbato, Emanuele TI - Absolute coronary flow and microvascular resistance reserve in patients with severe aortic stenosis AID - 10.1136/heartjnl-2022-321348 DP - 2023 Jan 01 TA - Heart PG - 47--54 VI - 109 IP - 1 4099 - http://heart.bmj.com/content/109/1/47.short 4100 - http://heart.bmj.com/content/109/1/47.full SO - Heart2023 Jan 01; 109 AB - Background Development of left ventricle (LV) hypertrophy in aortic stenosis (AS) is accompanied by adaptive coronary flow regulation. We aimed to assess absolute coronary flow, microvascular resistance, coronary flow reverse (CFR) and microvascular resistance reserve (MRR) in patients with and without AS.Methods Absolute coronary flow and microvascular resistance were measured by continuous thermodilution in 29 patients with AS and 29 controls, without AS, matched for age, gender, diabetes and functional severity of epicardial coronary lesions. Myocardial work, total myocardial mass and left anterior descending artery (LAD)-specific mass were quantified by echocardiography and cardiac-CT.Results Patients with AS presented a significantly positive LV remodelling with lower global longitudinal strain and global work efficacy compared with controls. Total LV myocardial mass and LAD-specific myocardial mass were significantly higher in patients with AS (p=0.001). Compared with matched controls, absolute resting flow in the LAD was significantly higher in the AS cohort (p=0.009), resulting into lower CFR and MRR in the AS cohort compared with controls (p<0.005 for both). No differences were found in hyperaemic flow and resting and hyperaemic resistances. Hyperaemic myocardial perfusion (calculated as the ratio between the absolute coronary flow subtended to the LAD, expressed in mL/min/g), but not resting, was significantly lower in the AS group (p=0.035).Conclusions In patients with severe AS and non-obstructive coronary artery disease, with the progression of LV hypertrophy, the compensatory mechanism of increased resting flow maintains adequate perfusion at rest, but not during hyperaemia. As a consequence, both CFR and MRR are significantly impaired.Data are available on reasonable request.