Oh, Jae K.

ABSTRACT Background The assessment of aortic stenosis (AS) severity remains a challenge in some patients, and hemodynamic exercise testing has been proposed as a diagnostic tool in this population. However, the current understanding of exercise hemodynamics in AS is limited. Methods Retrospective review of 34 adults (aged ≥ 18 years) with ≥ moderate AS and preserved left ventricular ejection fraction (LVEF) undergoing exercise invasive hemodynamics (supine cycle protocol) with simultaneous measurement of aortic and left ventricular pressures. Results Age was 77.1 (IQR 68.6; 84.1) years, and 50% were female. LVEF was 62.1 ± 6.6%. All patients were symptomatic. Resting aortic valve area (AVA) was 1.0 ± 0.2 cm 2 and aortic valve (AV) systolic mean gradient 22.0 ± 7.3 mmHg. At peak exercise (40 [IQR 30; 60] W), AV systolic mean gradient (Δ3 [0.6; 7] mmHg, p < 0.001) and AVA (Δ0.2 [0; 0.6] cm 2 , p = 0.002) significantly increased, while stroke volume (SV) did not (Δ6.8 ± 19.4 ml; p = 0.07). Exercise‐induced changes in AV systolic mean gradient were directly related to changes in cardiac output ( r = 0.53, p = 0.003), being inversely related to exercise systemic vascular resistance ( r = −0.60, p = 0.002). Elevated pulmonary artery wedge pressure was present in 41.2% at rest (≥ 15 mmHg) and 69.7% during exercise (≥ 25 mmHg). Conclusions Symptomatic patients with ≥ moderate AS and preserved LVEF experience small increases in AV mean gradient with exercise, and unlike the normal physiological response to exercise, there was no significant increase in SV. In most patients, AVA rose during exercise. Exercise‐induced elevation in filling pressures was highly prevalent.

Abstract OBJECTIVES The objective of this analysis was to assess the normal haemodynamic performance of contemporary surgical aortic valves at 1 year postimplant in patients undergoing surgical aortic valve replacement for significant valvular dysfunction. By pooling data from 4 multicentre studies, this study will contribute to a better understanding of the effectiveness of surgical aortic valve replacement procedures, aiding clinicians and researchers in making informed decisions regarding valve selection and patient management. METHODS Echocardiograms were assessed by a single core laboratory. Effective orifice area, dimensionless velocity index, mean aortic gradient, peak aortic velocity and stroke volume were evaluated. RESULTS The cohort included 2958 patients. Baseline age in the studies ranged from 70.1 ± 9.0 to 83.3 ± 6.4 years, and Society of Thoracic Surgeons risk of mortality was 1.9 ± 0.7 to 7.5 ± 3.4%. Twenty patients who had received a valve model implanted in fewer than 10 cases were excluded. Ten valve models (all tissue valves; n = 2938 patients) were analysed. At 1 year, population mean effective orifice area ranged from 1.46 ± 0.34 to 2.12 ± 0.59 cm2, and dimensionless velocity index, from 0.39 ± 0.07 to 0.56 ± 0.15. The mean gradient ranged from 8.6 ± 3.4 to 16.1 ± 6.2 mmHg with peak aortic velocity of 1.96 ± 0.39 to 2.65 ± 0.47 m/s. Stroke volume was 75.3 ± 19.6 to 89.8 ± 24.3 ml. CONCLUSIONS This pooled cohort is the largest to date of contemporary surgical aortic valves with echocardiograms analysed by a single core lab. Overall haemodynamic performance at 1 year ranged from good to excellent. These data can serve as a benchmark for other studies and may be useful to evaluate the performance of bioprosthetic surgical valves over time. Clinical trial registration number NCT02088554, NCT02701283, NCT01586910 and NCT01531374.