Introduction: Coronavirus disease 2019 (COVID-19) is a systemic disease characterized by a disproportionate inflammatory response in the acute phase. This study sought to identify clinical sequelae and their potential mechanism. Methods: We conducted a prospective single-center study (NCT04689490) of previously hospitalized COVID-19 patients with and without dyspnea during mid-term follow-up. An outpatient group was also evaluated. They underwent serial testing with a cardiopulmonary exercise test (CPET), transthoracic echocardiogram, pulmonary lung test, six-minute walking test, serum biomarker analysis, and quality of life questionaries. Results: Patients with dyspnea (n = 41, 58.6%), compared with asymptomatic patients (n = 29, 41.4%), had a higher proportion of females (73.2 vs. 51.7%; p = 0.065) with comparable age and prevalence of cardiovascular risk factors. There were no significant differences in the transthoracic echocardiogram and pulmonary function test. Patients who complained of persistent dyspnea had a significant decline in predicted peak VO₂ consumption (77.8 (64–92.5) vs. 99 (88–105); p < 0.00; p < 0.001), total distance in the six-minute walking test (535 (467–600) vs. 611 (550–650) meters; p = 0.001), and quality of life (KCCQ-23 60.1 ± 18.6 vs. 82.8 ± 11.3; p < 0.001). Additionally, abnormalities in CPET were suggestive of an impaired ventilatory efficiency (VE/VC_O2 slope 32 (28.1–37.4) vs. 29.4 (26.9–31.4); p = 0.022) and high PET_CO2 (34.5 (32–39) vs. 38 (36–40); p = 0.025). Interpretation: In this study, >50% of COVID-19 survivors present a symptomatic functional impairment irrespective of age or prior hospitalization. Our findings suggest a potential ventilation/perfusion mismatch or hyperventilation syndrome.

Transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve (BAV) stenosis is technically challenging and is burdened by an increased risk of paravalvular regurgitation (PVR). To identify the incidence, predictors, and clinical outcomes of PVR following TAVR in Sievers type 1 BAV stenosis. Consecutive patients with severe Sievers type 1 BAV stenosis undergoing TAVR with current generation transcatheter heart valves (THVs) in 24 international centres were enrolled. PVR was graded as none/trace, mild, moderate, and severe according to echocardiographic criteria. The endpoint of major adverse events (MAE), defined as a composite of all-cause death, stroke, or hospitalization for heart failure, was assessed at the last available follow-up. A total of 946 patients were enrolled. PVR occurred in 423 patients (44.7%): mild, moderate, and severe in 387 (40.9%), 32 (3.4%), and 4 (0.4%) patients, respectively. Independent predictors of moderate or severe PVR were larger virtual raphe ring (VRR) perimeter (OR_adj 1.07, 95% CI 1.02-1.13), severe annular or left ventricular outflow tract (LVOT) calcification (OR_adj 5.21, 95% CI 1.45-18.77), self-expanding valve (OR_adj 9.01, 95% CI 2.09-38.86), and intentional supra-annular THV positioning (OR_adj 3.31, 95% CI 1.04-10.54). At a median follow-up of 1.3 [IQR 0.5-2.4] years, moderate or severe PVR was associated with an increased risk of MAE (HR_adj 2.52, 95% CI 1.24-5.09). After TAVR with current-generation THVs in Sievers type 1 BAV stenosis, moderate or severe PVR occurred in about 4% of cases and was associated with an increased risk of MAE during follow-up.