Two-year cardio-pulmonary follow-up after severe COVID-19: a prospective study

Short- and medium-term cardio-pulmonary sequelae after COVID-19 have been extensively studied. However, studies with longer follow-ups are required. This study aims to identify and characterise cardio-pulmonary sequelae, in patients hospitalised for SARS-CoV-2 pneumonia, at 24 months follow-up. This is a prospective, observational cohort study conducted on consecutive patients hospitalised for COVID-19 and acute respiratory failure. Patients were followed up at 24 months with complete pulmonary function tests (PFTs), 6-min walking test and a dyspnoea score (Modified Medical Research Council scale). A subgroup of patients with at least one clinical or functional sign suggestive of increased pulmonary pressures also underwent transthoracic echocardiography (TTE) to evaluate the presence of direct or indirect signs of pulmonary hypertension (PH). Ninety consecutive patients (74% men, median age 59.1 years) were enrolled in the study. In regard to PFTs, carbon monoxide diffusion capacity (DLCO) impairment was observed in 23 cases (26%), in all cases of mild entity. When considering the dyspnoea, 30 (34%) patients showed some degree of breathlessness. Forty patients underwent TTE. No patients had overt PH or chronic thromboembolic PH. However, all patients showed a hyperdynamic state of the right ventricle, and 8 (20%) patients had a decreased acceleration time on pulmonary valve, signs of increased pulmonary vasculature resistances and afterload elevation. At 24-month follow-up after severe COVID-19, DLCO and TTE prove to be the most sensitive tool to detect cardio-pulmonary sequelae. Dyspnoea is still present in about one-third of patients and requires a multidisciplinary approach.