Recently published studies have found an impaired immune response after SARS-CoV-2 vaccination in solid organ recipients. However, most of these studies have not assessed immune cellular responses in liver and heart transplant recipients. We prospectively studied heart and liver transplant recipients eligible for SARS-CoV-2 vaccination. Patients with past history of SARS-CoV-2 infection or SARS-CoV-2 detectable antibodies (IgM or IgG) were excluded. We assessed IgM/IgG antibodies and ELISpot against the S protein 4 weeks after receiving the second dose of the mRNA-1273 (Moderna) vaccine. Side effects, troponin I, liver tests and anti-HLA donor-specific antibodies (DSA) were also assessed. A total of 58 liver and 46 heart recipients received two doses of mRNA-1273 vaccine. Median time from transplantation to vaccination was 5.4 years (IQR 0.3-27). Sixty-four percent of the patients developed SARS-CoV-2 IgM/IgG antibodies and 79% S-ELISpot positivity. Ninety percent of recipients developed either humoral or cellular response (87% in heart recipients and 93% in liver recipients). Factors associated with vaccine unresponsiveness were hypogammaglobulinemia and vaccination during the first year after transplantation. Local and systemic side effects were mild or moderate, and none presented DSA or graft dysfunction after vaccination. Ninety percent of our patients did develop humoral or cellular responses to mRNA-1273 vaccine. Factors associated with vaccine unresponsiveness were hypogammaglobulinemia and vaccination during the first year after transplantation, highlighting the need to further protect these patients.

Background—: Pulmonary hypertension (PH) and collagen metabolism abnormalities are prevalent in patients with heart failure with preserved ejection fraction (HFpEF). Peripheral endothelial dysfunction (PED) has been described in HF and in pulmonary arterial hypertension. Our aim is to determine whether PH is associated with PED and impaired collagen metabolism in patients with HFpEF.; Methods and Results—: Flow-mediated dilation of the brachial artery, matrix metalloproteinase-2 and matrix metalloproteinase-9, tissue metalloproteinase inhibitor 1, and C-terminal propeptide of type I procollagen were determined in 28 patients with HFpEF and 42 hypertensive controls. Patients with systolic pulmonary artery pressure >35 mm Hg on echocardiogram underwent a right heart catheterization. Patients with HFpEF had more severe PED than controls: flow-mediated dilation 1.95% (−0.81 to 4.92) versus 5.02% (3.90 to 10.12), P =0.002. Twenty patients with PH underwent right heart catheterization: mean pulmonary artery pressure 38 (27–52) mm Hg, wedge capillary pressure 18 (16–22) mm Hg, pulmonary vascular resistance 362 (235–603) dyn s cm ^-5 . There was a significant inverse correlation between flow-mediated dilation and pulmonary vascular resistance in patients with HFpEF and PH ( r =−0.679; P =0.002). Patients with HFpEF showed higher matrix metalloproteinase-2 and C-terminal propeptide of type I procollagen values than hypertensive controls. Patients with HFpEF and higher C-terminal propeptide of type I procollagen values also had higher mean pulmonary artery pressure ( r =0.553; P =0.014), transpulmonary gradient ( r =0.560; P =0.013), and pulmonary vascular resistance ( r =0.626; P =0.004). Conclusions—: In patients with HFpEF, there is a significant correlation between PED and pulmonary vascular resistance. Collagen metabolism was more impaired in patients with HFpEF and PH. PED and collagen metabolism assessment could be useful tools to identify patients with HFpEF at risk of developing PH.