Pre-surgery optimization of patients' expectations to improve outcome in heart surgery: Study protocol of the randomized controlled multi-center PSY-HEART-II trial

The PSY-HEART-I trial indicated that a brief expectation-focused intervention prior to heart surgery improves disability and quality of life 6 months after coronary artery bypass graft surgery (CABG). However, to investigate the clinical utility of such an intervention, a large multi-center trial is needed to generalize the results and their implications for the health care system. The PSY-HEART-II study aims to examine whether a preoperative psychological intervention targeting patients' expectations (EXPECT) can improve outcomes 6 months after CABG (with or without heart valve replacement). EXPECT will be compared to Standard of Care (SOC) and an intervention providing emotional support without targeting expectations (SUPPORT). In a 3-arm multi-center randomized, controlled, prospective trial (RCT), N = 567 patients scheduled for CABG surgery will be randomized to either SOC alone or SOC and EXPECT or SOC and SUPPORT. Patients will be randomized with a fixed unbalanced ratio of 3:3:1 (EXPECT: SUPPORT: SOC) to compare EXPECT to SOC and EXPECT to SUPPORT. Both psychological interventions consist of 2 in-person sessions (à 50 minute), 2 phone consultations (à 20 minute) during the week prior to surgery, and 1 booster phone consultation post-surgery 6 weeks later. Assessment will occur at baseline approx. 3-10 days before surgery, preoperatively the day before surgery, 4-6 days later, and 6 months after surgery. The study's primary end point will be patients' illness-related disability 6 months after surgery. Secondary outcomes will be patients' expectations, subjective illness beliefs, quality of life, length of hospital stay and blood sample parameters (eg, inflammatory parameters such as IL-6, IL-8, CRP). This large multi-center trial has the potential to corroborate and generalize the promising results of the PSY-HEART-I trial for routine care of cardiac surgery patients, and to stimulate revisions of treatment guidelines in heart surgery.

Genetic Ablation of PDGF-Dependent Signaling Pathways Abolishes Vascular Remodeling and Experimental Pulmonary Hypertension

OBJECTIVE

Despite modern therapies, pulmonary arterial hypertension (PAH) harbors a high mortality. Vascular remodeling is a hallmark of the disease. Recent clinical studies revealed that antiremodeling approaches with tyrosine-kinase inhibitors such as imatinib are effective, but its applicability is limited by significant side effects. Although imatinib has multiple targets, expression analyses support a role for platelet-derived growth factor (PDGF) in the pathobiology of the disease. However, its precise role and downstream signaling events have not been established.

APPROACH AND RESULTS

Patients with PAH exhibit enhanced expression and phosphorylation of β PDGF receptor (βPDGFR) in remodeled pulmonary arterioles, particularly at the binding sites for phophatidyl-inositol-3-kinase and PLCγ at tyrosine residues 751 and 1021, respectively. These signaling molecules were identified as critical downstream mediators of βPDGFR-mediated proliferation and migration of pulmonary arterial smooth muscle cells. We, therefore, investigated mice expressing a mutated βPDGFR that is unable to recruit phophatidyl-inositol-3-kinase and PLCγ (βPDGFR(F3/F3)). PDGF-dependent Erk1/2 and Akt phosphorylation, cyclin D1 induction, and proliferation, migration, and protection against apoptosis were abolished in βPDGFR(F3/F3) pulmonary arterial smooth muscle cells. On exposure to chronic hypoxia, vascular remodeling of pulmonary arteries was blunted in βPDGFR(F3/F3) mice compared with wild-type littermates. These alterations led to protection from hypoxia-induced PAH and right ventricular hypertrophy.

CONCLUSIONS

By means of a genetic approach, our data provide definite evidence that the activated βPDGFR is a key contributor to pulmonary vascular remodeling and PAH. Selective disruption of PDGF-dependent phophatidyl-inositol-3-kinase and PLCγ activity is sufficient to abolish these pathogenic responses in vivo, identifying these signaling events as valuable targets for antiremodeling strategies in PAH.

Hypoxia- or PDGF-BB-dependent paxillin tyrosine phosphorylation in pulmonary hypertension is reversed by HIF-1α depletion or imatinib treatment

Chronic exposure to hypoxia induces a pronounced remodelling of the pulmonary vasculature leading to pulmonary hypertension (PH). The remodelling process also entails increased proliferation and decreased apoptosis of pulmonary arterial smooth muscle cells (PASMC), processes regulated by the cytoskeletal protein paxillin. In this study, we aimed to examine the molecular mechanisms leading to deregulation of paxillin in PH. We detected a time-dependent increase in paxillin tyrosine 31 (Y31) and 118 (Y118) phosphorylation following hypoxic exposure (1 % O2) or platelet-derived growth factor (PDGF)-BB stimulation of primary human PASMC. In addition, both, hypoxia- and PDGF-BB increased the nuclear localisation of phospho-paxillin Y31 as indicated by immunofluorescence staining in human PASMC. Elevated paxillin tyrosine phosphorylation in human PASMC was attenuated by hypoxia-inducible factor (HIF)-1α depletion or by treatment with the PDGF-BB receptor antagonist, imatinib. Moreover, we observed elevated paxillin Y31 and Y118 phosphorylation in the pulmonary vasculature of chronic hypoxic mice (21 days, 10 % O2) which was reversible by imatinib-treatment. PDGF-BB-dependent PASMC proliferation was regulated via the paxillin-Erk1/2-cyclin D1 pathway. In conclusion, we suggest paxillin up-regulation and phosphorylation as an important mechanism of vascular remodelling underlying pulmonary hypertension.