Contemporary Hospitalization Rate Among Adults With Complex Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease are hospitalized at increasing rates in the Western world. Identification of rates of and risk factors for hospitalization is essential for research and improving patient outcomes. METHODS: We conducted a single-center retrospective analysis of patients with a primary diagnosis of tetralogy of Fallot (TOF), transposition of the great arteries (both d- and l-transposition of the great arteries [TGAs]), or single ventricle (SV). We investigated the rates of mortality, annual hospitalization, and patient-specific risk factors for unplanned cardiac hospitalization. RESULTS: Adult patients with complex congenital heart disease are hospitalized at a rate four to eight times greater than the general US population (P < .001). In addition, there are significant differences between the rates of hospitalization in TOF and TGA (0.39 and 0.41 hospitalizations per patient-year, respectively) and SV (0.72 hospitalizations per patient-year). The majority of excess hospitalizations in the study group were due to cardiac disease (P < .001 for all three groups). Risk factors for unplanned cardiac hospitalization in TOF included pulmonary atresia, depressed left ventricular and right ventricular ejection fraction, and smoking; in TGA, they included Ebstein malformation, surgeries other than primary repair, noncardiac diagnoses, atrial arrhythmias, atrioventricular nodal block, left ventricular ejection fraction, and smoking; and in SV, they included atrial arrhythmias and cyanosis. CONCLUSIONS: Patients born with complex congenital heart disease are hospitalized far more frequently than the general US population, primarily for cardiac-related illness. Future research should focus on confirming the present findings and on identification of strategies to improve outcomes in this growing group of patients.

Hierarchical mechanisms build the DNA-binding specificity of FUSE binding protein.

The far upstream element (FUSE) binding protein (FBP), a single-stranded nucleic acid binding protein, is recruited to the c-myc promoter after melting of FUSE by transcriptionally generated dynamic supercoils. Via interactions with TFIIH and FBP-interacting repressor (FIR), FBP modulates c-myc transcription. Here, we investigate the contributions of FBP's 4 K Homology (KH) domains to sequence selectivity. EMSA and missing contact point analysis revealed that FBP contacts 4 separate patches spanning a large segment of FUSE. A SELEX procedure using paired KH-domains defined the preferred subsequences for each KH domain. Unexpectedly, there was also a strong selection for the noncontacted residues between these subsequences, showing that the contact points must be optimally presented in a backbone that minimizes secondary structure. Strategic mutation of contact points defined in this study disabled FUSE activity in vivo. Because the biological specificity of FBP is tuned at several layers: (i) accessibility of the site; (ii) supercoil-driven melting; (iii) presentation of unhindered bases for recognition; and (iv) modular interaction of KH-domains with cognate bases, the FBP-FIR system and sequence-specific, single-strand DNA binding proteins in general are likely to prove versatile tools for adjusting gene expression.