Why is disease progression more rapid in the proximal segments of grafted coronary arteries?

Coronary artery segments proximal to the site of graft placement are prone to accelerated atherosclerosis. This has been generally (and somewhat simplistically) attributed to competitive flows between the graft and the native vessel. A more plausible mechanism, linking the rapid induction and progression of atherosclerosis to abnormal flow patterns, and the consequent deleterious alterations in shear stress, is presented here.     

Effectiveness of a National Transitional Care Program in Reducing Acute Care Use

This study evaluated the effectiveness of a national transitional care program for elderly adults with complex care needs and limited social support. The Aged Care Transition (ACTION) Program was designed to improve coordination and continuity of care and reduce rehospitalizations and visits to emergency departments (EDs). Dedicated care coordinators provided coaching to help individuals and families understand the individuals' conditions, effectively articulate their preferences, and enable self‐management and care planning. Participants were individuals aged 65 and older hospitalized and enrolled from five public general hospitals in Singapore between February 2009 and July 2010 (N = 4,132). The coordinators worked with participants during hospitalization and followed up with telephone calls and home visits for 1 to 2 months after discharge and coordinated placements with appropriate community service providers. Unplanned rehospitalization and ED visit (up to 6 months after discharge) rates were compared with those of a comparator group of individuals who did not receive care coordination using propensity score‐based weighting. Participant and caregiver surveys on quality of life and self‐rated health were also administered. Recipients of the ACTION program had fewer unplanned rehospitalizations and ED visits after discharge. Propensity score–adjusted odds ratios of participants versus control for number of unplanned rehospitalization and ED visits were 0.5 (95% confidence interval (CI) = 0.5–0.6) and 0.81 (95% CI = 0.72–0.90) 30 days after discharge and 0.6 (95% CI = 0.6–0.7) and 0.90 (95% CI = 0.82–0.99) 180 days after discharge. Quality of life and self‐rated health were better 4 to 6 weeks after discharge than 1 week after discharge. These findings confirm the effectiveness of the ACTION program in improving the transition of vulnerable older adults from hospital to community. Such transitional care should be considered as an integral part of care integration.     

Effect of obstructive sleep apnea on mitral valve tenting

Obstructive apneas produce high negative intrathoracic pressure that imposes an afterload burden on the left ventricle. Such episodes might produce structural changes in the left ventricle over time. Doppler echocardiograms were obtained within 2 months of attended polysomnography. Patients were grouped according to apnea-hypopnea index (AHI): mild/no obstructive sleep apnea (OSA; AHI <15) and moderate/severe OSA (AHI ≥15). Mitral valve tenting height and area, left ventricular (LV) long and short axes, and LV end-diastolic volume were measured in addition to tissue Doppler parameters. Comparisons of measurements at baseline and follow-up between and within groups were obtained; correlations between absolute changes (Δ) in echocardiographic parameters were also performed. After a mean follow-up of 240 days mitral valve tenting height increased significantly (1.17 ± 0.12 to 1.28 ± 0.17 cm, p = 0.001) in moderate/severe OSA as did tenting area (2.30 ± 0.41 to 2.66 ± 0.60 cm(2), p = 0.0002); Δtenting height correlated with ΔLV end-diastolic volume (rho 0.43, p = 0.01) and Δtenting area (rho 0.35, p = 0.04). In patients with mild/no OSA there was no significant change in tenting height; there was a borderline significant increase in tenting area (2.20 ± 0.44 to 2.31 ± 0.43 cm(2), p = 0.05). Septal tissue Doppler early diastolic wave decreased (8.04 ± 2.49 to 7.10 ± 1.83 cm/s, p = 0.005) in subjects with moderate/severe OSA but not in in those with mild/no OSA. In conclusion, in patients with moderate/severe OSA, mitral valve tenting height and tenting area increase significantly over time. This appears to be related, at least in part, to changes in LV geometry.