Matching pathophysiology and evidence-based medicine for optimal management of ischemic heart disease

A nondenatured, noncrosslinked collagen matrix to deliver stem cells to the heart

AIMS

Stem cell transplantation holds promise as a therapeutic approach for the repair of damaged myocardial tissue. One challenge of this approach is efficient delivery and long-term retention of the stem cells. Although several synthetic and natural biomaterials have been developed for this purpose, the ideal formulation has yet to be identified.

MATERIALS & METHODS

Here we investigate the utility of a nondenatured, noncrosslinked, commercially available natural biomaterial (TissueMend(®) [TEI Biosciences, Boston, MA, USA]) for delivery of human mesenchymal stem cells (MSCs) to the murine heart.

RESULTS

We found that MSCs attached, proliferated and migrated within and out of the TissueMend matrix in vitro. Human MSCs delivered to damaged murine myocardium via the matrix (2.3 × 10(4) ± 0.8 × 10(4) CD73(+) cells/matrix) were maintained in vivo for 3 weeks and underwent at least three population doublings during that period (21.9 × 10(4) ± 14.4 × 10(4) CD73(+) cells/matrix). In addition, collagen within the TissueMend matrix could be remodeled by MSCs in vivo, resulting in a significant decrease in the coefficient of alignment of fibers (0.12 ± 0.12) compared with the matrix alone (0.28 ± 0.07), and the MSCs were capable of migrating out of the matrix and into the host tissue.

CONCLUSION

Thus, TissueMend matrix offers a commercially available, biocompatible and malleable vehicle for the delivery and retention of stem cells to the heart.

Cardiologists' workflow in small to medium-sized German hospitals: an observational work analysis

AIMS

Due to recent changes in national health policy and a subsequent increase in clinicians' workload, medical residents in Germany feel that the growing burden of documentation duties leaves too little time for direct patient care. Thus, to describe the daily workflow in cardiology wards with more accuracy, this real-time observational study detailed all tasks performed by resident cardiologists during daily shifts at German hospitals.

METHODS

Daily routines of 20 resident cardiologists at four German hospitals were observed and recorded in real time during the study period from September 2009 to January 2010. Each participant was shadowed during three entire day shifts by an observer, who recorded all tasks performed by the cardiologist.

RESULTS

During the study period, 60 workdays (512 h) of observation took place. On average, doctors worked 08:31 h per day (SD = 00:32 h). Most time was spent on meetings (2:51 h), on administration duties (1:22 h), on ward rounds and admission to hospital (0:42 h) and on breaks (0:30 h). Doctors were interrupted every 16 min and spent 16.20% of each workday multitasking.

CONCLUSION

Ward rounds, meetings and administrative duties took up two-thirds of an average workday. Little time was spent on direct patient care relative to other clinical tasks such as paperwork and management. High rates of interruptions and multitasking were found. As the medical workforce is valuable, changes in the organization of workflow should be made in order to minimize residents' administrative duties and paperwork; thus, cardiologists' job satisfaction might increase.