Transthoracic Doppler echocardiography compared with positron emission tomography for assessment of coronary microvascular dysfunction: The iPOWER study.

BACKGROUND: Coronary microvascular function can be assessed by transthoracic Doppler echocardiography as a coronary flow velocity reserve (TTDE CFVR) and by positron emission tomography as a myocardial blood flow reserve (PET MBFR). PET MBFR is regarded the noninvasive reference standard for measuring coronary microvascular function but has limited availability. We compared TTDE CFVR with PET MBFR in women with angina pectoris and no obstructive coronary artery disease and assessed repeatability of TTDE CFVR. METHODS: From a cohort of women with angina and no obstructive coronary artery stenosis at invasive coronary angiography, TTDE CFVR by dipyridamole induced stress and MBFR by rubidium-82 PET with adenosine was successfully measured in 107 subjects. Repeatability of TTDE CFVR was assessed in 10 symptomatic women and in 10 healthy individuals. RESULTS: MBFR was systematically higher than CFVR. Median MBFR (interquartile range, IQR) was 2.68 (2.29-3.10) and CFVR (IQR) was 2.31 (1.89-2.72). Pearson's correlation coefficient was 0.36 (p<0.01). Limits of agreement (2·standard deviation) assessed by the Bland-Altman (confidence interval, CI) method was 1.49 (1.29;1.69) and unaffected by time-interval between examinations. Results were similar when adjusting for rate pressure product or focusing on perfusion of the left anterior descending artery region. Limits of agreement (CI) for repeated CFVR in 10 healthy individuals and in 10 women with angina was 0.44 (0.21;0.68) and 0.48 (0.22; 0.74), respectively. CONCLUSION: CFVR had a good repeatability, but the agreement between CFVR and MBFR was modest. Divergence could be due to methodology differences; TTDE estimates flow velocities whereas PET estimates myocardial blood flow.

"Systematizing" ethics consultation services.

While valuable work has been done addressing clinical ethics within established healthcare systems, we anticipate that the projected growth in acquisitions of community hospitals and facilities by large tertiary hospitals will impact the field of clinical ethics and the day-to-day responsibilities of clinical ethicists in ways that have yet to be explored. Toward the goal of providing clinical ethicists guidance on a range of issues that they may encounter in the systematization process, we discuss key considerations and potential challenges in implementing system-wide ethics consultation services. Specifically, we identify four models for organizing, developing, and enhancing ethics consultation activities within a system created through acquisitions: (1) train-the-trainer, (2) local capacity-building, (3) circuit-riding, and (4) consolidated accountability. We note each model's benefits and challenges. To our knowledge, this is the first paper to consider the broader landscape of issues affected by consolidation. We anticipate that clinical ethicists, volunteer consultants, and hospital administrators will benefit from our recommendations.

The side-effects of the "Facebook effect": challenging Facebook's "organ donor" application.

A recent study published in the American Journal of Organ Transplantation proposes that an organ donor application in Facebook can increase the rates at which individuals donate organs. While I offer support for the use of social media mechanisms in the service of the promotion of organ donation public health initiatives, there are several ethical concerns surrounding informed consent. While Facebook has made a noble effort to aid public health initiatives focused on organ donation, the current application does not promote decisions that are based on individuals' personal values and goals. Without an intervention that promotes an understanding and appreciation of a decision for or against donation, the application does not obtain informed consent. Without first ensuring that a Facebook member has registered with her or his own state donor registry, this social media mechanism may create more confusion than clarity about an individual's organ donor status. If Facebook desires to have a positive impact on the rates of organ donation, it must do so in a manner that obtains proper consent and promotes ethically informed decisions.