creased risk of both abnormal hematocrit values and cardiovascular complications of noncardiac surgery. 1,2 Despite nearly universal measurement of hematocrit values prior to major surgery, 3 the prognostic implications of preoperative anemia or polycythemia are incompletely understood for this high-risk population. Although we have previously found that even mild degrees of anemia increase the mortality risk of elderly patients with acute myocardial infarction, 4 surgical studies of mild anemia have not shown it to be a risk factor for death, unless cardiac disease is present or major blood loss occurs. [5][6][7] The limited physiologic reserve and the higher prevalence of unrecognized cardiovascular disease may still render the elderly population vulnerable to milder degrees of anemia when undergoing the stress of surgery. [8][9][10] For editorial comment see p 2525.

Amiodarone and sotalol are equally efficacious in converting atrial fibrillation to sinus rhythm. Amiodarone is superior for maintaining sinus rhythm, but both drugs have similar efficacy in patients with ischemic heart disease. Sustained sinus rhythm is associated with an improved quality of life and improved exercise performance.

Large-scale multi-ethnic cohorts offer unprecedented opportunities to elucidate the genetic factors influencing complex traits related to health and disease among minority populations. At the same time, the genetic diversity in these cohorts presents new challenges for analysis and interpretation. We consider the utility of race and/or ethnicity categories in genome-wide association studies (GWASs) of multi-ethnic cohorts. We demonstrate that race/ethnicity information enhances the ability to understand population-specific genetic architecture. To address the practical issue that self-identified racial/ethnic information may be incomplete, we propose a machine learning algorithm that produces a surrogate variable, termed HARE. We use height as a model trait to demonstrate the utility of HARE and ethnicity-specific GWASs.

Intraoperative blood transfusion is associated with a lower 30-day postoperative mortality among elderly patients undergoing major noncardiac surgery if there is substantial operative blood loss or low preoperative hematocrit levels (<24%). Transfusion is associated with increased mortality risks for those with preoperative hematocrit levels between 30% and 35.9% and <500 mL of blood loss.

In patients with persistent AF, restoration and maintenance of SR was associated with improvements in QOL measures and EP. There was a strong correlation between QOL measures and EP.