The thermodilution (Td) and estimated oxygen uptake Fick (eFick) methods are often used interchangeably in clinical practice to assess cardiac index (CI), but there are limited comparative data. Opotowsky and coauthors assessed catheterization data in 12 232 patients in the Veterans Affairs Clinical Assessment Reporting and Tracking program. Thermodilution and eFick CI estimates correlated only modestly (r = 0.65), with wide 95% limits of agreement between methods, and estimates differed by greater than 20% for 38.1% of patients. Low Td CI more strongly predicted mortality than low eFick CI at 90 days. Results showing discordance between the Td and eFick methods were corroborated in 3391 patients cared for at Vanderbilt University.
Prospective comparative investigations of the accuracy of current imaging modalities for diagnosis of coronary artery disease (CAD) are lacking. Danad and coauthors studied 208 patients with suspected CAD with coronary computed tomography angiography (CCTA), single-photon emission tomography (SPECT), and positron emission tomography (PET) compared with invasive fractional flow reserve. Diagnostic accuracy was highest for PET (85%; 95% CI, 80-90) and was not enhanced by hybrid imaging with SPECT/CCTA or PET and CCTA. In an Invited Commentary, Douglas and Shaw note the need for further research to determine whether such findings translate into effectiveness and not just efficacy and whether changes in testing practices affect patient care processes and outcomes.
Invited Commentary
Whether resuscitation care and outcomes vary by racial demographic characteristics in neighborhoods where out-of-hospital cardiac arrests (OHCAs) occur is uncertain. Starks and coauthors examined 22 816 OHCAs from 2008 through 2011 in the Resuscitation Outcomes Consortium database. Compared with neighborhoods with a lower proportion of black residents, patients experiencing OHCA in neighborhoods with greater than 75% black residents were younger but had lower rates of initial shockable rhythm and a lower percentage of bystander cardiopulmonary resuscitation or lay automatic external defibrillation use and lower adjusted survival rates to hospital discharge. Within neighborhoods, survival was not significantly different among black and white individuals. In an Invited Commentary, Merchant and Groeneveld comment that these findings should galvanize patients, researchers, and policy makers to improve OHCA response and outcomes in minority communities.
Invited Commentary
Author Audio Interview
Stroke is often the first clinical manifestation of atrial fibrillation (AF). To determine the incidence of AF in patients at high risk for AF (ie, patients with a CHADS2 score of 3 or greater or 2 with at least 1 additional risk factor), Reiffel and coauthors studied 385 patients (mean age, 71.5 years) using an insertable cardiac monitor (ICM) in the multicenter REVEAL study, which included 57 centers. Detection rates of AF at 30 days and 6, 12, 24, and 30 months were 6.2%, 20.4%, 27.1%, 33.6%, and 40.0%, respectively. Median time from ICM insertion to first AF episode detection was 123 days. In an Invited Commentary, Healey notes these data that indicate that AF is extremely common among older individuals with stroke risk factors require additional research to translate these insights into cost-effective stroke prevention strategies for high-risk individuals.
Invited Commentary