Limitations included the images being interpreted by their individual healthcare centers and that the stroke centers had lower recurrent rates of stroke compared with community centers. If only a CT can be used, it should be noted that the sensitivity is lower when compared with an MRI in this study.
Bottom line: This categorization of tissue- or non-tissue-positive TIAs improved the prognostic information provided by the ABCD2 score and might improve management decisions.
Citation: Giles MF, Albers GW, Amarenco P, et al. Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study. Neurology. 2011;77:1222-1228.
ETT Comparable to MPI as Initial Diagnostic Test for Women Suspected of CAD
Clinical question: Is the exercise treadmill test (ETT) equivalent to myocardial perfusion imaging (MPI) as an initial diagnostic test for low-risk women capable of exercising with suspected coronary artery disease (CAD)?
Background: To date, the evidence base for diagnostic testing in women with suspected CAD has been limited, with no randomized trials to guide appropriate clinical decision-making in the choice of noninvasive testing strategies. The aim of this trial was to provide comparative-effectiveness data for women capable of performing exercise testing with regard to whether the addition of imaging to standard ETT provided incremental clinical benefit over index ETT alone.
Study design: Prospective randomized.
Settings: Forty-three cardiology practices across the U.S.
Synopsis: A total of 824 women 40 years of age or older with intermediate pretest CAD likelihood were randomized to ETT or MPI. All the women included in the study were symptomatic with suspected CAD, had an interpretable ECG, and were >5 on DASI (Duke Activity Status Index). A total of 17 primary end points were confirmed, including three nonfatal myocardial infarctions, one heart failure hospitalization, 12 acute coronary syndrome hospitalizations, and only one sudden cardiac death reported in 772 women.
At two years, major adverse cardiovascular events (MACE)-free survival was identical (98%) for women randomized to the ETT or exercise MPI arm (P=0.59). The observed two-year MACE rate was 1.7% for ETT and 2.3% for exercise MPI. For secondary end points, the overall rate of hospitalization for chest pain was 3%. By randomization, the two-year rate of hospitalization for chest pain symptoms was 3% for women in the ETT arm and 4% for those in the exercise MPI arm (P=0.39). An additional six women died from non-cardiac causes (ETT arm, 0.5%; exercise MPI arm, 1%; P=0.39).
Bottom line: ETT is of comparable diagnostic efficacy to MPI as an initial diagnostic test for women suspected of CAD, capable of exercising, based on two-year outcome of cardiac death, nonfatal myocardial infarction, or hospital admission for acute coronary syndrome or heart failure.
Citation: Shaw LJ, Mieres JH, Hendel RH, et al. Comparative effectiveness of exercise electrocardiography with or without myocardial perfusion single photon emission computed tomography in women with suspected coronary artery disease: results from the What Is the Optimal Method for Ischemia Evaluation in Women (WOMEN) trial. Circulation. 2011;124:1239-1249.
Controlled Forced Diuresis Is More Effective in High-Risk Patients for CI-AKI Prevention
Clinical question: Is a system of hydration that creates high urine output while maintaining fluid balance better than routine hydration in high-risk patients for preventing contrast-induced acute kidney injury (CI-AKI)?
Background: Hydration with sodium bicarbonate solution and administration of N-acetylcysteine (NAC) help prevent CI-AKI in low- to medium-risk patients. A recent study (PRINCE) suggests that increasing the urine flow rate (≥150 mL/hr) reduces the toxic effect of contrast, but this regimen requires forced diuresis with high doses of furosemide that may result in further renal damage due to negative fluid balance. The RenalGuard system (PLC Medical Systems Inc., Franklin, Mass.) can simultaneously achieve high urine output and maintain fluid balance.