Is a timely assessment of the hematocrit necessary for cardiovascular magnetic resonance-derived extracellular volume measurements?

BACKGROUND: Cardiovascular magnetic resonance (CMR)-derived extracellular volume (ECV) requires a hematocrit (Hct) to correct contrast volume distributions in blood. However, the timely assessment of Hct can be challenging and has limited the routine clinical application of ECV. The goal of the present study was to evaluate whether ECV measurements lead to significant error if a venous Hct was unavailable on the day of CMR. METHODS: 109 patients with CMR T1 mapping and two venous Hcts (Hct0: a Hct from the day of CMR, and Hct1: a Hct from a different day) were retrospectively identified. A synthetic Hct (Hctsyn) derived from native blood T1 was also assessed. The study used two different ECV methods, (1) a conventional method in which ECV was estimated from native and postcontrast T1 maps using a region-based method, and (2) an inline method in which ECV was directly measured from inline ECV mapping. ECVs measured with Hct0, Hct1, and Hctsyn were compared for each method, and the reference ECV (ECV0) was defined using the Hct0. The error between synthetic (ECVsyn) and ECV0was analyzed for the two ECV methods. RESULTS: ECV measured using Hct1 and Hctsyn were significantly correlated with ECV0 for each method. No significant differences were observed between ECV0 and ECV measured with Hct1 (ECV1; 28.4 ± 6.6% vs. 28.3 ± 6.1%, p = 0.789) and between ECV0 and ECV calculated with Hctsyn (ECVsyn; 28.4 ± 6.6% vs. 28.2 ± 6.2%, p = 0.45) using the conventional method. Similarly, ECV0 was not significantly different from ECV1 (28.5 ± 6.7% vs. 28.5 ± 6.2, p = 0.801) and ECVsyn (28.5 ± 6.7% vs. 28.4 ± 6.0, p = 0.974) using inline method. ECVsyn values revealed relatively large discrepancies in patients with lower Hcts compared with those with higher Hcts. CONCLUSIONS: Venous Hcts measured on a different day from that of the CMR examination can still be used to measure ECV. ECVsyn can provide an alternative method to quantify ECV without needing a blood sample, but significant ECV errors occur in patients with severe anemia.

Anti-anxiety drugs use and cardiovascular outcomes in patients with myocardial infarction: a national wide assessment.

OBJECTIVE: Anti-anxiety medication in patients with anxiety may lessen the stress and thereby lower their risk for myocardial infarction (MI). The aim of current study is to examine an association between the use of anti-anxiety medication and long-term mortality risk in patients following MI. METHODS: A universal national health insurance (NHI) program has been implemented in Taiwan since 1995. We used system sampling database from 1997 to 2008 with a total of 1,000,000 subjects. We included subjects with first episode of MI and were above 30 years old. Sudden death, cardiovascular mortality, and heart failure hospitalization were assessed in all included subjects. Anti-anxiety as well as other medications and risk factors were obtained. Cox regression analysis was used to evaluate the adjusted hazard ratio (HR) for all patients and subgroups. RESULTS: The adjusted HRs of sudden death were significantly associated with increased benzodiazepam (BZD) dosage (HRs = 0.639, 1.003, 1.957 from Q2 to Q4 vs. Q1, p = .019 for trend) during approximately 4.8 years. For cardiac mortality and heart failure hospitalization, there was a J-curve dose-response relationship. The HRs for cardiac mortality were 0.255 (p < .001) and 0.385 (p < .001) for Q2 and Q3 vs. Q1, respectively. For patients receiving higher doses of daily BZDs (>5 mg), protective effects for cardiac mortality and heart failure hospitalization decreased and a J-curve dose-response relationship was seen. CONCLUSION: Anti-anxiety medications are independent associated with a decreased risk of cardiac mortality and heart failure hospitalization in patients after a new MI.

Association of area socioeconomic status with lung function in children.

OBJECTIVE: The study investigates the association between area-level socioeconomic status (SES) and children's lung function. METHODS: Participants were 3994 seventh grade students from the Taiwan Children Health Study living in 14 communities in Taiwan and were recruited in 2007. Area-level SES predictors were population size, occupation type, income and education level. Hierarchical linear models (HLM) were used to examine the effects of area-level SES on lung function, after accounting for area air pollution and individual SES (parental education and family income). RESULTS: Areas with high income were independently associated with lower child lung function. The coefficients for log transformation of area tax per person in HLM were -47.8 (95% confidence interval (CI): -80.9, -14.8) in FEV(1), -43.8 (95% CI: -75.2, -12.5) in FVC, -93.4 (95% CI: -179.3, -7.5) in FEF(25-75) and -203.2 (95% CI: -349.1, -57.2) in PEF. All SES predictors influenced in the same direction and affected males more. The interaction of area tax per person with parental educational level was significant on PEF, suggesting significant association of greater parental education with lower lung function in children. CONCLUSION: High area SES was inversely associated with lung function in Taiwanese children.