Left atrial volume quantification using cardiac MRI in atrial fibrillation: comparison of the Simpson’s method with biplane area-length, ellipse, and three-dimensional methods

PURPOSELeft atrial volume is an important predictor of future arrhythmias, and it can be assessed by several different methods. Simpson’s method is well accepted as a reference standard, although no standardization exists for cardiac magnetic resonance (CMR). We aimed to compare the estimations of left atrial volumes obtained by the Simpson’s method with three other methods. MATERIALS AND METHODSEighty-one consecutive patients referred for CMR imaging between February 2007 and May 2010 were included in the study (47 males; mean age, 59.4±11.5 years; body mass index, 26.3±3.7 kg/m2). Left atrial volume measurements were performed using the Simpson’s, biplane area-length, ellipse, and three-dimensional methods. Results were correlated using a Bland-Altman plot and linear regression models and compared by two-tailed paired-sample t tests. Reader variability was also calculated. RESULTSLeft atrial volume measurements using the biplane area-length technique showed the best correlation with Simpson’s method (r=0.92; P 0.99). CONCLUSIONThe biplane area-length method can be used for left atrial volume measurement when the Simpson’s method cannot be performed. If these two methods are not feasible, then all methods are highly reproducible and can be used, but should not be used interchangeably for follow-up studies

Doença de Alzheimer e espectroscopia por ressonância magnética do hipocampo

OBJETIVOS: Obtenção de dados do espectro de metabolitos por ressonância magnética da formação hipocampal no idoso normal e com doença de Alzheimer (DA). MÉTODO: Os indivíduos foram pareados por idade, sendo 20 na amostra normal, CDR=0 e 40 com DA 3 CDR=1 e 2. Utilizou-se aparelho Signa Horizon LX-GE, 1.5T, ¹H-ERM com aplicativo automatizado PROBE/SV, VOI: hc (direito e esquerdo); voxel único (2x2x2cm); TR 1500ms/TE 50ms; PRESS; metabolitos: N-acetilaspartato (Naa), colina (Cho), creatina (Cr), mio-inositol (mI). RESULTADOS: Os presentes dados se referem aos quocientes de Naa, Cho e mI, com Cr tomada como referência e relação mI/Naa. O estudo mostrou o Naa reduzido, o mI e a relação mI/Naa aumentados e os resultados em relação à Cho foram variados. Os resultados da amostra global dos pacientes com DA em comparação à média ± dp da amostra normal foram significativos para Naa, mI e mI/Naa (p<0,01). A precisão, tomando os valores de modo individual das duas amostras, mostrou sensibilidade, especificidade e valor preditivo positivo satisfatórios. CONCLUSÃO: Os presentes resultados podem ser usados como ferramenta útil para detectar alterações patológicas no hipocampo de pacientes com DA, permitindo diagnóstico de maior precisão e mais precoce da doença

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline