Rogério Teixeira

Left Atrial Mechanics: Echocardiographic Assessment and Clinical Implications

The importance of the left atrium in cardiovascular performance has long been acknowledged. Quantitative assessment of left atrial (LA) function is laborious, requiring invasive pressure-volume loops and thus precluding its routine clinical use. In recent years, novel postprocessing imaging methodologies have emerged, providing a complementary approach for the assessment of the left atrium. Atrial strain and strain rate obtained using either Doppler tissue imaging or two-dimensional speckle-tracking echocardiography have proved to be feasible and reproducible techniques to evaluate LA mechanics. It is essential to fully understand the clinical applications, advantages, and limitations of LA strain and strain rate analysis. Furthermore, the techniques prognostic value and utility in therapeutic decisions also need further elucidation. The aim of this review is to provide a critical appraisal of LA mechanics. The authors describe the fundamental concepts and methodology of LA strain and strain rate analysis, the reference values reported with different imaging techniques, and the clinical implications.

Circumferential ascending aortic strain and aortic stenosis.

BACKGROUND Two-dimensional speckle tracking (2D-ST) echocardiography for the measurement of circumferential ascending thoracic aortic strain (CAAS) in the context of aortic stenosis (AS) is not elucidated. Purpose This study assesses the thoracic ascending aortic deformation using 2D-ST echocardiography in AS patients. Population and methods Forty-five consecutive patients with an aortic valvular area (AVA) ≤0.85 cm(2)/m(2) were included. Regarding aortic deformation, the global peak CAAS was the parameter used, and an average of six segments of arterial wall deformation was calculated. The corrected CAAS was calculated as the global CAAS/pulse pressure (PP). Aortic stiffness (β2) index was assessed according to ln(Ps/Pd)/CAAS. The sample was stratified according to the stroke volume index (SVI) as: Group A (low flow, SVI ≤35 mL/m(2); n = 19) and Group B (normal flow, SVI >35 mL/m(2); n = 26). RESULTS The mean age was 76.8 ± 10.3 years, 53.3% were male, the mean indexed AVA was 0.43 ± 0.15 cm(2)/m(2), and the mean CAAS was 6.3 ± 3.0%. The CAAS was predicted by SVI (β = 0.31, P < 0.01) and by valvulo-arterial impedance (Zva). The corrected CAAS was correlated with the M-mode guided aortic stiffness index (β1) (r = -0.39, P < 0.01), and was predicted by SVI, Zva, and systemic arterial compliance (β = 0.15, P < 0.01). The β2 index was significantly higher for the low-flow patients (16.1 ± 4.8 vs. 9.8 ± 5.3, P < 0.01), and was predicted by SVI (β -0.58, P < 0.01) and PP (β = 0.17, P < 0.01). Global CAAS was more accurate to predict low flow than Zva, systolic function and systemic vascular resistance. CONCLUSION In patients with moderate-to-severe aortic stenosis, SVI and LV afterload-related variables were the most important determinants of 2S-ST global CAAS.

Ultrasonographic vascular mechanics to assess arterial stiffness: a review

In recent years, the role of arterial stiffness in the development of cardiovascular diseases has been explored more extensively. Local arterial stiffness may be gauged via ultrasound, measuring pulse transit time relative to changing vessel diameters and distending pressures. Recently, direct vessel-wall tracking systems have been devised based on new ultrasonographic methodologies, such as tissue Doppler imaging and speckle-tracking analysis--vascular mechanics. These advances have been evaluated in varying arterial distributions, are proved surrogates of pulse wave velocity, and are ascending in clinical importance. In the course of this review, we describe fundamental concepts and methodologies involved in ultrasound assessment of vascular mechanics. We also present relevant clinical studies and discuss the potential clinical utility of such diagnostic pursuits.

One-shot diagnostic and prognostic assessment in intermediate- to high-risk acute pulmonary embolism: The role of multidetector computed tomography

INTRODUCTION Contrast-enhanced multidetector computed tomography (MDCT) is useful for the diagnosis of pulmonary embolism (PE). However, current guidelines do not support its use for risk assessment in acute PE patients. OBJECTIVES We compared the prognostic impact of MDCT-derived indices regarding medium-term mortality in a population of intermediate- to high-risk PE patients, mostly treated by thrombolysis. METHODS Thirty-nine consecutive patients admitted to an intensive care unit with acute PE were studied. All patients had a pulmonary MDCT on admission to the emergency room as part of the diagnostic algorithm. We assessed the following MDCT variables: right ventricular/left ventricular diameter (RV/LV) ratio, arterial obstruction index, pulmonary artery-to-aorta diameter ratio and azygos vein diameter. A 33-month follow-up was performed. RESULTS Mean age was 59.1±19.6 years, with 80% of patients receiving thrombolysis. Follow-up all-cause mortality was 12.8%. Of the MDCT-derived variables, only the RV/LV ratio had significant predictive value, being higher in patients who suffered the endpoint (1.6±0.5 vs. 1.9±0.4, p=0.046). Patients with an RV/LV ratio ≥1.8 had 11-fold higher medium-term all-cause mortality (3.8% vs. 38.8%, p<0.001). Regarding this endpoint, the c-statistic was 0.78 (95% CI, 0.60-0.96) for RV/LV ratio and calibration was good (goodness-of-fit p=0.594). No other radiological index was predictive of mortality. CONCLUSIONS MDCT gives the possibility, in a single imaging procedure, of diagnosing and assessing the prognosis of patients with intermediate- to high-risk PE. Although further studies are needed, the simple-to-calculate RV/LV ratio has good discrimination and calibration for predicting poorer outcomes in patients with acute PE.

Can We Improve Outcomes in Patients With Previous Coronary Artery Bypass Surgery Admitted for Acute Coronary Syndrome

INTRODUCTION AND OBJECTIVES Prognosis and in-hospital management of patients with acute coronary syndrome (ACS) and a history of coronary artery bypass graft (CABG) surgery are still debated. The objective of this study was to characterize ACS patients with a CABG and to compare their in-hospital and postdischarge outcomes with those of patients without a CABG. METHODS This ongoing prospective observational study included 1,495 consecutive patients admitted for ACS to a coronary care unit and followed up for a mean of 19 months. There were two groups: group A (n=73), with CABGs; and group B (n=1,223), without CABGs. RESULTS Group A patients were more often male (86.3% versus 69.1%; P=.002), and more frequently had a history of diabetes, myocardial infarction and heart failure. Group B patients more frequently had ST-elevation myocardial infarction, and had a higher median ejection fraction (53% [interquartile range, 47%-60%] vs. 50% [42%-55%]; P< .01) and peak troponin-I concentration. There was no difference in the use of invasive techniques. Regarding medication, Group B patients were more likely to receive dual antiplatelet therapy at discharge. No significant difference was observed in in-hospital mortality (9.5% versus 5.9%; P=.2) or mortality at 1 month, 6 months or 1 year (9.8% versus 9.1%; log-rank test, P=.87) and the cumulative major adverse cardiac event rate was equally low in both groups. The presence of a CABG was associated with more readmissions for unstable angina (11.3% vs. 3.1%; P< .01). CONCLUSIONS In our ACS patients, the presence of a CABG had no significant influence on short- or medium-term outcomes, such as all-cause mortality and adverse cardiac events.

Platelet aggregation at discharge, A useful tool in acute coronary syndromes?

INTRODUCTION Inhibition of platelet aggregation appears two hours after the first dose of clopidogrel, becomes significant after the second dose, and progresses to a steady-state value of 55% by day seven. Low response to clopidogrel has been associated with increased risk of stent thrombosis and ischemic events, particularly in the context of stable heart disease treated by percutaneous coronary intervention. OBJECTIVE To stratify medium-term prognosis of an acute coronary syndrome (ACS) population by platelet aggregation. METHODS We performed a prospective longitudinal study of 70 patients admitted for an ACS between May and August 2009. Platelet function was assessed by ADP-induced platelet aggregation using a commercially available kit (Multiplate(®) analyzer) at discharge. The primary endpoint was a combined outcome of mortality, non-fatal myocardial infarction, or unstable angina, with a median follow-up of 136.0 (79.0-188.0) days. RESULTS The median value of platelet aggregation was 16.0U (11.0-22.5U) with a maximum of 41.0U and a minimum of 4.0U (normal value according to the manufacturer: 53-122U). After ROC curve analysis with respect to the combined endpoint (AUC 0.72), we concluded that a value of 18.5U conferred a sensitivity of 75.0% and a specificity of 68% to that result. We therefore created two groups based on that level: group A - platelet aggregation <18.5U, n=44; and group B - platelet aggregation ≥18.5U, n=26. The groups were similar with respect to demographic data (age 60.5 [49.0-65.0] vs. 62.0 [49.0-65.0] years, p=0.21), previous cardiovascular history, and admission diagnosis. There were no associations between left ventricular ejection fraction, GRACE risk score, or length of hospital stay and platelet aggregation. The groups were also similar with respect to antiplatelet, anticoagulant, proton pump inhibitor (63.6 vs. 46.2%, p=0.15) and statin therapy. The variability in platelets and hemoglobin was also similar between groups. Combined event-free survival was higher in group A (96.0 vs. 76.7%, log-rank p<0.01). Platelet aggregation higher than 18.5U was an independent predictor of the combined event (HR 6.75, 95% CI 1.38-32.90, p=0.02). CONCLUSION In our ACS population platelet aggregation at discharge was a predictor of medium-term prognosis.

Acute myocardial infarction--historical notes.

For the time being, acute myocardial infarction represents a history of success concerning diagnose, management and treatment, whereas it was considered a fatal disease in the beginning of the 1900s. The present paper is aimed at reviewing the landmarks of acute myocardial infarction, as key historical concepts are an important tool for understanding disease management, the daily dilemmas and future perspectives.

Left ventricular end diastolic pressure and acute coronary syndromes

BACKGROUND Data is lacking in the literature regarding the prognostic impact of left ventricular-end diastolic pressure (LVEDP) across acute coronary syndromes (ACS). OBJECTIVE To assess LVEDP and its prognostic implications in ACS patients. METHODS Prospective, longitudinal and continuous study of 1329 ACS patients from a single center between 2004 and 2006. Diastolic function was determined by LVEDP. Population was divided in two groups: A - LVEDP < 26.5 mmHg (n = 449); group B - LVEDP ≥ 26.5 mmHg (n = 226). RESULTS There were no significant differences between groups with respect to risk factors for cardiovascular disease, medical history and medical therapy during admission. In group A, patients with non-ST elevation ACS were more frequent, as well as normal coronary angiograms. In-hospital mortality was similar between groups, but one-year survival was higher in group A patients (96.9 vs 91.2%, log rank p = 0.002). On a multivariate Cox regression model, a LVEDP ≥ 26.5 mmHg (HR 2.45, 95%CI 1.05 - 5.74) remained an independent predictor for one-year mortality, when adjusted for age, LV systolic ejection fraction, ST elevation ACS, peak troponin, admission glycemia, and diuretics at 24 hours. Also, a LVEDP ≥ 26.5 mmHg was an independent predictor for a future readmission due to congestive HF (HR 6.65 95%CI 1.74 - 25.5). CONCLUSION In our selected population, LVEDP had a significant prognostic influence.FUNDAMENTO: Ha falta de dados sobre o impacto prognostico da pressao diastolica final do ventriculo esquerdo (PDFVE) sobre as sindromes coronarianas agudas (SCA). OBJETIVO: Avaliar a PDFVE e suas implicacoes prognosticas em pacientes com SCA. METODOS: Estudo prospectivo, longitudinal e continuo de 1.329 pacientes com SCA de um unico centro, realizado entre 2004 e 2006. A funcao diastolica foi determinada atraves da PDFVE. A populacao foi dividida em dois grupos: Grupo A - PDFVE 26,5 mmHg (n = 226). RESULTADOS: Nao houve diferencas significantes entre os grupos em relacao aos fatores de risco para doenca cardiovascular, historico medico e terapia medica durante a admissao. Nos pacientes do grupo A, a SCA sem elevacao do segmento ST foi mais frequente, bem como angiogramas coronarios normais. A mortalidade hospitalar foi similar entre os grupos, mas a sobrevida de um ano foi maior entre os pacientes do grupo A (96,9 vs 91,2%, log rank p = 0,002). Em um modelo multivariado de regressao de Cox, uma PDFVE > 26,5 mmHg (RR 2,45, IC95% 1,05 - 5,74) permaneceu um preditor independente para mortalidade de um ano, quando ajustado para idade, fracao de ejecao sistolica do VE, SCA com elevacao do segmento ST, pico da troponina, glicemia na admissao hospitalar e diureticos apos 24 horas. Alem disso, uma PDFVE > 26,5 mmHg foi um preditor independente de uma futura rehospitalizacao por IC congestiva (RR 6,65 IC95% 1,74 - 25,5). CONCLUSAO: Em nossa populacao selecionada, a PDFVE apresentou uma influencia prognostica significante.

Prognosis following acute coronary syndromes according to prior coronary artery bypass grafting: Meta-analysis

Purpose: Conduct a meta-analysis to study the prognostic influence of a previous coronary artery bypass grafting (CABG) in patients admitted for an acute coronary syndrome (ACS). Methods: A systematic review of the literature was performed using electronic reference databases through January 2013 (MEDLINE, Cochrane Library, Web of Knowledge, Google Scholar and references cited in other studies). Studies in which ACS outcomes with a previous history of CABG were compared with ACS outcomes with no history of previous CABG were considered for inclusion. The main endpoints of interest were mortality and non-fatal acute myocardial infarction. Data was aggregated at three follow-up times using random-effects meta-analysis models. Results: Twenty-four studies were included which provided 387,181 patients for analysis. Previous CABG ACS patients were older, more diabetic and had a more frequent history of a previous myocardial infarction. Pooled in-hospital mortality was higher for the previous CABG ACS patients (OR 1.22 [1.04–1.44], p<0.01, I2 88%). The pooled adjusted OR showed no significant differences for the two groups (adjusted OR 1.13 [0.93–1.37], p=0.22, I2 92%). Previous CABG ACS patient had a higher pooled 30-day mortality (OR 1.28 [1.05–1.55], p=0.02, I2 74%); a higher non-adjusted (OR 1.61 [1.38–1.88], p<0.01, I2 70%) and adjusted (adjusted OR 1.37 [1.15–1.65], p<0.01, I2 0%) long-term mortality. Both the in-hospital and the long-term re-infarction rates were higher for the previous CABG ACS patients. Conclusions: According to our data, ACS patients with previous CABG history had a higher risk for short- and long-term adverse events.

Pressão diastólica final do ventrículo esquerdo e síndromes coronarianas agudas

BACKGROUND Data is lacking in the literature regarding the prognostic impact of left ventricular-end diastolic pressure (LVEDP) across acute coronary syndromes (ACS). OBJECTIVE To assess LVEDP and its prognostic implications in ACS patients. METHODS Prospective, longitudinal and continuous study of 1329 ACS patients from a single center between 2004 and 2006. Diastolic function was determined by LVEDP. Population was divided in two groups: A - LVEDP < 26.5 mmHg (n = 449); group B - LVEDP ≥ 26.5 mmHg (n = 226). RESULTS There were no significant differences between groups with respect to risk factors for cardiovascular disease, medical history and medical therapy during admission. In group A, patients with non-ST elevation ACS were more frequent, as well as normal coronary angiograms. In-hospital mortality was similar between groups, but one-year survival was higher in group A patients (96.9 vs 91.2%, log rank p = 0.002). On a multivariate Cox regression model, a LVEDP ≥ 26.5 mmHg (HR 2.45, 95%CI 1.05 - 5.74) remained an independent predictor for one-year mortality, when adjusted for age, LV systolic ejection fraction, ST elevation ACS, peak troponin, admission glycemia, and diuretics at 24 hours. Also, a LVEDP ≥ 26.5 mmHg was an independent predictor for a future readmission due to congestive HF (HR 6.65 95%CI 1.74 - 25.5). CONCLUSION In our selected population, LVEDP had a significant prognostic influence.FUNDAMENTO: Ha falta de dados sobre o impacto prognostico da pressao diastolica final do ventriculo esquerdo (PDFVE) sobre as sindromes coronarianas agudas (SCA). OBJETIVO: Avaliar a PDFVE e suas implicacoes prognosticas em pacientes com SCA. METODOS: Estudo prospectivo, longitudinal e continuo de 1.329 pacientes com SCA de um unico centro, realizado entre 2004 e 2006. A funcao diastolica foi determinada atraves da PDFVE. A populacao foi dividida em dois grupos: Grupo A - PDFVE 26,5 mmHg (n = 226). RESULTADOS: Nao houve diferencas significantes entre os grupos em relacao aos fatores de risco para doenca cardiovascular, historico medico e terapia medica durante a admissao. Nos pacientes do grupo A, a SCA sem elevacao do segmento ST foi mais frequente, bem como angiogramas coronarios normais. A mortalidade hospitalar foi similar entre os grupos, mas a sobrevida de um ano foi maior entre os pacientes do grupo A (96,9 vs 91,2%, log rank p = 0,002). Em um modelo multivariado de regressao de Cox, uma PDFVE > 26,5 mmHg (RR 2,45, IC95% 1,05 - 5,74) permaneceu um preditor independente para mortalidade de um ano, quando ajustado para idade, fracao de ejecao sistolica do VE, SCA com elevacao do segmento ST, pico da troponina, glicemia na admissao hospitalar e diureticos apos 24 horas. Alem disso, uma PDFVE > 26,5 mmHg foi um preditor independente de uma futura rehospitalizacao por IC congestiva (RR 6,65 IC95% 1,74 - 25,5). CONCLUSAO: Em nossa populacao selecionada, a PDFVE apresentou uma influencia prognostica significante.