Ana Faustino

Cardiac troponin I: Prothrombotic risk marker in non-valvular atrial fibrillation

BACKGROUND Evidence of a link between small rises in cardiac troponin I (cTnI) and an increased risk of thromboembolic events (TE) in atrial fibrillation (AF) is currently scarce. OBJECTIVES We aimed to assess the relation between cTnI and findings of an increased thromboembolic risk in patients with non-valvular AF using transesophageal echocardiography. METHODS We have included 245 patients performing transthoracic and transesophageal echocardiogram, alongside with laboratory assessment (including cTnI) in a cross-sectional survey. Changes associated to TE were sought on transesophageal echocardiogram: left atrial or left atrial appendage thrombus, dense spontaneous echocardiographic contrast, low flow velocities in the left atrial appendage and protuberant aortic plaques. Comparisons were performed according to the baseline concentration of cTnI, regarding the prevalence of these changes. We have added cTnI to CHADS2 and CHA2DS2-VASc scores in order to assess its capability to refine risk stratification using transesophageal markers as surrogate endpoints and assessed it by means of ROC-curve analysis and Net Reclassification Improvement (NRI). RESULTS A direct relation between rising concentrations of cTnI and a higher prevalence of transesophageal echocardiogram changes was found. Furthermore, the addition of cTnI to CHADS2 and CHA2DS2-VASc scores improved their ability to predict changes associated to TE on transesophageal echocardiography both through ROC-curve analysis and NRI. CONCLUSION cTnI seems to be associated to thromboembolic risk in patients with AF. The possible role of cTnI in the refinement of risk stratification schemes needs to be tested in further prospective studies using clinical endpoints.

Decreased Glomerular Filtration Rate and Markers of Left Atrial Stasis in Patients with Nonvalvular Atrial Fibrillation

Background: It is currently unknown if the increased risk of stroke in subjects with chronic kidney disease and atrial fibrillation (AF) is due to the presence of left atrial stasis or to any other vascular or systemic conditions. Methods: This was a retrospective study of 372 subjects undergoing evaluation during an AF episode. The following markers of left atrial stasis were sought on transesophageal echocardiogram: left atrial or left atrial appendage thrombus (LAAT), dense spontaneous echocardiographic contrast (DSEC), and low flow velocities (LFV) in the left atrial appendage. Subgroup comparisons were performed according to the level of estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration equation as follows: ≥90, 45–89.9, and <45 ml/min/1.73 m2. Results: LAAT was found in 11.6%, DSEC in 29.0%, and LFV in 14.9% of cases. A significant increase in the prevalence of DSEC was observed in the lower categories of eGFR: 37.8% in eGFR <45 ml/min, 30.7% in eGFR 45–89.9 ml/min, and 17.0% in eGFR ≥90 ml/min (p = 0.009; γ for trend = 0.297, p = 0.002). The same was observed when assessing left atrial abnormality, i.e. the presence of at least one of the former transesophageal echocardiogram changes. On multivariate analysis, clinical parameters from CHADS2 (congestive heart failure, hypertension, age ≥75, diabetes mellitus and stroke) and CHA2DS2-VASc (age 65–74, history of vascular disease, and female gender along with the clinical variables from CHADS2) were predictors of transesophageal echocardiogram changes and an additive predictive value was found for eGFR. Conclusions: Our results suggest an association between compromised renal function as assessed through eGFR and markers of left atrial stasis in patients with AF. The increased risk of stroke in this population may be due to thromboembolism.

Cardiovascular Risk Assessment of Pulmonary Embolism With the GRACE Risk Score

Despite the existence of several risk scores, the accurate prediction of the prognosis in pulmonary embolism (PE) remains a challenge. The Global Registry of Acute Coronary Events (GRACE) risk score has a high diagnostic performance for adverse outcomes in acute coronary syndrome. We aimed to assess the applicability and extend the use of the GRACE risk score to PE. A case-control study of 206 consecutive patients admitted with PE was performed. The GRACE, Geneva, Simplified Pulmonary Embolism Severity Index, Shock Index, and European Society of Cardiology risk scores were tested for the prediction of the primary end point: all-cause 30-day mortality. Comparisons between GRACE and the other risk scores were performed using receiver operating characteristic area under the curve and the integrated discrimination improvement index. All-cause 30-day mortality was observed in 18.9% of the patients. Unlike the other classifications, no adverse outcomes were observed in patients classified as low risk using the GRACE risk score (100% negative predictive value for GRACE risk score ≤113). The GRACE score showed greater discriminative performance than the Geneva score (area under the curve 0.623, 95% confidence interval [CI] 0.53 to 0.71), Shock Index (area under the curve 0.639, 95% CI 0.55 to 0.73), European Society of Cardiology (area under the curve 0.662, 95% CI 0.57 to 0.76), and Simplified Pulmonary Embolism Severity Index (area under the curve 0.705, 95% CI 0.61 to 0.80), although statistical significance was not reached. The integrated discrimination improvement index suggested a more appropriate risk classification with the GRACE score. In conclusion, our results have demonstrated that the GRACE risk score can accurately predict 30-day mortality in patients admitted for acute PE. Compared to previously proposed PE prediction rules, the GRACE risk score presented improved overall risk classification.

Which method of left atrium size quantification is the most accurate to recognize thromboembolic risk in patients with non-valvular atrial fibrillation?

BackgroundLeft atrial (LA) size is a predictor of cardiovascular outcomes in patients in sinus rhythm, whereas conflicting results have been found in atrial fibrillation (AF). This study aims to: (1) Evaluate the accuracy of LA size to identify surrogate markers of an increased thromboembolic risk in patients with AF; (2) Assess the best method to evaluate LA size in this setting.MethodsCross-sectional study enrolling 500 consecutive patients undergoing transthoracic and transesophageal echocardiography evaluation during a non-valvular AF episode. LA size was measured on transthoracic echocardiography using several methods: anteroposterior diameter, area in four-chamber view, and volumes by the ellipsoid, single- and biplane area-length formulas. Surrogate markers of stroke were evaluated by transesophageal echocardiography: LA appendage (LAA) thrombus, LAA low flow velocities, dense spontaneous echocardiographic contrast and LA abnormality.ResultsExcept for non-indexed anteroposterior diameter, increased LA size quantified by all the other methods showed a moderate to high discriminatory power to identify all the surrogate markers of stroke. A higher accuracy was observed for indexed LA area in four-chamber view (LAA thrombus: AUC = 0.708, CI95% 0.644- 0.772, p<0.001; LAA low flow velocities: AUC = 0.733, CI95% 0.674- 0.793, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.693, CI95% 0.638- 0.748, p<0.001; LA abnormality: AUC = 0.705, CI95% 0.654-0.755, p<0.001), indexed single-plane area-length volume (LAA thrombus: AUC = 0.701, CI95% 0.633-0.770, p<0.001; LAA low flow velocities: AUC = 0.726, CI95% 0.660-0.792, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.673, CI95% 0.611-0.736, p<0.001; LA abnormality: AUC = 0.687, CI95% 0.629-0.744, p<0.001), and indexed biplane area-length volume (LAA thrombus: AUC = 0.707, CI95% 0.626-0.788, p<0.001; LAA low flow velocities: AUC = 0.737, CI95% 0.664-0.810, p<0.001; dense spontaneous echocardiographic contrast: AUC = 0.651, CI95% 0.578-0.724, p<0.001; LA abnormality: AUC = 0.683, CI95% 0.617-0.749, p<0.001), without significant difference between them. Indexed LA area in four-chamber view and indexed area-length volumes also were independent predictors of surrogate markers of stroke.ConclusionsLeft atrium enlargement is associated with an increased prevalence of surrogate markers of stroke in patients with non-valvular AF. Indexed LA area in four-chamber view and indexed area-length volumes displayed the strongest association.

Cardioversion safety in patients with nonvalvular atrial fibrillation: which patients can be spared transesophageal echocardiography?

The objective of this study was to derive and test a score that can accurately predict the presence of left atrial or left atrial appendage thrombus (LAAT) in order to identify patients with nonvalvular atrial fibrillation who can be spared transesophageal echocardiogram (TEE) and safely cardioverted. This cross-sectional observational study including 180 individuals (37.2% women) undergoing clinical, echocardiographic and laboratory evaluation (including cardiac troponin I and C reactive protein; CRP) during an atrial fibrillation episode. LAAT was sought on TEE and predictors of this transesophageal echocardiographic finding were assessed. Based on predictors of LAAT (CRP, atrial volume, troponin, episode duration and stroke or embolism) we derived the CATES score and tested its accuracy through receiver operating curve analysis. LAAT was found in 9.4%. CHADS2 and CHA2DS2-VASc had a modest performance in predicting these changes displaying a 0.620 (c-statistic) in average. Using CATES score displayed a higher area under the curve value 0.816 for LAAT. No patients with LAAT were observed in patients with CATES scores ranging from ‘0’ to ‘2’, which corresponded to 49.4% (n = 89) of the sample. We developed a score that presented a very good accuracy for the detection of LAAT in our sample. Further studies in other populations, such as with bigger dimensions, are needed to validate this score and confirm its capability of selecting a very low risk group of patients that can be spared transesophageal echocardiography.

Can cardiac computed tomography predict cardiovascular events in asymptomatic type-2 diabetics?: results of a long term follow-up

BackgroundDoubts remain about atherosclerotic disease and risk stratification of asymptomatic type-2 diabetic patients (T2DP). This study aims to evaluate the usefulness of calcium score (CS) and coronary computed tomography (CT) angiography (CTA) to predict fatal and non fatal cardiovascular events (CVEV) in T2DP.MethodsEighty-five consecutive T2DP undergoing CT (Phillips Brilliance, 16-slice) with CS and CTA were prospectively enrolled in a transversal case-control study. Patients were followed for 48 months (range 18 - 68) to assess CVEV: cardiovascular death, acute coronary syndrome, revascularisation and stroke. Potential predictors of CVEV were identified. Predictive models based on clinical features, CTA and CS were created and compared.ResultsPerforming CT impacted T2DP treatment. Cardiovascular risk was lowered during follow-up but metabolic control remained suboptimal. CVEV occurred in 11.8% T2DP (3.1%/year). CS ≥86.6 was predictor of CVEV over time, with a high negative predictive value, an 80% sensitivity and 74.7% specificity. Although its prognostic value was not independent of the presence/absence of obstructive CAD, adding CS and CTA data to clinical parameters improved the prediction of CVEV: the combined model had the highest AUC (0.888, 95%CI 0.789-0.987, p < 0.001) for the prediction of the study endpoints.ConclusionsCS showed great value in T2DP risk stratification and its prognostic value was further enhanced by CTA data. Information provided by CT may help predict CVEV in T2DP and potentially improve their outcome.

Troponin rise in patients with atrial fibrillation: A marker of adverse prognosis and increased thromboembolic risk

We have read with interest the article by Parwani and colleagues addressing the role of atrial fibrillation (AF) in induction of troponin release in patients presenting to the Emergency Department with AF and clinical symptoms suggestive of myocardial ischemia [1]. In face of their findings in 100 patients undergoing coronary angiography, of whom 23 had an elevated cardiac troponin I (N0.09 μg/L), the authors have suggested that troponin rise may be “falsely elevated” in this setting, since the prevalence of significant stenosis was similar irrespective of troponin rise: 26% in patients with positive troponin vs. 33% in patients with normal troponin (p = ns). However, we feel that, contrary to the authors opinion, troponin rise in this setting must be addressed with care in face of the recent evidence that we will shortly present. Conti and colleagues have recently shown that elevated cardiac troponin I is a predictor of poor outcome (a composite of stroke, acute coronary syndrome, revascularization, and global death) in patients presenting to the Emergency Department with AF lasting for less than 12 h [2]. The association of minor troponin elevations with an adverse prognosis in patients with AF has also been previously addressed by Van den Bos et al. in a prospective cohort study of 407 consecutive patients with AF admitted to the cardiology ward or intensive coronary unit (patients with ST elevation myocardial infarction were excluded) [3]. These authors have found that minor rises (N0.015 ng/ mL) were present in 20% of patients and associated with death, fatal myocardial infarction and major cardiovascular events (all-cause mortality, myocardial infarction and revascularization). As far as risk stratification of AF is concerned, minor rises in troponin seem also to have a major role in the prediction of thromboembolic events and may improve the discriminative capability of current risk classification schemes (CHADS2 and CHA2DS2-VASc), according to data from the “Randomised Evaluation of Long Term Anticoagulant Therapy” (RE-LY) trial biomarkers substudy [4]. Based on data from patients with AF undergoing transesophageal echocardiogram, this may be explained by the increased prevalence of markers of left atrial stasis (i.e., left atrial and left atrial appendage thrombi, dense spontaneous echocardiographic contrast and low flow velocities in the left atrial appendage), which are known to very strongly associate with embolism, and to increase in prevalence as troponin levels rise [5]. Therefore, we feel that minor elevations of troponin in patients with AF should be handled with care and not promptly assumed as false positives. In a first instance, ongoing myocardial ischemia should be ruled out if the clinical context is suggestive and the pretest probability is moderate or elevated. Then, even if the results are negative or the context is not suggestive of myocardial ischemia, an adequate prevention of thromboembolism should be considered, preferentially with anticoagulants, according to data of the RE-LY Biomarkers sub-analysis, if the bleeding risk of each particular patient is not prohibitive. The authors of this manuscript have verified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology and complies with the Statement on Matching Language to the Type of Evidence Used in Describing Outcomes Data [6].

Improving risk stratification in non-ST-segment elevation myocardial infarction with combined assessment of GRACE and CRUSADE risk scores

BACKGROUND Risk assessment is fundamental in the management of acute coronary syndromes (ACS), enabling estimation of prognosis. AIMS To evaluate whether the combined use of GRACE and CRUSADE risk stratification schemes in patients with myocardial infarction outperforms each of the scores individually in terms of mortality and haemorrhagic risk prediction. METHODS Observational retrospective single-centre cohort study including 566 consecutive patients admitted for non-ST-segment elevation myocardial infarction. The CRUSADE model increased GRACE discriminatory performance in predicting all-cause mortality, ascertained by Cox regression, demonstrating CRUSADE independent and additive predictive value, which was sustained throughout follow-up. The cohort was divided into four different subgroups: G1 (GRACE<141; CRUSADE<41); G2 (GRACE<141; CRUSADE≥41); G3 (GRACE≥141; CRUSADE<41); G4 (GRACE≥141; CRUSADE≥41). RESULTS Outcomes and variables estimating clinical severity, such as admission Killip-Kimbal class and left ventricular systolic dysfunction, deteriorated progressively throughout the subgroups (G1 to G4). Survival analysis differentiated three risk strata (G1, lowest risk; G2 and G3, intermediate risk; G4, highest risk). The GRACE+CRUSADE model revealed higher prognostic performance (area under the curve [AUC] 0.76) than GRACE alone (AUC 0.70) for mortality prediction, further confirmed by the integrated discrimination improvement index. Moreover, GRACE+CRUSADE combined risk assessment seemed to be valuable in delineating bleeding risk in this setting, identifying G4 as a very high-risk subgroup (hazard ratio 3.5; P<0.001). CONCLUSIONS Combined risk stratification with GRACE and CRUSADE scores can improve the individual discriminatory power of GRACE and CRUSADE models in the prediction of all-cause mortality and bleeding. This combined assessment is a practical approach that is potentially advantageous in treatment decision-making.

Encerramento percutâneo do apêndice auricular esquerdo para profilaxia de tromboembolismo na fibrilhação auricular

Atrial fibrillation is a common arrhythmia in clinical practice. It is associated with high morbidity and mortality due to its thromboembolic potential, which makes thromboembolic prevention particularly important. Warfarin has been the first-line therapy for this purpose, but it has various limitations and is often contraindicated or underutilized. The fact that thrombi are frequently located in the left atrial appendage in atrial fibrillation led to the development of percutaneous closure for thromboembolic prevention. This article examines the current evidence on percutaneous closure of the left atrial appendage by reviewing the results of the numerous clinical trials on the technique.

Síndrome cardiorrenal na insuficiência cardíaca aguda: um círculo vicioso?

INTRODUCTION AND OBJECTIVE Worsening renal function has an unquestionably negative impact on prognosis in patients with acute heart failure (HF). In Portugal there is little information about the importance of this entity in HF patients admitted to hospital. The objective of this work was to assess the prevalence of cardiorenal syndrome and to identify its key predictors and consequences in patients admitted for acute HF. METHODS This was a retrospective study of 155 patients admitted for acute HF. Cardiorenal syndrome was defined as an increase in serum creatinine of ≥26.5 μmol/l. Clinical, laboratory and echocardiographic parameters were analyzed and compared. Mortality was assessed at 30 and 90 days. RESULTS Cardiorenal syndrome occurred in 46 patients (29.7%), 5.4 ± 4.4 days after admission; 66.7% (n=24) did not recover baseline creatinine levels. The factors associated with cardiorenal syndrome were older age, chronic renal failure, moderate to severe mitral regurgitation, higher admission blood urea nitrogen, creatinine and troponin I, and lower glomerular filtration rate. Patients who developed cardiorenal syndrome had longer hospital stay, were treated with higher daily doses of intravenous furosemide, and more often required inotropic support and renal replacement therapy. They had higher in-hospital and 30-day mortality, and multivariate analysis identified cardiorenal syndrome as an independent predictor of in-hospital mortality. CONCLUSIONS Renal dysfunction is common in acute HF patients, with a negative impact on prognosis, which highlights the importance of preventing kidney damage through the use of new therapeutic strategies and identification of novel biomarkers.