B-type natriuretic peptide levels predict functional capacity in postcardiac surgery patients.

OBJECTIVE: Plasma levels of B-type natriuretic peptide (BNP) are often increased in postcardiac surgery patients. The six-minute walking test (6MWT) is useful to assess functional capacity in postcardiac surgery patients. The aim of this study was to determine whether BNP levels are associated with exercise capacity evaluated by 6MWT in patients after cardiac surgery. METHODS: Plasma BNP was measured in 101 consecutive patients referred to our center 8 ± 5 days after cardiac surgery who underwent echocardiography and 6MWT. We considered age, sex, diabetes, renal insufficiency, anemia, chronic obstructive pulmonary disease, hypertension, atrial fibrillation, beta-blocker therapy, left ventricular ejection fraction (LVEF), E/E', indexed left atrial volume (iLAV), type of surgery, and plasma BNP levels as potential predictors of reduced performance at 6MWT evaluated as percentages of the predicted values calculated according to the regression equation obtained in healthy individuals. RESULTS: The mean distance walked at 6MWT was 325 ± 100 m corresponding to 65 ± 20% of the predicted values. This was independent of the LVEF, E/E' or iLAV. Female patients or patients with atrial fibrillation had a reduced performance compared with male patients or patients with sinus rhythm (52 ± 19 vs. 70 ± 19%, P < 0.001; 50 ± 19 vs. 66 ± 19%, P = 0.017, respectively). BNP levels were inversely related to the performance at 6MWT (Pearson's correlation coefficient = -0.25, P = 0.010). At multivariate analysis, female sex (P < 0.001), atrial fibrillation (P = 0.031), and BNP levels (P = 0.040) remained the only independent predictive factors for reduced exercise capacity. CONCLUSION: The increase in BNP levels in postcardiac surgery patients is associated with reduced exercise capacity.

Relationship between B-type natriuretic peptide levels and echocardiographic indices of left ventricular filling pressures in post-cardiac surgery patients.

BACKGROUND: B-type natriuretic peptide (BNP) is increased in post-cardiac surgery patients, however the mechanisms underlying BNP release are still unclear. In the current study, we aimed to assess the relationship between postoperative BNP levels and left ventricular filling pressures in post-cardiac surgery patients. METHODS: We prospectively enrolled 134 consecutive patients referred to our Center 8 +/- 5 days after cardiac surgery. BNP was sampled at hospital admission and related to the following echocardiographic parameters: left ventricular (LV) diastolic volume (DV), LV systolic volume (SV), LV ejection fraction (EF), LV mass, relative wall thickness (RWT), indexed left atrial volume (iLAV), mitral inflow E/A ratio, mitral E wave deceleration time (DT), ratio of the transmitral E wave to the Doppler tissue early mitral annulus velocity (E/E'). RESULTS: A total of 124 patients had both BNP and echocardiographic data. The BNP values were significantly elevated (mean 353 +/- 356 pg/ml), with normal value in only 17 patients (13.7%). Mean LVEF was 59 +/- 10% (LVEF >or=50% in 108 pts). There was no relationship between BNP and LVEF (p = 0.11), LVDV (p = 0.88), LVSV (p = 0.50), E/A (p = 0.77), DT (p = 0.33) or RWT (p = 0.50). In contrast, BNP was directly related to E/E' (p < 0.001), LV mass (p = 0.006) and iLAV (p = 0.026). At multivariable regression analysis, age and E/E' were the only independent predictors of BNP levels. CONCLUSION: In post-cardiac surgery patients with overall preserved LV systolic function, the significant increase in BNP levels is related to E/E', an echocardiographic parameter of elevated LV filling pressures which indicates left atrial pressure as a major determinant in BNP release in this clinical setting.

'Lone' increase in C-reactive protein after cardiac surgery: prevalence, clinical characteristics, in-hospital course, and prognostic value.

BACKGROUND: Serum C-reactive protein (CRP) is involved in the acute phase reaction after surgery, even though its clinical significance remains a matter of debate. We evaluated CRP levels in cardiac surgery patients without clinical or laboratory signs of infection. METHODS: We screened 737 consecutive patients referred to our center 8+/-5 days after cardiac surgery. Patients with fever (>37.2 degrees C), elevated white blood cell count (>11,000/ml), neutrophilia (>70%), or any inflammatory, infective or malignant disease were excluded. CRP levels were measured on admission and at discharge and the values were related to the following variables: age, sex, diabetes mellitus, renal failure, type of surgery, postoperative atrial fibrillation, pericardial or pleural effusion, and length of hospital stay. Follow-up (mean: 23+/-8.5 months) was available for 175 patients (94%). RESULTS: In the 187 patients enrolled in the study, the CRP values were significantly elevated (median: 4.23 mg/dl, interquartiles range: 2.68-6.64) independent of any variable analyzed. At discharge, CRP levels were significantly reduced compared with values on admission (median: 1.55 mg/dl, interquartiles range: 0.84-2.37, P<0.001). At follow-up, 19 events (10.8%) occurred (two noncardiac deaths, 17 hospital readmissions for cardiac reasons); nonetheless, no correlation was found with CRP values either on admission or at discharge. CONCLUSION: Early after cardiac surgery, in patients without clinical or laboratory signs of acute infection, CRP levels are significantly elevated, do not correlate with clinical variables, and decrease at discharge. These findings suggest a systemic inflammatory response to surgery-related stress, which carries a favorable prognosis at follow-up.

Echocardiographic estimation of pulmonary pressures.

Cardiac ultrasound plays a pivotal role in assessing pulmonary artery pressures. Estimation of right atrial pressure can be derived from the dimensions and respiratory variation of the inferior vena cava and Doppler modalities provide an accurate and comprehensive evaluation of right ventricular and pulmonary artery pressures. Peak pulmonary artery pressure can be calculated from continuous wave Doppler sampling of the tricuspid regurgitant jet, while pulsed wave Doppler sampling of the pulmonary regurgitant jet allows evaluation of mean and diastolic pulmonary artery pressures. In patients with tricuspid regurgitation that is either absent or not adequately detectable by Doppler method, Doppler right ventricular outflow tract investigation can be helpful. Recent data indicate that analysis of right ventricular function using myocardial Doppler echocardiography may also provide new insights for the non-invasive estimation of pulmonary artery pressures. In particular, right ventricular isovolumic relaxation time measured by myocardial Doppler echocardiography at the tricuspid annulus may provide an alternative method for estimating pulmonary artery pressure, especially in patients with tricuspid regurgitation not detectable or spectral Doppler not properly interpretable.

[Mitral valve prolapse]. / Il prolasso valvolare mitralico.

Mitral valve prolapse (MVP) is still a clinical challenging problem. In this report, we review the main characteristics of this entity. Epidemiology of MVP, which relies on the diagnostic criteria adopted, and the incidence of complications, both arrhythmic and structural, are influenced by the characteristics of the population studied, which may lead to bias in data interpretation. Even the definition of MVP may differ according to the cardiologist's or cardiac surgeon's point of view. Usually, cardiologists define MVP as the protrusion of all or part of the mitral leaflets into the left atrium, independent of maintenance of coaptation. Therefore, using this definition, mitral regurgitation is considered as a complication rather than a diagnostic criterion. Arrhythmias, either supraventricular or ventricular, are other possible complications, mostly not life-threatening and associated with myxomatous degeneration of the valve. Diagnosis of MVP is based on echocardiography, which provides detailed anatomic and functional evaluation of the affected valve. Leaflet thickness and motion as well as presence and severity of mitral regurgitation can be assessed, with important diagnostic and prognostic implications. Echocardiographic evaluation of the mitral valve requires a systematic approach in order to define the leaflet/scallop involved and the mechanisms of mitral regurgitation. To this aim, three-dimensional reconstruction may add further insights into objective rendering of mitral valve pathology. Finally, surgical timing in mitral regurgitation due to MVP is an evolving issue and the likelihood of surgical repair is a crucial factor in the optimal timing of surgical intervention, especially in asymptomatic patients with severe mitral regurgitation.

Bedside diagnosis and follow-up of patients with pleural effusion by a hand-carried ultrasound device early after cardiac surgery.

OBJECTIVES: The aim of this study was to assess the potential value of hand-carried ultrasound (HCU) devices in the diagnosis and follow-up of patients with pleural effusion (PE) after cardiac surgery. METHODS: Seventy consecutive patients were evaluated at bedside early after cardiac surgery, in the upright sitting position, using an HCU device on hospital admission and every 3 days until hospital discharge. The posterior chest wall was scanned along the paravertebral, scapular, and posterior axillary lines. For each hemithorax, an effusion index was derived as the sum of the intercostal spaces between the lower and upper limits of the PE along the lines of scanning, divided by 3. A standard chest radiograph was performed in all patients on hospital admission and at hospital discharge, and was qualitatively scored (0, absent; 1, small; 2, large PE). The findings of the HCU device and radiograph were compared using kappa statistics and the Kruskal-Wallis test. RESULTS: A chest ultrasound was feasible in all patients (mean [+/- SD] time, 5 +/- 2 min). Compared with the chest ultrasound, a physical examination showed a sensitivity of 69% and a specificity of 77%. On hospital admission, the HCU device detected a PE in 72 of 140 hemithoraxes. Agreement with the finding of the radiograph was 76% (kappa = 0.52). In 15 hemithoraxes, the HCU device revealed a PE that had not been diagnosed using the radiograph. Conversely, in 18 hemithoraxes a PE that had been diagnosed with a radiograph was not confirmed by the HCU device. The correlation between ultrasound and radiographic scores was statistically significant (p < 0.001). At hospital discharge, a PE was present in 31 of 140 hemithoraxes according to the findings of the HCU device, and in 38 of 140 hemithoraxes according to the findings of the radiograph (agreement, 78%; kappa = 0.44). CONCLUSIONS: In patients early after cardiac surgery, HCU devices allow rapid PE detection and improve the clinical diagnosis. Compared to a radiograph, this method offers the unique advantage of the bedside evaluation of patients without the need for radiation exposure.

[Digital echocardiography laboratory]. / L'acquisizione e la gestione delle immagini nel laboratorio digitale di ecocardiografia.

The implementation of a digital echocardiography laboratory exists today using the DICOM (Digital Imaging Communication in Medicine) standard to acquire, store and transfer echocardiographic digital images. The components of a laboratory include: 1) digital echocardiography machines with DICOM output, 2) a switched high-speed local area network, 3) a DICOM server with abundant local storage, and 4) a software to manage image and measurement information. The aim of this article was to describe the critical components of a digital echocardiography laboratory, discuss strategies for implementation, and describe some of the pitfalls that we encountered in our own implementation of the digital third level echocardiography laboratory.

Clinical, exercise electrocardiographic, and pharmacologic stress echocardiographic findings for risk stratification of hypertensive patients with chest pain.

Exercise electrocardiography (ECG) is of limited usefulness in hypertensive patients, whereas pharmacologic stress echocardiography can provide diagnostic and prognostic information. The aim of this study was to compare the prognostic value of clinical data, exercise ECG, and pharmacologic stress echocardiography in hypertensive patients with chest pain and to identify the best strategy for their risk stratification. Three hundred sixty-seven hypertensive patients (189 men, age 61 +/- 9 years) with chest pain of unknown origin underwent exercise ECG and pharmacologic stress echocardiography (237 with dipyridamole and 130 with dobutamine) and were followed up for 31 +/- 24 months. Positive exercise ECG (ST-segment shift of > or =1 mm at 80 ms after the J point) and stress echocardiography (new wall motion abnormalities) were found in 130 (35%) and 86 (23%) patients, respectively. During follow-up, there were 13 deaths and 16 myocardial infarctions. Additionally, 43 patients underwent coronary revascularization and were censored accordingly. Of 12 clinical, electrocardiographic, and echocardiographic variables analyzed, a positive result of stress echocardiography was the only multivariate predictor of either death (hazard ratio [HR] 4.7, 95% confidence interval [CI] 1.5 to 14.5, p = 0.007) or hard events (death, myocardial infarction) (HR 4.1, 95% CI 1.8 to 9.3, p = 0.0009). Using an interactive stepwise procedure, stress echocardiography provided additional prognostic information to clinical evaluation and exercise ECG. However, the negative predictive value of the 2 tests was similarly (p = NS) high in assessing 4-year event-free survival. In conclusion, a negative exercise electrocardiographic test identifies low-risk hypertensive patients with chest pain and should be the first-line approach for risk stratification. In contrast, positive exercise ECG is unable to distinguish between patients with different levels of risk. In this case, stress echocardiography provides strong and incremental prognostic power over clinical and exercise electrocardiographic data.