Umberto Conti

Added Value of 99mTc-HMPAO–Labeled Leukocyte SPECT/CT in the Characterization and Management of Patients with Infectious Endocarditis

The clinical performance of the Duke Endocarditis Service criteria to establish the diagnosis of infectious endocarditis (IE) can be improved through functional imaging procedures such as radiolabeled leukocytes (99mTc-hexamethylpropyleneamine oxime [HMPAO]–labeled white blood cells [WBC]). Methods: We assessed the value of 99mTc-HMPAO-WBC scintigraphy including SPECT/CT acquisitions in a series of 131 consecutive patients with suspected IE. Patients with permanent cardiac devices were excluded. 99mTc-HMPAO-WBC scintigraphy results were correlated with transthoracic or transesophageal echocardiography, blood cultures, and the Duke criteria. Results: Scintigraphy was true-positive in 46 of 51 and false-negative in 5 of 51 cases (90% sensitivity, 94% negative predictive value, and 100% specificity and positive predictive value). No false-positive results were found, even in patients with early IE evaluated within the first 2 mo from the surgical procedure. In 24 of 51 patients with IE, we also found extracardiac uptake, indicating septic embolism in 21 of 24. Despite the fact that septic embolism was found in 11 of 18 cases of Duke-definite IE, most of the added value from the 99mTc-HMPAO-WBC scan for decision making was seen in patients in whom the Duke criteria yielded possible IE. The scan was particularly valuable in patients with negative or difficult-to-interpret echocardiographic findings because it correctly classified 11 of 88 of these patients as having IE. Furthermore, 3 patients were falsely positive at echocardiography but correctly negative at 99mTc-HMPAO-WBC scintigraphy: these patients had marantic vegetations. Conclusion: Our results demonstrate the ability of 99mTc-HMPAO-WBC scintigraphy to reduce the rate of misdiagnosed cases of IE when combined with standard diagnostic tests in several situations: when clinical suspicion is high but echocardiographic findings are inconclusive; when there is a need for differential diagnosis between septic and sterile vegetations detected at echocardiography; when echocardiographic, laboratory, and clinical data are contradictory; and when valve involvement (especially of a prosthetic valve) needs to be excluded during febrile episodes, sepsis, or postsurgical infections.

Prognostic Value of N-Terminal Pro–Type-B Natriuretic Peptide and Doppler Left Ventricular Diastolic Variables in Patients With Chronic Systolic Heart Failure Stabilized by Therapy

Prognostication of patients with chronic heart failure (HF) stabilized by therapy may be difficult. Therefore, the aim was to evaluate whether combined assessment of plasma N-terminal pro-B natriuretic peptide (NT-pro-BNP) and Doppler left ventricular (LV) diastolic variables was relevant to the prognosis of patients with stable HF. Outpatients with LV systolic HF (ejection fraction < or =45%), classified using clinical criteria as decompensated (n = 94) and stable HF (n = 219), underwent a complete Doppler echocardiographic study. NT-pro-BNP was measured together with mitral wave velocities, E wave deceleration time, and tissue Doppler early septal annular velocity. Median follow-up was 22 months. Freedom from all-cause mortality or HF hospitalization at 24 months was worst (44%) in patients with decompensated HF, intermediate (58%) in patients with stable HF with NT-pro-BNP higher than the median (>1,129 pg/ml), and best (92%) in patients with lower NT-pro-BNP (log-rank p <0.0001). In patients with stable HF, NT-pro-BNP >1,129 pg/ml (hazard ratio [HR] 2.84, p = 0.003), E wave deceleration time <150 ms (HR 2.31, p = 0.004), and tissue Doppler early septal annular velocity <8 cm/s (HR 2.18, p = 0.01) were predictors of the end point at multivariate analysis. The addition of Doppler LV diastolic variables and NT-pro-BNP significantly improved the chi-square test for outcome prediction (from 14.4 to 46.4). In conclusion, NT-pro-BNP and spectral and tissue Doppler variables of LV diastolic dysfunction added independent and incremental contributions to prognostic stratification of patients with stable HF.

Coronary Flow Reserve in Idiopathic Dilated Cardiomyopathy: Relation with Left Ventricular Wall Stress, Natriuretic Peptides, and Endothelial Dysfunction

Studies have demonstrated impaired coronary blood flow reserve (CBFR) in idiopathic dilated cardiomyopathy (IDCM). It was the aim of this study to examine the potential underlying mechanisms for CBFR reduction in patients with IDCM by Doppler ultrasound techniques. Forty-eight clinically stable patients with heart failure caused by IDCM (New York Heart Association classes 1-3) were evaluated by echocardiographic and Doppler techniques with the assessments of CBFR and brachial artery flow-mediated dilation (FMD). CBFR was estimated as the hyperemic (dipyridamole: 0.84 mg/kg in 10 minutes, intravenously) to resting coronary diastolic peak velocities ratio. N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) plasma levels were measured at the time of the index echocardiogram. Left ventricular (LV) ejection fraction was 30% +/- 8%, and wall motion score index was 2.0 +/- 0.25. The best correlation with CBFR was found with LV wall thickness-to-cavity radius (r = 0.77, P < .0001). A strong correlation of log-transformed Nt-pro-BNP levels was observed with CBFR (r = -0.64; P < .0001). No significant correlation was documented between CBFR and FMD. The stepwise regression model showed that LV wall thickness-to-cavity radius was the strongest independent predictor of CBFR followed by New York Heart Association class and log-transformed Nt-pro-BNP leading to a cumulative R value of 0.82 (P < .0001). The results of the study indicate that by measuring variables related to LV end-diastolic wall stress, such as LV wall thickness-to-cavity radius and plasma Nt-proBNP, it is possible to have information about CBFR in patients with heart failure secondary to IDCM.

Plasma N-terminal protype-B natriuretic peptide levels in risk assessment of patients with mitral regurgitation secondary to ischemic and nonischemic dilated cardiomyopathy

BACKGROUND Functional mitral regurgitation (MR) is a factor affecting prognosis of patients with chronic left ventricular (LV) dysfunction. The aim of the study was to investigate whether the evaluation of plasma N-terminal protype-B natriuretic peptide (NT-proBNP) concentrations is useful for prognostic assessment of patients with functional MR due to either ischemic or nonischemic chronic LV dysfunction. METHODS Echocardiograms were obtained in 207 patients with chronic LV dysfunction (ejection fraction <or=45%) and secondary MR at color flow imaging. The NT-proBNP was measured at the time of the index echocardiogram. The MR was graded as mild when a small central jet <4 cm(2) or <20% of left atrial area or a vena contracta width <0.3 cm was present. It was considered moderate in the presence of signs of more-than-mild MR without criteria for severe MR. A vena contracta width >or=0.7 cm raised MR grade to severe. Median follow-up duration was 29 months. RESULTS The NT-proBNP levels increased significantly with MR severity. At multivariate analysis, NT-proBNP was an independent predictor of cardiac death (hazard ratio 2.17, CI 1.10-4.30, P = .026) and the most powerful predictor of cardiac death or heart failure-related hospitalization (hazard ratio 3.19, CI 1.89-5.37, P < .0001). A progressively worse outcome was apparent when patients were stratified by a graded increase in MR severity and by quartiles of NT-proBNP levels. Increased NT-proBNP concentrations and more-than-mild MR identified patients with the highest risk of cardiac mortality. CONCLUSION Assessment of plasma NT-proBNP allows for stratifying patients with functional MR regardless of their degree of valvular incompetence. Even in case of only mild or moderate MR, but increased NT-proBNP, patients have to face poor outcome.

Post-cardioversion transesophageal echocardiography (POSTEC) strategy with the use of enoxaparin for brief anticoagulation in atrial fibrillation patients: the multicenter POSTEC trial (a pilot study).

Objectives In patients with atrial fibrillation (AF), we sought to evaluate the feasibility and safety of a new transesophageal echocardiography (TEE)-guided strategy, aimed at selecting, 7 days post-cardioversion, those patients who are at low risk (i.e. who can terminate anticoagulation after a second TEE) and those at high risk (i.e. who have to continue it). Methods We enrolled 206 patients with non-valvular AF into a randomized, multicenter clinical trial. Group A patients underwent a TEE-guided cardioversion with heparin and at least 4 weeks of oral anticoagulation therapy (OAT) after cardioversion. Group B patients received enoxaparin and underwent a TEE-guided cardioversion. After 7 days, a second TEE was carried out. In the absence of TEE thromboembolic risk factors and left atrial appendage (LAA) dysfunction anticoagulation was discontinued. Results In group A, 88 out of 102 patients underwent TEE and cardioversion was efficacious in 77 of 78. In group B, 100 out of 104 patients underwent TEE and cardioversion was efficacious in 80 of 87 patients; 55 patients underwent the second TEE and enoxaparin was stopped in 50 without LAA dysfunction. In group A, one transient ischemic attack and one sudden cardiac death occurred. In group B, one patient with complex aortic plaques suffered a stroke during enoxaparin. There was a minor hemorrhage in groups A and B, and a severe hemorrhage in a patient during OAT because of persistent atrial stunning. Hospitalization length and duration of anticoagulation were significantly shorter in group B. Conclusions The pre/post-cardioversion TEE strategy with enoxaparin in AF may constitute a feasible and safe approach in selecting patients at low thromboembolic risk who can benefit from precocious termination of anticoagulation (7 days after cardioversion). It may be also useful to identify those patients in whom a life-lasting anticoagulation could be beneficial. A larger trial to confirm these findings is under way.

Peak Power Output to Left Ventricular Mass: An Index to Predict Ventricular Pumping Performance and Morbidity in Advanced Heart Failure

BACKGROUND Similar to power-to-weight ratio and weight-to-power ratio, which are measurements of the actual performance of any engine, the ratios of peak power output to left ventricular (LV) mass (peak power/mass) and of peak LV mass to power output (peak mass/power) are indices of LV performance potentially useful in heart failure (HF). This Doppler echocardiographic study was designed to evaluate peak power/mass and peak mass/power in patients with advanced HF compared with healthy subjects and to assess their prognostic value. METHODS Power output was measured at rest and at peak exercise in 75 subjects, 60 patients with advanced HF (LV ejection fraction ≤ 35%) and 15 controls. Peak LV power output (W) was calculated as the maximal product of (133 × 10⁻⁶) × stroke volume (mL) × mean arterial pressure (mm Hg) × heart rate (beats/min). LV mass was assessed using a standard M-mode echocardiographic method. RESULTS Peak power/mass was 1.84 ± 0.46 W/100 g and 0.76 ± 0.31 W/100 g, and peak mass/power was 32 ± 10 g/m²/W and 84 ± 38 g/m²/W in controls and in patients with HF, respectively (both P values < .0001). Peak power/mass was a powerful predictor of outcome on multivariate logistic regression analysis (hazard ratio, 0.907; P = .009). On receiver operating characteristic curve analysis, the areas under the curve for HF-related events were greater for peak power/mass (P = .002) and peak mass/power (P = .011) with respect to resting ejection fraction. Comparisons of Cox models showed that peak power/mass added prognostic value to a model that included age, New York Heart Association class, etiology, ejection fraction, and diastolic dysfunction (P < .0001). CONCLUSION Peak power/mass is useful to discriminate and risk stratify patients with advanced HF with additional power with respect to ejection fraction.

Incremental diagnostic value of dipyridamole echocardiography and exercise thallium 201 scintigraphy in the assessment of presence and extent of coronary artery disease

BackgroundThe incremental diagnostic information of two noninvasive tests for the detection of coronary artery disease (CAD), dipyridamole echocardiography, and exercise201Tl myocardial scintigraphy was assessed in a series of 102 patients with ordered logistic regression and receiver-operating characteristic curves.Methods and ResultsPatients were selected from those referred to our cardiovascular centers with the clinical suspicion of CAD. After clinical evaluation, all patients underwent both noninvasive tests during hospitalization 2 weeks before coronary arteriography. The coronary arteriogram was used as a gold standard: CAD was defined as the presence of one or more vessels with 50% or greater narrowing of the luminal diameter. Clinical data were 73.0%±5.7% accurate in the prediction of CAD. The addition of dipyridamole echocardiographic data to the clinical model yielded a diagnostic accuracy of 88.3%±4.3% (p<0.00001), whereas the addition of thallium scintigraphic parameters to the clinical model improved diagnostic accuracy to 93.8%±2.6% (p<0.00001). A significant increase in accuracy to 97.2%±1.4% was achieved when thallium scintigraphic data were added to the clinical and dipyridamole-echocardiographic model (p<0.00001).ConclusionBoth noninvasive methods for detection of CAD, DET, and ETS showed a good diagnostic accuracy especially when tests-derived parameters were combined with clinical data by means of relative logistic models; nevertheless the ETS model showed a higher sensitivity in comparison with the DET model, essentially in presence of a lower extent of CAD.

Prevalence and clinical characteristics of adult patients with congenital heart disease in Tuscany.

Aims The clinical features of the adult population with congenital heart disease (CHD) are still not well characterized, particularly in the subset with more severe lesions. We report the data collected in the National Association of Hospital Cardiologists Toscana grown-up CHD (GUCH) registry over its first 8-month enrolment period. Methods The Registry included consecutive patients aged more than 16 years with a documented diagnosis of CHD, enrolled in seven different Tuscan hospitals using a web-based electronic form. Severe CHD was defined as cyanotic CHD, or acyanotic lesion with significant haemodynamic impact requiring surgical and/or percutaneous correction. Results Between November 2009 and June 2010 a total of 1641 patients (mean age 41.8 ± 19.3 years, 52.2% women) were enrolled. Atrial septal defect was the most common lesion, accounting for more than one-third of cases. Atrial and ventricular septal defects together accounted for about half of all CHDs. Nearly one-third of patients had New York Heart Association (NYHA) class 2 or more. A history of recurrent arrhythmias was reported in 15% of cases, and 12% of patients were on oral anticoagulants at the time of enrolment. The prevalence of pulmonary hypertension was 6%, and the prevalence of Eisenmenger syndrome was 1.2%. Severe CHD was present in 42% of patients. Younger age, higher NYHA class, male sex, and the need for oral anticoagulants were the only independent predictors of severe CHD. Conclusion Information about the clinical characteristics and the CHD type distribution of a sample of Tuscan GUCH population was provided. Severe CHD accounts for about 40% of all CHDs in this population. CHD severity is associated with younger age, male gender, worse NYHA class, and need for oral anticoagulation.