Roberto Favaloro

Accurate real-time PCR strategy for monitoring bloodstream parasitic loads in chagas disease patients.

Background This report describes a real-time PCR (Q-PCR) strategy to quantify Trypanosoma cruzi (T. cruzi) DNA in peripheral blood samples from Chagas disease patients targeted to conserved motifs within the repetitive satellite sequence. Methodology/Principal Findings The Q-PCR has a detection limit of 0.1 and 0.01 parasites/mL, with a dynamic range of 106 and 107 for Silvio X10 cl1 (T. cruzi I) and Cl Brener stocks (T. cruzi IIe), respectively, an efficiency of 99%, and a coefficient of determination (R 2) of 0.998. In order to express accurately the parasitic loads: (1) we adapted a commercial kit based on silica-membrane technology to enable efficient processing of Guanidine Hydrochloride-EDTA treated blood samples and minimize PCR inhibition; (2) results were normalized incorporating a linearized plasmid as an internal standard of the whole procedure; and (3) a correction factor according to the representativity of satellite sequences in each parasite lineage group was determined using a modified real-time PCR protocol (Lg-PCR). The Q-PCR strategy was applied (1) to estimate basal parasite loads in 43 pediatric Chagas disease patients, (2) to follow-up 38 of them receiving treatment with benznidazole, and (3) to monitor three chronic Chagas heart disease patients who underwent heart-transplantation and displayed events of clinical reactivation due to immunosupression. Conclusion/Significance All together, the high analytical sensitivity of the Q-PCR strategy, the low levels of intra- and inter-assay variations, as well as the accuracy provided by the Lg-PCR based correction factor support this methodology as a key laboratory tool for monitoring clinical reactivation and etiological treatment outcome in Chagas disease patients.

Cardiomyocyte hypertrophy, oncosis, and autophagic vacuolization predict mortality in idiopathic dilated cardiomyopathy with advanced heart failure.

OBJECTIVES The aim of this study was to identify the remodeling parameters cardiomyocyte (CM) damage or death, hypertrophy, and fibrosis that may be linked to outcomes in patients with advanced heart failure (HF) in an effort to understand the pathogenic mechanisms of HF that may support newer therapeutic modalities. BACKGROUND There are controversial results on the influence of fibrosis, CM hypertrophy, and apoptosis on outcomes in patients with HF; other modalities of cell damage have been poorly investigated. METHODS In endomyocardial biopsy specimens from 100 patients with idiopathic dilated cardiomyopathy and advanced HF, CM diameter and the extent of fibrosis were determined by morphometry. The proportion of CMs with evidence of apoptosis, autophagic vacuolization (AuV), and oncosis was investigated by immunohistochemical methods and by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling. Those parameters were correlated with mortality in 3 years of follow-up by univariate analysis and with multivariate models incorporating the clinical variables more relevant to the prediction of outcomes. RESULTS CM AuV occurred in 28 patients (0.013 ± 0.012%) and oncosis in 41 (0.109 ± 0.139%). Nineteen patients showed both markers. Apoptotic CM nuclei were observed in 3 patients. In univariate analysis, CM diameter and AuV, either alone or associated with oncosis, were predictors of mortality. In multivariate analysis, CM diameter (hazard ratio: 1.37; 95% confidence interval: 1.12 to 1.68; p = 0.002) and simultaneous presence in the same endomyocardial biopsy specimen of AuV and oncosis (hazard ratio: 2.82; 95% confidence interval: 1.12 to 7.13; p = 0.028) were independent predictors of mortality. CONCLUSIONS CM hypertrophy and AuV, especially in association with oncosis, are predictors of outcome in patients with idiopathic dilated cardiomyopathy and severe HF.

Tyrosine Kinase c-Src Constitutes a Bridge between Cystic Fibrosis Transmembrane Regulator Channel Failure and MUC1 Overexpression in Cystic Fibrosis

Cystic fibrosis (CF), a disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) chloride channel, is associated in the respiratory system with the accumulation of mucus and impaired lung function. The role of the CFTR channel in the regulation of the intracellular pathways that determine the overexpression of mucin genes is unknown. Using differential display, we have observed the differential expression of several mRNAs that may correspond to putative CFTR-dependent genes. One of these mRNAs was further characterized, and it corresponds to the tyrosine kinase c-Src. Additional results suggest that c-Src is a central element in the pathway connecting the CFTR channel with MUC1 overexpression and that the overexpression of mucins is a primary response to CFTR malfunction in cystic fibrosis, which occurs even in the absence of bacterial infection.

Transcatheter aortic valve implantation without balloon predilation: A single-center pilot experience

To assess the results of transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve prosthesis (Medtronic, Minneapolis, MN), without balloon predilation, in high‐risk patients with degenerated severe aortic stenosis.

Primary pulmonary artery sarcoma resembling chronic thromboembolic pulmonary disease

Two cases of primary pulmonary artery sarcoma resembling chronic thromboembolic disease features are presented. Tumour identification was achieved after pulmonarv thromboendarterectomy, which was indicated by documentation of a prothrombotic state in both patients. A doubtful history of pulmonary emboli or deep venous thrombosis should alert medical personnel to the possible presence of a primary pulmonary artery sarcoma. Advanced imaging methods such as gadolinium-enhanced magnetic resonance imaging could be useful in considering pulmonary thromboendarterectomy. If a tumour is detected, its surgical resection should be considered with caution, taking into account the poor survival results. Invasion of the adventitia or the right ventricle, as documented in the present cases, is unusual. As far as the present authors know, this is the first report of this kind of tumour and its coexistence with an activated protein C resistance state and type II heparin-induced thrombocytopenia.

Coronary Microcirculation Remodeling in Patients with Idiopathic Dilated Cardiomyopathy

Background: In patients with idiopathic dilated cardiomyopathy (IDCM), the myocardial blood flow is markedly depressed. The presence of alterations in the number and length of the coronary microcirculation has not been explored. Methods: In explanted hearts of 6 patients with IDCM and in 6 normal control hearts, the arteriolar length density and capillary numerical density were determined in sections stained with orcein (vessels 50–200 µm in diameter), for smooth muscle actin (vessels 6–50 µm in diameter) and CD34 (capillaries). Results: No difference with normal hearts was observed in capillary numerical density and in length density of vessels above 50 µm in diameter. In IDCM, more than 50% of arterioles below 50 µm in diameter displayed an incomplete smooth muscle wall, and length density, especially for arterioles between 6 and 20 µm in diameter, was significantly lower (42.84 ± 8.51 mm/mm3) than in controls (75.34 ± 3.05 mm/mm3, p = 0.001). Conclusions: In IDCM, arterioles below 50 µm in diameter display an incomplete smooth muscle wall and a significant decrease in length density. These observations provide an anatomical basis for a decreased coronary flow reserve in IDCM.

Open lung biopsy for diffuse disease in patients with and without previously transplanted solid organs.

BACKGROUND Studies on whether surgical lung biopsy (SLB) modifies the treatment of patients with diffuse lung disease are conflicting, and information is limited on whether it alters treatment in solid-organ transplant recipients. Our objective was to determine and compare the rate of treatment change after SLB for diffuse lung disease in patients with and without a history of solid-organ transplantation. METHODS Patients undergoing SLB for diffuse lung disease between March 2004 and March 2009 were identified. A retrospective review was performed. RESULTS Sixty patients had SLB. Thirty-four patients (57%) had solid-organ transplantation. Twenty of 60 patients (33%) had a change in treatment as a result of the findings of the SLB. No significant differences in the treatment change rate were found between the transplant and nontransplant groups (10 of 34 versus 10 of 26; p = 0.46). Transplant patients were more likely to be on mechanical ventilation at the time of SLB (12 of 34 versus 3 of 26; p = 0.03). Mechanical ventilatory support at the time of SLB was associated with increased postoperative complications (odds ratio, 6.20; 95% confidence interval [CI], 1.70 to 22.66; p = 0.006) and in-hospital mortality (odds ratio, 9.75; 95% CI, 2.54 to 37.38; p = 0.001). Being on mechanical ventilation (hazard ratio, 3.91; 95% CI, 1.40 to 10.93; p = 0.009), a diagnosis of cancer (hazard ratio, 13.20; 95% CI, 2.87 to 60.78; p = 0.001), and a history of solid-organ transplantation (hazard ratio, 5.52; 95% CI, 1.08 to 28.14; p = 0.04) were independent predictors of survival. CONCLUSIONS Surgical lung biopsy changes treatment in one third of patients, with no significant difference between patients without transplantation and solid-organ transplant recipients. Patients who undergo SLB while on mechanical ventilation have a significantly increased risk of postoperative complications and death.

Extent of Coronary and Myocardial Disease and Benefit from Surgical Revascularization in Patients with Ischemic Left Ventricular Dysfunction

BACKGROUND Patients with ischemic left ventricular dysfunction have higher operative risk with coronary artery bypass graft surgery (CABG). However, those whose early risk is surpassed by subsequent survival benefit have not been identified. OBJECTIVES This study sought to examine the impact of anatomic variables associated with poor prognosis on the effect of CABG in ischemic cardiomyopathy. METHODS All 1,212 patients in the STICH (Surgical Treatment of IsChemic Heart failure) surgical revascularization trial were included. Patients had coronary artery disease (CAD) and ejection fraction (EF) of ≤35% and were randomized to receive CABG plus medical therapy or optimal medical therapy (OMT) alone. This study focused on 3 prognostic factors: presence of 3-vessel CAD, EF below the median (27%), and end-systolic volume index (ESVI) above the median (79 ml/m(2)). Patients were categorized as having 0 to 1 or 2 to 3 of these factors. RESULTS Patients with 2 to 3 prognostic factors (n = 636) had reduced mortality with CABG compared with those who received OMT (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.56 to 0.89; p = 0.004); CABG had no such effect in patients with 0 to 1 factor (HR: 1.08; 95% CI: 0.81 to 1.44; p = 0.591). There was a significant interaction between the number of factors and the effect of CABG on mortality (p = 0.022). Although 30-day risk with CABG was higher, a net beneficial effect of CABG relative to OMT was observed at >2 years in patients with 2 to 3 factors (HR: 0.53; 95% CI: 0.37 to 0.75; p<0.001) but not in those with 0 to 1 factor (HR: 0.88; 95% CI: 0.59 to 1.31; p = 0.535). CONCLUSIONS Patients with more advanced ischemic cardiomyopathy receive greater benefit from CABG. This supports the indication for surgical revascularization in patients with more extensive CAD and worse myocardial dysfunction and remodeling. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).