Detection of Trypanosoma cruzi DNA in blood by PCR is associated with Chagas cardiomyopathy and disease severity.

BACKGROUND: The significance of detection of Trypanosoma cruzi DNA in blood of antibody-positive patients for risk of development of Chagas heart disease is not well established. The objective of this study was to compare detection of T. cruzi DNA with known clinical and laboratory markers of Chagas cardiomyopathy (CC) severity. METHODS: This is a case-control study nested within a retrospective cohort developed in Brazil to understand the natural history of Chagas disease. The study enrolled 499 T. cruzi seropositive blood donors (SP-BD) and 488 frequency matched seronegative control donors (SN-BD) who had donated between 1996 and 2002, and 101 patients with clinically diagnosed CC. In 2008-2010 all enrolled subjects underwent a health questionnaire, medical examination, electrocardiograms and echocardiograms and polymerase chain reaction (PCR) analyses. A blinded panel of three cardiologists adjudicated the outcome of CC. Trypanosoma cruzi kinetoplast minicircle sequences were amplified by real-time PCR using an assay with a sensitivity of one parasite per 20 mL of blood. All testing was performed on coded samples. RESULTS: Rates of PCR detection of T. cruzi DNA were significantly (P = 0.003) higher in CC patients and SP-BD diagnosed with CC (79/105 [75.2 %]) compared with SP-BD without CC (143/279 [51.3%]). The presence of parasitaemia was significantly associated with known markers of disease progression such as QRS and QT interval duration, lower left ventricular ejection fraction, higher left ventricular index mass, and elevated troponin and NTpro-BNP levels. CONCLUSION: Trypanosoma cruzi PCR positivity is associated with presence and severity of cardiomyopathy, suggesting a direct role of parasite persistence in disease pathogenesis.

N-terminal prohormone brain natriuretic peptide (NT-proBNP) as a noninvasive marker for restrictive syndromes.

Constrictive pericarditis (CP) and restrictive cardiomyopathy share many similarities in both their clinical and hemodynamic characteristics and N-terminal prohormone brain natriuretic peptide (NT-proBNP) is a sensitive marker of cardiac diastolic dysfunction. The objectives of the present study were to determine whether serum NT-proBNP was high in patients with endomyocardial fibrosis (EMF) and CP, and to investigate how this relates to diastolic dysfunction. Thirty-three patients were divided into two groups: CP (16 patients) and EMF (17 patients). The control group consisted of 30 healthy individuals. Patients were evaluated by bidimensional echocardiography, with restriction syndrome evaluated by pulsed Doppler of the mitral flow and serum NT-proBNP measured by immunoassay and detected by electrochemiluminescence. Spearman correlation coefficient was used to analyze the association between log NT-proBNP and echocardiographic parameters. Log NT-proBNP was significantly higher (P < 0.05) in CP patients (log mean: 2.67 pg/mL; 95%CI: 2.43-2.92 log pg/mL) and in EMF patients (log mean: 2.91 pg/mL; 95%CI: 2.70-3.12 log pg/mL) compared with the control group (log mean: 1.45; 95%CI: 1.32-1.60 log pg/mL). There were no statistical differences between EMF and CP patients (P = 0.689) in terms of NT-proBNP. The NT-proBNP log tended to correlate with peak velocity of the E wave (r = 0.439; P = 0.060, but not with A wave (r = -0.399; P = 0.112). Serum NT-proBNP concentration can be used as a marker to detect the presence of diastolic dysfunction in patients with restrictive syndrome; however, serum NT-proBNP levels cannot be used to differentiate restrictive cardiomyopathy from CP.

N-terminal prohormone brain natriuretic peptide (NT-proBNP) as a noninvasive marker for restrictive syndromes

Constrictive pericarditis (CP) and restrictive cardiomyopathy share many similarities in both their clinical and hemodynamic characteristics and N-terminal prohormone brain natriuretic peptide (NT-proBNP) is a sensitive marker of cardiac diastolic dysfunction. The objectives of the present study were to determine whether serum NT-proBNP was high in patients with endomyocardial fibrosis (EMF) and CP, and to investigate how this relates to diastolic dysfunction. Thirty-three patients were divided into two groups: CP (16 patients) and EMF (17 patients). The control group consisted of 30 healthy individuals. Patients were evaluated by bidimensional echocardiography, with restriction syndrome evaluated by pulsed Doppler of the mitral flow and serum NT-proBNP measured by immunoassay and detected by electrochemiluminescence. Spearman correlation coefficient was used to analyze the association between log NT-proBNP and echocardiographic parameters. Log NT-proBNP was significantly higher (P < 0.05) in CP patients (log mean: 2.67 pg/mL; 95 percentCI: 2.43-2.92 log pg/mL) and in EMF patients (log mean: 2.91 pg/mL; 95 percentCI: 2.70-3.12 log pg/mL) compared with the control group (log mean: 1.45; 95 percentCI: 1.32-1.60 log pg/mL). There were no statistical differences between EMF and CP patients (P = 0.689) in terms of NT-proBNP. The NT-proBNP log tended to correlate with peak velocity of the E wave (r = 0.439; P = 0.060, but not with A wave (r = -0.399; P = 0.112). Serum NT-proBNP concentration can be used as a marker to detect the presence of diastolic dysfunction in patients with restrictive syndrome; however, serum NT-proBNP levels cannot be used to differentiate restrictive cardiomyopathy from CP.

Left ventricular function after a new pregnancy in patients with peripartum cardiomyopathy.

BACKGROUND: A new pregnancy is usually discouraged in patients with peripartum cardiomyopathy (PPCM), particularly when there is persistent left ventricular dysfunction. This study was undertaken to evaluate left ventricular systolic function after a new pregnancy in patients with PPCM. METHODS AND RESULTS: Nine of 44 patients with PPCM became pregnant and were selected for this study. Two patients were lost to follow-up, 1 immediately after the new pregnancy diagnosis, and the other 1 after the latest delivery, and, thus, were excluded. The remaining 7 patients had regular clinical and obstetric examinations until delivery, continued follow-up, and were submitted to echocardiography 6 to 12 months thereafter. Pregnancy was relatively well tolerated in the patients, and they gave birth to 7 healthy newborns. After this latest pregnancy, 4 patients with heart failure functional class II and 2 patients with functional class III remained unchanged. A patient, initially in functional class III, improved and was then in functional class II. Although left ventricular end-diastolic diameter did not change (61 to 58 mm), left ventricular end-systolic dimension decreased (50 to 47 mm, P =.008), resulting in a significant increase in left ventricular fractional shortening (19% to 23%, P =.02). CONCLUSION: Although based only in a small number of patients, the present results suggest that cardiac function does not deteriorate during a new pregnancy in patients with PPCM.

Abnormal neurovascular control during exercise is linked to heart failure severity.

The purpose of this study was to determine if abnormalities of sympathetic neural and vascular control are present in mild and/or severe heart failure (HF) and to determine the underlying afferent mechanisms. Patients with severe HF, mild HF, and age-matched controls were studied. Muscle sympathetic nerve activity (MSNA) and forearm vascular resistance (FVR) in the nonexercising arm were measured during mild and moderate static handgrip. MSNA during moderate handgrip was higher at baseline and throughout exercise in severe HF vs. mild HF (peak MSNA 67 +/- 3 vs. 54 +/- 3 bursts/min, P < 0.0001) and higher in mild HF vs. controls (33 +/- 3 bursts/min, P < 0.0001), but the change in MSNA was not different between the groups. The change in FVR was not significantly different between the three groups during static exercise. During isolation of muscle metaboreceptors, MSNA and blood pressure remained elevated in normal controls and mild HF but not in severe HF. During mild handgrip, the increase in MSNA was exaggerated in severe HF vs. controls and mild HF, in whom MSNA did not increase. In summary, the increase in MSNA during static exercise in severe HF appears to be attributable to exaggerated central command or muscle mechanoreceptor control, not muscle metaboreceptor control.

[Dynamics of patient selection for heart transplantation or cardiomyoplasty]. / Dinâmica da avaliação de pacientes para transplante cardíaco ou cardiomioplastia.

PURPOSE: To evaluate patient selection for heart transplantation or dynamic cardiomyoplasty. METHODS: We evaluated 380 patients from April 1991 to July 1993. The ages ranged between 16 and 68 (mean 43.5 +/- 11.46) years, 303 (79.7%) were male. The diagnoses were dilated cardiomyopathy in 163 (42.9%), Chagas' cardiomyopathy in 70 (18.4%), ischemic heart disease in 61 (16.1%), hypertensive heart disease in 40 (10.5%), valvular heart disease in 23 (6.1%), alcoholic cardiomyopathy in 12(3.2%), peripartum cardiomyopathy in 5 (1.3%) and myocarditis of unknown etiology in 5 (1.3%). RESULTS: The indication of heart transplantation was eventually done in 55 (14.4%), and 19 (5%) were submitted to transplantation. Dynamic cardiomyoplasty was indicated in 9 (2.3%) patients and was performed in 8 (2.1%). In 30 (7.8%) patients there were clinical contraindications for transplantation. Conventional surgical treatment was indicated for 12 (3.1%) patients: myocardial revascularization and/or ventricular aneurismectomy in 5, surgical treatment of valvular heart disease in 6 and of atrial fibrillation in 1. Socioeconomic limitations precluded transplantation in 43 (11.3%) and psychic limitations hindered transplantation in 23 (6.0%) patients. Refusal of procedure by the patient occurred in 10 (2.6%) cases. Improvement of the symptoms occurred in 69 (18.1%) patients. CONCLUSION: A small percentage of patients are eligible and are eventually submitted to heart transplantation or dynamic cardiomyoplasty. New strategies may be delineated during follow up, as deferring transplantation or conventional surgical treatment of ischemic or valvular heart disease. Sociopsychic evaluation is an important step in the care of the patients.

[Preoperative cardiological evaluation. Report of 255 cases]. / Avaliação cardiológica pré-operatória. Estudo de 255 casos.

PURPOSE: To study preoperative cardiological consultations in a cardiology referral center in a general hospital. METHODS: Two hundred and fifty five patients were studied between June and December 1989; the ages ranged between 16 and 82 (mean 55) years, 120 (47%) were male and 135 (53%) female. A questionnaire was applied by the physicians during consultation. RESULTS: Main symptoms were thoracic pain in 30 (11.8%) cases, dyspnea in 57 (22.4%), palpitations in 13 (5.1%). Symptoms of cardiac disease were absent in 141 (55.3%) patients. On physical examination arterial hypertension was detected in 75 (29.4%) cases and a cardiac murmur in 21 (8.2%). Diagnosis of coronary artery disease was made in 30 (11.8%) cases--13 (5.1%) with history of previous myocardial infarction, aortic valve stenosis in 5 (1.9%), other valvular heart diseases in 14 (5.5%), cardiac arrhythmias in 11 (4.3%). Heart disease was absent in 90 (35.4%) patients. Sixty-five (25.5%) patients were on drug therapy for heart diseases. Consultations were obtained for patients that had been already admitted to the hospital in 171 (67%) cases. Cardiological follow up was recommended to 150 (58.8%) patients. Seven patients died; the cause of the death was related to the primary disease. Contraindication for surgery imposed by cardiological evaluation did not occur. CONCLUSION: In this study, patients with heart disease tolerated the surgical procedures. Preoperative cardiological evaluation added useful data for postoperative care and also for long term follow-up of the patients.