Prolonged heart rate recovery time after 6-minute walk test is an independent risk factor for cardiac events in heart failure: a prospective cohort study

OBJECTIVES: To determine whether the time for peak exercise heart rate to return to resting heart rate after the 6-minute walk test (6MWT) can predict cardiac events in patients with heart failure (HF) within 2 years. DESIGN: Prospective cohort study. SETTING: HF outpatient facility at a tertiary teaching hospital. PARTICIPANTS: Seventy-six patients with HF, New York Heart Association functional classification II and III, and left ventricular ejection fraction <50% MAIN OUTCOME MEASURES: Patients used a heart rate monitor to measure the time for peak exercise heart rate to return to resting heart rate after the 6MWT. Data were analysed using Polar Pro-Trainer 5 software (Kempele, Finland). Patients were followed for >2 years for cardiac events (hospitalisations and death). RESULTS: Thirty-four patients had cardiac events during the 2-year follow-up period. There was a significant difference in time to return to resting heart rate between the groups with and without cardiac events {with 3.6 [standard deviation (SD) A] vs without 2.8 (SD B) minutes; mean difference C; 95% confidence interval (CI) of the difference D to E; P=0.003}. No significant differences between patients with and without cardiac events were found for mean walking distance, mean heart rate recovery at 1 minute and mean heart rate recovery at 2 minutes. The receiver operating curve discriminated between patients with and without cardiac events (área under the curve 0.71, 95% CI 0.61 to 0.81; P< 0.001). Using logistic regression analysis, prolonged time to return to resting heart rate (≥3 minutes) independently increased the risk for cardiac events 6.9-fold (95% CI 2.34 to 20.12; P< 0.001). The Kaplan­Meier curve showed more cardiac events in patients with prolonged time to return to resting heart rate (P=0.028). CONCLUSIONS: Prolonged time to return to resting heart rate (≥3 minutes) after the 6MWT was an independent predictor of cardiac events in patients with HF.

Prolonged heart rate recovery time after 6-minute walk test is an independent risk factor for cardiac events in heart failure: A prospective cohort study.

OBJECTIVES: To determine whether the time for peak exercise heart rate to return to resting heart rate after the 6-minute walk test (6MWT) can predict cardiac events in patients with heart failure (HF) within 2 years. DESIGN: Prospective cohort study. SETTING: HF outpatient facility at a tertiary teaching hospital. PARTICIPANTS: Seventy-six patients with HF, New York Heart Association functional classification II and III, and left ventricular ejection fraction <50%. MAIN OUTCOME MEASURES: Patients used a heart rate monitor to measure the time for peak exercise heart rate to return to resting heart rate after the 6MWT. Data were analysed using Polar Pro-Trainer 5 software (Kempele, Finland). Patients were followed for >2 years for cardiac events (hospitalisations and death). RESULTS: Thirty-four patients had cardiac events during the 2-year follow-up period. However, there was a significant difference in the time to return to resting heart rate between the groups with and without cardiac events {with 3.6 (SD 1.1) vs without 2.8 (SD 1.1) minutes; mean difference of 0.79 (95% confidence interval (CI) of the difference 0.28 to 1.28; P=0.003}. No significant differences between patients with and without cardiac events were found for mean walking distance, mean heart rate recovery at 1minute and mean heart rate recovery at 2minutes. The receiver operating curve discriminated between patients with and without cardiac events (área under the curve 0.71, 95% CI 0.61 to 0.81; P<0.001). Using logistic regression analysis, prolonged time to return to resting heart rate (≥3minutes) independently increased the risk for cardiac events 6.9-fold (95% CI 2.34 to 20.12; P<0.001). The Kaplan-Meier curve showed more cardiac events in patients with prolonged time to return to resting heart rate (P=0.028). CONCLUSIONS: Prolonged time to return to resting heart rate (≥3minutes) after the 6MWT was an independent predictor of cardiac events in patients with HF.

Tempo de recuperação da frequência cardíaca como marcador prognóstico de eventos cardíacos / Heart rate recovery time as a prognostic marker of cardiac events

INTRODUÇÃO: O teste de caminhada de 6 minutos (TC6M) é um teste funcional amplamente utilizado em pacientes com insuficiência cardíaca crônica (IC). A distância percorrida no teste, bem como o delta de frequência cardíaca entre o repouso e a recuperação no 1° minuto (HRR1) e o delta de frequência cardíaca entre o repouso e a recuperação no 2° minuto (HRR2) têm sido propostos como marcadores prognósticos de eventos cardíacos em pacientes com IC. Nós hipotetizamos que a variação do tempo em minutos (denominado THRR) entre o pico da frequência cardíaca e o retorno à frequência cardíaca no repouso possa ser um marcador simples e de fácil obtenção no contexto clínico para estimar eventos cardíacos em pacientes com IC. OBJETIVOS: Nós investigamos se o THRR pode ser usado para estimar hospitalizações e morte ao longo de 2 anos de acompanhamento em pacientes com IC. MÉTODOS: Setenta e seis pacientes (média de idade 57 anos, NYHA II e III, IMC 25.5kg/m2, média FEVE de 33%) foram incluídos nesse estudo e divididos em Com eventos e Sem eventos. RESULTADOS: Trinta e quatro pacientes do grupo Com eventos e 42 pacientes do grupo Sem eventos tiveram, respectivamente as seguintes médias: THRR= 3.6 vs 2.8 min (p=0,003), distância percorrida= 463 vs 465 metros (p=0,930), HRR1=12 bpm para ambos grupos (p=0,952) e HRR2= 23 vs 22 bpm (p=0,723). A área sob a curva ROC para discriminar eventos e não eventos foi de 0,70 (IC95%: 0,58-0,82 e p=0,001). Usando a análise de regressão logística, o THRR ≥ 3 minutos dobrou o risco para eventos cardíacos (p=0,003). CONCLUSÃO: A variação de tempo entre o pico do exercício no TC6M e a recuperação da frequência cardíaca de repouso ≥ 3 minutos é um eficiente marcador clínico preditor de hospitalizações e morte em 2 anos para pacientes com IC. (AU)

Immunohistochemical quantification of inflammatory cells in endomyocardial biopsy fragments after heart transplantation: a new potential method to improve the diagnosis of rejection after heart transplantation.

Inconsistencies in cardiac rejection grading systems corroborate the concept that the evaluation of inflammatory intensity and myocyte damage seems to be subjective. We studied in 36 patients the potential role of the immunohistochemical (IHC) counting of inflammatory cells in endomyocardial biopsy (EMB) as an objective tool, testing the hypothesis of correlation between the International Society for Heart and Lung Transplantation 2004 rejection and IHC counting of inflammatory cells. We observed a progressive increment in CD68+ cells/mm(2) (P = .000) and CD3+ cells/mm(2) (P = .000) with higher rejection grade. A strong correlation between the grade of cellular rejection and both CD68+ cells/mm(2) and CD3+ cells/mm(2) was obtained (P = .000). One patient with CD3+ and CD68+ cells/mm(2) above the upper limit of the 95% confidence interval for cells/mm(2) found in rejection grade 1R evolved to rejection grade 2R without treatment. In patients with 2R that did not respond to treatment the values of CD68+ or CD3+ cells were higher than the overall median values for rejection grade 2R. For diagnosis of rejection needing treatment, the CD68+ and CD3+ cells/mm(2) areas under the receiver operating characteristic curves were 0.956 and 0.934, respectively. IHC counting of mononuclear inflammatory infiltrate in EMB seems to have additive potential role in evaluation of EMB for the diagnosis and prognosis of rejection episodes.

Comparative analysis of the complications of 5347 endomyocardial biopsies applied to patients after heart transplantation and with cardiomyopathies: a single-center study.

INTRODUCTION: Endomyocardial biopsy (EMB) plays an important role in allograft surveillance to screen an acute rejection episode after heart transplantation (HT), to diagnose an unknown cause of cardiomyopathies (CMP) or to reveal a cardiac tumor. However, the procedure is not risk free. OBJECTIVE: The main objective of this research was to describe our experience with EMB during the last 33 years comparing surgical risk between HT versus no-HT patients. METHOD: We analyzed retrospectively the data of 5347 EMBs performed from 1978 to 2011 (33 years). For surveillance of acute rejection episodes after HT we performed 3564 (66.7%), whereas 1777 (33.2%) for CMP diagnosis, and 6 (1.0%) for cardiac tumor identification. RESULTS: The main complications due to EMB were divided into 2 groups to facilitate analysis: major complications associated with potential death risk, and minor complications. The variables that showed a significant difference in the HT group were as follows: tricuspid injury (.0490) and coronary fistula (.0000). Among the no-HT cohort they were insufficient fragment (.0000), major complications (.0000) and total complications (.0000). CONCLUSIONS: EMB can be accomplished with a low risk of complications and high effectiveness to diagnose CMP and rejection after HT. However, the risk is great among patients with CMP due to their anatomic characteristics. Children also constitute a risk group for EMB due to their small size in addition to the heart disease. The risk of injury to the tricuspid valve was higher among the HT group.

Successful endomyocardial biopsy guided by transthoracic two-dimensional echocardiography.

INTRODUCTION: Two-dimensional (2-D) echocardiography is an excellent alternative method to perform endomyocardial biopsies (EB) in special situations, mainly when the patient is in a critical state and cannot go to the catheterization laboratory or when there are contraindications to the use of fluoroscopy as in the pregnancy. OBJECTIVE: This single-center experience analyzed the last 25 years use of an EB technique guided by echocardiography realized at the bedside on critical patients. METHODS: From 1985 to 2010, we performed 76 EB guided by 2-D echocardiography on 59 patients, among whom 38 (64.4%) were critically ill with examinations at the bedside; among 10 (16.9%) subjects, the procedure was carried out simultaneously with fluoroscopy for safety's sake during the learning period. In addition, 8 (13.6%) were unavailable for fluoroscopy, and 3 (5.1%) required a hybrid method due to an intracardiac tumor. RESULTS: The main adverse effects included local pain (n = 4, 5.6%); difficult out successful puncture due to previous biopsies (n = 4, 5.6%); local hematoma without major consequences (n = 3, 4.2%); failed but ultimately successful puncture on the first try due to previous biopsies or (n = 3, 4.2%); obesity and immediate postoperative period with impossibility to pass the bioptome into the right ventricle; however 2 days later the procedure was repeated successfully by echocardiography (n = 1, 1.4%). All myocardial specimens displayed suitable size. There were no undesirable extraction effects on the tricuspid valve tissue. In this series, there was no case of death, hemopericardium, or other major complication as a direct consequence of the biopsy. CONCLUSION: 2-D echocardiography is a special feature to guide EB is mainly in critically ill patients because it can be performed at the bedside without additional risk or disadvantages of fluoroscopy. The hybrid method associating 2-D echocardiography and fluoroscopy allows the procedure in different situations such as intracardiac tumor cases.

Heart transplantation in 107 cases of Chagas' disease.

INTRODUCTION: Chagas' disease is endemic in South America. OBJECTIVE: This research reviewed the experience with cardiac transplantation in Chagas' disease, emphasizing reactivation, immunosuppression, and mortality. METHODS: Over 25 years from March 1985 to March 2010, 107/409 (26.2%) patients with Chagas' disease underwent heart transplantation, patients including 74 (71.1%) men and 72 (67.2%), in functional class IV with 33 (30.8%) on vasopressors and 17 (10.7%) on mechanical circulatory support. RESULTS: The diagnosis of disease reactivation was performed by identifying the parasite in the myocardium (n = 23; 71.8%) in the subcutaneous tissue (n = 8; 25.0%), in blood (n = 11; 34.3%), or in central nervous tissue (n = 1; 3.1%). Hospital mortality was 17.7% (n = 19) due to infection (n = 6; 31.5%), graft dysfunction (n = 6; 31.5%), rejection (n = 4; 21.1%), or sudden death (n = 2; 10.5%). Late mortality was 27 (25.2%) cases, which were distributed as: rejection (n = 6; 22.2%), infection (n = 6; 22.2%), (n = lymphoma 4; 14.8%), sarcoma (n = 2; 7.4%), for constrictive pericarditis (n = 2; 7.4%) reactivation of Chagas' disease in the central nervous system (n = 1; 7.1%). CONCLUSIONS: Transplantation in Chagas' disease has peculiar problems that differ from other etiologies due to the possibility of disease reactivation and the increased possibility of emergence of cancers. However, transplantation is the only treatment able to modify the natural progression of the disease in its terminal phase. Early diagnosis and rapid introduction of benzonidazole reverses the histological patterns. Immunosuppression, especially steroids, predisposes to the development of cancer and disease reactivation.

Long-term pulmonary vascular reactivity after orthotopic heart transplantation by the biatrial versus the bicaval technique.

INTRODUCTION: Advantages of the bicaval versus the biatrial technique have been reported, emphasizing atrial electrical stability and less tricuspid regurgitation. OBJECTIVE: To analyze the impact of the surgical technique on long-term pulmonary pressures, contractility, and graft valvular behavior after heart transplantation. METHODS: Among 400 orthotopic heart transplantation recipients from 1985 to 2010, we selected 30 consecutive patients who had survived beyond 3 years. The biatrial versus bicaval surgical technique groups included 15 patients each. Their preoperative clinical characteristics were similar. None of the patients displayed a pulmonary vascular resistance or pulmonary artery pressure over 6U Wood or 60 mm Hg, respectively. We evaluated invasive hemodynamic parameters during routine endomyocardial biopsies. Two-dimensional echocardiographic parameters were obtained from routine examinations. RESULTS: There were no significant differences regarding right atrial pressure, systolic pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, cardiac index, systolic blood pressure, left ventricular ejection fraction, and mitral regurgitation (P > .05). Tricuspid regurgitation increased significantly over the 3 years of observation only among the biatrial group (P = .0212). In both groups, the right atrial pressure, pulmonary wedge capillary pressure, transpulmonary gradient, and pulmonary vascular resistance decreased significantly (P < .05) from the pre- to the postoperative examination. In both groups cardiac index and systemic blood pressure increased significantly after transplantation (P < .05). Comparative analysis of the groups only showed significant differences regarding right atrial pressure and degree of tricuspid regurgitation; the bicaval group showing the best performance. CONCLUSIONS: Both surgical techniques ensure adequate left ventricular function in the long term; however, the bicaval technique provided better trends in hemodynamic performance, as well as a lower incidence and severity of tricuspid valve dysfunction.

Haemodynamic, metabolic and neuro-humoral abnormalities in young normotensive women at high familial risk for hypertension.

We analysed the haemodynamic, metabolic and hormonal status at rest and in response to exercise, in young normotensive women with two hypertensive parents (FH++; n=17; 25.1±4.8 years), one hypertensive parent (FH+; n=18; 24.9±4.1 years) and normotensive parents (FH-; n=15; 25.3±3.8 years). Casual and ambulatorial blood pressure (BP), carotid-femoral pulse wave velocity (PWV) and biochemistry were analysed. BP, nor-epinephrine (NE), epinephrine (EPI), endothelin-1 (ET-1) and nitrite/nitrate (NOx) levels were also analysed during a graded exercise test (GXT). Casual and ambulatorial BP were not different between groups, but PWV was 7.5 and 12.6% higher in FH++ than FH+ and FH-, respectively, and 4.8% higher in FH+ than FH- (P≤0.01). Insulin and insulin-to-glucose ratio were increased in FH++ and FH+ (P<0.05), and low-density lipoprotein (LDL)-cholesterol tended to be higher only in FH++ (P=0.07). FH++ showed higher exercise and recovery diastolic BP and EPI levels, and increased resting, exercise and recovery NE, and ET-1 levels than FH- (P<0.05). FH+ showed only greater resting, exercise and recovery NE, and rest ET-1 (P<0.05). Resting, exercise and recovery NOx were lower in FH++ and FH+ than FH- (P<0.01). Haemodynamic, metabolic and hormonal abnormalities were presented in nonhypertensive young women offspring of hypertensive parents before any increase in BP. Greater abnormalities were observed in women with a strong family history of hypertension (FH++). These results suggest that there is an early vascular, metabolic and hormonal involvement in a familial hypertensive disorder.

Validation of a cutoff value on echo Doppler analysis to replace right heart catheterization during pulmonary hypertension evaluation in heart transplant candidates.

BACKGROUND: Heart transplantation (OHT) has traditionally been contraindicated in the presence of severe pulmonary hypertension (PH), as detected by right heart catheterization. Noninvasive methods are still not reliably accurate to make this evaluation. OBJECTIVES: Determine the efficacy of echo Doppler analysis for the diagnosis of severe PH. METHODS: One hundred thirty patients (mean age = 42 +/- 15 years, 82 men) showed severe left ventricular dysfunction (mean ejection fraction = 29 +/- 12%; functional class III-IV). We excluded patients with atrial fibrillation, heart failure secondary to congenital disease, and valvulopathy. The pulmonary parameters defined as severe PH were: systolic pulmonary artery pressure (sPAP) >or= 60 mm Hg; a mean transpulmonary gradient >or= 15; or pulmonary vascular resistance >or= 5 Wood units. Patients underwent a right heart catheterization using a Swan-Ganz catheter to measure hemodynamic parameters and to noninvasively estimate right-sided pressures from spectral Doppler recordings of tricuspid regurgitation velocity (right ventricular systolic pressure [RVsP]). A Pearson correlation of sPAP was obtained with RVsP by; the sensitivity of RVsP for the diagnosis of PH was determined by a receiver operating characteristic (ROC) curve. RESULTS: A good correlation between sPAP and RVsP was obtained by Pearson correlation analysis (r = 0.64; 95% confidence interval [CI] 0.50-0.75; P < .001). The ROC curve analysis showed a sensitivity of 100%, a specificity of 37.2%, (95% CI 0.69-0.83, P < .0001) of a RVsP < 45 mm Hg (cutoff) on the exclusion of severe PH. CONCLUSIONS: The cutoff of RVsP < 45 mm Hg, on noninvasive echo Doppler evaluation of PH is an efficient method to replace invasive heart catheterization in OHT candidates.

Dobutamine stress echocardiography in heart transplant recipients' evaluation: the role of reinnervation.

INTRODUCTION: Orthotopic heart transplantation renders the recipient denervated. This remodeling of the intrinsic cardiac nervous system should be taken in account during functional evaluation for allograft coronary artery disease. Dobutamine stress echocardiography (DSE) has been used to detect patients at greater risk. The aim of this study was to determine whether patients with various autonomic response levels, and supposed reinnervation patterns, show the same response to DSE. METHODS: We studied 20 patients who had survived more than 5 years after orthotopic heart transplantation. All patients underwent a Holter evaluation. We considered patients with low variability to be those with less than a 40-bpm variation from the lowest to highest heart rate, so-called "noninnenervated" (group NI). Patients who had 40-bpm or more variation were considered to show high variability and called "reinnervated" (group RI). After that, all patients performed an ergometric test and DSE. RESULTS: Groups were defined as NI (n = 9) and RI (n = 11). Ergometric tests confirmed this response with NI patients showing less variability when compared to RI patients (P = .0401). During DSE, patients showed similar median heart rate responses according to the dobutamine dose. Spearmen correlation showed r = 1.0 (P = .016). CONCLUSIONS: DES was effective to reach higher heart rates, probably related to catecholamine infusion. These findings may justify a better response when evaluating cardiac allograft vasculopathy in heart transplant patients.

Recovery of renal function in heart transplantation patients after conversion from a calcineurin inhibitor-based therapy to sirolimus.

BACKGROUND: Renal failure is the most important comorbidity in patients with heart transplantation, it is associated with increased mortality. The major cause of renal dysfunction is the toxic effects of calcineurin inhibitors (CNI). Sirolimus, a proliferation signal inhibitor, is an imunossupressant recently introduced in cardiac transplantation. Its nonnephrotoxic properties make it an attractive immunosuppressive agent for patients with renal dysfunction. In this study, we evaluated the improvement in renal function after switching the CNI to sirolimus among patients with new-onset kidney dysfunction after heart transplantation. METHODS: The study included orthotopic cardiac transplant (OHT) patients who required discontinuation of CNI due to worsening renal function (creatinine clearance < 50 mL/min). We excluded subjects who had another indication for initiation of sirolimus, that is, rejection, malignancy, or allograft vasculopathy. The patients were followed for 6 months. The creatinine clearance (CrCl) was estimated according to the Cockcroft-Gault equation using the baseline weight and the serum creatinine at the time of introduction of sirolimus and 6 months there after. Nine patients were included, 7 (78%) were males and the overall mean age was 60.1 +/- 12.3 years and time since transplantation 8.7 +/- 6.1 years. The allograft was beyond 1 year in all patients. There was a significant improvement in the serum creatinine (2.98 +/- 0.9 to 1.69 +/- 0.5 mg/dL, P = .01) and CrCl (24.9 +/- 6.5 to 45.7 +/- 17.2 mL/min, P = .005) at 6 months follow-up. CONCLUSION: The replacement of CNI by sirolimus for imunosuppressive therapy for patients with renal failure after OHT was associated with a significant improvement in renal function after 6 months.

Behavior profile of family members of donors and nondonors of organs.

UNLABELLED: Organ transplant shortage is a global problem caused by several factors, most of which are related to members of the family, who play a major role in the donation process. OBJECTIVE: We sought to determine the most determinant features in the donor profile that relate to positive decisions versus refusal of donation. MATERIAL AND METHODS: Fifty-six families who were approached by the Organ Procurement Organization (OPO) from November 2004 to April 2006 agreed to participate in this work. To assess donor profiles, we used a structured interview. RESULTS: Parental involvement directly in decisions about donation lead to significantly less frequent consent (P = .005), young donor age was associated with a reduced probability of donation (P = .002), violent death negatively influenced donation consent, excluding suicide (P = .004). CONCLUSION: The present study showed violent death, young patient age, and parental donation consent to be the most important factors that make it harder to obtain consent organ donation. When a collateral relative (sibling/uncle) or children were responsible for the donation decision, there was more success of consent.

Endomyocardial biopsy as risk factor in the development of tricuspid insufficiency after heart transplantation.

OBJECTIVE: Endomyocardial biopsy (EMB), which is used to monitor for rejection, may cause tricuspid regurgitation (TR) after orthotopic heart transplantation (OHT). The purpose of this investigation was to examine the occurrence of tricuspid valve tissue in myocardial specimens obtained by routine EMB performed after OHT. PATIENTS AND METHODS: From January 2000 to July 2008, 125 of the patients who underwent OHT survived more than 1 month. Their follow-up varied from 1 month to 8.5 years (mean, 5.1 +/- 3.7 years). EMB was the gold standard examination and myocardial scintigraphy with gallium served as a screen to routinely monitor rejection. RESULTS: Each of 428 EMB including 4 to 7 fragments, totaling 1715 fragments, were reviewed for this study. The number of EMB per patient varied from 3 to 8 (mean, 4.6 +/- 3.5). Histopathological analysis of these fragments showed tricuspid tissue in 4 patients (3.2%), among whom only 1 showed aggravation of TR. CONCLUSIONS: EMB remains the standard method to diagnose rejection after OLT. It can be performed with low risk. Reducing the number of EMB using gallium myocardial scintigraphy or other alternative methods as well as adoption of special care during the biopsy can significantly minimize trauma to the tricuspid valve.

Massive degeneration and atrophy of the native heart after heterotopic transplantation: a case report.

Extreme myocardial degeneration leading to advanced stages of cardiomyopathy with extensive atrophy is rarely observed before patients die. However, heterotopic transplantation is a special situation wherein this phenomenon can be observed. The greater part of the failed heart shows recuperation after receiving circulatory assistance by reduction of myocardial work. Herein we have reported an unusual behavior of degenerative cardiomyopathy associated with intense myocardial apoptosis resulting in extreme ventricular atrophy after heterotopic heart transplantation. An 11-year-old girl with end-stage heart failure due to dilated cardiomyopathy of undetermined etiology without pulmonary hypertension underwent heterotopic cardiac transplantation with an undersized (by weight mismatch) donor heart. After 9 years heart failure reappeared due to native heart enlargement leading to allograft compression. The patient underwent native heart replacement leaving her with 2 donor hearts. Despite normal hemodynamic recuperation, the patient experienced massive arterial microemboli which led to death. Pathological studies showed exuberant myocardial degeneration in the native heart with intense atrophy of the muscle and gigantic ventricular enlargement. The left ventricle wall was extremely thin with rarefaction of cardiomyocytes and replacement by fibrosis. The right ventricle showed old extensive thrombosis. In conclusion, this report is not usual as it is not frequent to observe cardiomyopathy with an intense degree of myocardial degeneration and atrophy, because the patient dies earlier. In special situations it is possible that a recipient may have 2 donor hearts with normal hemodynamics. Heterotopic heart transplantation is a surgical alternative in a priority situation offering excellent outcomes; however, the native heart must be removed when there is compromise of the function of the heterotopic allograft.

Cardiomyopathy, adult valve disease and heart failure in South America.

Continued assessment of temporal trends in mortality and epidemiology of specific cardiovascular diseases in South America is needed to provide a scientific basis for rational allocation of the limited healthcare resources and introduction of strategies to reduce risk and predict the future burden of cardiovascular disease. The epidemiology of cardiomyopathies, adult valve disease and heart failure (HF) in South America is reviewed here. Diseases of the circulatory system are the main cause of death based on data from about 50% of the South American population. Among the cardiovascular causes of death, cerebrovascular disease is predominant followed by ischaemic heart disease, other heart diseases and hypertensive disease. Of note, cerebrovascular disease is the main cause of death in women, and race also influenced cardiovascular mortality rates. HF is the most important cardiovascular reason for admission to hospital due to cardiovascular disease of ischaemic, idiopathic dilated cardiomyopathic, valvular, hypertensive and chagasic aetiologies. Also, mortality due to HF is high, especially owing to Chagas' disease. HF and aetiologies associated with HF are responsible for 6.3% of deaths. Rheumatic fever is the leading cause of valvular heart disease. The findings have important public health implications because the allocation of healthcare resources, and strategies to reduce the risk of HF should also consider controlling Chagas' disease and rheumatic fever in South American countries.

Acute effects of a single dose of phosphodiesterase type 5 inhibitor (sildenafil) on systemic arterial blood pressure during exercise and 24-hour ambulatory blood pressure monitoring in heart transplant recipients.

BACKGROUND: Arterial systemic hypertension (SH) can be associated with a decrease in endothelium-dependent nitric oxide (NO). Sildenafil increases cyclic guanosine monophosphate (cGMP), a mediator of NO. However, little is known about the effects of PDE5 inhibition on 24-hour ambulatory pressure (ABP) and exercise blood pressure, noreprinephrine (Nor), and exercise capacity, especially after orthotopic heart transplantation (OHT). METHODS: We studied 22 OHT patients who on the 1st day underwent a cardiopulmonary (CP) self-controlled treadmill 6' walk test (6') and, then, an ECG monitored CP treadmill maximal exercise test (Ex) within 60 and 90 minutes after oral Sildenafil (Sil; 50 mg) or placebo (Pl) given at random, and ABP. We determined at basal position (b), in the last minute of the 6' and at the peak Ex, the HR (bpm), Systolic blood pressure (SBP), and diastolic blood pressure (DBP), (mm Hg), VO2 (mL/kg/min), Slope VE/VCO2, exercise time (ET, min), distance (D; miles), and Nor (pg/mL). Also, after CP tests, 24-h SBP and DBP, the measurements were repeated on the 2nd day when the cross-over was done. RESULTS: Sil significantly reduced blood pressure in the basal position and during exercise. It also promoted a significant reduction in SBP and DBP during 24 hours, daytime and nighttime. Sil did not change exercise capacity. CONCLUSION: The NO-cGMP pathway seems to play a role in blood pressure control in OHT. In addition to antihypertensive therapy, PDE5 inhibition may have potential beneficial effects on hypertensive OHT.

Prophylactic donor tricuspid annuloplasty in orthotopic bicaval heart transplantation.

OBJECTIVE: The objective of this study was to evaluate the effects of prophylactic heart donor tricuspid annuloplasty to improve the degree of valvar regurgitation and the hemodynamic performance after orthotopic heart transplantation using bicaval anastomosis. METHODS: From March 1985 to December 2005, of the 368 patients undergoing orthotopic heart transplantation, 20 patients were selected because they survived more than 6 months. They were divided into 2 groups: group I-10 patients underwent prophylactic heart donor tricuspid annuloplasty by the De Vega technique; group II-10 patients did not receive a graft with this procedure. Their presurgical clinical characteristics were the same. In the postsurgical period, tricuspid regurgitation degree evaluated by transthoracic Doppler echocardiography was qualified from 0 to 3: 0 = absent; 1 = mild; 2 = moderate; and 3 = severe. Myocardial performance was evaluated by the ventricular ejection fraction and by an invasive hemodynamic study, performed during routine endomyocardial biopsies. RESULTS: At a follow-up of 14.6 +/- 4.3 months (6 and 16 months), group I showed no mortality, whereas group II had 10% (P > .05). However, it was not related to the annuloplasty. The mean degree of tricuspid regurgitation in group I was 0.4 +/- 0.6; in group II, 1.6 +/- 0.8 (P < .05). There was a significant difference between the 2 groups in the right atrium pressure, which was higher in group II. CONCLUSIONS: Prophylactic tricuspid annuloplasty in the heart donor significantly reduced the degree of valvular regurgitation after heart transplantation using a bicaval anastomosis without significantly interfering with the hemodynamic performance of the allograft.