Cancer Incidence in Heart Transplant Recipients With Previous Neoplasia History.

Neoplasm history increases morbidity and mortality after solid organ transplantation and has disqualified patients from transplantation. Studies are needed to identify factors to be considered when deciding on the suitability of a patient with previous tumor for heart transplantation. A retrospective epidemiological study was conducted in heart transplant (HT) recipients (Spanish Post-Heart Transplant Tumor Registry) comparing the epidemiological data, immu-nosuppressive treatments and incidence of post-HT tumors between patients with previous malignant noncardiac tumor and with no previous tumor (NPT). The impact of previous tumor (PT) on overall survival (OS) was also assessed. A total of 4561 patients, 77 PT and 4484 NPT, were evaluated. The NPT group had a higher proportion of men than the PT group (p < 0.001). The incidence of post-HT tumors was 1.8 times greater in the PT group (95% confidence interval [CI] 1.2-2.6; p < 0.001), mainly due to the increased risk in patients with a previous hematologic tumor (rate ratio 2.3, 95% CI 1.3-4.0, p < 0.004). OS during the 10-year posttransplant period was significantly lower in the PT than the NPT group (p = 0.048) but similar when the analysis was conducted after a first post-HT tumor was diagnosed. In conclusion, a history of PT increases the incidence of post-HT tumors and should be taken into account when considering a patient for HT.

Health-related quality of life, social support, and caregiver burden between six and 120 months after heart transplantation: a Spanish multicenter cross-sectional study.

A multicenter cross-sectional study was conducted to determine the current heart transplant (HTx) outcomes in Spain. Clinical and functional status, health-related quality of life (HRQoL), social support, and caregiver burden were analyzed in 303 adult transplant recipients (77.9% males) living with one functioning graft. Mean age at time of HTx (SD) was 56.4 (11.4) years, and the reason for transplantation in all patients was congestive heart failure. All patients had received a first heart transplant 6 (± 1), 12 (± 2), 36 (± 6), 60 (± 10), or 120 (± 20) months previously. Participants completed the Kansas City Cardiomyopathy Questionnaire (KCCQ), the EQ-5D, the Duke-UNC Functional Social Support Questionnaire, and the Zarit Caregiver Burden Scale. Reasonable HRQoL, social support, and caregiver burden levels were found at all time points, although a slight decrease in HRQoL was recorded at 120 months (p ≤ 0.033). Multivariate regression analyses showed that complications, comorbidities, and hospitalizations were associated with HRQoL (EQ-5D: 48.4% of explained variance, F4,164 = 38.46, p < 0.001; KCCQ overall summary score: 45.0%, F3,198 = 54.073, p < 0.001). Patient functional capabilities and complications affected caregiver burden (p < 0.05). In conclusion, HTx patients reported reasonable levels of HRQoL with low caregiver burden. Clinical variables related to these outcomes included functional status, complications, and number of admissions.

Risk factors associated with cytomegalovirus infection in heart transplant patients: a prospective, epidemiological study.

BACKGROUND: The objectives of this epidemiological, prospective study were to describe the characteristics of cytomegalovirus (CMV) infection in heart transplant (HT) recipients and to identify the variables that may influence the development of CMV viremia and CMV disease in these patients. METHODS: HT recipients ≥18 years of age (n=199) were included in the study. Variables studied included CMV serostatus, immunosuppressive treatment, and administration of anti-CMV prophylaxis. RESULTS: The mean age of the population was 52 years, and 84% were males. Immunosuppressive regimens were administered as induction therapy to 92.5% of patients; 88.5% of patients received calcineurin inhibitors as maintenance therapy. Anti-CMV treatment was given to 59% of 199 patients as prophylaxis (70%), preemptive therapy (10%), or to treat CMV infection (20%). Overall, 43% of patients had at least 1 positive viremia test. No patient with a high-risk serostatus (donor+/recipient-) receiving prophylaxis developed CMV syndrome, and only 2.5% of 199 patients developed CMV invasive disease. Multivariate analysis showed that having a positive donor CMV serostatus was associated with an increased risk of developing CMV viremia (P<0.012), while use of mammalian target of rapamycin (mTOR) inhibitors was associated with a decreased risk (P=0.005). CONCLUSIONS: In a population of HT recipients, the CMV infection rate was similar to that seen in previous studies, but the progression to overt CMV disease was very low. Having a CMV-positive donor was identified as an independent risk factor for developing CMV viremia, while the use of mTOR inhibitors was protective against viremia.

Sinogram bow-tie filtering in FBP PET reconstruction.

Low-pass filtering of sinograms in the radial direction is the most common practice to limit noise amplification in filtered back projection (FBP) reconstruction of positron emission tomography studies. Other filtering strategies have been proposed to prevent the loss in resolution due to low-pass radial filters, although results have been diverse. Using the well-known properties of the Fourier transform of a sinogram, the authors defined a binary mask that matches the expected shape of the support region in the Fourier domain of the sinogram ("bow tie"). This mask was smoothed by a convolution with a ten-point Gaussian kernel which not only avoids ringing but also introduces a pre-emphasis at low frequencies. A new filtering scheme for FBP is proposed, comprising this smoothed bow-tie filter combined with a standard radial filter and an axial filter. The authors compared the performance of the bow-tie filtering scheme with that of other previously reported methods: Standard radial filtering, angular filtering, and stackgram-domain filtering. All the quantitative data in the comparisons refer to a baseline reconstruction using a ramp filter only. When using the smallest size of the Gaussian kernel in the stackgram domain, the authors achieved a noise reduction of 33% at the cost of degrading radial and tangential resolutions (14.5% and 16%, respectively, for cubic interpolation). To reduce the noise by 30%, the angular filter produced a larger degradation of contrast (3%) and tangential resolution (46% at 10 mm from the center of the field of view) and showed noticeable artifacts in the form of circular blurring dependent on the distance to the center of the field of view. For a similar noise reduction (33%), the proposed bow-tie filtering scheme yielded optimum results in resolution (gain in radial resolution of 10%) and contrast (1% increase) when compared with any of the other filters alone. Experiments with rodent images showed noticeable image quality enhancement when using the proposed bow-tie filtering scheme.

Design and performance evaluation of a coplanar multimodality scanner for rodent imaging.

This work reports on the development and performance evaluation of the VrPET/CT, a new multimodality scanner with coplanar geometry for in vivo rodent imaging. The scanner design is based on a partial-ring PET system and a small-animal CT assembled on a rotatory gantry without axial displacement between the geometric centers of both fields of view (FOV). We report on the PET system performance based on the NEMA NU-4 protocol; the performance characteristics of the CT component are not included herein. The accuracy of inter-modality alignment and the imaging capability of the whole system are also evaluated on phantom and animal studies. Tangential spatial resolution of PET images ranged between 1.56 mm at the center of the FOV and 2.46 at a radial offset of 3.5 cm. The radial resolution varies from 1.48 mm to 1.88 mm, and the axial resolution from 2.34 mm to 3.38 mm for the same positions. The energy resolution was 16.5% on average for the entire system. The absolute coincidence sensitivity is 2.2% for a 100-700 keV energy window with a 3.8 ns coincident window. The scatter fraction values for the same settings were 11.45% for a mouse-sized phantom and 23.26% for a rat-sized phantom. The peak noise equivalent count rates were also evaluated for those phantoms obtaining 70.8 kcps at 0.66 MBq/cc and 31.5 kcps at 0.11 MBq/cc, respectively. The accuracy of inter-modality alignment is below half the PET resolution, and the image quality of biological specimens agrees with measured performance parameters. The assessment presented in this study shows that the VrPET/CT system is a good performance small-animal imager, while the cost derived from a partial ring detection system is substantially reduced as compared with a full-ring PET tomograph.

Malignancy after heart transplantation: incidence, prognosis and risk factors.

The Spanish Post-Heart-Transplant Tumour Registry comprises data on neoplasia following heart transplantation (HT) for all Spanish HT patients (1984-2003). This retrospective analysis of 3393 patients investigated the incidence and prognosis of neoplasia, and the influence of antiviral prophylaxis. About 50% of post-HT neoplasias were cutaneous, and 10% lymphomas. The cumulative incidence of skin cancers and other nonlymphoma cancers increased with age at HT and with time post-HT (from respectively 5.2 and 8.9 per 1000 person-years in the first year to 14.8 and 12.6 after 10 years), and was greater among men than women. None of these trends held for lymphomas. Induction therapy other than with IL2R-blockers generally increased the risk of neoplasia except when acyclovir was administered prophylactically during the first 3 months post-HT; prophylactic acyclovir halved the risk of lymphoma, regardless of other therapies. Institution of MMF during the first 3 months post-HT reduced the incidence of skin cancer independently of the effects of sex, age group, pre-HT smoking, use of tacrolimus in the first 3 months, induction treatment and antiviral treatment. Five-year survival rates after first tumor diagnosis were 74% for skin cancer, 20% for lymphoma and 32% for other tumors.

Cardiofemoral index as an ultrasound marker of fetal anemia in isoimmunized pregnancy.

OBJECTIVE: To test a new noninvasive ultrasound method for diagnosing fetal anemia in red blood cell isoimmunized pregnancies. METHODS: A diagnostic accuracy study was carried out to determine the cutoff point of an ultrasound measurement, the cardiofemoral index (CFI), calculated using the biventricular outer dimension (BVOD) and femur length to diagnosis severe anemia. The CFI measurement was performed before each of the 336 cordocenteses on 131 fetuses. Diagnosis test analysis and receiver-operating characteristics (ROC) curves were used and the area under the curve (AUC) was calculated to compare the overall accuracy of the CFI for anemia diagnosis, between fetuses with or without previous intrauterine transfusions (IUT). RESULTS: At first cordocentesis (n=131) the AUC was 0.75 (95% CI, 0.66-0.84). For cases where fetuses had undergone 1 previous transfusion (n=88) the AUC was 0.76 (95% CI, 0.64-0.88) and at the time of the third cordocentesis for IUT (n=53) it was 0.73 (95% CI, 0.59-0.86). For a 0.59 CFI threshold to diagnosis fetuses with hemoglobin deficit above 5 g/dL, sensitivity values were 87.2%, 88.0%, and 94.1% respectively for fetuses without IUT, with 1 IUT, and with 2 IUTs. Likelihood ratios for positive (LR+) and negative (LR-) test results were 1.98, 2.05, 1.69 and 0.23, 0.21, 0.13 respectively. CONCLUSION: The cardiofemoral index may be an effective noninvasive marker of severe fetal anemia in high-risk fetuses, with accuracy similar for fetuses either with or without previous transfusions.

Is an emergency heart transplantation justified?

INTRODUCTION: Emergency heart transplantation remains an important controversy due to the shortage of donors and the previously demonstrated results inferior to other patients. These recipients display a worse clinical status and their donors are more often considered suboptimal. Nevertheless, it is the only therapeutic option for patients with advanced cardiomyopathy and acute decompensation with no response to other therapies. We compared results among the emergency indication with those of elective transplants. METHODS: We analyzed the 213 patients who underwent cardiac transplantation in our center up to December 2004 to compare emergency with elective heart transplantations for preoperative and surgical variables as well as outcomes. RESULTS: A higher percentage of emergency patients were New York Heart Association class IV, displayed renal dysfunction, and were women. Regarding donors, a higher percentage were over 40 years of age. No differences were observed in the early and first-year mortality or morbidity rates, although we noted a greater 5-year mortality rate among emergency cases. CONCLUSIONS: In our center emergency heart transplantation was associated with only slightly worse results compared with elective transplantations. Both donors and recipients should be carefully selected to improve results.

Is it possible to reduce the number of endomyocardial biopsies with new immunosuppressive drugs?

INTRODUCTION: Using previous immunosuppressive regimens the considerable number of rejections of heart transplantations required routine surveillance myocardial biopsies, particularly during the early months. More effective immunosuppressive regimens would probably allow routine biopsies to be reduced. Our objectives were to assess the incidence of and the time to rejection with a new immunosuppressive protocol, considering the possibility of reducing the number of routine biopsies. MATERIALS AND METHODS: We undertook a retrospective study of patients who had undergone heart transplantation from January 2002 to August 2005 and who received induction therapy with Daclizumab (two doses) and maintenance therapy with tacrolimus + mycophenolate + low doses of steroids. RESULTS: Among 42 patients, 13 (31%) showed myocardial rejection in the first 3 months. All episodes were grade 3A and none had hemodynamic consequences. After 3 months, three patients (7.1%) experienced 3A rejection and 1 (2.4%), grade 4 acute rejection after ceasing medical treatment. Each episode of rejection was predictable, either owing to reduction in immunosuppression therapy or to a previous history of rejection. CONCLUSIONS: The majority of rejection episodes occur in the first 3 months posttransplantation. After that time, the incidence of rejection is less and clinically predictable. Therefore, surveillance biopsies should be limited to the first 3 months, and performed later either in symptomatic patients (with a history of previous rejection) or in those whose immunosuppressive therapy needs to be reduced.

Combination therapy with sildenafil and bosentan reverts severe pulmonary hypertension and allows heart transplantation: case report.

INTRODUCTION: Severe pulmonary hypertension with no response to vasodilators on an acute hemodynamic study is a contraindication to cardiac transplantation. The development of oral pulmonary vasodilators improves the prognosis in these patients. We present the case of a patient whose admission to the waiting list for cardiac transplantation was possible after 6 months of combination therapy with Sildenafil and Bosentan. CASE REPORT: The patient was a 50-year-old man with severe dilated alcohol-induced cardiomyopathy. A pretransplantation study, including a right hemodynamic analysis, revealed irreversible pulmonary hypertension, with 59 mm Hg mean pulmonary artery pressure and 6.4 Wood IU pulmonary vascular resistance, with no response to acute vasodilators with nitric oxide or prostacyclin. Initially, heart transplantation was not possible and the patient started treatment with oral Sildenafil. After 6 months there was no improvement in echocardiographic or hemodynamic parameters, and combination therapy with Bosentan was started. With the combination therapy, the patient progressively improved clinically and hemodynamically, the pressures becoming normal at the sixth month, at which time he was included on the waiting list for a heart transplantation. Eight months later he received a graft with a good posttransplantation course, no right ventricular failure in the acute phase, and absence of pulmonary hypertension on echocardiogrphic and invasive studies. CONCLUSION: Combinations of an oral pulmonary vasodilator with diverse action mechanisms may represent an alternative for patients with irreversible pulmonary hypertension who do not respond to monotherapy.

Sirolimus experience in heart transplantation.

INTRODUCTION: Sirolimus is a potent, nonnephrotoxic immunosuppressant with antiproliferative activity in nonimmune cells. Recent data support the conversion in late renal failure secondary to calcineurin inhibitors (CNIs), with limited experience in de novo regimens in patients with predictive factors of postoperative renal impairment. OBJECTIVE: We evaluated our experience of sirolimus-based immunosuppression administered to 25 heart transplant recipients. METHODS: A retrospective analysis of 25 heart transplant recipients who received sirolimus included 17 conversions due to late CNI-related chronic renal dysfunction, six patients with a de novo regimen, and two patients who developed posttransplant pulmonary neoplasms. The conversion from CNI to sirolimus was started with 2 mg, with an average time after transplantation of 78 +/- 43 months and a mean baseline serum creatinine level of 2.1 +/- 0.45 mg/dL. The mean clinical follow-up was 17 +/- 9 months postconversion, and included echocardiography and laboratory studies. In the de novo group successive endomyocardial biopsies were performed during the first semester. RESULTS: Serum creatinine fell from 2.1 +/- 0.45 mg/dL to 1.8 +/- 0.51 mg/dL (P = .012). Mean sirolimus levels were 15 +/- 9 ng/mL (doses 2.2 +/- 0.4 mg). This improvement continued until 3 months (creatinine 1.5 +/- 0.35 P < .01)/sirolimus levels 11.7 +/- 5 ng/mL [1.9 +/- 0.7 mg]), with maintenance at 6 months (1.58 +/- 0.3 mg/dL/14 +/- 4 ng/mL [1.85 +/- 0.7 mg]) and 1-year postconversion (1.53 +/- 0.39 mg/dL; P = .019/10.7 +/- 2.5 ng/mL [1.5 +/- 0.7 mg]). De novo, after a mean follow-up of 13 months (range 3 to 35), sirolimus appeared to increase the incidence of a moderate histological grade of rejection without hemodynamic compromise. Side effects were common (63%), including peripheral edema, skin eruptions, and pericardial effusion. Only one patient discontinued treatment, due to intestinal intolerance. Four patients died during follow-up: two because of lung neoplasms and two because of progressive graft vessel disease. CONCLUSION: Sirolimus improved late CNI-related chronic renal dysfunction. Kidney function was preserved using a de novo CNI-free immunosuppressive regimen for recent cardiac transplant recipients.

Infections in cardiac transplant recipients: clinical and microbiological characteristics and consequences.

INTRODUCTION: Infections are one of the main complications that cause morbidity and mortality in cardiac transplant recipients. We sought to establish the incidence of infections, identify the predisposing factors and determine their consequences. PATIENTS: A prospective study of 30 patients who received cardiac transplantations in our hospital from July 2003 to May 2005. RESULTS: Of the 30 transplant recipients, 93.3% were men (average age, 48 years); the average age of the women was 53 years. The incidence of infection was 70%: 21 episodes of infection. The main clinical symptoms were bacteriemia (28%), pneumonia (19%), and surgical wound infections (14%). The etiology of the infection, as established in 12 cases (57%), was bacterial (66%), viral (25%), or fungal (9%). The most common microorganisms were cytomegalovirus and coagulase-negative staphylococcus. None of the donors had a history of infection. There was a higher frequency of serious complications, such as renal failure (12.9%), respiratory insufficiency (9.6%), and multiorgan failure (9.6%) among patients with versus without infections (P < .05). The 1-year survival rate of patients with infections was similar to that of patients with no infections (83% vs 88%, P = NS). CONCLUSIONS: The incidence of infections was 70%. Bacteremia, pneumonia, and surgical wound infections occurred most frequently. Cytomegalovirus and coagulase-negative staphylococcus were the most frequent microorganisms. Patients with infections had the most serious complications, but their survival rate was similar to that of patients free of this complication.

Sirolimus improves renal function in cardiac transplantation.

In kidney and liver transplantation, sirolimus therapy has been shown to be comparable to cyclosporine in a head-to-head comparison, but it results in better preservation of renal reserve. In heart transplantation, information about the use of sirolimus is limited. We present the results of the progressive conversion from cyclosporine to sirolimus in a series of 8 heart transplant patients in whom renal dysfunction developed. The baseline creatinine level was 2.4 +/- 0.5 mg/dL, and plasma levels of cyclosporine were within the therapeutic range. After the introduction of sirolimus, the creatinine level fell within the first month to 1.76 +/- 0.2 mg/dL, or mean decrease of 0.6 +/- 0.25 mg/dL (P < .05). After 3 +/- 2.2 months the improvement continued (1.69 +/- 0.2 mg/dL). In 1 patient sirolimus was withdrawn during the first 24 hours, because of gastric intolerance. No patient developed an opportunist infection, allograft rejection, or important hematologic disorder. We conclude that sirolimus appears to be effective in heart transplant patients to improve renal function.

Use of oral sildenafil in patients with irreversible pulmonary hypertension not eligible for heart transplantation.

Heart transplantation is contraindicated in patients with acute irreversible pulmonary hypertension (PH), but new drugs are opening up therapeutic possibilities. Sildenafil citrate is a nonselective pulmonary vasodilator that is being used in our hospital to treat several patients with PH and which has allowed the inclusion of 1 patient on the waiting list for heart transplantation. A 20-year-old man with Becker muscular dystrophy was diagnosed at the age of 19 years with dilated cardiomyopathy with severe pulmonary artery systolic pressure (PH = 60 mm Hg). A pretransplantation study, including a right hemodynamic analysis with an acute vasodilator test using intravenous epoprostenol, revealed the irreversible character of the PH. Inasmuch as the administration of dobutamine did not achieve an adequate reduction of PH, oral sildenafil was started (25 mg every 12 hours) as salvage therapy. An echocardiogram obtained 2 months after starting sildenafil therapy showed normal right cavities, previously dilated, as well as minimal protosystolic tricuspid regurgitation without PH. A new right hemodynamic study performed after 4 months showed a reduction in pulmonary vascular resistance, from 8 U to 3.5 U Woods. As a result, the patient has now been included on the waiting list for heart transplantation. The promising example of this patient confirms the necessity to carry out controlled trials to establish definitively the indications for the use of sildenafil in patients with irreversible PH.

Myocardial preservation using Celsior: clinical results in high-risk cardiac transplantation.

Graft failure during the first few days posttransplantation remains one of the main unresolved complications. The objective of this study was to evaluate the influence of Celsior preservation solution on the incidence of early graft failure in high-risk cardiac transplant recipients. A retrospective study was carried out evaluating the cardiac transplants in 179 heart recipients. The patients were divided into 2 groups: (1) Celsior preservation solution (n = 37), and (2) Control solution (n = 142). To evaluate the efficacy of the Celsior solution, a subgroup of transplants from older donors or with ischemia times greater than 4 hours was compared with the other cases. The incidence of early graft failure was lower among the Celsior subgroups with longer ischemia times or of older donors compared with the control groups. We conclude that preservation with Celsior solution in cardiac transplantation is safe and effective. It even has advantages to reduce early graft failure compared with conventional solutions, a benefit that may be more evident in subgroups at high risk for myocardial dysfunction.

Comparative study of muromonab-CD3 (OKT3) versus daclizumab (Zenapax) in cardiac transplantation at our center.

Recent studies support the addition of new immunosuppressive drugs as cytolytic induction therapy in cardiac transplantation. We carried out a comparative study comprising 52 patients who had undergone cardiac transplantation at our center. Thirty patients received muromonab-CD3 (OKT3, Janssen-Cilag, The Netherlands) as the induction therapy, whereas 22 patients received Daclizumab (Zenapax, Hoffman-La Roche, Nutley, NJ, USA) instead. All patients received cyclosporine or tacrolimus, mycophenolate, and steroids. Over an average follow-up period of 23.21 +/- 18 months, we analyzed retrospectively the incidence of grade > or = 3A biopsy-confirmed acute rejection episodes, the presence of infectious processes at 1 and 6 months, the occurrence of significant secondary effects, and the necessity to modify the immunosuppressive therapy during the follow-up. The results suggest that daclizumab is linked to a decreased incidence of grade > or = 3A biopsy-confirmed acute rejection and to a reduced necessity to modify the immunosuppressive therapy during the medium-term follow-up.

Simulation of triple coincidences in PET.

Although current PET scanners are designed and optimized to detect double coincidence events, there is a significant amount of triple coincidences in any PET acquisition. Triple coincidences may arise from causes such as: inter-detector scatter (IDS), random triple interactions (RT), or the detection of prompt gamma rays in coincidence with annihilation photons when non-pure positron-emitting radionuclides are used (ß(+)γ events). Depending on the data acquisition settings of the PET scanner, these triple events are discarded or processed as a set of double coincidences if the energy of the three detected events is within the scanner's energy window. This latter option introduces noise in the data, as at most, only one of the possible lines-of-response defined by triple interactions corresponds to the line along which the decay occurred. Several novel works have pointed out the possibility of using triple events to increase the sensitivity of PET scanners or to expand PET imaging capabilities by allowing differentiation between radiotracers labeled with non-pure and pure positron-emitting radionuclides. In this work, we extended the Monte Carlo simulator PeneloPET to assess the proportion of triple coincidences in PET acquisitions and to evaluate their possible applications. We validated the results of the simulator against experimental data acquired with a modified version of a commercial preclinical PET/CT scanner, which was enabled to acquire and process triple-coincidence events. We used as figures of merit the energy spectra for double and triple coincidences and the triples-to-doubles ratio for different energy windows and radionuclides. After validation, the simulator was used to predict the relative quantity of triple-coincidence events in two clinical scanners assuming different acquisition settings. Good agreement between simulations and preclinical experiments was found, with differences below 10% for most of the observables considered. For clinical scanners and pure positron emitters, we found that around 10% of the processed double events come from triple coincidences, increasing this ratio substantially for non-pure emitters (around 25% for (124)I and > 50% for (86)Y). For radiotracers labeled with (18)F we found that the relative quantity of IDS events in standard acquisitions is around 18% for the preclinical scanner and between 14 and 22% for the clinical scanners. For non-pure positron emitters like (124)I, we found a ß(+)γ triples-to-doubles ratio of 2.5% in the preclinical scanner and of up to 4% in the clinical scanners.

Prevalence of sleep breathing disorders in outpatients on a heart transplant waiting list.

Sleep related periodic breathing with recurrent episodes of apnea and hypopnea is known to occur in patients with heart failure. We investigated the prevalence of sleep related breathing disorders (SRBD) in 14 outpatients on a heart transplant waiting list. All were younger than 60 years and had severe stable heart failure. Three patients (21%) exhibited 10 or more apneas and hypopneas per hour of sleep; these apneas and hypopneas were predominantly of the central type and occurred during Cheyne-Stokes respiration. There were no statistically significant differences between the apneic and non-apneic group in terms of age, left ventricular ejection fraction or pulmonary function tests. The group with SRBD had worse quality of life and less tolerance to exercise.

[Epidemiology, risk factors, and pathogeny of atrial fibrillation and atrial flutter]. / Epidemiología, factores de riesgo y patogenia de la fibrilación auricular y del flutter auricular.

Atrial fibrillation is a frequent arrhythmia which has a high prevalence after 65 years of age, thus the typical patient's age is about 75. There are two atrial fibrillation predictors: traditional factors of cardiovascular risk (age, male sex, high blood pressure, diabetes), and structural heart disorders (heart failure, valvular heart disease). All preventive measures to reduce atrial fibrillation incidence, must be directed towards these factors. Additionally, left atrial size, ejection fraction and ventricular hypertrophy are echocardiographic predictors. Atrial fibrillation doubles the mortality rate and is related to an annual stroke rate of 4.5%. The stroke risk factors are: age, hypertension, diabetes, previous stroke, congestive heart failure, coronary heart disease, mitral stenosis, prosthetic heart valves and thyrotoxicosis. Left atrial size and ventricular disfunction are echocardiographic stroke risk factors. Each patient's risk can be stratified on the basis of these factors. All of this information is essential to handle the arrhythmia appropriately; this arrhythmia may be more important than has been thought. Atrial flutter is not very frequent and so it is less studied; however it is an arrhythmia with a similar clinical context to atrial fibrillation, although, probably, with a smaller embolic risk.

[Electrical cardioversion and thrombogenesis. Apropos a case]. / Cardioversión eléctrica y trombogénesis. A propósito de un caso.

We report a case of a 73-years-old patient with atrial fibrillation who underwent direct current cardioversion. The transesophageal echocardiography performed before cardioversion excluded the presence of atrial thrombus. After cardioversion a new transesophageal echocardiography detected a thrombus in the left atrial appendage despite oral anticoagulation. Mechanism of thrombus formation and the need for oral anticoagulation before the procedure is being discussed.