Valvular calcifications at the start of dialysis predict the onset of cardiovascular events in the course of follow-up.

OBJECTIVE: To analyse the presence of VC at the start of dialysis and its relationship with events and/or death from cardiovascular causes in the course of follow-up. METHODS: In the study, we included patients who started dialysis between November 2003 and September 2007. In the first month of treatment, we assessed the presence of VC by Doppler echocardiography, along with demographic factors and risk factors for cardiovascular disease, coronary artery disease, stroke, atrial fibrillation (AF), and cardiac dimensional and functional electrocardiographic and echocardiographic parameters. The biochemistry values assessed were: haemoglobin, calcium/phosphorous/iPTH metabolism, cholesterol and fractions, triglycerides, troponin I, albumin, CRP and glycosylated haemoglobin. We analysed the association between VC and the presence of myocardial infarction (MI), stroke and/or death from cardiovascular causes up to transplantation, death or the end of the study (December 2012). RESULTS: Of 256 enrolled patients (83% haemodialysis, 17% peritoneal dialysis), 128 (50%) had VC (mitral: 39, aortic: 20, both: 69). In the multivariate analysis, VC was associated with older age (OR: 1.110; 95% CI: 1.073-1.148; p = 0.000) and lower albumin levels (OR: 0.29; 95% CI: 0.14-0.61; p = 0.001). In a follow-up lasting 42.1 ± 30.2 months (898.1 patient-years), 68 patients suffered MI, stroke and/or died from cardiovascular causes. In the Cox regression analysis, older age (HR: 1.028; 95% CI: 1.002-1.055; p = 0.037), coronary artery disease and/or stroke (HR: 1.979; 95% CI: 1.111-3.527; p = 0.021), AF (HR: 2.474; 95% CI: 1.331-4.602; p = 0.004), and the presence of VC at the start of dialysis (HR: 1.996; 95% CI: 1.077-3.700; p = 0.028) were the predictor variables for the occurrence of the analysed events. CONCLUSIONS: The prevalence of VC at the start of dialysis is high and its presence predicts the occurrence of events and/or cardiovascular death in the course of follow-up.

Las calcificaciones valvulares al inicio de diálisis predicen la aparición de eventos cardiovasculares en la evolución / Valvular calcification upon initiating dialysis predict the appearance of cardiovascular events in patient evolution

La calcificación valvular (CV) en la enfermedad renal crónica es frecuente, aunque la mayor parte de la información procede de pacientes prevalentes en diálisis. Son pocos los estudios que analicen la CV en los pacientes que inician diálisis. Objetivo: Analizar la presencia de CV al inicio de diálisis y su relación con eventos y/o muerte cardiovascular en la evolución. Métodos: Incluimos en el estudio los pacientes incidentes en diálisis entre nov/03 y sept/07. En el 1o mes de tratamiento analizamos la presencia de CV mediante Ecocardiograma-doppler, junto a factores demográficos y de riesgo cardiovascular, enfermedad coronaria, accidente cerebrovascular (ACV), fibrilación auricular (FA) y parámetros de electro y ecocardiográficos dimensionales y funcionales cardiacos. Los valores bioquímicos analizados fueron: hemoglobina, metabolismo calcio/fósforo/iPTH, colesterol y fracciones, triglicéridos, troponina I, albúmina, PCR y hemoglobina glicosilada. Analizamos la asociación de la CV con la presentación de infarto de miocardio (IAM), ACV y/o muerte cardiovascular hasta el trasplante, muerte, o fin del estudio (dic/2012). Resultados: De 256 pacientes incluidos (83% hemodiálisis, 17% diálisis peritoneal), 128 (50%) presentaban CV (mitral: 39, aórtica: 20, ambas: 69). En el análisis multivariante la CV se asoció a mayor edad (OR: 1,110; IC 95%: 1,073-1,148; p = 0,000) y menor albúmina (OR: 0,29; IC 95%: 0,14-0,61; p = 0,001). En un seguimiento de 42,1 ± 30,2 meses (898,1 pacientesaño), 68 pacientes presentaron IAM, ACV y/o murieron por causa cardiovascular. En el análisis de regresión de Cox, la mayor edad (HR: 1,028; IC 95%: 1,002-1,055; p = 0,037), la enfermedad coronaria y/o ACV (HR: 1,979; IC95%: 1,111-3,527; p = 0,021), la FA (HR: 2,474; IC 95%: 1,331-4,602; p = 0,004) y la presencia de CV antes de entrar en diálisis (HR: 1,996; IC 95%: 1,077-3,700; p = 0,028), fueron predictores independientes de la presentación de los eventos analizados. Conclusiones: La prevalencia de CV en el momento de iniciar diálisis es alta y su presencia predice la presentación de eventos y/o muerte cardiovascular en la evolución (AU)

The estimated frequency of cardiac valvular calcification (VC) in patients on dialysis is high, although the majority of studies published to date regarding the rate of VC have dealt with prevalent patients in dialysis. There are few studies of VC at the commencement of dialysis and its relationship to future events or cardiovascular mortality. Objective: To establish the prevalence of VC at the start of dialysis and the relationship between VC and the presentation of composite endpoints of acute myocardial infarction (MI), stroke or death from cardiovascular causes in the follow-up of incident dialysis patients. Methods: We conducted an analysis of dialysis patients (haemodialysis or peritoneal dialysis) who commenced dialysis between November 03 and September 07. VC was assessed by Doppler-echocardiography and its association with MI, stroke or cardiovascular mortality in the follow-up until death, transplant, or study end in December 2012 was analysed. Other variables assessed in the first month of dialysis were ECG, age, gender, smoking habit, diabetes, hypertension, previous ischemic stroke, coronary arterial disease and atrial fibrillation. Biochemical analyses included: haemoglobin, urea, creatinine, lipids, calcium, phosphorus, parathyroid hormone, albumin, troponin I, glycosylated haemoglobin and C-reactive protein. Results: Of 256 enrolled patients (83% Haemodialysis, 17% Peritoneal dialysis), 128 (50%) had VC at the commencement of dialysis (aortic 20, mitral 39, both 69). VC was associated with older age (OR: 1.110; CI 95%: 1.073-1.148; P=.000) and lower albumin levels (OR: 0.29; CI 95%: 0.14-0.61; P=.001). In a follow-up lasting a mean of 42.1±30.2 months (898.1 patient-years), 68 patients suffered an MI, a stroke or died from cardiovascular causes. The factors that predicted the presentation of the endpoint (Cox regression analysis) were older age (HR: 1.028; CI 95%: 1.002-1.055; P=.037), previous coronary arterial disease or stroke (HR: 1.979; CI 95%: 1.111-3.527; P=.021), atrial fibrillation (HR: 2.474; CI 95%: 1.331-4.602; P=.004) and VC at the start of dialysis (HR: 1.996; CI 95%: 1.077-3.700; P=.028). Conclusions: The prevalence of VC at the commencement of dialysis is very high and its presence is an independent predictor of event and cardiovascular mortality presentation in the course of follow-up (AU)

Sudden death in incident dialysis patients.

BACKGROUND: Sudden death (SD) constitutes one of the principal causes of death and is an important problem in healthcare provision. Cardiovascular diseases have a high prevalence in dialysis patients and constitute the principal cause of death. We sought to analyze retrospectively the incidence of SD in patients commencing dialysis and the factors related to its presence. METHODS: We evaluated all the patients who began dialysis in our center between 1/11/2003 and 15/9/2007, and who were followed up until death, transplant, or study completion on 31/12/2012. We determined the presence of SD according to the following criteria: SD at 24 h (SD 24H): unexpected death occurring in the 24 h following the start of symptoms, or when the patient was found dead and had been seen alive 24 h earlier; SD at 1 h (SD 1H): death witnessed as occurring in the first hour following the start of symptoms. RESULTS: We evaluated 285 patients, mean age 65.67 ± 15.7 years. In a follow-up of 39.9 ± 34.2 months (947.6 patient-years of follow-up) 168 died (59%), 28 (10%) patients presented SD 24H (2.9/100 patient-years), and 16 (6%) patients presented SD 1H (1.7/100 patient-years). In the multivariate analysis, having had a myocardial infarction or having had electrocardiographic abnormalities (Q wave, negative T wave, subendocardial lesion or QRS >120 ms) were the principal independent predictors of SD 24H (OR 7.83; 95% CI 2.20-27.86; p = 0.001) and of SD 1H (OR 13.43; 95% CI 1.56-115.42; p = 0.018). CONCLUSIONS: SD on dialysis is very frequent. Two groups can be identified easily, with risk profiles clearly differentiated.

Ischaemic stroke in incident dialysis patients.

BACKGROUND: Despite the high frequency of cardiovascular disease among the population on dialysis, there are few studies on ischaemic stroke and associated factors. The objective of the present study is to assess the prevalence of ischaemic stroke at the start of dialysis, its incidence in the course of follow-up and possible factors associated in its presentation. METHODS: All patients in our dialysis programme between 1 January 1999 and 31 December 2005 were included in the study and followed up until death, transplant, transfer out of our catchment area, or conclusion of the study on 31 December 2008. Factors analysed were age, gender, smoking habit, diabetes, hypertension, previous ischaemic stroke, ischaemic coronary disease, peripheral vascular disease and atrial fibrillation. Other factors measured in the first month of dialysis were haematocrit, urea, creatinine, lipids, calcium, phosphorus, parathyroid hormone and albumin. RESULTS: Of 449 patients included in the study (age 64.4 ± 16 years), 30 commenced dialysis having had previous stroke (prevalence 6.7%). In a follow-up of 38.77 ± 29 months, 34 patients presented with one or more strokes; an incidence of 2.41/100 patient-years. Greater age [odds ratio (OR): 1.05; 95% confidence interval (CI): 1.01-1.09; P = 0.007], diabetes (OR: 2.29; 95% CI: 1.15-4.55; P = 0.018) and presence of atrial fibrillation (OR: 3.11; 95% CI: 1.53-6.32; P = 0.002) were independent predictors of stroke occurrence. Conclusions. The prevalence of ischaemic stroke is high at the commencement of dialysis, and its incidence is elevated in the course of follow-up. As with the general population, atrial fibrillation is an important factor predictive of ischaemic stroke, and as such, the clinical implication is that prophylactic anti-coagulation therapy needs to be considered for these individuals.

Atrial fibrillation in incident dialysis patients.

Despite the importance of cardiovascular disease in dialysis patients, the frequency of atrial fibrillation in incident dialysis patients has not been determined. We analyzed the prevalence of atrial fibrillation in patients starting dialysis over a 4-year period, its occurrence over the course of dialysis, and its influence on ischemic stroke and mortality. Factors predisposing to atrial fibrillation were noted, as was the influence of arrhythmia on mortality and presentation of ischemic stroke. Of the 256 patients studied, 31 had atrial fibrillation at the start of dialysis. Increased age, larger left atrium, and female gender were independently related to the presence of atrial fibrillation at dialysis inception. Of the 225 patients who were in sinus rhythm at the start of dialysis, 28 developed atrial fibrillation during a mean follow-up time of 2 years. The presence of valvular calcifications, bundle branch block, previous ischemic stroke, lower ejection fraction, higher pulse pressure, and lower hemoglobin concentration were predictors of the clinical evolution of atrial fibrillation. Overall, atrial fibrillation increased mortality risk 1.72-fold and ischemic stroke risk 9.8-fold. Therefore, it appears that atrial fibrillation is quite prevalent and its presence is associated with significant risk.

Should we perform an echocardiogram in hypertensive patients classified as having low and medium risk?

BACKGROUND: Left ventricular hypertrophy is an important predictor of cardiovascular risk and its detection contributes to risk stratification. However, echocardiography is not a routine procedure and electrocardiography (ECG) underestimates its prevalence. OBJECTIVE: To evaluate the prevalence of echocardiographic left ventricular hypertrophy in low and medium risk non-treated hypertensive subjects, in order to find out the percentage of them who would be reclassified as high risk patients. METHODS: Cross-sectional, multicenter study was performed in hospital located hypertension units. An echocardiogram was performed in 197 previously untreated hypertensive patients, > 18 years, classified as having low (61%) or medium (39%) risk, according to the OMS/ISH classification. The presence of left ventricular hypertrophy was considered if left ventricular mass index was > or = 134 or 110 g/m(2) in men and women, respectively (Devereux criteria). A logistic regression analysis was performed to identify factors associated to left ventricular hypertrophy. RESULTS: The prevalence of left ventricular hypertrophy was 23.9% (95% CI:17.9-29.9), 25.6% in men and 22.6% in women. In the low risk group its prevalence was 20.7% and in medium risk group 29.5%. Factors associated to left ventricular hypertrophy were: years since the diagnosis of hypertension, OR:1.1 (95% CI:1.003-1.227); systolic blood pressure, OR:1.08 (95% CI:1.029-1.138); diastolic blood pressure, OR:0.9 (95% CI:0.882-0.991); and family history of cardiovascular disease, OR:4.3 (95% CI:1.52-12.18). CONCLUSIONS: These findings underline the importance of performing an echocardiogram in low and high risk untreated hypertensive patients in which treatment would otherwise be delayed for even one year.

Ought dialysis patients with atrial fibrillation be treated with oral anticoagulants?

BACKGROUND: Dialysis patients with atrial fibrillation have an increased thrombolic risk. Dicoumarin anticoagulant therapy is often considered contra-indicated in chronic renal insufficiency in which the risk of haemorrhage, though not defined, is perceived to be high. We assessed haemorrhage complications in dialysis patients receiving dicoumarin anticoagulant therapy to establish whether the haemorrhage risk justifies the contra-indication of anticoagulant therapy in patients with atrial fibrillation. PATIENTS AND METHODS: Over a period of a decade in our dialysis centre, 29 patients receiving anticoagulant therapy over a protracted period presented haemorrhage complications. These were classified with respect to severity and location and compared with 211 patients not receiving anticoagulant therapy. The relative risk of haemorrhage was calculated and was compared to risk of thrombo-embolism in dialysis patients with atrial fibrillation. RESULTS: Of the 29 patients, nine had 13 episodes of haemorrhage complications (26 episodes/100 patient-years). None was fatal, nor intra-cranial nor with serious clinical sequelae. In the group without anticoagulants, 29 patients had 39 haemorrhage complications (11 episodes/100 patient-years); four (10.2%) intra-cranial and all fatal. The relative risk of bleeding with anticoagulant therapy was 2.36 (95% confidence interval=1.19-4.27). CONCLUSIONS: (1) Dialysis patients with anticoagulant therapy presented with a higher risk of haemorrhage; (2) the relative risk of bleeding was double that of the dialysis population without anticoagulant therapy; (3) despite the high risk of haemorrhage that we observed, the high risk of thrombo-embolism and the attendant serious sequelae to which dialysis patients with atrial fibrillation are predisposed indicates that oral anticoagulation therapy ought not to be considered automatically contra-indicated in this patient group but that an exhaustive evaluation of the risk-benefit needs to be conducted on an individual patient basis.