Relation of atrial electromechanical delay to P‐wave dispersion on surface ECG using vector velocity imaging in patients with hypertrophic cardiomyopathy

ObjectivesHeterogeneity of structural and electrophysiologic properties of atrial myocardium is common characteristic in hypertrophic cardiomyopathy (HCM). We assessed the dispersion of atrial refractoriness on surface ECG using P‐wave dispersion (PWD) and its relation to atrial electromechanical functions using vector velocity imaging (VVI) in HCM population.MethodsSeventy‐nine HCM patients (mean age: 43.7 ± 13 years, 67% male) were compared with 25 healthy individuals as control. P‐wave durations, P_max and P_min, P‐wave dispersion (PWD), and P terminal force (PTF) were measured from 12‐lead ECG. LA segmental delay (TTP‐d) and dispersion (TTP‐SD) of electromechanical activation were derived from atrial strain rate curves.ResultsHCM patients had longer PR interval, PW duration, higher PWD, PTF, QT_c compared to control (p < .001). HCM patients were classified according to presence of PWD into two groups, group I with PWD > 46 ms (n = 25) and group II PWD ≤ 46 ms (n = 54). Group I showed higher prevalence of female gender, higher PTF, QTc interval, left ventricular outflow tract (LVOT) obstruction, p < .01, LVOT gradient (p < .001), LV mass index (p < .01), E/E'' (p < .01), and severe mitral regurgitation (p < .001). Moreover, PWD was associated with increased atrial electromechanical delay (TTP‐d) and LA mechanical dyssynchrony (TTP‐SD), p < .001. LA segmental delay and dispersion of electromechanical activation were distinctly higher among HCM patient.ConclusionPWD is simple ECG criterion, and it is associated with more severe HCM phenotype and LA electromechanical delay while PTF is linked only to atrial remodeling.     

Dengue: Status of current and under‐development vaccines

Dengue is an emerging mosquito‐borne viral infection with increasing reports of outbreaks. The clinical picture ranges from a benign febrile illness through to severe and potentially fatal manifestations. No specific anti‐viral treatment exists, and therapy only consists of supportive care. During the last three decades, several attempts to develop an effective vaccine have been made. The first dengue vaccine to obtain licensure was Dengvaxia, which was authorized in 2015 and is currently available in over 20 countries. Its use has been approved with strict limitations regarding age and serostatus of the recipients, highlighting the necessity for a more safe and efficacious vaccine. At present several vaccine, candidates are undergoing clinical and pre‐clinical trials. The most advanced candidates are TDV and TDV 003/005, two live‐attenuated vaccines, but another 15 vaccines are under development, introducing novel immunization strategies to the traditional dengue vaccine scenario. This work reviews the current research status on dengue vaccines.     

Profil clinico-biologique et immunohématologique des patients atteints de β-thalassémie en Tunisie : à propos de 26 cas

Aim of the studyTo study the clinical and biological profile of β-thalassemic patients in our region, reflecting the quality of their care.Patients and methodsA retrospective study (2010–2011) on 26 β-thalassemic patients followed in the pediatrics service at CHU Farhat Hached Sousse, Tunisia. Epidemiological, clinical and biological data were collected from medical records and transfusion files of patients. The transfusion protocol adopted was to maintain a hemoglobin level > 10 g/dL by regular transfusions every 3–4 weeks. Iron chelation therapy, in order to maintain serum ferritin < 1500 ng/mL, was introduced when serum ferritin exceeded 800–1000 ng/mL.ResultsThe mean age of patients at diagnosis was 15 months. The clinical impact of anemia had resulted in failure to thrive in 54% of patients and facial dysmorphism in 23%. The average transfusion requirement was estimated at 311.02 mL/kg/year with 6 cases of hyperconsumption. The immunohaematological monitoring showed the appearance of anti-RBC alloimmunization in one patient and 4 cases of autoimmunization. Poor adherence of chelation therapy was 62% and causing 5 cases of cardiac complications, 4 cases of liver injury and 14 cases of endocrine complications.ConclusionImproving the therapeutic care of β-thalassemic children requires better monitoring of transfusion recovery and improved adherence to chelation therapy.     

RHD positive among C/E+ and D-negative blood donors in Tunisia

Purpose of the studyThe aim of this study was to investigate RHD alleles among Tunisian blood donors with D-negative phenotype and positive for C and/or E antigen.Patients and methodsA total of 100 D-negative and C/E+ samples were analyzed by RHD genotyping using an initial test for RHD exon 10. In case of a positive reaction, further molecular investigations including real time quantitative PCR, allele specific PCR and nucleotide sequencing were done to elucidate the RHD involved mechanisms.ResultsSeventy-five percent of the studied samples lacked the RHD gene. Twenty-three percent carried the hybrid RHD-CE-D alleles (16 RHD-CE(3-7)-D, 5 RHD-CE(4-7)-D, 1 RHD-CE(4-8)-D, 1 RHD-CE(3-8)-D) and 2% were weak D (1 weak D type 1 and 1 weak D type 5).ConclusionOur study proved the high frequency of RHD gene among serologically D-negative samples, positive for C and/or E antigen. Thus achieving systematically RHCE phenotyping in all transfusion centers on the Tunisian territory and considering blood donated from D-negative C/E+ persons as D-positive will be recommended to reduce anti-D allo-immunization.     

Outcome of conditioning intensity in acute myeloid leukemia with monosomal karyotype in patients over 45 year‐old: A study from the acute leukemia working party (ALWP) of the European group of blood and marrow transplantation (EBMT)

Acute myeloid leukemia with monosomal karyotype (MK AML) carries a very poor prognosis, even after allogeneic stem cell transplantation (SCT). However, SCT remains the only curative option in this high‐risk population. Because myeloablative conditioning regimen (MAC) is associated with less relapse, we hypothesized that more intensive conditioning regimen might be beneficial for MK AML patients. We reviewed 303 patients over age 45 diagnosed with either de novo or secondary MK AML. One hundred and five patients received a MAC and 198 a reduced‐intensity conditioning (RIC). The median age at SCT was 57‐year‐old, significantly lower in the MAC (53‐year‐old) than in the RIC group (59‐year‐old). The median follow‐up was 42 months (range, 3 ? 156 months). The 3‐year overall survival (OS), leukemia‐free survival (LFS), and relapse rate (RR) were not significantly different between both groups with overall values of 34%, 29%, and 51%, respectively. On the contrary, the 3‐year nonrelapse mortality (NRM) was significantly higher in MAC recipients (28%) compared with RIC patients (16%, P = 0.004). The incidence of Grades II to IV acute graft‐versus‐host disease (GvHD) was significantly higher after a MAC (30.5%) than after a RIC (19.3%, P = 0.02). That of chronic GvHD was comparable between both groups (35%) and did not impact on LFS. Interestingly, within our MK AML cohort, hypodiploidy was significantly associated with worse outcomes. Due to reduced toxicity and comparable OS, LFS, and RR, RIC appears as a good transplant option in the very high‐risk population, including older patients, diagnosed with MK AML. Am. J. Hematol. 90:719–724, 2015. © 2015 Wiley Periodicals, Inc.