Clinical characteristics and treatment outcomes of patients with Brugada syndrome in northeastern Thailand

INTRODUCTION

Brugada syndrome (BrS) is a common genetic cause of sudden cardiac arrest (SCA) due to polymorphic ventricular tachycardia and ventricular fibrillation. The current recommended therapy for high-risk BrS patients is the use of an implantable cardioverter defibrillator (ICD). The present study aimed to report the clinical characteristics and treatment outcomes of BrS patients in northeastern Thailand.

METHODS

Patients who were diagnosed with BrS or had a Brugada electrocardiogram (ECG) between 2005 and 2012 at Khon Kaen University’s hospitals were enrolled in the present study. Patients’ clinical characteristics, ECG type, laboratory results and treatment were reviewed.

RESULTS

A total of 90 eligible patients were enrolled. Of these, 79 (87.8%) patients were symptomatic – 65 (82.3%) had documented SCA and 14 (17.7%) had unexplained syncope. The remaining 11 (12.2%) patients were asymptomatic with Brugada ECG. A majority of the patients enrolled were born in northeastern Thailand. The mean age of the symptomatic patients was 44.49 ± 8.55 years. Among the symptomatic patients, a majority were male (n = 77, 97.5%) and 23 (29.1%) patients had a family history of SCA. Almost all BrS patients who were symptomatic (96.2%) received ICD treatment for secondary prevention. The number of patients who received appropriate ICD therapy was 4.2 times of those who received inappropriate shocks. Only 3 (3.8%) symptomatic BrS patients refused ICD treatment.

CONCLUSION

Clinical characteristics did not distinguish between symptomatic BrS patients and asymptomatic patients with Brugada ECGs. The clinical characteristics and treatment outcomes for the symptomatic BrS patients with SCA and unexplained syncope were similar. Among the BrS patients implanted with secondary prevention ICD in Northeastern Thailand, nearly one-third had received appropriate ICD therapy, far exceeding the incidence of device-related complications and inappropriate therapy.     

Personal use of hair dyes--increased risk of non-Hodgkin's lymphoma in Thailand

The use of hair dyes has been inconsistently associated with an increased risk of lymphomas. To further evaluate this possibility, we examined hair dye use and lymphoma risk in a case-control study in the Thai population. A total of 390 histologically confirmed incident non-Hodgkin's lymphoma (NHL) cases and 422 controls were included. Information on hair dye use was obtained through a personal interview together with information on other known risk factors of lymphoma. Analysis was performed using logistic regression; odds ratios (ORs) estimates and 95% confidence intervals (CI) were calculated. Ever use of hair dyes was not associated with an increase risk of NHL both overall (OR=1.1, 95%CI 0.8-1.5) and in women (OR=1.4, 95%CI 0.9-2.3). However, NHL was significantly higher among persons who began using hair dyes before 1980 (OR=2.1, 95%CI 1.0-4.1). An increased risk was also observed among women who reported use of permanent hair dye product (OR=1.8, 95% CI 1.0-3.1). Analyses by NHL subtype showed an increased risk for diffuse large B-cell lymphoma among users of permanent hair dyes (OR=1.6, 95%CI 1.0-2.5) while follicular lymphoma was associated with the use of dark-colored dyes (OR=3.7, 95%CI 1.1-12.8). No association was observed with duration of use, nor total lifetime applications. These results indicate that personal hair dye use may play role in risks of NHL among person who used hair dyes before 1980.     

Impact of the heterozygous TPMT*1/*3C genotype on azathioprine-induced myelosuppression in kidney transplant recipients in Thailand

Background: Thiopurine S-methyltransferase (TPMT) is a polymorphic enzyme associated with detoxification of azathioprine, an immunosuppressant used after renal transplantation in several Asian countries. Patients with variations of the TPMT gene may be at risk for myelosuppression after they receive a standard dosage of the drug. The frequency of TPMT*3C has been reported to be higher in the Thai population than in other Asian populations, possibly putting the Thais at higher risk for myelosuppression.Objective: The aim of this study was to assess the impact of the heterozygous TPMT*1/*3C genotype on azathioprine-induced myelosuppression in kidney transplant recipients in Thailand.Methods: This study was conducted at Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand, and Chulalongkorn Hospital, Chulalongkorn University, Bangkok, Thailand. Eligible patients underwent kidney transplantation from deceased or living-related donors from 1984 to 2007. Electronic medical records were assessed retrospectively for the 6-month period after initiation of azathioprine treatment. TPMT genotyping and phenotyping were studied prospectively using real-time polymerase chain reaction and biochemical assay, respectively. The odds ratios (ORs), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined.Results: A total of 139 patients were enrolled (89 men, 50 women; median age, 42 years [range, 17–70 years]; mean weight, 58 kg [range, 37–87 kg]). The heterozygous TPMT*1/*3C genotype was found in 9 of the 139 patients (6.47%) (95% CI, 3.00–11.94). The TPMT activity of those patients was significantly lower than that of patients with the homozygous wild-type genotype (median, 21.37 vs 37.12 nmol 6-methylthioguanine/g · Hb/h, respectively; P < 0.001). The risk for azathioprine-induced myelosuppression in the patients with the heterozygous TPMT*1/*3C genotype was significantly higher than that in patients with the wild-type genotype (adjusted OR, 14.18 [95% CI, 3.07–65.40]; P < 0.005). The sensitivity and specificity of TPMT*3C genotyping for the prediction of azathioprine-induced myelosuppression in these kidney transplant recipients were 27% and 97%, respectively. Assuming a prevalence of azathioprine-induced myelotoxicity of 7% according to previously published data, the PPV and NPV were estimated to be 50% and 95%, respectively.Conclusion: In these kidney transplant recipients, patients who carried the TPMT*3C allele were at a higher risk for azathioprine-induced myelosuppres-sion than noncarriers.     

Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients

Purpose

The prevalence of both hypertension and obstructive sleep apnea (OSA) are increased in patients with age greater than 60 years. We studied the clinical differences of OSA in hypertensive patients with age greater or less than 60 years. In addition, rate of OSA-induced hypertension in Thai population is limited.

Methods

We retrospectively reviewed medical records of patients treated at the hypertension/sleep clinic at Srinagarind Hospital, Khon Kaen University, between 2010 and 2011. The inclusion criteria used were hypertensive patients who had at least one symptom of OSA and had been tested for the sleep study. Rate and clinical features of OSA were studied and categorized by age of 69 years. Factors associated with likelihood of having OSA in hypertensive patients age over 60 years were identified by multiple logistic regression analysis.

Results

During the study period, 49 patients met the criteria. Of those, 42 patients (85.71 %) had an apnea–hypopnea index (AHI) of more than 5/h. The average AHI was 22.22?±?13.86 times/h. The common symptoms of OSA were snoring (100 %), daytime sleepiness (28.57 %), unexplained nocturia (28.57 %), and gastroesophageal reflux disease (28.57 %). The numbers of patients with age less than 60 years and more than 60 years were 20 and 22 cases, respectively. Most patients (88.10 %) had well-controlled blood pressure level. Only BMI was significantly associated with OSA-induced hypertension in patients aged over or equal to 60 years. The adjusted odds ratio was 0.743 (0.560, 0.985).

Conclusions

OSA is very common in Thai hypertensive patients aged 40–70 years who have at least one symptom of OSA. Lower BMI is a predictor of obstructive sleep apnea in elderly Thai hypertensive patients