Staphylococcal driveline infections are the predominant type of left ventricular assist device associated infections in Singapore.

BACKGROUND: Left ventricular assist device (LVAD) associated infections (LVADIs) have substantial morbidity and mortality. We aim to describe the incidence and epidemiology of LVADIs in an Asian cohort. This is currently not well studied. METHODS: We conducted a retrospective review of 52 patients who underwent LVAD implantation from 1 May 2009-31 December 2014 in National Heart Centre Singapore. LVADIs were defined based on definitions proposed by the International Society for Heart and Lung Transplantation. RESULTS: There were 39 males and 13 females. Seventy-three percent had Heartmate II LVAD implant while 27% received Heartware HVAD. Eighty-one percent were implanted as bridge to heart transplantation, 19% as destination therapy. Forty-five episodes of LVADIs occurred in 25 patients. Overall LVADI incidence was 47.5 cases per 100 patient-years. Driveline infections (58%) were the commonest type of LVADI. The commonest causative organisms were coagulase-negative staphylococci (33%), Staphylococcus aureus (31%) and Corynebacterium species (19%). Twelve percent of patients with LVADI required surgical debridement and one patient required pump exchange due to pump pocket infection. All-cause mortality was 13%. CONCLUSIONS: The findings of our study add to the understanding and epidemiology of LVADIs, particularly in the Asian setting. This can contribute to the development of evidence based strategies to prevent and manage LVADIs.

Genetic polymorphisms in MDR1 and CYP3A4 genes in Asians and the influence of MDR1 haplotypes on cyclosporin disposition in heart transplant recipients.

Intestinal cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp) both play a vital role in the metabolism of oral cyclosporine (CsA). We investigated the genetic polymorphisms in CYP3A4(promoter region and exons 5, 7 and 9) and MDR1 (exons 12, 21 and 26) genes and the impact of these polymorphisms on the pharmacokinetics of oral CsA in stable heart transplant patients (n = 14). CYP3A4 polymorphisms were rare in the Asian population and transplant patients. Haplotype analysis revealed 12 haplotypes in the Chinese, eight in the Malays and 10 in the Indians. T-T-T was the most common haplotype in all ethnic groups. The frequency of the homozygous mutant genotype at all three loci (TT-TT-TT) was highest in the Indians (31%) compared to 19% and 15% in the Chinese and Malays, respectively. In heart transplant patients, CsA exposure (AUC(0-4 h), AUC(0-12 h) and C(max)) was high in patients with the T-T-T haplotypes compared to those with C-G-C haplotypes. These findings suggest that haplotypes rather than genotypes influence CsA disposition in transplant patients.

Successful clearance of human parainfluenza virus type 2 viraemia with intravenous ribavirin and immunoglobulin in a patient with acute myocarditis.

Human parainfluenza virus (HPIV) infection as an aetiology of acute viral myocarditis is rare, with only few cases reported in the literature to date. Here we report a case of fulminant HPIV-2 myocarditis in a 47 year-old man with viraemia who was successfully treated with intravenous ribavirin and intravenous immunoglobulin (IVIG). There are currently no recommendations on the treatment of HPIV myocarditis. We are, to our knowledge, the first to report a patient with a documented HPIV-2 viraemia that subsequently cleared after the initiation of antiviral therapy. Although it is difficult to definitively attribute the patient's clinical improvement to ribavirin or IVIG alone, our case does suggest that clinicians may wish to consider initiating ribavirin and IVIG in patients with HPIV myocarditis and persistent viraemia not responding to supportive measures alone.

Heart transplantation in Singapore

<p><b>INTRODUCTION</b>The status of heart transplantation in Singapore is reviewed in this article.</p><p><b>MATERIALS AND METHODS</b>The database of 40 consecutive heart transplantations from July 1990 through December 2007 is reviewed retrospectively. The data is compared with the 2008 registry data of the International Society for Heart and Lung Transplantation (ISHLT).</p><p><b>RESULTS</b>The average age of recipients was 45.3 years. Ages ranged from 14 to 64 years. Ischaemic cardiomyopathy (52.5%) and dilated cardiomyopathy (42.5%) were the major indications. From 1990 to 1999, 50% of the donors sustained brain death from road traffic accident, 25% from cerebrovascular accident and 25% from falling from height, whereas the cause of brain death in the donors from 2000 to 2007 was 33%, 47% and 9.5%, respectively. The average donor age increased from 28.3 to 38.1 years. The significant morbidities in the recipients were hypertension, cytomegalovirus (CMV) infection, cardiac allograft vasculopathy and renal dysfunction. Thirtytwo required treatment for hypertension. 67.5% developed CMV disease requiring treatment. Cardiac allograft vasculopathy was diagnosed in 10. Rising creatinine levels reaching over 2.5 mg/dL was seen in 7. Three required renal dialysis. Epstein-Barr virus related lympho proliferative disorder occurred in 2 patients. One patient developed adenocarcinoma of stomach. The 30-day mortality was 10% and half life was 10 years. Cardiac allograft vasculopathy and sepsis caused 41.7% of mortality each. 11.7% of the mortality was due to cerebrovascular accident.</p><p><b>CONCLUSION</b>The status of heart transplantation in Singapore is comparable to the ISHLT registry data. Transplant provides excellent early survival of 80%; however, the expected half life is around 10 years after cardiac transplantation. The late mortality is mainly caused by cardiac allograft vasculopathy (CAV) and renal failure. More effort and research needs to be directed towards these issues to improve the long-term results.</p>