Login to Access Video or Poster Abstract: MP06-08
Sources of Funding: none

Introduction

As the waiting time increases for listed renal failure patients, it is becoming common to encounter patients with minimal or no urine output with small shrunken bladders at the time of transplant. Mirabegron has proven benefit in treating overactive bladder(OAB) symptoms by relaxing the bladder through beta-3-adrenergic receptors. Our aim is to evaluate the efficacy of Mirabegron following kidney transplantation on patients with small bladder capacity.

Methods

Kidney transplant recipients with small bladder volumes who experienced OAB symptoms and were started on Mirabegron therapy within 3 months after transplant were included in this study. Patients were excluded if they had evidence of urinary tract infection or a history of complex urologic surgeries preceding transplantation. We used the OAB-symptom score (OAB-SS; Journal of Urology, 2007), a simple self-report questionnaire evaluating OAB symptoms. The minimum OAB-SS score for inclusion was 12. Patient demographics and OAB-SS pre and post-Mirabegron were collected and compared using paired t-test analysis.

Results

The 36 participants were predominantly male (83%) and deceased-donor kidney transplant recipients (86%). Median age was 48 years (IQR 36.5-60). 47% of patients reported pre-transplant urinary symptoms, most commonly recurrent UTI (28%). BPH-lower urinary tract symptoms (LUTS) reported by 30% of males may contribute to the sample sex imbalance. Before Mirabegron initiation, 44% of patients had failed trials of at least one pharmacologic agent and over 20% had failed trials of at least two medications. After starting Mirabegron therapy, 86% reported a decrease in OAB-SS. Overall mean score change was -4.7 points (p<0.001). Mean score on each OAB-SS survey question also decreased significantly (p<0.001, Table 2).

Conclusions

Mirabegron effectively reduces severity of symptoms related to small bladder volume following renal transplantation by increasing bladder relaxation and storage capacity.

Funding

none