Serious Adverse Events associated with Re-admission through One Year after Two Different Approaches to Vertebral Augmentation

Presented at SMISS Annual Forum 2016
By Douglas Beall MD
With

Disclosures: Douglas Beall MD A; Benvenue Medical Inc. B; Benvenue Medical Inc.

Introduction

Vertebral compression fractures (VCFs) are costly, with expenditures exceeding one billion dollars annually in the United States. It is important to evaluate different treatment approaches for improved effectiveness in helping prevent re-admissions associated with VCFs or other conditions. 

Aims/Objectives

To compare risk of serious adverse events (SAEs) associated with re-admission during the one year after vertebral augmentation in patients randomly assigned to and undergoing one of two different augmentation procedures. 

Methods

Post-hoc analysis of KAST (Kiva Safety and Effectiveness Trial), a pivotal, multicenter, randomized, controlled investigational device exempt (IDE) trial conducted to evaluate an implant-based vertebral augmentation approach (implant) against balloon kyphoplasty (BK). In KAST, adults with painful VCFs due to osteoporosis in the thoracic and/or lumbar spine were randomly assigned to implant (n=144) or BK (n=141). Treatment effect of each approach on SAEs requiring unplanned re-admission was evaluated by estimating the risk of SAEs associated with re-admissions in KAST while controlling for key baseline covariates using multivariate Poisson regression modeling. 

Results

Forty (27.8%) implant patients had 69 SAEs associated with re-admission compared to 44 (31.2%) BK patients having 103 events. The risk estimate for all SAEs leading to unplanned re-admission was 34.4% lower with the implant than for BK (95% confidence interval = 11.1%, 51.7%; p=0.007). The multivariate Poisson regression model controlling for other influential baseline covariates showed that the risk of SAEs associated with unplanned re-admission was increased by 38.2% in subjects treated with BK (p=0.049), by 42.9% in subjects with prior history of VCFs (p=0.032) and by 79.6% in subjects with significant osteoporosis (DEXA spine T-score of -2.5 or worse) (p=0.001). 

Conclusions

Although two vertebral augmentation approaches may provide equivalent pain relief and quality of life improvements over non-surgical management, the lower risk of repeated re-admissions using one interventional approach over another are salient to healthcare organizations.