As risk assessment for autosomal dominant polycystic kidney disease (ADPKD) evolves, guidelines that enrich for selection of high-risk patients for advanced therapies will have the most clinical utility, according to a recent prospective study presented at Kidney Week 2019, November 7-9, Washington, DC.
Canadian and European risk assessment guidelines applied to a cohort of 474 individuals with ADPKD both resulted in cohorts enriched with high-risk patients in excess of 80%, according to researchers led by Syed Essam Ahmed, Toronto General Hospital, Ontario Canada.
According to Ahmed and colleagues, ADPKD guideline performance had not been previously assessed and approval of the vasopressin receptor antagonist tolvaptan has heightened the need for appropriate patient selection. While tolvaptan provides a new, mechanism-based therapy for ADPKD, the authors emphasize that it is costly and can be associated with serious adverse events and therefore is currently reserved for patients at high risk for disease progression. Determining how well current guidelines identify such patients was the current study's objective.
Patients recruited for the formal guideline assessment had typical MRI evidence of ADPKD and laboratory data including total kidney volume (TKV). Investigators used age- and height-adjusted TKV to derive Mayo Clinic Imaging Class (MCIC) as a gold standard for risk assessment.
Then, they applied the updated Canadian Expert Consensus on ADPKD risk and pharmacological management, and the European recommendations on risk assessment and tolvaptan use to assess how well these guidelines identified patients at high risk for rapid disease progression.
The Canadian risk assessment algorithm excluded 245 out of 474 patients (52%), authors found, with a resulting cohort that was enriched with 88% high-risk patients by MCIC criteria.
The European guidelines, which include a 5-step hierarchal approach, provided differing results depending on the steps applied. Using the first step, which is based on CKD stage and age, 74% of patients were excluded, and the resultant cohort was enriched with 72% high-risk patients.
After applying the second step of the European approach—based on rate of estimated glomerular filtration decline—the exclusion rate climbed to 93%, with an 82% enrichment for high-risk patients.
Reference: Ahmed SE, Akbari P, Guiard E, et al. How well do risk assessment guidelines perform for autosomal dominant polycystic kidney disease (ADPKD)? Presented at ASN Kidney Week, November 8, 2019. Abstract TH-PO833.