Abstract: FR-PO473

Incidence and Outcomes of Syncope in Patients with CKD

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 303 CKD: Epidemiology, Outcomes - Cardiovascular

Authors

  • Sood, Manish M., Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
  • Massicotte-Azarniouch, David, None, Ottawa, Ontario, Canada
  • Kuwornu, John Paul, Institute for Clinical Evaluative Sciences, Ottawa, Ontario, Canada
  • Mccallum, Megan K., Institute for Clinical Evaluative Sciences, Ottawa, Ontario, Canada
  • Garg, Amit X., London Health Sciences Centre, London, Ontario, Canada
  • Lam, Ngan, University of Alberta, Edmonton, Alberta, Canada
  • Molnar, Amber O., McMaster University, Hamilton, Ontario, Canada
Background

Syncope is common condition, occurring in roughly 1 in 3 people during their lifetime, and may be a sign of life-threatening illness. CKD patients may be at an elevated risk of syncope due to concurrent medical conditions, medication usage or the etiology of CKD itself. We set out to examine the incidence of first episode and recurrent syncope and its outcomes in patients with CKD > 66 years of age.

Methods

A population-based, retrospective cohort study using administrative databases between 2006 and 2015. A total of 272,149 patients with no history of syncope, a urine albumin to creatinine ratio (ACR) and eGFR measure were included. First syncope by strata of eGFR and ACR was examined using Fine and Gray Models sub-distribution hazards ratio (sHR) and recurrent syncope by negative binomial models (RRR). Models were adjusted for demographics, resource utilization, demographics and medications. Among those with syncope, the incidence of adverse outcomes (ACS, arrhythmia, stroke, fracture and death) was determined by eGFR strata.

Results

A total of 15,074 (5.5%) first and 36,710 (13.5%) recurrent syncope events occurred during the study period. Lower eGFR was associated with a higher risk of first episode of syncope [eGFR 60-90: sHR 1.24(1.15-1.33), eGFR 45-60: sHR 1.45(1.34-1.57), eGFR 30-45: sHR 1.49 (1.36-1.62), eGFR < 30: sHR 1.40 (1.25-1.57), eGFR > 90 referent] whereas ACR was not. Recurrent syncope was associated with lower eGFR and higher ACR [eGFR 60-90: RRR 1.21(1.13-1.31), eGFR 45-60: RRR 1.46(1.34-1.58), eGFR 30-45: RRR 1.58 (1.44-1.73), eGFR < 30: RRR 1.73(1.53-1.94), eGFR > 90 referent; ACR 3-30: RRR 1.09 (1.04-1.13), ACR > 30: RRR 1.15(1.06-1.24), ACR < 3 referent]. Among those with a first syncope event, the event rate (per 100 pt-yrs) of all adverse outcomes was higher with lower eGFR strata compared to normal eGFR (ACS: eGFR < 30: 2.44, eGFR > 90: 0.98, Arrhythmia: GFR < 30: 21.63, eGFR > 90: 8.88, stroke: eGFR<30: 5.02, eGFR >90: 2.32, fracture: eGFR<30: 5.40, eGFR >90: 2.62, death: eGFR < 30: 23.23 eGFR>90: 5.31).

Conclusion

First episode and recurrent syncope events are associated with lower eGFR and only marginally with a higher ACR. The risk of all adverse events (cardiovascular, fracture and death) is higher post-syncope in patients with eGFR < 30.