Kidney Week

Abstract: TH-PO421

Association Between Use of Alpha-Blockers in Older Adults and Hypotension and Hypotension-Related Clinical Events

Session Information

• Hypertension and CVD: Epidemiology, Risk Factors, Prevention
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Hypertension and CVD

• 1401 Hypertension and CVD: Epidemiology, Risk Factors, and Prevention

Authors

• Hiremath, Swapnil, University of Ottawa, Ottawa, Ontario, Canada

Swapnil Hiremath,

• Ruzicka, Marcel, University of Ottawa, Ottawa, Ontario, Canada

Marcel Ruzicka,

• Petrcich, William, Institute for Clinical Evaluative Sciences, Ottawa, Ontario, Canada

William Petrcich,

• Hundemer, Gregory L., Massachusetts General Hospital, Arlington, Massachusetts, United States

Gregory L. Hundemer,

• Burns, Kevin D., The Ottawa Hospital - Riverside Campus, Ottawa, Ontario, Canada

Kevin D. Burns,

• Edwards, Cedric A.W., The Ottawa Hospital - Riverside Campus, Ottawa, Ontario, Canada

Cedric A.W. Edwards,

• Garg, Amit X., London Health Sciences Centre, London, Ontario, Canada

Amit X. Garg,

• Sood, Manish M., Ottawa Hospital Research Institute, Ottawa, Ontario, Canada

Manish M. Sood,

Background

Alpha- blockers (AB) are effective and commonly prescribed medications as part of a multi-drug regiment in the management of hypertension. Little is known regarding the risk of hypotension and hypotension-related clinical outcomes in older adults with ongoing AB use. We set out to assess the risk of hypotension and related adverse events with AB use compared to other anti-hypertensives in the older adults.

Methods

A population-based, retrospective cohort study of 933,033 older adults (> 66 years) prescribed an anti-hypertensive medication between 1995 and 2015 in Ontario, Canada. A high dimensional propensity score was used to match the dispensing of AB compared to other anti-hypertensives. AB exposure was modeled as a time-varying and cumulative covariate using extended, conditional Cox proportional hazards to examine the association with outcomes. Study outcomes were hospital admissions or emergency room visits for hypotension, related events (syncope, fractures, falls), major adverse cardiovascular events (MACE) and all-cause mortality. We examined subgroups of age, total number of anti-hypertensives and concurrent beta-blocker use.

Results

Among 69,092 matched patients prescribed AB (mean age 75.1 SD 6.5 years) with a median follow up 3.7 (IQR 1.4 to 9.5) years, the incident rate of hypotension and related events were significantly higher compared to other anti-hypertensives (hypotension 1.15 vs. 0.39, syncope 1.47 vs. 0.46, falls 4.37 vs. 1.37, fractures 2.23 vs. 0.69 per 100 person-years of follow-up). In time-varying exposure models with additional adjustment for the total number of anti-hypertensives, the higher risk persisted (hypotension HR 1.34 95%CI 1.26-1.43, syncope HR 1.49 95%CI 1.41-1.57, falls HR 1.27 95%CI 1.23-1.32, HR fractures 1.41 95%CI 1.34-1.48). Secondary outcomes of MACE and all-cause mortality were higher or similar among AB users (MACE IR 7.03 vs. 2.31, mortality 6.54 vs 6.37 per 100 person-years follow-up).

Conclusion

Treatment of hypertension in older adults with AB is associated with a higher risk of hypotension, hypotension-related events and MACE. Our findings suggest that AB should be used with caution, even as add on therapy for hypertension in older adults.