Kidney, Cardiac, and Safety Outcomes Associated With α-Blockers in Patients With CKD: A Population-Based Cohort Study - Journal club.
Published:September 10, 2020DOI:https://doi.org/10.1053/j.ajkd.2020.07.018
Kidney, cardiac, and safety outcomes of alpha blockers
1. Kidney, Cardiac, and Safety Outcomes
Associated With Alpha Blockers in
Patients With CKD
BY: KHALED GHANAYEM
DEPARTMENT OF INTERNAL MEDICINE G’, HAEMEK MEDICAL CENTER
1
4. OVERVIEW
• Chronic kidney disease (CKD) is highly prevalent in the older population (>20%)
• Hypertension (HTN) is nearly ubiquitous in this population (>80%)
• In many cases a combination of blood pressure (BP) lowering medications are needed
• Alpha-Blockers (AB) are reliable BP lowering meds
5. OVERVIEW
• AB: Competitive inhibition of postsynaptic α1-adrenoreceptors of vascular smooth muscle
• Vasodilation of veins and arterioles -> decrease in peripheral vascular resistance
• AB in most cases are add-on therapy rather than 1st line
• Concerns over side effects:
• Orthostatic hypotension
• Syncope
• Falls
• Fractures
• Lack the reno-protective effects
• Potent BP lowering capability
6. METHODS
• Population-level, retrospective, matched cohort study
• Conducted in Ontario, Canada
• Study period 2007 – 2015
• BP lowering meds included:
• Angiotensin-converting enzyme (ACE) inhibitors
• Angiotensin II receptor blockers (ARBs)
• Calcium channel blockers
• β-blockers
• Thiazide diuretics
7. DESIGN
Inclusion Exclusion
• Age: 66 or older
• Previous HTN diagnosis (diagnostic code or BP
lowering med prescription)
• 2 estimated glomerular filtration rate (eGFR)
assessments (CKD-EPI calc)
• Prior AB use
• History of:
o Benign prostatic hyperplasia
o Hypotension
o Dialysis
o Kidney transplantation
• 1:1 high dimensional propensity score (HDPS) matching
• Index event was new BP lowering med
10. RESULTS
Pre-matching
AB group had a higher proportion of:
‒ Men
‒ eGFR
‒ Diabetes + DM meds
‒ BP-lowering medications
‒ Statin use
Post-matching
• All characteristics were similar
• Mean age – 76 y/o
• Mean eGFR - 62 mL/min/1.73 m2
11. RESULTS – PATIENTS
• Similar and diverse socioeconomic backgrounds
• Nearly half study population eGFR 60 – 89 mL/min/1.73 m2
• Majority were on 4-5 BP lowering meds (60%+)
• Most commonly used: ACE-I, CCB, and BB
• Most widely use AB – Terazosin (66%) > Doxazosin (30%) > Prazosin
21. DISCUSSUION
AB use was associated with:
• Higher relative risk for ≥30% eGFR decline
• Need for KRT
• Reduced risk for cardiac events
• All-cause mortality
• Patients with lower eGFR benefited from AB
• Lower eGFR = similar adverse events except syncope
• Are ABs the real culprit for eGFR decline?
• Need for AB = poor BP control?
22. LIMITAIONS
• Observational study
• Single state
• No BP measurements available
• Chance of AB use for urological symptoms
• Adverse events required hospitalization
• Index BP med could be the reason for results
23. CONCLUSION
• Alpha blockers are potent blood pressure medications
• In patients with low eGFR they hold a cardiac + mortality advantage
• Consider avoiding in normal/at risk eGFR patients