1/7/2013
Aspirin for Primary Prevention of Cardiovascular Events
Just another day in clinic… 69 yo Filipina woman, non-smoker
ALI BLOCK, R2 GERIATRICS TALK JANUARY 2013
DM on metformin, hgb A1c 7.1 Hyperlipidemia on atorva, TC 190, TG 199, LDL 81, HDL 69 HTN on benazepril, BP 146/84
80 yo Eritrean man, non-smoker
HTN on lisinopril, BP 159/85 HLD not on meds, TC 241, TG 102, LDL 165, HDL 56
49 yo Latino man, non-smoker
Roadmap
DM on metformin and insulin, s/p amputation, A1C 7.9 HLD starting meds, TC 366, TG 351, LDL 243, HDL 53 HTN on benaz, 138/82
Epidemiology (a.k.a. Why We Care)
Epidemiology
CV disease leading cause of death in U.S.
Pathophysiology and Dosing
1 out of 2.8 deaths
Contraindications
Aspirin known to work for secondary prevention
Guidelines and Evidence for:
LOTS of trials for 1˚prevention mixed results
General population Diabetes Very elderly Colon cancer prevention
Simple approach + resources
Cases revisited
MI Stroke Mortality GI bleeds Hemorrhagic stroke
Mechanism of Action and Dosing Low dose: blocks thromboxane A2 blocks platelet
aggregation
Absolute:
75-300mg/day
Higher dose can block prostacyclin thrombosis
Contraindications
500mg/day
Cumulative effect if taken daily Reduces C-reactive protein – anti-inflammatory U.S. use 81mg/day
Miser, AFP, 2011
Active peptic ulcer Allergy/intolerance Bleeding disorder Recent GI bleed Recent intracranial bleed Renal failure Severe liver Disease Thrombocytopenia
Relative:
harm (A) Women 55-79 for ischemic stroke reduction when
benefit > harm (A)
Potential harm: GI bleed, hemorrhagic stroke
Insufficient evidence for men/women >80 (I)
Lowest dose (81mg for us)
Men benefit Berger, JAMA, 2006
Effect of Aspirin by Risk Category: Women and Stroke
Summary: Harms ≈ Benefits
Berger, JAMA, 2006 Bold typeface harms > benefit Assume net strokes prevented (ischemic prevented – hemorrhagic incurred)
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1/7/2013
Geriatrics – USPSTF
Geriatrics – Beers Criteria
>80 yo: insufficient evidence
“Potentially Inappropriate Medications” in older
adults
Stroke/MI and GI bleed risks all go up
No aspirin >325mg/day, esp if h/o GI ulcer
Consider aspirin if:
No risk factors for GI bleed Good potential to tolerate GI bleed: normal hgb, good renal function, easy access to emergency care
Asa for primary prevention >80yo may do more
harm than good use with caution
Low quality evidence, weak recommendation
Counsel on signs/symptoms GI bleed Discuss harms/benefits
What about in Diabetes? 2-4x increased risk CV events
Diabetes Continued 2010 Meta-analysis 7 RCTs
68% deaths from CAD, 16% from stroke
Mixed data on efficacy of asa for 1˚ prevention
Guidelines:
Yes for >10% risk, No for 50 or Women > 60 with another risk factor No for Men 10% risk, no for 50 or women >60 with additional risk factor
Geriatrics (>80)
81mg is sufficient Calculate 10-year risk to
determine whether pt should be on aspirin – lower threshold at younger age
Consider GI bleed risk factors, physiologic reserve Shared decision-making
Colon cancer prevention
Some evidence, could tip the balance
References
“Aspirin for the Prevention of Cardiovascular Disease: Recommendation Statement.” U.S. Preventive Services Task Force, March 2009. Berger, JS et al. “Aspirin for the Primary Prevention of Cardiovascular Events in Women and Men: A Sex-Specific Meta-analysis of Randomized Controlled Trials.” JAMA. 2006; 295(3):306-313. “American Geriatrics Society updated Beers Criteria for potentially inappropriate medication use in older adults.” American Geriatrics Society 2012 Beers Criteria Update Expert Panel. J Am Geriatr Soc. 2012 Apr, 60(4):616-31. Rothwell PM et al. “Long-term effect of aspirin on colorectal cancer incidence and mortality: 20-year follow-up of five randomised trials.” Lancet. 2010 Nov 20; 376(9754): 1741-50. Stavrakis, S, et al. “Low-dose aspirin for primary prevention of cardiovascular events in patients with diabetes: a meta-analysis.” Am J Med Sci. 2011 Jan; 341(1):1-9. Pignone, M et al. “Aspirin for Primary Prevention of Cardiovascular Events in People with Diabetes: A position statement of the American Diabetes Association, a scientific statement of the American Heart Association, and an expert consensus document of the American College of Cardiology Foundation.” Diabetes Care June 2010 vol. 33 no. 6 1395-1402. Miser, WF. “Appropriate Aspirin Use for Primary Prevention of Cardiovascular Disease.” Am Fam Physician. 2011 Un 15;83(12):1380-1390.
Thank You!
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