Anticoagulation in the Elderly

Abhay J. Dhond, MD, MPH, Hector I. Michelena, MD, Michael D. Ezekowitz, MD, PhD


Am J Geriatr Cardiol. 2003;12(4) 

In This Article

Barriers to Anticoagulation

Despite evidence showing that anticoagulation can reduce the risk of stroke in individuals with AF, only 15%-44% patients who have AF receive anticoagulation therapy.[40] The elderly are least likely to receive warfarin treatment, even though they would be most likely to benefit.[41]

The decision to use anticoagulation is based on an interplay of factors related to the patient, the physician, and the health care system. Several patient-related factors have been identified.[42] Age is the most important, with older patients less likely to receive treatment. Other patient-related factors include the perceived embolic risk or perceived risk of hemorrhage, the patient's medical history, the patient's risk of falling, and patient refusal of therapy or nonadherence to treatment.

Many physician-related factors have been identified that can influence anticoagulation. An important consideration is the perceived risk-benefit ratio of anticoagulation. Results of a recent pilot study[43] suggest that physicians attach more importance to the perceived risks of therapy than to benefits. An adverse outcome due to an "act of commission" is regretted more than a similar outcome due to an "act of omission." Thus, physicians may be unwilling to take the risk, for example, of an elderly patient falling. Interestingly, a recent study[44] demonstrated that the risk of an adverse event from falling is far less than the risk for stroke in many elderly patients with AF, and that patients must fall more than 295 times a year to justify not giving them anticoagulation therapy.

Other physician-related factors include lack of awareness of, or disbelief in, the accuracy of the results of recent clinical trials, fear of litigation, and perception of patient reliability. Warfarin use is also influenced by physician specialty, and is more likely to be prescribed by internists and cardiologists than general practitioners or family physicians.[41] Physicians may also believe that they prescribe anticoagulation more often than they actually do. In one study,[45] physicians reported prescribing warfarin for 51% of their patients, but chart review revealed only 24% of their patients received prescriptions. Many physicians consider anticoagulation management to be inconvenient and time consuming; a survey of doctors in the United Kingdom found that 94% of those surveyed preferred that anticoagulation be managed by someone else.[42]

The health care system can also influence treatment, although this has not been studied as extensively as patient-related or physician-related factors. Application of clinical practice guidelines vary between regions and institutions. Patients in routine clinical practice generally do not receive anticoagulation as dependably as patients do in clinical trials. The effects of managed care can be either positive (e.g., implementation of practice guidelines by a health maintenance organization can increase the number of patients who receive anticoagulation) or negative (if time constraints limit the amount of time spent with the patient, physicians may be less likely to advise anticoagulation).

Thus, even though the efficacy of anticoagulation in the management of patients with AF has been proved beyond doubt by several clinical trials, the effectiveness can be improved further by ensuring that a larger percentage of eligible patients are anticoagulated appropriately. Further research is required in this field.