Advances in Prevention and Health Services Delivery 2009

It is estimated that only about half of patients currently receive therapies of proven value in reducing stroke risk. The reasons for this “treatment gap” are varied and complex but represent important missed opportunities for prevention. For example, a cohort study found that high adherence to antihypertensive drugs lowered the risk of cerebrovascular disease events by 22% (rate ratio=0.78; 95% CI, 0.70 to 0.87) compared with lower adherence.1 Despite this, sizable proportions of adults are unaware that they have the condition, and hypertension control is frequently inadequate.2Last reviewed in “Advances in Prevention and Health Services Delivery 2007,”3 atrial fibrillation (AF) remains a major, preventable cause of stroke. New research shows that the risk of stroke-related death in patients with AF and congestive heart failure treated with rhythm compared with rate control (≈90% of whom were also treated with warfarin) are similar (3% for rhythm control vs 4% for rate control; hazard ratio [HR]=0.74; 95% CI, 0.40 to 1.35; P =0.32).4Warfarin is recommended to prevent thromboembolism in high-risk patients with AF unless the drug is contraindicated.5 Similar to the situation for hypertension and consistent with prior work, a prospective audit of “high-risk” (based on American College of Chest Physicians guidelines) persons with AF admitted to 12 Canadian hospitals found that 60% of those with a first-ever stroke were not receiving warfarin at the time of admission, despite having no contraindications for treatment.6 In addition, 74% of those who were receiving warfarin were underanticoagulated. The strokes that occurred were frequently severe: 20% were fatal and 60% were disabling. As pointed out in an accompanying editorial, the reasons for the underuse of warfarin may, in part, be related to misperceptions about the risk and inconvenience of the drug compared with other, less-effective treatments.7A …