Abstract
BACKGROUND: There is clear evidence that long-term statin therapy can prevent the recurrence of vascular events, but in clinical practice, many patients discontinue statin therapy. OBJECTIVE: To evaluate the effect of statin interruption on clinical outcome in patients discharged after an acute ischemic stroke. DESIGN AND INTERVENTION: The present study was conducted at an Italian community hospital and enrolled consecutive stroke patients who were discharged from January 2000 to June 2005. Inclusion criteria were absence of any major concurrent illness, absence of any clinical and laboratory evidence of coronary heart disease (CHD) or of any other major cardiac affect or cardiac embolism, and discharge on statin therapy. After exclusions, 631 patients (51% male; mean ± SD age 70.2 ± 7.6 years) were enrolled. All participants were followed up for 12 months. Adherence to prescribed medications was evaluated by telephone interview at 1, 6 and 12 months after discharge. Switching from one cardiovascular agent to another of the same class was considered adherence to the prescribed therapy. Univariate and multivariate Cox proportionalhazards regression analyses were performed to identify risk factors for occurrence of the primary end point, and to identify clinical and demographic variables associated with statin therapy discontinuation during the follow-up period. OUTCOME MEASURES: The primary end point was death from any cause within 12 months of discharge. RESULTS: At discharge, 409 (77.6%) patients received a prescription for atorvastatin and 222 (22.4%) patients received a prescription for simvastatin. During the follow-up period, 246 (38.9%) patients discontinued statin therapy; the discontinuation rates were similar for both statins (P=0.544). Seventy-one (28.8%) patients stated mild adverse effects—such as dyspepsia, fatigue, headache and myalgia—as the reason for statin interruption. No instance of major adverse event was reported. In the remaining 175 (71.2%) cases, neither the patient nor the primary care physician could provide any specific medical reason for statin discontinuation. Multivariate analysis identified increasing age (hazard ratio [HR] 1.006 per year, 95% CI 1.004-1.009; P= 0.01) and female sex (HR 1.07, 95% CI 1.03-1.11; P= 0.02) as risk factors for statin discontinuation. By contrast, patients with diabetes were more likely to continue statin therapy (HR 0.86, 95% CI 0.79-0.91; P=0.03). A total of 116 patients died within 1 year of discharge. Ninety-two (79.3%) of these patients had discontinued statin therapy compared with 154 (29.9%) patients who survived (P=0.0001), and statin interruption was identified as an independent predictor of 12-month all-cause mortality (HR 2.78, 95% CI 1.96-3.72; P=0.003). Other independent predictors of death within the first year after the stroke event were increased age, obesity, diabetes, stroke severity on admission, and antiplatelet therapy discontinuation. CONCLUSION: A considerable proportion of patients with acute ischemic stroke are at increased risk of death within the first year after the index event because they discontinue statin therapy, often without a specific medical reason.