Discontinuing statin therapy 3-6 months after a stroke may increase the risk of recurrent stroke within a year, according to findings from a large retrospective Taiwanese cohort study.
And being older or male in the Stroke Belt increases the likelihood that statins won’t be prescribed at all at the time of hospital discharge after a stroke, a separate cohort study from the United States suggests.
Both studies were reported online in the Journal of the American Heart Association.
Of 45,151 ischemic stroke patients from the Taiwan National Health Insurance Research Database who were on a moderate- or high-intensity statin within 90 days of discharge after an ischemic stroke between 2001 and 2012, 3,175 (7%) were on a reduced dosage by the 90- to 180-day period, and 8,353 (18.5%) were not on any statin by that period. After adjustment for numerous factors including age, sex, several comorbid conditions, and stroke severity index, discontinuation of statins was associated with an increased hazard of recurrent ischemic or hemorrhagic stroke (6.2% vs. 4.4%; adjusted hazard ratio [HR], 1.42), Meng Lee, MD, of Chang Gung Memorial Hospital, Chiayi Branch, Puzy, Taiwan and colleagues reported.
Discontinuation of statins was also linked to higher risks of ischemic stroke (5.6% vs. 3.9%, adjusted HR, 1.45), all-cause mortality (1.4% vs. 1%; adjusted HR, 1.37), all major events (7.8% vs. 5.6%, adjusted HR 1.38), and any hospitalization (31.7% vs. 27.1%; adjusted HR, 1.19), but had neutral effects on intracerebral hemorrhage and myocardial infarction.
“Reduced dosage statin therapy was not associated with increased risks of ischemic stroke, intracerebral hemorrhage, all-cause mortality, myocardial infarction, or all major events,” they said.
The findings support and extend those of some prior studies, and the study “affirms the deleterious effect of stopping statins after the initial period following a stroke,” they noted, adding: “Our study has both clinical and policy implications ... After a stroke due to large or small vessel atherosclerosis, patients are at high risk of recurrent stroke and should be treated aggressively in the absence of clear contraindications. Physicians also need to increase awareness among stroke patients about the potential risk of discontinuing their medications and to encourage greater adherence.”
Statin therapy should not be discontinued in the absence of a “highly compelling reason for doing so,” they added, concluding that prospective studies are needed to clarify the mechanisms underlying the association between statin discontinuation and higher recurrent stroke risk.
In a press statement, Dr. Lee said that based on these “real world” findings, statins should be a lifelong therapy for ischemic stroke patients who need a statin to lower cholesterol.
“Discontinuation of statin treatment in patients with ischemic stroke should be strongly discouraged in any stage, acute or chronic, of stroke,” Dr. Lee said. “Shifting to low-intensity statin therapy could be an alternative for stroke patients not able to tolerate moderate or high-intensity statin therapy in the years following a stroke.”
As for the findings regarding starting statin therapy at the time of discharge, an analysis of discharge prescriptions for U.S. ischemic stroke patients from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study showed that 48.7% of 323 patients who were not statin users at the time of admission and who had no history of atrial fibrillation were prescribed a statin at discharge.
Overall, after adjustment for age, race, sex, numerous comorbid conditions, impaired cognition, current smoking status, stroke buckle or Stroke Belt residence, and other factors, patients aged 65 years and older were less likely to receive a statin prescription at discharge (risk ratio, 0.75), and those with dyslipidemia were more likely to be prescribed a stain at discharge (risk ratio, 1.67), Karen C. Albright, PhD, DO, of the Birmingham (Ala.) VA Medical Center, and her colleagues found.
Further, there were no significant overall differences in statin prescribing by race (black:white risk ratio, 1.13), or by sex (male:female risk ratio, 0.97).
When subjects were analyzed based on Stroke Belt residence (defined as residence in Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia), adults aged 65 and older in the Stroke Belt were 47% less likely to be discharged on a statin, compared with younger patients (risk ratio, 0.53). This association was not observed in non–Stroke Belt residents (risk ratio, 1.14), the investigators found (J Am Heart Assoc. 2017 Aug 2. doi: 10.1161/JAHA.117.005523).
Also, among non–Stroke Belt residents, blacks were more likely to be discharged on a statin (risk ratio, 1.42), but this association was not seen in the Stroke Belt (risk ratio, 0.93).
Male Stroke Belt residents were 31% less likely than were female Stroke Belt residents to be discharged on a statin (risk ratio, 0.69), while men who were non–Stroke Belt residents were more likely than were female non–Stroke Belt residents to be discharged on a statin (risk ratio 1.38).
“Although statin prescribing increased over time in the current study, statins were prescribed at discharge to only 49% of patients with ischemic stroke. This represents a treatment gap given current American College of Cardiology/American Heart Association recommendations,” the investigators wrote.
This gap was particularly seen in men and those over aged 65 years – but not among blacks – in the Stroke Belt.
This leaves the reasons for higher rates of recurrent stroke in blacks unresolved, they noted.
“A next step in our efforts to understand the reasons for the higher rate of recurrent stroke in blacks is to evaluate statin adherence in ischemic stroke survivors,” they said.
The Taiwanese cohort study was funded by the Ministry of Science and Technology, Taiwan and Chang Gung Memorial Hospital, Taiwan. Dr. Lee and colleagues reported having no disclosures. The REGARDS study was funded by the National Institutes of Health and the Department of Health and Human Services. Dr. Albright reported having no disclosures, as did all other authors except Paul Muntner, PhD, who receives research support from Amgen Inc.