By Deborah J. DeWaay, MD, FACP
Assistant Professor,
Medical University of South Carolina,
Charleston, SC

Dr. DeWaay reports no financial relationships in this field of study

SYNOPSIS: Patients with transient ischemic attacks were not given evidence-based secondary prevention for stroke at discharge from the hospital as often compared to patients with stroke, thus creating a missed opportunity to decrease the incidence of future stroke and cardiovascular disease.

SOURCE: Bangalore S, Schwamm L, Smith E, Singh I, Liang L, Fonarow G, Bhatt D. Secondary Prevention after Ischemic Stroke or Transient Ischemic Attack. Am J Med. 2014; 127(8):728-738

Patients who experience a transient ischemic attack (TIA) have an 11% chance of developing a stroke within 90 days and a 13% chance of having another TIA. Almost 25% of patients who have a stroke experience a TIA prior to the stroke, usually within days of the stroke. Therefore, there is a small amount of time to prevent future ischemic events in a patient who experiences a TIA. Patients who experience a TIA have the same rate of major cardiovascular events as those who experience a stroke, 22% within one year. The American Heart Association/American Stroke Association (AHA/ASA) guidelines recommend aggressive secondary prevention following stroke or TIA to reduce the risk of recurrent stroke as well as to decrease cardiovascular morbidity and mortality. This study evaluated the implementation of and adherence to secondary prevention measures at the time of discharge between 2007 and 2011.

The data source for this study was the Get With The Guidelines-Stroke Program (GWTG) database. This Internet-based system, in which hospitals volunteer to participate, includes patient demographics, medical history, in-hospital diagnostic work-up, treatment, discharge medications, counseling, and disposition on patients admitted for TIA or stroke. Previous validation studies have confirmed reliability of the data. Patients diagnosed with a TIA or ischemic stroke were included in the study. Patients were excluded if there were missing data, a transfer between hospitals took place, the stroke occurred in hospital, discharge data were missing, they left AMA, or they were discharged to hospice.

Researchers used multivariable logistic regression analyses to determine the adherence rates of guideline-based care in patients with TIA and stroke. Specifically, the authors looked at the following metrics at the time of discharge: antithrombotic agent (antiplatelet or anticoagulant), anticoagulation for atrial fibrillation, smoking cessation, stroke education, intensive statin therapy, LDL documentation and lipid-lowering agent for patients with LDL >100, weight loss education for those with a BMI >25, treatment of hypertension and diabetes education. In order to account for in-hospital clustering and adjustment for baseline patient characteristics, the Generalized Estimating Equation was used. Since the study period was several years, a time-trend analysis was also performed to account for any changes over time.

Of the 1.4 million patients with stroke or TIA, 858,835 patients met inclusion criteria. Thirty percent had a TIA and 70% had a stroke. The two patient populations were not equivalent. Patients with TIAs were more likely to be white women with a history of prior stroke or TIA and hyperlipidemia on a lipid-lowering agent compared to those with stroke. They also scored lower on the NIH stroke scale and were more likely to ambulate on admission. Stroke patients, on the other hand, were more likely to have atrial fibrillation, diabetes, hypertension, and tobacco abuse.

Patients with TIAs received secondary stroke prevention statistically less often than their stroke counterparts in the following areas: antithrombotic therapy (96.3% vs. 97.7%), anticoagulation for atrial fibrillation (90.6% vs. 93.7%), statin for LDL <100 mg/dL (75.0% vs. 82.8%), stroke education (73.5% vs. 79.4%) and weight loss counseling (52.2% vs. 55.1%). Patients with TIAs were also less likely to have anti-hypertensives and intensive statin therapy prescribed at discharge. Adherence to guidelines improved over time in both groups, although adherence in the TIA group did not improve as much over time as the stroke group.

COMMENTARY

Stroke is a leading cause of disability and death in the U.S. Forty percent of stroke patients have moderate to severe impairments, which costs the healthcare system billions of dollars. Approximately 1 in 4 strokes are recurrent, and for this reason it is critical to adhere to secondary prevention measures. This was illustrated in the EXPRESS (Early use of eXisting PREventive Strategies for Stroke) study, which demonstrated an 80% decrease in stroke in patients with TIA who were appropriately following risk-reduction strategies. Subsequent hospital bed-days, acute costs and 6-month disability were also significantly reduced. The current study illustrates that TIA patients are not receiving guideline-based therapy at the rate of their stroke counterparts, suggesting that their morbidity and mortality could be improved if this gap in their care could be closed.

 This study is also a useful reminder to hospitalists that adherence to AHA/AHS guidelines is important for patients with TIA or stroke. Of the secondary prevention measures, it should be noted that rates of statin administration for LDL <100, stroke education, and weight loss counseling are not optimal for patients with either diagnosis. This opportunity to improve care for all patients being discharged after TIA and stroke could decrease the incidence of future stroke and cardiovascular disease.