HONOLULU – Ischemic stroke patients at high risk of coronary artery disease rarely receive guideline-supported cardiac stress testing, a study found.
Among 2,377 veterans with stroke, 28% were at high risk of coronary artery disease (CAD), and only 6.2% received CAD screening within 6 months of discharge.
Moreover, 1-year all-cause mortality was significantly lower among high-risk patients who received CAD screening than among their counterparts who did not (5% vs. 19%; P = .018), Dr. Jason Sico said at the International Stroke Conference.
American Heart Association/American Stroke Association guidelines (Circulation 2003;108:1278-90) recommend that acute ischemic stroke patients at high risk of CAD, defined by a Framingham Risk Score of at least 20%, should receive cardiac screening for occult disease.
Studies have shown that 20%-40% of stroke patients have silent cardiac ischemia, and up to 6% of stroke patients die from cardiac causes or are readmitted with a myocardial infarction in the first 3 months following a stroke, said Dr. Sico, of the department of neurology at Yale New Haven (Conn.) Hospital.
Cardiac stress testing may be underutilized because most medical professionals caring for stroke survivors are not aware of the recommendation, he said in an interview. When they are made aware, one study found that providers may not be convinced that screening for cardiac disease within the stroke population will help their patients or is cost-effective (Stroke 2009;40:3407-9).
"In their favor, there has not been a large prospective study that has demonstrated that cardiac screening for stroke patients improves such important outcomes as mortality and hospital readmission," he added.
The investigators reviewed medical records for a sample of 3,965 patients from 131 Veterans Health Administration facilities admitted for a confirmed diagnosis of ischemic stroke in 2007. Framingham Risk Scores were calculated for 2,377 patients after exclusion of 1,588 patients with a prior cardiac stress test or a known history of CAD, or if they died during hospitalization or had unaccountable data.
In all, 676 (28%) patients had a high Framingham Risk Score of 20% or more, and 1,701 (72%) had a low/intermediate Framingham Risk Score.
Cardiac stress testing within 6 months of discharge from the index stroke was not performed more frequently among high-risk than among low/intermediate-risk patients (6.2% vs. 7.5%; odds ratio, 0.81), Dr. Sico said.
Patients who underwent screening had significantly lower baseline National Institutes of Health Stroke Severity scores than those who did not (mean, 3.3 vs. 4.1; P = .003) and were younger by about 2 years (64.5 years vs. 66.4 years; P = .01). Rates of hypertension, hyperlipidemia, diabetes, and white race were similar between groups, he said at the meeting, which was sponsored by the American Heart Association.
Among all patients, 1-year mortality was significantly lower at 5% in cases where screening was performed, compared with 14% when it was not (P = .001).
Dr. Sico said the strength of the study was the relatively large cohort but that the study was limited by its makeup of primarily male veterans, data from fiscal year 2007, and the inability to explain the reasons for the underutilization of guideline-concordant cardiac screening.
Future work includes understanding the barriers to cardiac testing, the reasons behind the mortality differences among patients who did and did not receive CAD screening, and how implementation of CAD screening guidelines affects outcomes.
"To borrow a page from the diabetes literature, it was dogma that if you were diabetic because it is a coronary equivalent, you should get cardiac stress testing, but when it was prospectively looked at [in the DIAD trial] it really didn’t affect outcome; so we don’t have any prospective [study] in the stroke population to answer this question," he said.
Session moderator Dr. Jennifer Juhl Majersik, of the University of Utah, Salt Lake City, said, "This is a great example of stroke neurologists’ need to look beyond the brain."
The Veterans Health Administration provided funding for the study. Dr. Sico and his coauthors reported no disclosures.