Jay Shah, MD
There is great interest in developing clinical scoring systems that stratify patients based upon ischemic stroke risk profiles. CHA2DS2VASc score is one such system where congestive heart failure, hypertension, age 65-74 years, diabetes, peripheral artery disease, and female gender earn a point while history of stroke or TIA and age >75 register 2 points. This score has been validated in patients with atrial fibrillation (AF) and is utilized to determine anticoagulation candidacy. It has also been shown to predict recurrent stroke in non-AF population but has not been adequately replicated. In this observational cohort study, the authors assessed the ability of CHA2DS2VASc score to predict recurrent stroke, death, and cardiovascular event using registry-based data of adults without AF and first-time stroke across a 10-year span. Essen Stroke Risk Score, a risk score specifically developed for the stroke population, was also calculated as a comparison. It allocates one point for age 65-75 years (2 for >75), hypertension, diabetes, myocardial infarction, other cardiovascular disease, peripheral arterial disease, smoking and previous stroke or TIA.
The cohort consisted of 42,182 patients. Patients were followed-up for an average of 3.5 years. Mean CHA2DS2VASc score was 4.3 and mean Essen Stroke Risk Score was 2.4. Increasing values of both scoring systems were associated with an increased risk of all three outcomes. One and five-year hazard ratios for CHA2DS2VASc score of > 7 were 1.56 and 1.90, respectively. Essen Stroke Risk Score had marginally better discriminatory performance in relation to stroke recurrence.
The difference in stroke recurrence rates between the lowest and highest risk scores were fairly modest, as reflected in the low hazard ratios (hazard ratio of 1.2 in CHA2DS2VASc score of 4 versus 1.56 in CHA2DS2VASc score of > 7). This implies that incremental addition of stroke risk factors only minimally increased stroke risk and prior ischemic infarct results in much higher baseline risk outweighing the impact of other risk factors. Overall, the CHA2DS2VASc score did correlate with increased risk of stroke, death, and cardiovascular events but further refinement is needed and clinical application and decision making based upon the score in this population may be premature. An area of further interest would be to determine mechanism of stroke recurrence and evaluate if there is correlation with clinical scoring systems. Finding such an association would help guide tailored therapy thereby decreasing stroke risk.
