Blood pressure misclassification among stroke survivors followed in a comprehensive stroke prevention clinic

Background

Hypertension is the most important modifiable risk factor for secondary stroke prevention; however, blood pressure (BP) remains uncontrolled for at least 50 % of stroke survivors following an incident stroke. Accurate in-clinic assessment of BP is important for appropriate medication titration. We evaluated misclassification of clinic BP control in a racially diverse stroke clinic population using two BP measurement methods.

Observations

We followed ischemic stroke, intracerebral hemorrhage, and transient ischemic attack patients after hospital discharge in a comprehensive stroke clinic. Casual BP was obtained using a standard office automated machine, attended by a medical assistant. BP was also measured with an unattended automated office BP (AOBP) machine and was categorized as concordant control, concordant uncontrolled, pseudoresistant hypertension, and masked uncontrolled. Multinomial logistic regression was used to assess relationships between demographic/clinical variables and misclassification categories, controlling for confounders. Among 216 patients, mean age was 59.5 (SD 12.9); 57 % were male, and by race, 50.5 % were non-Hispanic Black/ African American, 21.3 % Hispanic, and 25.5 % non-Hispanic White. BP control was misclassified by casual office BP for 27.3 % of patients. Race was significantly associated with misclassification in regression analysis. The odds ratio for masked uncontrolled compared to concordant controlled BP was 12.2 (95 % CI 1.5, 99.2) for non-Hispanic Black/ African American and 9.9 (95 % CI 1.1, 87.4) for Hispanic compared to non-Hispanic White patients.

Conclusions

These findings highlight barriers to assessment of BP control using standard office measurements among stroke survivors. Accurate BP measurement tools, including AOBP, home BP, and ambulatory BP monitoring, should be utilized to optimize BP treatment after stroke.