In Annals of Internal Medicine, my colleagues and I published a systematic review and meta-analysis evaluating the cardiovascular risks of white coat hypertension (WCH, ie elevated office blood pressure and normal out-of-office blood pressure). The goal of the meta-analysis was to clarify previous mixed results regarding the risks of untreated WCH and treated WCH. The meta-analysis examined 27 studies—including 64,273 patients—and demonstrated that untreated WCH is associated with an increased risk of cardiovascular events (36%), all-cause mortality (33%), and cardiovascular mortality (109%) when compared with normotension. This risk was strongest in studies with a mean patient age of 55 years or older, or in those that included participants with cardiac risk factors, such as diabetes and chronic kidney disease. We found no increased cardiovascular risk associated with treated WCH.

Importantly, the meta-analysis did not demonstrate that individuals with untreated WCH should be initiated on antihypertensive treatment. Future studies need to assess if treating these patients helps to reduce cardiovascular risk, balanced with the real risk of out-of-office hypotension. Instead, individuals with untreated WCH should be closely monitored with out-of-office blood pressure monitoring. These individuals are at a high risk of developing sustained hypertension; the often-uncaptured transition to sustained hypertension likely drives their increased cardiovascular risk. We also recommend being cautious not to overtreat individuals with treated WCH, as they may be prone to out-of-office hypotension and unnecessary side effects from medications.

Of note, CMS announced in July 2019 plans to expand reimbursement for ambulatory blood pressure monitoring—which provides the highest-quality out-of-office blood pressure readings—to include treated and untreated WCH, as well as masked hypertension. In individuals who require repeated monitoring over time (eg, for medication titration), home blood pressure monitoring can be valuable, but requires training on correct technique and use of a validated monitor.