Plante, Timothy B.

Cardiovascular disease surveillance involves quantifying the evolving population‐level burden of cardiovascular outcomes and risk factors as a data‐driven initial step followed by the implementation of interventional strategies designed to alleviate this burden in the target population. Despite widespread acknowledgement of its potential value, a national surveillance system dedicated specifically to cardiovascular disease does not currently exist in the United States. Routinely collected health care data such as from electronic health records (EHRs) are a possible means of achieving national surveillance. Accordingly, this article elaborates on some key strengths and limitations of using EHR data for establishing a national cardiovascular disease surveillance system. Key strengths discussed include the: (1) ubiquity of EHRs and consequent ability to create a more “national” surveillance system, (2) existence of a common data infrastructure underlying the health care enterprise with respect to data domains and the nomenclature by which these data are expressed, (3) longitudinal length and detail that define EHR data when individuals repeatedly patronize a health care organization, and (4) breadth of outcomes capable of being surveilled with EHRs. Key limitations discussed include the: (1) incomplete ascertainment of health information related to health care–seeking behavior and the disconnect of health care data generated at separate health care organizations, (2) suspect data quality resulting from the default information‐gathering processes within the clinical enterprise, (3) questionable ability to surveil patients through EHRs in the absence of documented interactions, and (4) the challenge in interpreting temporal trends in health metrics, which can be obscured by changing clinical and administrative processes.

Orthostatic hypotension (OH) is frequently observed with hypertension treatment, but its contribution to adverse outcomes is unknown. The SPRINT (Systolic Blood Pressure Intervention Trial) was a randomized trial of adults, age ≥50 years at high risk for cardiovascular disease with a seated systolic blood pressure (BP) of 130 to 180 mm Hg and a standing systolic BP ≥110 mm Hg. Participants were randomized to a systolic BP treatment goal of either <120 or <140 mm Hg. OH was defined as a drop in systolic BP ≥20 or diastolic BP ≥10 mm Hg 1 minute after standing from a seated position. We used Cox models to examine the association of OH with cardiovascular disease or adverse study events by randomized BP goal. During the follow-up period (median 3years), there were 1170 (5.7%) instances of OH among those assigned a standard BP goal and 1057 (5.0%) among those assigned the intensive BP goal. OH was not associated with higher risk of cardiovascular disease events (primary outcome: hazard ratio 1.06 [95% CI, 0.78–1.44]). Moreover, OH was not associated with syncope, electrolyte abnormalities, injurious falls, or acute renal failure. OH was associated with hypotension-related hospitalizations or emergency department visits (hazard ratio, 1.77 [95% CI, 1.11–2.82]) and bradycardia (hazard ratio, 1.94 [95% CI, 1.19–3.15]), but these associations did not differ by BP treatment goal. OH was not associated with a higher risk of cardiovascular disease events, and BP treatment goal had no effect on OH’s association with hypotension and bradycardia. Symptomless OH during hypertension treatment should not be viewed as a reason to down-titrate therapy even in the setting of a lower BP goal. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT01206062.