Missed Opportunities for Stroke Prevention in Hypertensive Patients: A Retrospective Case-Control Study

Background Hypertension is the leading modifiable risk factor for ischemic stroke, yet the adequacy of preventative hypertension care in routine clinical practice remains suboptimal. Whether gaps in hypertension management represent missed opportunities for stroke prevention remains unclear. Objective To evaluate the association between hypertension care delivery and the risk of incident ischemic stroke. Methods We conducted a retrospective, matched, nested case-control study among adults with hypertension using electronic health record data from a large regional health system (2010–2024). Patients with a first-ever ischemic stroke were matched 1:2 to controls on age, sex, race and ethnicity, and calendar time. Three care metrics were assessed during follow-up: (1) outpatient visits with blood pressure (BP) measurement per year; (2) number of antihypertensive medication ingredients; and (3) medication intensification score. Conditional logistic regression estimated adjusted odds ratios (aORs). Results The study included 13,476 cases and 26,952 matched controls (N = 40,428). Mean (SD) age was 64.8 (12.2) years, 54.1% were female, and mean follow-up was 2,497 (1,308) days. Cases had fewer BP visits per year (median, 2.50 vs. 3.01; p < 0.001), similar number of medication ingredients (2.00 vs 2.00), and lower treatment intensification scores (-0.211 vs -0.125). In adjusted models, >5 BP visits per year was associated with lower stroke odds (aOR, 0.55; 95% CI, 0.51-0.59) compared with ≤1 visit. Use of 2-3 medication ingredients (vs 0) was also associated with reduced stroke odds (aOR, 0.80; 95% CI, 0.75-0.86), whereas >3 ingredients was not significant. The highest quartile of treatment intensification showed the strongest association (aOR, 0.47; 95% CI, 0.44-0.51). Findings were consistent across subgroup and sensitivity analyses, including strata defined by baseline SBP and follow-up SBP. Conclusions Greater engagement in hypertension care was associated with lower odds of ischemic stroke, suggesting that gaps in routine management may represent missed opportunities for prevention. Novelty and Relevance What Is New? In this nested case-control study, differences in hypertension care over time—including follow-up frequency, medication use, and treatment adjustments—were associated with incident ischemic stroke. What Is Relevant? Variations in hypertension care delivery over time may represent missed opportunities for stroke prevention regardless of baseline or average SBP levels during follow-up. Improving follow-up and timely treatment adjustments may offer actionable targets for primary prevention. Clinical/Pathophysiological Implications Longitudinal gaps in hypertension management may contribute to stroke risk beyond BP control, highlighting opportunities to improve prevention through more consistent care delivery.