21st European Meeting on Hypertension and Cardiovascular Prevention
A meta-analysis of primary care hypertension trials has shown that between-arm differences in systolic blood pressure (SBP) readings of 10 mmHg or more predict an increased risk in all-cause and cardiovascular mortality. Christopher E. Clark, Peninsula College of Medicine & Dentistry, Exeter, UK, presented the results of the meta-analysis.
Accurate blood pressure assessment is critical to the diagnosis and management of hypertension. Between-arm differences in SBP readings are common, with differences of 10 mmHg or more in up to 20% of hypertensive patients. Although inter-arm differences are an established marker of peripheral vascular disease (PVD) and mortality in patients with high vascular risk, the role of inter-arm differences as a risk marker in general practice is not well defined. The current meta-analysis was designed to evaluate the prevalence of inter-arm differences in SBP measurements in the primary care setting, as well as the association between inter-arm differences in SBP and long-term patient outcomes.
The meta-analysis included 5 trials of hypertensive patients who were managed in primary care clinics (n = 2,309). Hazard ratios for all-cause and cardiovascular mortality were adjusted for age, gender, smoking status, lipid profile, diabetes, and absolute blood pressure measurements.
High inter-arm differences in SBP readings significantly predicted all-cause mortality and cardiovascular mortality in this primary care population. An inter-arm difference in SBP of ≥10 mmHg increased the risk of all-cause mortality by 60% (HR, 1.60; 95% CI, 1.10 to 2.33; p = 0.001). A higher inter-arm difference in SBP (≥15 mmHg) had a similar effect on all-cause mortality (HR, 1.60; 95% CI, 1.13 to 2.27; p = 0.008).
Systolic inter-arm differences of ≥10 mmHg more than doubled the risk of cardiovascular mortality (HR, 2.15; 95% CI, 1.23 to 3.76; p <0.01). However, the threshold of ≥15 mmHg for inter-arm differences in SBP did not reach statistical significance for increased cardiovascular mortality (HR, 1.34; 95% CI, 0.82 to 2.18; p = 0.24).
Bilateral blood pressure measurements are feasible as part of the routine assessment of patients with hypertension. These findings highlight the importance of inter-arm differences in SBP as a marker of underlying PVD and increased mortality risk. Detecting an inter-arm difference of ≥10 mmHg should prompt the clinician to screen patients for other signs of vascular disease and consider aggressive cardiovascular risk factor modification.