IMPACT OF MEDICAL TREATMENT ON CENTRAL AORTIC SYSTOLIC BLOOD PRESSURE - THE MONICA/KORA STUDY: PP.7.279

Abstract

Background: Elevated central aortic blood pressure (BP) is associated with left ventricular hypertrophy and risk of stroke. BP lowering drugs have substantially different effects on central aortic BP despite a similar impact on brachial BP. This effect may partly explain differences in clinical outcomes. Methods: Subjects (1005 men and women, aged 35 to 84 years) originated from a gender and age stratified random sample of German residents of the Augsburg area (MONICA F3) and were examined by standardized pulse wave analysis using the SphygmoCor system. It uses the principle of applanation tonometry to record a peripheral arterial waveform. Central aortic systolic BP was determined by applying a generalised transfer function. Brachial BP was measured under strictly standardized conditions. For this particular analysis we extracted individuals who were on antihypertensive treatment using a single drug (n = 160). The effects of different groups of antihypertensive medications [calcium channel blockers (CaB, n = 20), beta blockers (BB, n = 79), ACE inhibitors (ACE, n = 29), AT1 antagonists (AT1, n = 11), and diuretics (Diu, n = 21)] on brachial and central aortic BP were compared using adjusted statistical models. Results: Brachial systolic BP was similar throughout all treatment groups (CaB: 135mmHg [95%-CI 125; 145], BB: 137mmHg [132; 142], ACE: 140mmHg [131; 148], AT1: 135mmHg [120; 149], Diu: 142mmHg [131; 154]; p > 0.326). Additionally, there were no statistically significant differences found for brachial and central aortic diastolic BP. In contrast, individuals treated with BB presented with significantly higher central systolic BP when compared to all other treatment groups (BB: 130mmHg [129; 131] vs. CaB: 126mmHg [124; 128], p = 0.001; ACE: 128mmHg [126; 130], p = 0.029; AT1: 127mmHg [124; 130], p = 0.046; Diu: 127mmHg [125; 129]; p = 0.010). Conclusions: Beta blocker treatment was much less effective than treatment with calcium channel blockers, ACE inhibitors, AT1 antagonists, or diuretics at lowering central aortic systolic blood pressure. Our findings may suggest a mechanism to support recent meta-analyses that have challenged the recommendation for beta blockers as an optimal treatment for uncomplicated hypertension.