S-52-2: PARAMETERS INDICATING HYPERTENSION PREVALENCE IN THREE-YEAR FOLLOW-UP STUDY OF INDIVIDUALS WITH HIGH NORMAL BLOOD PRESSURE

Abstract

Objective: Assess the relation of blood pressure response to treadmill exercise test in subjects with high normal blood pressure (BP) while sympathetic overactivity assessed by muscle sympathetic nerve activity (MSNA) and arterial stiffening are linked with development of hypertension (HTN). Design and method: 100 consecutive subjects with high normal BP according ESC guidelines (systolic BP = 130 to 139mmHg and/or diastolic BP = 85 to 89mmHg), underwent a negative for ischemia treadmill exercise test (Bruce protocol). Arterial stiffness was evaluated based on carotid-femoral pulse wave velocity (PWV). Sympathetic drive was assessed by (MSNA). A new index the SBP/MET-slope ((peakSBP minus restingSBP)/(peakMET minus 1)) was used. Follow-up was scheduled every 6 months for 3 consecutive years, where BP measurements were assessed in office and with ambulatory BP monitoring (ABPM). All participants offered lifestyle advise to lower their BP. Endpoint was development of HTN either with OffBP or ABPM. Then they divided into Group I those who developed HTN and Group II without HTN. Results: From 100 subjects (54 ± 8 years, 42 males, baseline office BP: 132/82 mmHg, 24-hour BP: 122/76 mmHg) 40 developed HTN (Group I) and 50 developed HRE (BP > 210mmHg in men and > 190mmHg in women). Group I vs II had higher HRE (75%vs13%, p = 0.026) with intermediate stage intervals of 3 min (160vs147mmHg, p = 0.068) and 6 min (181vs164mmHg, p = 0.035). The SBP/MET-slope in Group I was increased in all stages till peak exercise independently of sex type (stage1: 6.25vs4.25, stage2: 7.6vs5.3, peak: 7.22vs5.1, p = 0.035). Their exercise capacity was reduced (10vs11.5METs, p = 0.05) as their maximum exercise heart rate (154vs164, p = 0.001). They demonstrated higher levels of PWV (8.35vs7.5m/sec, p = 0.043) and MSNA levels (37vs31 bursts, p = 0.04) both correlated with development of hypertension (p = 0.002), while did not differ regarding their metabolic profile at the followup. The correlation Echocardiographicly LVMI did not differ, but LVEDD (47vs45 mm, p = 0.02), E/A ratio of mitral valve inflow (0.92vs1.05, p = 0.034) and left atrium diameter (3.8vs3.6 mm p < 0.1) were statistically significant. At their initial ECG had shorter P wave duration (101.3vs93.2, p = 0.013) and QRS duration (93.4vs85.7, p = 0.006). In ABPM they demonstrated higher night systolic BP (116vs112mmHg, p < 0.04). Conclusion: In subjects with high normal BP, MSNA identifies a state of increased sympathetic overdrive, PWV demonstrates arterial stiffening and exercise testing provides a prognostic value as a hypertension screening tool acknowledging a state of increased systemic vascular resistance progressing to development of hypertension.