The Autonomic Regulation of Circulation and Adverse Events in Hypertensive Patients during Follow-Up Study

Purpose. Comprehensive study of autonomic regulation assessed during follow-up could provide new detailed information about the risks stratification for hypertensive patients. Therefore, we investigated the associations of these indices with death, stroke, and revascularization during the follow-up observation of 55 patients. Methods. All patients were with target organ damage, and 27 of them had associated clinical conditions (ACC). Mean age of patients with and without ACC was 62.6 +/- 4.2 and 51.9 +/- 9.9 (mean +/- SD) years, respectively. Follow-up was from 66 to 95 months. At entry, autonomic regulation was assessed by the tilt test, Valsalva maneuver, hand-grip test, and cold-stress vasoconstriction. Hemodynamic parameters were measured by continuous blood pressure monitoring, occlusion plethysmography, and electrocardiography. Re-examination of patients was carried out by questioning and physical and laboratory examination. Results. We found that fatal outcomes were associated with a lower Valsalva index (1.34 +/- 0.16 vs. 1.69 +/- 0.37, P<0.05) and depressed cold vasoconstriction (0.20 +/- 0.02 vs. 0.39 +/- 0.16%, P<0.05) but with higher peripheral resistance (1.36 +/- 0.19 vs. 0.89 +/- 0.25, P<0.001) and respiratory-range blood pressure variability (BPV) (18.2 +/- 14.2 vs. 6.2 +/- 4.2 mmHg, P<0.001). Higher total-range BPV (103 +/- 51 vs. 65 +/- 45 mmHg, P<0.05) in patients who had a stroke was observed. Initial diastolic orthostatic hypertension (6.6 +/- 10.8 vs. 0.4 +/- 6.3 mmHg, P<0.05) and lower Valsalva index (1.36 +/- 0.11 vs. 1.82 +/- 0.37, P<0.05) in patients who suffered a new ACC were important findings as well. Conclusions. This study shows that such autonomic regulation indices as Valsalva index, blood pressure dynamics in the tilt test, cold-stress vasomotor reactivity, and BPV are important for prognosis of hypertension course.