Clinical Research Papers

Brinton TJ, Walls ED, Hu W-C, Hsu T-L, Chio S-S, Chang M-S, Liu C-P, Pulse Metric, Inc., San Diego, CA, Chung Yuan University, Taiwan, R.O.C. and Veterans General Hospital, Taipei, Taiwan, R.O.C.

i) Objectives: To evaluate the effects of angiotensin converting enzyme inhibitors (ACEI) on vascular compliance (C_m) and the efficiency of the pump system in hypertensive patients.

ii) Design and Methods: 14 hypertensive patients were treated with ACEI (either Lisinopril or Perindotril) for 4 to 6 months. We measured the mean arterial blood pressure (MAP), double product (MAP*HR, an index of energy consumption), C_m and dP/dt_max by using a cuff sphygmomanometer waveform analysis. Submaximal exercise (10 mets) was used to evaluate cardiovascular reserve function.

iii) Results: Following 4 to 6 months of treatment, the MAP and dP/dt_max decreased significantly, while the C_m showed a significant increase (p<0.05) (TABLE). However, the time course of blood pressure reduction was much earlier than the improvement of C_m (2 vs 8 weeks). Data are expressed as mean± sem.

The change in double product required to reach the submaximal exercise level was significantly reduced after treatment (20.8% vs 11.2%; p<0.05). These results suggest that pump efficiency was promoted after chronic ACEI therapy. and that advantage was not due to systolic enhancement.

iv) Conclusion: We conclude that ACEI therapy can improve vascular compliance, and this structural benefit is not directly dependent on its antihypertensive effect. Furthermore, this vascular remodeling may lead to a more efficient pump system during exercise.

*Presented at the International Society of Hypertension 16th Scientific Meetings, 1996.