Is there any difference between intermediate-acting and long-acting calcium antagonists in diurnal blood pressure and autonomic nervous activity in hypertensive coronary artery disease patients?

Recently, there have been some reports indicating that calcium antagonists induce a reflex increase in sympathetic activity, triggering cardiac events , especially in coronary artery disease (CAD) patients, In this study, we a ssessed heart rate (HR) variability (HRV) using power spectral analysis of the 24-h RR interval in 25 hypertensive outpatients with CAD treated with n ifedipine. We compared blood pressure (BP), HR, and HRV variation in the sa me patients substituting benidipine (long-acting) for nifedipine (intermedi ate-acting). There were no significant differences in 24-h, daytime, nightt ime, and morning BP between the nifedipine phase and the benidipine phase. HRV parameters (LF: low frequency power, HF: high frequency power, LF/HF ra tio) also showed no significant differences in 24-h, daytime, nighttime, an d morning LF, HF, and LF/HF ratio between the nifedipine phase and the beni dipine phase. Blood pressure, HR, and HRV parameters, except the LF compone nt from 2 to 4 h after nifedipine administration(the most effective duratio n), showed no differences compared to before administration. The LF compone nt after the nifedipine administration was lower than before administration . In conclusion, in hypertensive patients with CAD, whose BP levels were we ll-controlled by twice-daily use of intermediate-acting nifedipine, switchi ng from nifedipine to a long-acting calcium antagonist, benidipine, maintai ned well-controlled BP levels to a similar degree, but it may not have addi tional benefit in sympatho-vagal balance.