Doctors popularly prescribe heart drugs to be taken in the morning, rather a convenience than scientifically based. It is especially true for hormone blockers on hormones like angiotensin converting enzyme (ACE).
It has been seen that heart attack commonly seen in the early morning when the blood pressure is at its zenith. That is because of circardian rhythm of hormone surge. Those are due to activation of ACE-Aldesterone axis and more steroid hormone secretion.
ACE inhibitors are particularly helpful in hypertension where signal originate from kidneys, called renovascular hypertension.
The sleep-time benefit of giving the ACE inhibitor correlates with the biological rhythm of this hormone by targeting those hormones when they're highest during sleep, thereby dropping their levels to the extent that damage is limited/curtailed.
The study revealed that angiotensin-converting enzyme (ACE) inhibitors – commonly given to patients with high blood pressure or after a heart attack or during heart failure – improve heart structure and function when given at sleep time. In fact, when administered during wake time, ACE inhibitors are no more effective than a placebo, the study found.
The research was conducted on mice with high blood pressure.