HOUSTON – The use of nicardipine following cardiac surgery in children appears to be safe and effective, results from a single-center study suggest.
“There has been a traditional hesitation to use calcium channel blockers, particularly in infants, due to underdevelopment of their calcium channels,” study investigator Matthew L. Stone, MD, PhD, said in an interview at the annual meeting of the Society of Thoracic Surgeons.
“Further, these agents have commonly lacked selectivity to the vascular smooth muscles affecting both the blood vessels and the heart. Nicardipine offers a unique advantage over other calcium channel blockers in that it has more direct effects on vascular smooth muscles than it does on the actual myocardium.”
In their study, Dr. Stone, a first-year fellow in the division of cardiothoracic surgery at the University of Virginia Health System, Charlottesville, and his associates noted that nicardipine offers a favorable pharmacokinetic profile with both rapid onset and short half-life. The purpose of the study was to evaluate the use of nicardipine as a first-line agent for treatment of postoperative hypertension and to compare outcomes between children younger than 6 months of age and those older than 6 months. The researchers retrospectively reviewed the medical records of 68 children who received nicardipine for postoperative hypertension after undergoing cardiac surgery at the University of Virginia during 2010-2015. They compared the incidence of adverse postoperative events between 33 children who were younger than 6 months (group 1) and 35 who were older than 6 months (group 2). Major events including stroke or cardiogenic shock were considered failure of therapy.
Dr. Stone and his associates found that all children received nicardipine within a median of 90 minutes following cardiac surgery; 22 (33%) were started on the drug prior to leaving the operating room and most required dosing for less than 24 hours. Clinically significant hypertension that required dose titration or cessation of therapy occurred in 13% of patients, but there were no significant differences between age groups (17% in group 1 vs. 9% in group 2; P = 0.47). “While the incidence of hypotension following nicardipine administration did not reach statistical significance, it’s important to note that going forward, a lower starting dose in infants less than 6 months of age may be most appropriate. This would certainly be an important focus for future prospective study in the development of postoperative blood pressure control protocols,” said Dr. Stone.
No significant adverse events including stroke or cardiogenic shock occurred in either group. In addition, no operative or postoperative factors reviewed were associated with the development of complications during administration of nicardipine. This included cardiopulmonary bypass time, cross-clamp time, ventilator time, nicardipine duration, ICU length of stay, and hospital length of stay.
“Our traditional hesitation to use this class of agents in infants should be reevaluated,” Dr. Stone concluded. “As we move toward standardization and optimization of perioperative care, our study supports the use and prospective clinical study of nicardipine. Additionally, further pharmacologic study of dose-specific responses within myocardial and vascular smooth muscle cells may further optimize this treatment strategy and provide a more reliable standard with which to control blood pressure.
“Our traditional agents such as beta-blockers and nitroprusside have side effects that need to be considered, the most significant of which being myocardial depression and cyanide toxicity. In a limited number of very-high-risk children, we’ve shown that nicardipine may provide an option with less deleterious side effects. It’s a foundation for future study.”
Dr. Stone reported having no financial disclosures.