[Medical therapy for coronary heart disease. Perioperative relevance]

The aim of our review is to summarize relevant data on the perioperative use of anti-ischaemic drugs in patients at risk for or with proven coronary heart disease.

The accessible medical literature according to current electronic information sources was explored.

One in every eight general anaesthetics is administered to a patient at risk for or with proven coronary heart disease. Of these patients, it is estimated that 20%-40% have perioperative myocardial ischaemia (PMI), the majority being non-symptomatic. This figure correlates with the occurrence of postoperative cardiac complications and myocardial infarction. The anaesthetist therefore has an important role to play in reducing the rate of perioperative cardiac sequelae. This can be achieved with good control of haemodynamic stability and the timely and appropriate use of antiischaemic drugs. Nitrocompounds (nitrates, molsidomine) serve as the gold standard in current angina pectoris treatment. Acting as coronary and systemic vasodilators, they effect an immediate reduction in preload and have been shown to be the drugs of first choice for intraoperative myocardial ischaemia. Beta-blockers reduce the rate of PMI to a greater extent than nitrates. They are also effective in myocardial ischaemia not accompanied by an increased heart rate. Single pre-operative administration of beta-blockers has also been shown to be beneficial in reducing the incidence of perioperative tachycardia, hypertension, and PMI. Consequently, such one-time medication can be considered for previously untreated high-risk patients presenting for surgery. The continuation of oral calcium channel blockers to the morning of surgery also reduces the rate of PMI and myocardial infarction in coronary-bypass patients, and combination with beta-blockers enhances this effect. Intra-operative diltiazem infusions are similarly advantageous in this patient group. In addition to nitrates, calcium antagonists are the drug of choice for coronary vasospasm. Drugs inhibiting platelet aggregation have a particular role in patients with coronary heart disease, however, they also cause increased perioperative bleeding. Consequently, it is recommended that these medications be discontinued 5-10 days prior to major surgery, with the exception of high-risk patients. Pilot studies using alpha 2-agonists have shown reduced anaesthetic requirements and a reduction in PMI. The perioperative relevance of these drugs is currently being investigated.

Beta-blockers, calcium channel blockers, nitrates, and possibly alpha 2-agonists lead to reduced rates of PMI and other cardiac complications in risk patients. Current anti-anginal medications, with the exception of anti-platelet agents, should be maintained to the day of surgery and continued as soon as possible thereafter. All of these drugs except anti-platelet agents may also be used intra-operatively, however, possible interactions with anaesthetic agents should be carefully considered.