Antihypertensive Therapy in Patients Undergoing Noncardiac Surgery

Abstract

Thirty-one million patients in the United States undergo surgical procedures every year. Approximately 10%—the majority of these with hypertension—are at an increased risk for perioperative and postoperative cardiovascular morbidity and mortality. Thus, hypertensive patients requiring surgery, especially the 2.1 million undergoing noncar diac procedures, should be evaluated carefully for the magnitude, and if severe, the cause of the hypertension. Additionally, their associated metabolic and cardiovascular status should be characterized and corrected with aggressive therapy. Hypertensive patients with known ischemic heart disease, those with multiple risk factors for ischemic heart disease (IHD), some with valvular heart disease, and those with congestive heart failure should be evaluated for their ability to perform the physical and social activities of everyday life, and, when nec cssary, have formal stress testing. Most studies suggest that blood pressures of 180/110 mm Hg or greater are associated with a greater risk for perioperative ischemic events. Therefore, the goals of blood pressure control should be to reduce the blood pressure without jeopardiz ing organ function. Antihypertensive medication should be administered until the time of surgery. β-Reccptor blockers should be instituted or continued in patients with angina and in some patients with congestive heart failure. Those without prior antihypertensive therapy might be best treated with β-blocker therapy perloperatively as evidenced by the Multicenter Study of Perioperative Research Group with atcnolol and those earlier studies with metopro lol. The risks of the surgery should be discussed with the patient so the risks can be weighed against the expected benefit. Studies suggest that perioperative risk for any patient, and espe cially patients with hypertension, are in part related to the adrenergic arousal before, during, and after the procedure as evidenced by the rise in heart rate and blood pressure, along with the liberation of clotting factors and increased risk for plaque rupture, coronary vasoplasm, and consequent myocardial infarction and fibrosis.