Wednesday, December 26, 2007

Top ten issues in hospital medicine for 2007, issue 7: new developments in perioperative medicine

The buzz this year was about perioperative beta blockers, statins and stents. Perioperative beta blockers were already being questioned in 2006. In response the American College of Cardiology (ACC) issued a focused update which recommended a much more restrictive strategy for perioperative beta blockers. In July of this year I discussed the new concerns, linked to the ACC focused update and cited the MaVS and DIPOM trials, both of which demonstrated no benefit from perioperative beta blockers.

In September the ACC released its 2007 updated guidelines for perioperative evaluation and care which incorporated the interim focused update on beta blockers. The class I recommendations were to continue beta blockers in patients already receiving the drugs for a cardiovascular indication and to administer them in patients undergoing major vascular surgery who had ischemia demonstrated on preoperative testing. Class IIa recommendations were to administer beta blockers to patients undergoing vascular surgery who had known CAD or risk factors (with certain caveats about the level of vascular surgical risk in relation to the number of risk factors).

Barely a month after the release of the ACC guideline update came the announcement of the disturbing results of the POISE trial at an American Heart Association meeting. As reported in Med Page Today (H/T to Wachter’s World):

Perioperative metoprolol (Lopressor, Toprol-XL) started two to four hours before surgery prevented 15 MIs, three revascularizations, and seven atrial fibrillation events per 1,000 treated patients compared with placebo, according to a large prospective trial presented here at the American Heart Association meeting.

But this came at the expense of eight deaths, five severe strokes, 42 cases of significant bradycardia, and 53 significant hypotension events per 1,000 patients, reported P.J. Devereaux, M.D., of McMaster University in Hamilton, Ontario, and colleagues.

Does this make the ACC guidelines obsolete concerning beta blockers one month after publication? The class I recommendation for continuation in patients already taking beta blockers still seems sound. The class IIa recommendations are now problematic. For an analysis of what it all means for real world practice Wachter’s follow up post on this issue is worth reading in its entirety.

Clinical Cases and Images blog weighed in about beta blockers here.

Statins are increasingly making news in the arena of perioperative medicine. I have blogged several times about possible beneficial effects of statins in the perioperative period, including this post from last September. Will statins replace beta blockers as a beneficial perioperative medication? The new ACC guidelines linked above contain recommendations for statins which, for the first time, give them virtually equal status with beta blockers, including a class I recommendation to continue statin drugs in patients already receiving them.

Patients with cardiac stents who require non-cardiac surgery provided fodder for intense discussion this year. How should we manage patients who require urgent or emergency surgery soon after implantation of stents? How long should we wait to do elective surgery after stent implantation? The guidelines address these questions. (According to the guidelines if the patient has a drug eluting stent, wait a year! You can read the rest in the guidelines linked above, which are available free in full text).

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