PHOENIX – Patients who are stable following a myocardial infarction and need isolated coronary artery bypass surgery (CABG) don’t need to wait 5 or so days for their surgery, a delay that many surgeons and cardiologists often impose.
The operation can safely occur after just a 1- or 2-day gap following either an ST-elevation MI or a non–ST-elevation MI, based on real-world outcomes seen in more than 3,000 patients treated at any of seven U.S. medical centers.
“Waiting an arbitrary 5 days is not important,” Elizabeth L. Nichols said during a video interview and during her report at the annual meeting of the Society of Thoracic Surgeons.
Ms. Nichols and her associates analyzed the in-hospital mortality rates among 3,060 patients who underwent isolated CABG during 2008-2014 at any of the seven medical centers that participate in the Northern New England Cardiovascular Disease Study Group and offer CABG. They included patients who had their surgery within 21 days of their MI, and excluded patients who had their CABG within 6 hours of their MI, had emergency surgery, or those with shock or incomplete data. The study group included 529 patients who had a ST-elevation MI and 2,531 patients with a non-ST-elevation MI.
The analysis divided patients into four groups based on timing of their CABG: 99 patients (3%) had surgery within the first 24 hours, 369 patients (12%) had their surgery 1-2 days after their MI, 1,966 (64%) had their operation 3-7 days following their MI, and 626 (21%) had their surgery 8-21 days after the MI.
The unadjusted mortality rates for these four subgroups were 5.1%, 1.6%, 1.6%, and 2.7%, respectively, reported Ms. Nichols, a health services researcher at the Dartmouth Institute for Health Policy & Clinical Practice, Lebanon, N.H.
After researchers adjusted for several demographic and clinical variables, the mortality rates remained identical for patients who underwent CABG 1 or 2 days following their MI, compared with patients whose surgery was deferred until 3-7 days after the MI. Patients with surgery 8-21 days following the MI had a small but not statistically significant higher rate of in-hospital death.
Patients who had their surgery 7-23 hours following an MI had a statistically significant increased hospital mortality following surgery that ran more than threefold greater than patients who underwent CABG 3-7 days after their MI.
The main message from the analysis is that for the typical, stable MI patient who requires CABG to treat multivessel coronary disease, no need exists to wait several days following an MI to do the surgery, Ms. Nichols explained. A delay of just 1 or 2 days is safe and sufficient, as long as it provides adequate time for any acutely administered antiplatelet or antithrombotic drugs to clear.
Dr. Jock N. McCullough
The findings “provide a degree of comfort for not waiting the 3-5 days that had previously been thought necessary,” said Dr. Jock N. McCullough, chief of cardiac surgery at Dartmouth-Hitchcock Medical Center in Lebanon and a collaborator on the study.
The findings are not meant to supersede clinical judgment, both Dr. McCullough and Ms. Nichols emphasized. Individual patients might have good reasons to either undergo faster surgery or to wait at least 8 days following their MI.
“The patients who waited 8-21 days had a lot of comorbidities and were sicker patients, and their delay is often warranted” to make sure the patient is stable enough for surgery, Ms. Nichols explained. Other patients might be worsening following their MI and need to undergo their surgery within 24 hours of their MI.
“Clinical judgment is always the trump card,” Ms. Nichols said.
Ms. Nichols and Dr. McCullough had no disclosures.
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