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Characteristics of patients at risk for perioperative myocardial infarction after infrainguinal bypass surgery: an
D L Gillespie1, W W LaMorte, L G Josephs
1Department of Surgery, Boston University School of Medicine, Mass., USA.
Insights
Patients undergoing infrainguinal bypass surgery face risks of perioperative myocardial infarction (MI). Preoperative cardiac medications, elevated white blood cell counts, and longer surgeries independently predict MI risk in these patients.
Area of Science:
- Cardiovascular Surgery
- Vascular Surgery
- Cardiac Anesthesia
Background:
- Infrainguinal bypass surgery patients often have diffuse atherosclerotic disease.
- Perioperative myocardial infarction (MI) is a serious complication in this population.
- Identifying patients at higher risk for perioperative MI is crucial for targeted cardiac evaluation.
Purpose of the Study:
- To identify clinical characteristics associated with perioperative MI after elective infrainguinal bypass surgery.
- To explore preoperative laboratory tests, ECG findings, medication use, and intraoperative factors as predictors of perioperative MI.
Main Methods:
- Exploratory case-control study.
- Compared 22 patients with perioperative MI to 191 uneventful control cases.
- Analyzed preoperative laboratory tests, ECG, medications, and intraoperative factors using logistic regression.
Main Results:
- Perioperative MI associated with history of angina, prior MI, coronary artery disease, and need for cardiac medications.
- Independent predictors of perioperative MI included preoperative antiarrhythmic agents, nitrates, calcium channel blockers, aspirin, ST-segment depression, elevated WBC count, and longer surgery duration.
Conclusions:
- Preoperative antiarrhythmic agents, nitrates, calcium channel blockers, aspirin, ST-segment depression, elevated WBC count, and longer surgery duration are independent predictors of perioperative MI.
- These factors can help identify patients needing more extensive cardiac evaluation before infrainguinal bypass surgery.
Abstract:
Patients requiring infrainguinal bypass surgery often have diffuse atherosclerotic disease, and perioperative myocardial infarction (MI) is a potentially lethal complication that is not uncommon in these patients. To establish additional clinical characteristics that might be useful in identifying patients who require more extensive cardiac evaluation, we conducted an exploratory case-control study comparing 22 patients who had a perioperative MI following elective infrainguinal bypass surgery with 191 control subjects whose bypasses were uneventful. In addition to previously recognized risk factors (e.g., history of angina or prior MI), we examined the association of perioperative MI with (1) results of common preoperative laboratory tests and ECG, (2) preoperative use of certain medications, and (3) intraoperative factors that might be anticipated prior to surgery (e.g., duration of surgery or type of anesthesia). Perioperative MI was associated not only with a history of angina, prior MI, or coronary artery disease but also with the need for certain cardiac medications, higher white blood cell (WBC) counts, ST-segment depression, left bundle branch block, and lengthy surgical procedures. Multiple logistic regression analysis identified the following factors as being independently associated with perioperative MI: preoperative antiarrhythmic agents (odds ratio [OR] = 26.4, p = 0.006), nitrates (OR = 8.4, p = 0.006), calcium channel blockers (OR = 5.5, p = 0.04), and aspirin (OR = 6.8, p < 0.01) and ST-segment depression (OR = 11.8, p = 0.01), WBC count (OR = 1.27/1000, p = 0.005), and duration of surgery (OR = 2.2/hr, p = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)