Chest Pain After Noncardiac Surgery Called ‘Serious’ Warning Sign

By Michael Vlessides

Originally published by our sister publication, Anesthesiology News

San Diego—New research has highlighted the importance of chest pain as a clinical sign following noncardiac surgery.

Study investigators found that nearly one in five patients who experienced postoperative chest pain were diagnosed with a myocardial infarction (MI), resulting in an alarming high mortality rate.

“Chest pain is quite common following noncardiac surgery,” said Kurt Ruetzler, MD, PhD, a staff physician with the Departments of General Anesthesia and Outcomes Research, Anesthesiology Institute at Cleveland Clinic. “This pain could be the product of a relatively unimportant outcome, but it may also be an important clinical sign of a life-threatening complication. What’s more, patients who experience a myocardial infarction stay at least six days longer in the hospital, and contribute to the hospital’s deficit to a cost of approximately $17,000 per patient.

“Given the lack of evidence in the literature on the subject, we sought to estimate the fraction of patients with chest pain who had myocardial infarctions, as well as the consequences of these events,” Ruetzler said.

The investigators analyzed data from a series of noncardiac surgical patients hospitalized on surgical wards, for whom postoperative chest pain triggered the institution’s multidisciplinary rapid response system.

“The idea behind the rapid response system is to facilitate early detection of potentially critical events to improve and initiate management, and ultimately bring critical care expertise to the bedside,” Ruetzler explained.

The primary outcome of the analysis was the occurrence of MI. Secondary end points included the proportion of patients who underwent an ECG, troponin measurement, echocardiography and/or cardiac catheterization, or were admitted to the ICU. Post hoc analyses assessed the association between MI and several potentially modifiable risk factors.

Troponin T

In a presentation at the Outcomes Research Consortium during the 2021 annual meeting of the American Society of Anesthesiologists, Ruetzler reported that a total of 5,850 surgical patients were included in the study (median age, 60 years; 55% female), all of whom had postoperative chest pain and activated the institution’s rapid response system.

“As soon as the rapid response team reaches the bedside, they need to determine if the patient’s chest pain is of cardiac origin or not,” Ruetzler said. “In about 55% of cases, we assumed that the chest pain could potentially be caused by cardiac problems.”

The analysis found that 3,110 patients had troponin T measured within six hours of the team’s activation, of whom 540 (17%) demonstrated elevated troponin levels and therefore met the American College of Cardiology’s Fourth Universal Definition criteria for MI.

“That percentage was much higher than we expected,” Ruetzler said.

Of the 540 patients who had an MI, 91 died in the hospital, yielding an overall all-cause mortality rate of 17% (Table).

“There was a fivefold increase in the mortality rate between patients who had a perioperative myocardial infarction and those who had troponin drawn but did not exhibit elevated levels,” Ruetzler said.

The researchers also conducted a post hoc sensitivity analysis to determine potentially modifiable risk factors for postoperative MI.

“Interestingly, this analysis only identified a clinically meaningful difference between groups for hemoglobin,” Ruetzler said. Hemoglobin was 10.3 g/dL among patients whose troponin levels were not elevated, compared with 9.5 g/dL among those with troponin levels indicating MI (P<0.001).

“That is a pretty important difference among these groups,” he noted, adding that the study showed the importance of chest pain as a postoperative clinical sign in patients undergoing noncardiac surgery.

“We have to be aware that if we draw troponin, the incidence of myocardial infarction is much, much higher than we would otherwise expect,” he said. “Almost one in five of those who have an MI are going to die.

“I believe chest pain is a serious clinical indicator, and I believe strongly that we should do troponin measurements and ECGs on a much more frequent basis,” Ruetzler added.

A Significant Study

Hilary P. Grocott, MD, a professor of anesthesiology, perioperative and pain medicine, and surgery at the Max Rady College of Medicine, University of Manitoba, in Winnipeg, said the study “adds significantly to the growing body of evidence regarding both the surprisingly frequent occurrence of troponin increases in the postoperative period as well as the significance of its impact on serious outcomes.

“As is common with retrospective studies, the index occurrence is often underestimated,” Grocott said. “For example, there may have been patients with chest pain insufficient to activate the rapid response system, or more importantly, silent ischemia in those with diabetes. Thus, the occurrence of myocardial infarction may be even higher than the authors reported.”