Case Presentation: A 70-year-old with a hyperlipidemia, diabetes, coronary artery disease, heart failure with mildly reduced ejection fraction and vascular dementia was admitted to the Orthopaedic Surgery service after a fall sustaining a femoral neck fracture. On assessment by the Hospital Medicine consultation service, the patient had clear lungs and no cardiac murmurs. Admission labs were notable for normal renal function and normal troponin-I. An admission EKG demonstrated normal sinus rhythm and pathologic q waves which had been present on prior EKGs. Preoperative cardiac risk stratification identified no active cardiac conditions with baseline functional status estimated to be 4 METs. Consultants estimated his perioperative risk to be high, based on RCRI, but also noted he was on maximal goal directed medication therapy for CHF and had no acute indication for PCI or cardiac catheterization. After discussions with the patient and family it was decided prefer to proceed with surgery without further preoperative risk stratification. The patient underwent hip hemiarthroplasty and was monitored post operatively in the acute care setting with stable ECG on the morning of Day 1. On post-operative day 2, the patient developed a new hypoxia. A chest radiograph demonstrated mild pulmonary edema and the patient was treated with intravenous furosemide with clinical improvement. The following day, the patient developed atrial fibrillation with rapid ventricular response and was treated with IV metoprolol. EKG obtained following this event demonstrated new lateral ST depressions, with troponin level measured to be elevated and the patient was taken for left heart catheterization.
Discussion: Myocardial injury following non cardiac surgery (MINS) is common, occurring in approximately 20% of patients undergoing non cardiac surgery, and is associated with an increased risk of 30 day mortality. In patients with baseline cognitive impairment who are delirious in the postoperative period, classic anginal equivalents may be less readily recognized. To overcome gaps in diagnosis, recent AHA guidelines suggest utility of monitoring baseline high sensitivity troponin as well as post operative cardiac enzymes at 24 and 48 hours following surgery. In patients such as this one with known history of CAD, troponin testing would have been appropriate and may have led to earlier detection of post-operative myocardial ischemia. In elevated-risk patients, monitoring for significant troponin elevations and acute ECG changes can modify inpatient management but debate remains whether an earlier diagnosis of MINS impacts longer term outcomes in patients who are already receiving optimized GDMT. Hospitalists should maintain a low threshold to check cardiac enzymes post operatively on patients who are felt to be at increased cardiovascular risk following non cardiac surgery who develop new cardiac or respiratory symptoms.
Conclusions: Hospitalists performing perioperative consults should be aware of the presentation of perioperative and post-operative myocardial injury and apply use of ECG and troponin monitoring in high-risk patients according to guidelines. Although patients with postoperative MINS have significantly worsened longer term outcomes, hospitalists should follow approaches that apply broader guideline-based evidence to optimize medical management as a first step.This case was identified through the national collaborative Achieving Diagnostic Excellence through Prevention and Teamwork (ADEPT).